Hybrid drive device

Abstract

There is provided a first and second bearing supporting a clutch case at first and second axial sides in a radial direction, a rotor of a rotary electrical machine is supported by the clutch case, a gap between an outer peripheral face of a pump drive shaft 10 and an inner peripheral face of a drive shaft insertion hole 90c is a distribution passage L of oil flowing from a pump chamber 18a to the first bearing 51, and a distribution passage diameter difference, which is a difference between a diameter Φa of the outer peripheral face of the pump drive shaft 10 and a diameter Φc of the inner peripheral face of the drive shaft insertion hole 90c in the distribution passage L, is set so that the distribution passage L functions as a narrowed portion which limits a flow rate of oil.

Description

INCORPORATION BY REFERENCE

The disclosure of Japanese Patent Application No. 2010-083055 filed on Mar. 31, 2010 including the specification, drawings and abstract is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates to a hybrid drive apparatus including a first shaft drive-coupled to an internal combustion engine, a second shaft drive-coupled to a speed change mechanism, a clutch drive-coupled selectively to the first shaft and the second shaft, a rotary electrical machine, and a case housing the clutch and the rotary electrical machine.

DESCRIPTION OF THE RELATED ART

As the above-described hybrid drive apparatus, for example, there has been already known a device illustrated in FIG. 7 of Japanese Patent Application Publication No. 2009-1127. As illustrated in FIG. 7 of Japanese Patent Application Publication No. 2009-1127, in this hybrid drive apparatus, an engine input shaft 10 (first shaft) drive-coupled to an engine 2 (internal combustion engine) and a transmission input shaft 45 (second shaft) drive-coupled to a belt-type continuously variable transmission (speed change mechanism) are structured to be capable of being selectively drive-coupled via a clutch 49. The clutch 49 is housed in a casing formed by joining a front cover 24 and a rear cover 102. A cylindrical part 38 provided on the rear cover 102 is disposed penetrating a body 35 of an oil pump 34 to engage with a rotor 37 disposed in a pump chamber, and the oil pump 34 is driven by rotation of the casing. That is, the cylindrical part 38 is a pump drive shaft driving the oil pump 34. In addition, the cylindrical part 38 is supported rotatably on the body 35 via a bush disposed between an outer peripheral face of the cylindrical part 38 and an inner peripheral face of the body 35.

SUMMARY OF THE INVENTION

Now, in the structure illustrated in FIG. 7 of Japanese Patent Application Publication No. 2009-1127, the cylindrical part 38 penetrates the body 35 and extends to the pump chamber, and there is a gap between the outer peripheral face of the cylindrical part 38 and the inner peripheral face of the body 35. Thus, part of oil increased in pressure in the pump chamber passes through this gap and leaks to the bush side in an axial direction. Such a leak of oil affects the amount of oil to be discharged via a discharge chamber from the pump chamber, and thus the structure is desired to be capable of limiting the amount of leaking oil via the gap.

However, Japanese Patent Application Publication No. 2009-1127 describes that an oil seal 39 is on the opposite side of the bush from the pump chamber in the axial direction, thereby preventing oil leakage to the space in which a motor-generator 3 (rotary electrical, machine) is disposed. However, there is no description mentioning about limiting the amount of oil leaking from the pump chamber 38 through the gap between the outer peripheral face of the cylindrical part 38 and the inner peripheral face of the body 35. Accordingly, as a matter of course, Japanese Patent Application Publication No. 2009-1127 does not describe a mechanism for limiting the amount of leaking oil via the gap.

Accordingly, achievement of a hybrid drive apparatus is desired, which is capable of limiting the amount of oil leaking in the axial direction along the outer peripheral face of the pump drive shaft from the pump chamber.

A hybrid drive apparatus according to a first aspect of the present invention includes: a first shaft drive-coupled to an internal combustion engine; a second shaft drive-coupled to a speed change mechanism; a clutch drive-coupled selectively to the first shaft and the second shaft; a rotary electrical machine; a case housing the clutch and the rotary electrical machine; a clutch case drive-coupled to one of the first shaft and the second shaft and housing the clutch; an oil pump including a pump case fixed to the case and forming a pump chamber inside and a pump rotor arranged rotatably in the pump chamber, the oil pump being arranged coaxially with the clutch case on one axial side with respect to the clutch case; a first bearing supporting the clutch case at one axial side in a radial direction on the case; and a second bearing supporting the clutch case at another axial side in the radial direction on the case, in which a rotor of the rotary electrical machine is supported by the clutch case, the first bearing includes an outer wheel, an inner wheel, and rolling elements intervening between the outer wheel and the inner wheel, the clutch case includes a pump drive shaft which extends toward one axial side and is drive-coupled to the pump rotor, the pump drive shaft is supported on the case via the first bearing and the pump case, the pump case includes a partition wall partitioning the first bearing and the pump rotor, the partition wall includes a drive shaft insertion hole through which the pump drive shaft is inserted, a gap between an outer peripheral face of the pump drive shaft and an inner peripheral face of the drive shaft insertion hole is a distribution passage of oil flowing from the pump chamber to the first bearing, and a distribution passage diameter difference, which is a difference between a diameter of the outer peripheral face of the pump drive shaft and a diameter of the inner peripheral face of the drive shaft insertion hole in the distribution passage, is set so that the distribution passage functions as a narrowed portion which limits a flow rate of oil.

According to the first aspect of the present invention, the distribution passage diameter difference is set so that the distribution passage, which is a route of oil when oil leaks in the axial direction along the outer peripheral face of the pump drive shaft from the pump chamber, functions as the narrowed portion which limits the flow rate of oil. Thus, the amount of oil leaking in the axial direction along the outer peripheral face of the pump drive shaft from the pump chamber can be limited, and the amount of oil discharged via a discharge chamber from the pump chamber can be secured properly.

Note that since it is unnecessary to dispose a dedicated member for limiting the flow rate of oil in the distribution passage, it is also possible to suppress the size in the axial direction and the cost of the hybrid drive apparatus to increase.

Further, the clutch case including the pump drive shaft is supported in the radial direction on the case at both sides in the axial direction by the first bearing and the second bearing. Moreover, the first bearing supporting the one axial side on which the pump drive shaft of the clutch case is provided is a bearing having an outer wheel, an inner wheel, and rolling elements, for which a bearing having high supporting precision in the radial direction compared to a bearing having no rolling element is employed. Accordingly, in this structure, it is possible to support the clutch case precisely in the radial direction, and it is easy to suppress displacement in the radial direction of the outer peripheral face of the pump drive shaft provided in the clutch case within a relatively narrow range. Further, the drive shaft insertion hole which is one member sectioning the distribution passage in the radial direction is provided in the pump case fixed to the case. That is, in this structure, a radial direction width of a gap between the outer peripheral face of the pump drive shaft and the inner peripheral face of the drive shaft insertion hole can be maintained within a relatively narrow range with a value decided according to the distribution passage diameter difference being a center. Therefore, in this structure, while suppressing a contact between the outer peripheral face of the pump drive shaft and the inner peripheral face of the drive shaft insertion hole, it is easy to set the distribution passage diameter difference to a minimal value so that the distribution passage functions properly as the narrowed portion.

According to a second aspect of the present invention, the distribution passage diameter difference may be set larger than a maximum value of an allowance of displacement in the radial direction of the pump drive shaft supported by the first bearing, and the distribution passage diameter difference may be set so that a flow passage sectional area of the distribution passage is smaller than a flow passage sectional area of a pump flow passage which is formed by a gap between the partition wall and the pump rotor and communicates with the distribution passage.

In this structure, since the distribution passage diameter difference is set larger than the maximum value of an allowance of displacement in the radial direction of the pump drive shaft supported by the first bearing, a contact between the outer peripheral face of the pump drive shaft and the inner peripheral face of the drive shaft insertion hole can be suppressed. Further, since the flow passage sectional area of the distribution passage is smaller than the flow passage sectional area of the pump flow passage, it is possible in this structure to discharge into the distribution passage only part of oil which is not discharged from the discharge chamber but flows through the pump flow passage. Therefore, while suppressing a contact between the outer peripheral face of the pump drive shaft and the inner peripheral face of the drive shaft insertion hole, the distribution passage can function properly as the narrowed portion.

According to a third aspect of the present invention, the pump drive shaft may be formed in a stepped shape with one axial side being a small diameter portion and another axial side being a large diameter portion, and may be arranged so that the inner peripheral face of the drive shaft insertion hole faces an outer peripheral face of the small diameter portion, the first bearing may be arranged in contact with an outer peripheral face of the large diameter portion, a difference between a diameter of the large diameter portion and a diameter of the small diameter portion may be designated as a pump shaft step width, and the distribution passage diameter difference may be set to a value larger than a maximum value of an allowance of displacement in the radial direction of the pump drive shaft supported by the first bearing and smaller than the pump shaft step width.

In this structure, since the distribution passage diameter difference is set larger than the maximum value of an allowance of displacement in the radial direction of the pump drive shaft supported by the first bearing, a contact between the outer peripheral face of the pump drive shaft and the inner peripheral face of the drive shaft insertion hole can be suppressed. Further, since the distribution passage diameter difference is set to a value smaller than the pump shaft step width, it is easy in this structure to arrange the inner peripheral face of the drive shaft insertion hole at a position close on a radially outer side to the outer peripheral face of the small diameter portion. Thus, a gap between the inner peripheral face of the drive shaft insertion hole and the outer peripheral face of the small diameter portion can be made as a minimal space. While suppressing a contact between the outer peripheral face of the pump drive shaft and the inner peripheral face of the drive shaft insertion hole, the distribution passage can function properly as the narrowed portion.

According to a fourth aspect of the present invention, the pump drive shaft may include a supply oil passage inside that supplies oil to the clutch, the pump case may include a section wall which is arranged on the opposite side of the pump rotor from the partition wall in the axial direction and sections one axial side of the pump chamber, and a section wall side pump flow passage formed by a gap between the section wall and the pump rotor may communicate with the supply oil passage.

In this structure, oil which is not discharged to the distribution passage due to that the distribution passage functions as the narrowed portion can be actively guided to the supply oil passage for supplying oil to the clutch. Thus, by securing a discharge destination of oil flowing in the pump chamber without being discharged from the discharge chamber, the amount of oil discharged to the distribution passage can be limited properly, and oil which is not discharged from the discharge chamber and flows in the pump chamber can be utilized effectively.

According to a fifth aspect of the present invention, the clutch case may include a one-side radially extending portion arranged on one axial side of the clutch to extend in the radial direction and having a radially inner end portion on which the pump drive shaft is provided, an another-side radially extending portion arranged on another axial side of the clutch to extend in the radial direction, and a cylindrical axially extending portion arranged on a radially outer side of the clutch to extend in the axial direction, the rotary electrical machine may be arranged coaxially with the clutch case and the rotor of the rotary electrical machine is fixed in contact with an outer peripheral face of the axially extending portion, the another-side radially extending portion and the axially extending portion may be formed integrally, the one-side radially extending portion and the axially extending portion may be joined by welding and integrated, and a joining part by welding may be located on a radially outer side with respect to an inner peripheral face of the rotor.

In this structure, the joining part by welding can be at a position apart in the radial direction from the pump drive shaft. Thus, it is possible to suppress deformation of the pump drive shaft and the one-side radially extending portion, on which the pump drive shaft is provided on the radially inner end portion, by heat during the welding. Therefore, the gap between the outer peripheral face of the pump drive shaft and the inner peripheral face of the drive shaft insertion hole can be suppressed from becoming uneven in the circumferential direction or from becoming locally too large or too small, and the function of the communication passage as the narrowed portion can be achieved as a desired function.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a schematic structure of a hybrid drive apparatus according to an embodiment of the present invention;

FIG. 2 is a partial cross-sectional view of the hybrid drive apparatus according to the embodiment of the present invention; and FIG. 3 is a partially enlarged view of FIG. 2.

DETAILED DESCRIPTION OF THE EMBODIMENTS

An embodiment of a hybrid drive apparatus according to the present invention will be described with reference to the drawings. The hybrid drive apparatus 1 is a drive apparatus for a hybrid vehicle using one or both of an internal combustion engine E and a rotary electrical machine MG as a driving force source of the vehicle. This hybrid drive apparatus 1 is structured as a hybrid drive apparatus of what is called one motor parallel type.

The hybrid drive apparatus 1 according to this embodiment includes, as illustrated in FIG. 1, an input shaft I drive-coupled to an internal combustion engine, a rotary electrical machine MG, an intermediate shaft M drive-coupled to a speed change mechanism TM, a clutch CL which selectively drive couples the input shaft I and the intermediate shaft M, and a case 2 housing the clutch CL and the rotary electrical machine MG. In such a structure, the hybrid drive apparatus 1 according to this embodiment has characteristics in that a clutch case CH is supported in a radial direction on the case 2 at both sides in an axial direction (see FIG. 2), and that a distribution passage L formed by a gap between an outer peripheral face of a pump drive shaft 10 and an inner peripheral face of a drive shaft insertion hole 90c (see FIG. 3) is structured to function as a narrowed portion which limits a flow rate of oil. Thus, it is possible to limit the amount of oil leaking from a pump chamber 18a in the axial direction along the outer peripheral face of the pump drive shaft 10. Hereinafter, the hybrid drive apparatus 1 according to the present invention will be described in detail.

Note that in the following description, unless otherwise specified, “axial direction or axially”, “circumferential direction or circumferentially”, and “radial direction or radially” are defined on the basis of the rotation axes of the input shaft I and the intermediate shaft M arranged coaxially. These rotation axes match the rotation axes of respective rotation elements provided in the clutch CL, the clutch case CH, an inner rotor 18b provided in an oil pump 18, and a rotor Ro provided in the rotary electrical machine MG Further, in the following description, unless otherwise specified, the left side in FIG. 2 is designated as “one axial side”, and the right side in FIG. 2 is designated as “another axial side”.

1. The Overall Structure of the Hybrid Drive Apparatus

First, the overall structure of the hybrid drive apparatus 1 according to this embodiment will be described. As illustrated in FIG. 1, this hybrid drive apparatus 1 includes an input shaft I drive-coupled to an internal combustion engine E as a first driving force source of the vehicle, a rotary electrical machine MG as a second driving force source of the vehicle, a speed change mechanism TM, an intermediate shaft M drive-coupled to the rotary electrical machine MG and also drive-coupled to the speed change mechanism TM, and output shafts O drive-coupled to wheels W. Further, the hybrid drive apparatus 1 includes a clutch CL provided to be capable of switching transmission and disconnection of driving force between the input shaft I and the intermediate shaft M, a counter gear mechanism C, and an output differential gear device DF. These structures are housed in a case 2 serving as a drive apparatus case. In this embodiment, the input shaft I and the intermediate shaft M function as a “first shaft” and a “second shaft” respectively in the present invention.

Note that being “drive-coupled” refers to a state that two rotation elements are coupled to be capable of transmitting driving force, and is used as a concept including a state that these two rotation elements are coupled to rotate integrally or a state that the two rotation elements are coupled to be capable of transmitting driving force via one or more transmission members. Such transmission members include various types of members which transmit rotation at the same speed or after shifting the speed thereof, and include, for example, a shaft, a gear mechanism, a belt, a chain, and the like. Further, “driving force” is used for the same meaning as torque. A “rotary electrical machine” is used as a concept including any one of a motor (electric motor), a generator (power generator), and a motor-generator performing both functions of a motor and a generator as necessary.

The internal combustion engine E is a device driven by combustion of fuel inside the engine to extract motive power, and for example, one of various publicly known engines, such as gasoline engines and diesel engines, can be used. In this example, an internal combustion engine output shaft Eo such as a crankshaft of the internal combustion engine E is drive-coupled to the input shaft I via a damper D. Further, the input shaft I is drive-coupled to the rotary electrical machine MG and the intermediate shaft M via the clutch CL, and the input shaft I is drive-coupled selectively to the rotary electrical machine MG and the intermediate shaft M by the clutch CL. In an engagement state of the clutch CL, the internal combustion engine E and the rotary electrical machine MG are drive-coupled via the input shaft I, and in a released state of the clutch CL, the internal combustion engine E and the rotary electrical machine MG are separated.

The rotary electrical machine MG is structured to have a stator St and a rotor Ro, and is capable of performing a function as a motor (electric motor) generating motive power while receiving supply of electric power and a function as a generator (power generator) generating electric power while receiving supply of motive power. Thus, the rotary electrical machine MG is connected electrically to a power storage (not-illustrated). In this example, a battery is used as the power storage. In addition, it is also preferred that a capacitor or the like be used as the power storage. The rotary electrical machine MG is powered to rotate while receiving supply of electric power from the battery, or supplies electric power generated from torque outputted by the internal combustion engine E or inertial force of the vehicle for storing the electric power therein. The rotor Ro of the rotary electrical machine MG is drive-coupled to the intermediate shaft M so as to integrally rotate therewith. This intermediate shaft M is an input shaft (speed change input shaft) of the speed change mechanism TM.

The speed change mechanism TM is a device which shifts the rotation speed of the intermediate shaft M with a predetermined speed ratio and transmits the rotation to a speed change output gear G. As such a speed change mechanism TM, in this embodiment, there is used an automatic speed change mechanism which is structured to include a single-pinion type and a Ravigneaux type planetary gear mechanism and plural engagement devices such as a clutch, a brake, and a one-way clutch, and has plural shift speeds with different speed ratios in a switchable structure. Note that as the speed change mechanism TM, an automatic speed change mechanism having another specific structure, an automatic continuously variable speed change mechanism capable of continuously varying a speed ratio, a manual stepped speed change mechanism having plural shift speeds with different speed ratios in a switchable structure, or the like may be used. The speed change mechanism TM shifts the rotation speed of the intermediate shaft M with the predetermined speed ratio at each time point, converts the torque, and transmits the rotation to the speed change output gear G.

The counter gear mechanism C transmits the rotation and torque of the speed change output gear G to the side of the wheels W. This counter gear mechanism C is structured to have a counter shaft Cs, a first gear C1, and a second gear C2. The first gear C1 meshes with the speed change output gear G The second gear C2 meshes with a differential input gear Di provided in the output differential gear device DF. The output differential gear device DF splits and transmits the rotation and torque of the differential input gear Di to the plural wheels W. In this example, the output differential gear device DF is a differential gear mechanism using plural bevel gears meshing with each other, and splits the torque transmitted to the differential input gear Di via the second gear C2 of the counter gear mechanism C and transmits the split torque to the two left and right wheels W via the respective output shafts O. Thus, the hybrid drive apparatus 1 transmits the torque of one or both of the internal combustion engine E and the rotary electrical machine MG to the wheels W to enable the vehicle to travel.

Note that in the hybrid drive apparatus 1 according to this embodiment, the input shaft I and the intermediate shaft M are arranged coaxially, and the counter shaft Cs and the output shafts O are arranged in parallel with each other on respective axes different from the input shaft I and the intermediate shaft M. Such a structure is suitable as the structure of the hybrid drive apparatus 1 mounted on, for example, a FF (Front Engine Front Drive) vehicle.

2. The Structures of Respective Parts of the Hybrid Drive Apparatus

Next, the structures of respective parts of the hybrid drive apparatus 1 according to this embodiment will be described. As illustrated in FIG. 2, the case 2 includes a case peripheral wall 3 covering the outer periphery of respective parts housed therein, such as the rotary electrical machine MG and the speed change mechanism TM, a first support wall 4 closing an opening on another axial side (the side of the internal combustion engine E) of the case peripheral wall 3, and a second support wall 7 arranged between the rotary electrical machine MG and the speed change mechanism TM in the axial direction on one axial side (the side opposite to the internal combustion engine E, that is, the speed change mechanism TM side) with respect to the first support wall 4. Moreover, this case 2 includes an end portion support wall (not illustrated) closing one axial end portion of the case peripheral wall 3.

The first support wall 4 has a shape extending at least in a radial direction, and extends in the radial direction and a circumferential direction in this embodiment. A through hole in an axial direction is formed in the first support wall 4, and the input shaft I inserted through this through hole penetrates the first support wall 4 and is inserted in the case 2. The first support wall 4 integrally has an axially projecting portion 5 having a cylindrical shape (boss shape) projecting toward one axial side. In this example, the first support wall 4 is a wall part having a shape curving in a dish form which protrudes toward the one axial side so that a radially inner portion thereof is located on the one axial side with respect to a radially outer portion thereof, in a portion which the input shaft I penetrates. The first support wall 4 is arranged adjacent at a predetermined space apart on another axial side with respect to the clutch case CH which will be described later. Further, to the first support wall 4, an oil passage forming member 71 inside which a discharged oil passage 72 is formed is attached along the radial direction.

The second support wall 7 has a shape extending at least in the radial direction and extends in the radial direction and the circumferential direction in this embodiment. A through hole in the axial direction is formed in the second support wall 7. Specifically, the second support wall 7 integrally has, on its radially inner end portion, a cylindrical portion 7a having a cylindrical form (boss shape) in its entirety extending in the axial direction, and an inner peripheral face of the cylindrical portion 7a defines an outer edge of the through hole formed in the second support wall 7. As will be described later, this cylindrical portion 7a functions as a resolver fixing part for fixing a sensor stator of a resolver 19, and also functions as a positioning part which positions a pump case 8 (pump body 90 in this example) of the oil pump 18 in the radial direction. Further, the second support wall 7 is arranged adjacent at a predetermined space on one axial side to the clutch case CH.

The oil pump 18 is provided on a radially inner side of the second support wall 7 with respect to the radial direction. Further, the oil pump 18 is provided between the speed change mechanism TM and the clutch case CH with respect to the axial direction, in other words, between the speed change mechanism TM and the rotary electrical machine MG. The oil pump 18 is arranged coaxially with the input shaft I and the intermediate shaft M. Further, as will be described later, also the clutch case CH is arranged coaxially with the input shaft I and the intermediate shaft M. The speed change mechanism TM is then arranged on one axial side with respect to the clutch case CH. Therefore, the oil pump 18 is arranged coaxially with the clutch case CH on the one axial side with respect to the clutch case CH.

The oil pump 18 includes a pump case 8 fixed to the case 2 and forming a pump chamber 18a inside, an inner rotor 18b arranged rotatably in the pump chamber 18a, and an outer rotor 18c likewise arranged rotatably in the pump chamber 18a. The pump case 8 is formed by joining a pump body 90 arranged on another axial side and a pump cover 91 arranged on one axial side with each other. Then, a through hole in the axial direction is formed in the pump case 8 (specifically, in both the pump body 90 and the pump cover 91), and the intermediate shaft M inserted through this insertion hole penetrates the pump case 8 (oil pump 18). In this embodiment, the inner rotor 18b functions as a “pump rotor” in the present invention.

The pump body 90 is an annular plate-shaped member extending in the radial direction and the circumferential direction, and integrally has, on another axial end portion, an axially projecting portion 90b having a cylindrical shape (boss shape) projecting on another axial side. Including such an axially projecting portion 90b, another axial side of the pump body 90 has a cylindrically expanding shape in its entirety, and has a shape projecting on the side of the clutch case CH and the rotary electrical machine MG in the axial direction. Further, in one axial end face of the pump body 90, a recessed portion for forming the pump chamber 18a is formed in a circular cross-sectional shape when it is seen from the axial direction.

As illustrated in FIG. 2, the pump body 90 is positioned in the radial direction by fitting of an outer peripheral face of the pump body 90 with an inner peripheral face of the cylindrical portion 7a of the second support wall 7. Specifically, in the pump body 90, the outer peripheral face of the pump body 90 and the inner peripheral face of the cylindrical portion 7a are arranged to face each other, and a fourth seal member 64 is interposed between the outer peripheral face of the pump body 90 and the inner peripheral face of the cylindrical portion 7a. In this example, the fourth seal member 64 is an O-ring, and is fitted in a recessed groove formed in the outer peripheral face of the pump body 90 to extend circumferentially. By thus interposing the fourth seal member 64 in between, the space between the outer peripheral face of the pump body 90 and the inner peripheral face of the cylindrical portion 7a of the second support wall 7 is sealed in an oil-tight (liquid-tight) state. That is, the pump body 90 is fitted inside the cylindrical portion 7a via the fourth seal member 64 and is held in position by the second support wall 7 in an oil-tight state.

The pump cover 91 is an annular plate-shaped member extending in the radial direction and the circumferential direction. The one axial end face of the pump body 90 and another axial end face of the pump cover 91 are then joined to form the pump chamber 18a for housing the inner rotor 18b and the outer rotor 18c inside the pump body 90 and the pump cover 91. Specifically, the pump chamber 18a is formed of the above-described recessed portion having a circular cross-sectional shape provided in the pump body 90, and the other axial end face of the pump cover 91. In this example, the pump body 90 and the pump cover 91 are fastened and fixed with each other with a fastening bolt (not-illustrated). Further, by fastening and fixing the pump cover 91 onto the case 2 with a fastening bolt 81, the pump case 8 is fixed to the case 2.

In this embodiment, the oil pump 18 is an inscribed type gear pump having the inner rotor 18b and the outer rotor 18c. The inner rotor 18b and the outer rotor 18c are housed rotatably in a state eccentric from each other in the pump chamber 18a. The inner rotor 18b is a pump gear arranged coaxially with the intermediate shaft M, and is drive-coupled at its center portion in the radial direction to the pump drive shaft 10, which will be described later, so as to integrally rotate therewith. In this example, as illustrated in FIG. 3, a pair of keys 18d projecting from an inner peripheral face of the inner rotor 18b engage with key grooves 10d formed in one axial end portion of the pump drive shaft 10, so as to drive couple the inner rotor 18b to the pump drive shaft 10. Alternatively, a structure in which the inner rotor 18b and the pump drive shaft 10 are spline-coupled may be employed. The pump drive shaft 10 is provided integrally on a member (one-side radially extending portion 45) forming the clutch case CH and integrally rotates with the clutch case CH, details of which will be described later.

Accompanying rotation of the clutch case CH, the oil pump 18 sucks in oil from a suction chamber 92 to the pump chamber 18a to generate an oil pressure, and discharges the oil to a discharge chamber (not-illustrated). Then, the oil discharged to the discharge chamber is supplied to the clutch CL and the speed change mechanism TM, and the like. That is, the oil pump 18 generates an oil pressure for causing the clutch CL and the speed change mechanism TM to operate. In addition, inside the pump case 8 (the pump body 90, the pump cover 91) and the intermediate shaft M, and the like, respective oil passages are formed, and the oil discharged by the oil pump 18 is distributed through a oil pressure control device (not-illustrated) and these oil passages, and supplied to respective parts serving as oil supply targets.

Then, in this embodiment, as illustrated in FIG. 2, the space in the case 2 is sectioned in the axial direction by the second support wall 7 extending in the radial direction and the circumferential direction and the pump case 8 (the pump body 90, the pump cover 91) likewise extending in the radial direction and the circumferential direction. That is, the second support wall 7 and the pump case 8 cooperatively forms a wall part extending in the radial direction and the circumferential direction, and the space in the case 2 is sectioned in the axial direction by this wall part. Here, assuming that a space located on another axial side with respect to this wall portion in the case is a first chamber and a space located on one axial side is a second chamber, it can be said that the clutch CL, the rotary electrical machine MG, and a resolver 19 are housed in the first chamber, and the speed change mechanism TM is housed in the second chamber. Note that in this embodiment, since the space between the outer peripheral face of the pump body 90 and the inner peripheral face of the cylindrical portion 7a of the second support wall 7 is sealed in an oil-tight state as described above, distribution of oil between the first chamber and the second chamber without passing through the oil passages is basically prohibited. Accordingly, the hybrid drive apparatus 1 according to this embodiment has a structure in which the space in the first chamber excluding the inside of the clutch case CH can be kept in a dry state in which no oil is distributed.

Now, as will be described later, the pump case 8 (pump body 90) supports the clutch case CH via a first bearing 51. The first bearing 51 is then supplied with oil leaking to another axial side through the space between the pump body 90 and the pump drive shaft 10 from the pump chamber 18a. In the pump body 90 and the pump cover 91, a discharged oil passage 9 for discharging oil which lubricated the first bearing 51 is formed. Note that the amount of oil discharged from the oil pump 18 via the discharge chamber (not illustrated) decreases according to the amount of oil leaking from the pump chamber 18a to the other axial side, and thus the amount of leaking oil from the pump chamber 18a is desired to be limited to a degree capable of properly lubricating the first bearing 51. In the present invention, it is possible to limit the amount of oil leaking to the other axial side from the pump chamber 18a without arranging a dedicated member (seal member or the like) for limiting the amount of leaking oil. This point will be described in detail in the section 3.

The input shaft I is a shaft for inputting torque of the internal combustion engine E to the hybrid drive apparatus 1, and is drive-coupled at another axial end portion to the internal combustion engine E. Here, the input shaft I is disposed in a state of penetrating the first support wall 4 and, as illustrated in FIG. 2, drive-coupled to the internal combustion engine output shaft Eo of the internal combustion engine E to integrally rotate therewith via the damper D on another axial side of the first support wall 4. The damper D is a device which transmits rotation of the internal combustion engine output shaft Eo to the input shaft I while damping torsional vibrations of the internal combustion engine output shaft Eo, and one of various publicly known types of dampers can be used. In this embodiment, the damper D is structured to have plural coil springs arranged along the circumferential direction, fixed to and integrated with a drive plate DP fixed to the internal combustion engine output shaft Eo, and spline-coupled to the input shaft I. The damper D is formed to have a smaller diameter in its entirety than the drive plate DP, and is arranged on one axial side of the drive plate DR Further, across the input shaft I and the first support wall 4, a third seal member 63 is disposed for creating a liquid-tight state therebetween for suppressing leakage of oil to another axial side (the side of the damper D and the internal combustion engine E).

In this embodiment, in an inner diameter portion on one axial end portion of the input shaft I, a shaft end hole portion 12 extending in the axial direction is formed. In this shaft end hole portion 12, another axial end portion of the intermediate shaft M is inserted in the axial direction. Further, the input shaft I integrally has, on its one axial end portion, a flange portion 11 extending in the radial direction from a body portion (portion extending in the axial direction) of the input shaft I. The flange portion 11 enters the inside of the clutch case CH and is coupled to a clutch hub 21 of the clutch CL housed in the clutch case CH. A fourth bearing 54 is disposed on another axial side of the flange portion 11, and a third bearing 53 is disposed on a radially outer side of the flange portion 11 and on one axial side of the clutch hub 21 provided in the clutch CL.

The intermediate shaft M is a shaft for inputting one or both of torque of the rotary electrical machine MG and torque of the internal combustion engine E via the clutch CL to the speed change mechanism TM, and is spline coupled to the clutch case CH. As illustrated in FIG. 2, this intermediate shaft M is disposed in a state of penetrating the oil pump 18. As described above, the through hole in the axial direction is formed in a radially center portion of the pump case 8, and the intermediate shaft M penetrates the oil pump 18 via this through hole. The intermediate shaft M is supported in the radial direction in a rotatable state with respect to the oil pump 18. In other words, the pump case 8 of the oil pump 18 rotatably supports the intermediate shaft M which is the input shaft (speed change input shaft) of the speed change mechanism TM. Further, the other axial end portion of the intermediate shaft M is inserted in the shaft end hole portion 12 of the input shaft I in the axial direction. At this point, a predetermined gap is formed between an end face on the other axial side of the intermediate shaft M and a face defining a bottom portion in the axial direction in the shaft end hole portion 12 of the input shaft I. In this embodiment, the intermediate shaft M has, in its inner diameter portion, plural oil passages including a supply oil passage 15 and a discharged oil passage 16. The supply oil passage 15 extends in the axial direction on the other axial side of the intermediate shaft M, and extends in the radial direction at a predetermined position in the axial direction and opens in an outer peripheral face of the intermediate shaft M, so as to communicate with an operating oil chamber 37 of the clutch CL. The discharged oil passage 16 extends in the axial direction on the other axial side of the intermediate shaft M at a position different from the supply oil passage 15 in the circumferential direction, and opens in the end face on the other axial side.

The clutch CL is a friction engagement device which is provided to be capable of switching transmission and disconnection of driving force between the input shaft I and the intermediate shaft M as described above, and selectively drive couples the internal combustion engine E and the rotary electrical machine MG In this embodiment, the clutch CL is structured as a wet multi-plate clutch mechanism which operates in a space supplied with oil. As illustrated in FIG. 2, the clutch CL is structured to include the clutch hub 21 as an input side member, a clutch drum 26 as an output side member, plural friction plates 31, and a piston 36.

The clutch hub 21 has a cylindrical portion 22 formed in a cylindrical shape and holding the plural friction plates 31 from a radially inner side, and an annular plate-shaped portion 24 extending on a radially inner side from another axial end portion of the cylindrical portion 22. The clutch hub 21 is coupled to the flange portion 11 of the input shaft I so as to integrally rotate with the input shaft I, and is arranged on a radially inner side with respect to the clutch drum 26. As described above, the input shaft I is drive-coupled to the internal combustion engine E. Thus, the clutch hub 21 is drive-coupled to the internal combustion engine E via the input shaft I. The clutch drum 26 is formed in a cylindrical shape and holds the plural friction plates 31 from a radially outer side. The clutch drum 26 is coupled to the intermediate shaft M via the clutch case CH so as to integrally rotate therewith. As described above, the intermediate shaft M is drive-coupled to the speed change mechanism TM. Therefore, the clutch drum 26 is drive-coupled to the speed change mechanism TM via the clutch case CH and the intermediate shaft M. In other words, the intermediate shaft M drive couples the clutch drum 26 and the speed change mechanism TM. The plural friction plates 31 are each held slidably in the axial direction by the clutch hub 21 and the clutch drum 26. On another axial side with respect to the plural friction plates 31, a backing plate 32 functioning as a pressing member for engaging the plural friction plates 31 with each other is held. This backing plate 32 is held in a state of being restricted in movement in the axial direction by a snap ring 33. The piston 36 is arranged on one axial side with respect to the plural friction plates 31 in a state of being biased toward the one axial side by a return spring.

In this embodiment, the operating oil chamber 37 in a liquid-tight state is formed between the clutch case CH, which is integrated with the clutch drum 26, and the piston 36. The operating oil chamber 37 is an oil chamber for controlling the engagement state (complete engagement, complete release, or partial engagement therebetween) of the clutch CL. To this operating oil chamber 37, pressure oil discharged by the oil pump 18 and adjusted to a predetermined oil pressure by a hydraulic control device (not-illustrated) is supplied via the supply oil passage 15 formed in the intermediate shaft M and a communication oil passage 48 formed in the clutch case CH. When the oil pressure in the operating oil chamber 37 increases and becomes larger than biasing force of the return spring, the piston 36 moves in a direction (another axial side in this example) to expand the volume of the operating oil chamber 37, to thereby engage the plural friction plates 31 with each other in cooperation with the backing plate 32. As a result, torque of the internal combustion engine E transmitted from the input shaft I is transmitted to the rotary electrical machine MG and the intermediate shaft M via the clutch CL. On the other hand, a circulation oil chamber 38 is formed on the opposite side of the piston 36 from the operating oil chamber 37. The circulation oil chamber 38 is an oil chamber in which oil mainly for cooling the clutch CL circulates. In this circulation oil chamber 38, the pressure oil discharged by the oil pump 18 and adjusted to a predetermined oil pressure by the hydraulic control device (not-illustrated) is supplied via a circulation oil passage 47 formed continuously in the axial direction in both the clutch case CH and the pump drive shaft 10. That is, the pump drive shaft 10 internally includes the circulation oil passage 47 which is an oil passage for supplying oil to the clutch CL. In this embodiment, the circulation oil passage 47 functions as a “supply oil passage” in the present invention.

The clutch case CH is a case for housing the clutch CL, and includes the pump drive shaft 10 extending toward the one axial side and is drive-coupled to the inner rotor 18b. The clutch case CH is disposed across the input shaft I and the intermediate shaft M in a state to relatively rotate with the input shaft I and integrally rotate with the intermediate shaft M. That is, in this embodiment, the clutch case CH is drive-coupled to the intermediate shaft M out of the input shaft I and the intermediate shaft M. The clutch case CH then houses the clutch CL so as to surround both sides in the axial direction and a radially outer side of the clutch CL, on a radially outer side of the input shaft I and the intermediate shaft M which are arranged coaxially. Accordingly, the clutch case CH is structured to have an another-side radially extending portion 41 arranged on another axial side of the clutch CL to extend in the radial direction, a one-side radially extending portion 45 arranged on one axial side of the clutch CL to extend in the radial direction, and a cylindrical axially extending portion 49 arranged on the radially outer side of the clutch CL to extend in the axial direction. The axially extending portion 49 couples the one-side radially extending portion 45 and the another-side radially extending portion 41 in the axial direction at radially outer end portions thereof.

The another-side radially extending portion 41 has a shape extending at least in the radial direction, and extends in the radial direction and the circumferential direction in this embodiment. The another-side radially extending portion 41 sections another axial side of the circulation oil chamber 38. A through hole in the axial direction is formed in a radially center portion of the another-side radially extending portion 41, and the input shaft I inserted through this through hole penetrates the another-side radially extending portion 41 and is inserted in the clutch case CH. The another-side radially extending portion 41 integrally has, on its radially inner end portion, an axially projecting portion 42 having a cylindrical shape (boss shape) projecting toward the other axial side. The axially projecting portion 42 is formed to surround the periphery of the input shaft I. A fifth bearing 55 is disposed between the axially projecting portion 42 and the input shaft I. Assuming that the portion of the another-side radially extending portion 41 excluding the axially projecting portion 42 is a body portion, in this example, the body portion of the another-side radially extending portion 41 is a member having a shape curving in a dish form which protrudes toward the one axial side so that a radially inner portion is located entirely on the one axial side with respect to a radially outer portion.

The another-side radially extending portion 41 is arranged adjacent at a predetermined space apart on one axial side with respect to the first support wall 4, with the axially projecting portion 42 being adjacent at a predetermined space apart on a radially inner side with respect to the axially projecting portion 5 of the first support wall 4. Further, the another-side radially extending portion 41 is arranged adjacent at a predetermined space apart on another axial side with respect to the clutch hub 21 and the flange portion 11 of the input shaft I. Then, across the axially projecting portion 42 and the axially projecting portion 5 of the first support wall 4, there are disposed a second bearing 52 and a second seal member 62 which creates a liquid-tight state between the axially projecting portion 42 and the axially projecting portion 5 for suppressing leakage of oil to the one axial side (the side of the rotary electrical machine MG). That is, the second bearing 52 supports the another-side radially extending portion 41 forming the clutch case CH so as to be relatively rotatable with respect to the case 2, which is a non-rotating member. As illustrated in FIG. 2, the second bearing 52 is disposed in a state of abutting a stepped portion 42a (a portion in which an outer diameter of the axially projecting portion 42 varies) formed on an outer peripheral face of the axially projecting portion 42 from the other axial side.

In this embodiment, the second bearing 52 is a bearing (rolling bearing) having an outer wheel, an inner wheel, and rolling elements intervening between the outer wheel and the inner wheel. Specifically, the second bearing 52 is a ball bearing with the rolling elements being balls, and is structured to be capable of receiving both of a radial load and an axial load. That is, the hybrid drive apparatus 1 according to this embodiment includes the second bearing 52 supporting the clutch case CH at another axial side in the radial direction and the axial direction on the case 2. Then, as illustrated in FIG. 2, the second bearing 52 is arranged to overlap with the another-side radially extending portion 41 (specifically, a radially outer portion of the another-side radially extending portion 41) in the axial direction. In other words, the second bearing 52 is arranged to overlap with the another-side radially extending portion 41 (specifically, the radially outer portion of the another-side radially extending portion 41) when it is seen from the radial direction. The second bearing 52 may be one at least capable of supporting the clutch case CH at the other axial side in the radial direction, and may be a bearing other than the ball bearing. For example, the second bearing 52 may be a roller bearing with the rolling elements being rollers. Note that in this specification, to “overlap” in a certain direction regarding the arrangement of two members means that the two members have, at least partially, portions at the same position with respect to the arrangement in this direction.

The axially extending portion 49 has a cylindrical shape surrounding the radially outer side of the clutch CL, and extends from the radially outer end portion of the another-side radially extending portion 41 toward the one axial side in this embodiment. The axially extending portion 49 sections a radially outer side of the circulation oil chamber 38. In this example, the axially extending portion 49 is formed integrally with the another-side radially extending portion 41. Further, in this embodiment, the axially extending portion 49 is arranged on a radially outer side of the clutch drum 26 and at a predetermined space apart from the clutch drum 26. That is, the axially extending portion 49 is arranged so that an inner peripheral face of the axially extending portion 49 and an outer peripheral face of the clutch drum 26 face each other at a predetermined space apart in the radial direction.

Further, as illustrated in FIG. 2, the axially extending portion 49 is formed in a stepped shape to proceed step-wise to the radially outer side in its entirety as this portion proceeds to the one axial side. Then, an outer peripheral face of a portion located on another axial side in the axially extending portion 49 is a first abutting portion 49a abutting and supporting an inner peripheral face of the rotor Ro of the rotary electrical machine MG from a radially inner side. That is, in this example, the rotor Ro of the rotary electrical machine MG is supported by the clutch case CH. Further, an inner peripheral face of a portion located on one axial side with respect to the first abutting portion 49a in the axially extending portion 49 is a second abutting portion 49b abutting an outer peripheral face of the one-side radially extending portion 45. Note that in this embodiment, the second abutting portion 49b is located on a radially outer side with respect to the first abutting portion 49a.

The one-side radially extending portion 45 has a shape extending at least in the radial direction, and extends in the radial direction and the circumferential direction in this embodiment. The one-side radially extending portion 45 sections one axial side of the circulation oil chamber 38 in a radially inner portion with respect to the piston 36 and a radially outer portion with respect to the operating oil chamber 37. In a radially center portion of the one-side radially extending portion 45, a through hole in the axial direction is formed, and the intermediate shaft M inserted through this through hole penetrates the one-side radially extending portion 45 and is inserted in the clutch case CH. The one-side radially extending portion 45 integrally has, in its radially inner end portion, an axially projecting portion 46 having a cylindrical shape (boss shape) projecting toward the one axial side. The axially projecting portion 46 is formed to surround the periphery of the intermediate shaft M. The one-side radially extending portion 45 (axially projecting portion 46) has its inner peripheral face of the radially inner end portion abutting the outer peripheral face of the intermediate shaft M across the entire circumferential direction. Assuming that the portion of the one-side radially extending portion 45 excluding the axially projecting portion 46 is a body portion, in this example, the body portion of the one-side radially extending portion 45 is a plate-shaped member having a shape in which a radially inner portion is offset entirely on another axial side from a radially outer portion so that the radially inner portion is located on another axial side with respect to the radially outer portion.

On the radially inner end portion of the one-side radially extending portion 45, the pump drive shaft 10 which extends toward the one axial side and is drive-coupled to the inner rotor 18b is provided. In this example, as illustrated in FIG. 2, the pump drive shaft 10 is formed integrally with the one-side radially extending portion 45, and specifically, another axial end portion of the pump drive shaft 10 and one axial end portion of the axially projecting portion 46 are coupled integrally. Then, the pump drive shaft 10 is spline-coupled to the intermediate shaft M so as to integrally rotate therewith. Note that as illustrated in FIG. 2, an outer diameter of the axially projecting portion 46 is larger than an outer diameter of the pump drive shaft 10. Accordingly, in a coupling portion as a boundary between the axially projecting portion 46 and the pump drive shaft 10, an annular face formed by one axial end face of the axially projecting portion 46 and a cylindrical face formed by the outer peripheral face of the pump drive shaft 10 are formed in a positional relation of being orthogonal to each other, which makes it possible to properly fix the first bearing 51 as described later.

The one-side radially extending portion 45 is arranged adjacent at a predetermined space apart on another axial side with respect to the second support wall 7 and the oil pump 18 (pump body 90), with the axially projecting portion 46 and the pump drive shaft 10 being adjacent at a predetermined space apart on a radially inner side with respect to the axially projecting portion 90b provided on the pump body 90. Moreover, the one-side radially extending portion 45 has its radially inner portion arranged adjacent at a predetermined space apart on one axial side with respect to the clutch hub 21 and the flange portion 11 of the input shaft I. Then, the first bearing 51 is disposed across the pump drive shaft 10 and the axially projecting portion 90b of the pump body 90, and a first seal member 61 is disposed across the axially projecting portion 46 and the axially projecting portion 90b of the pump body 90 to create a liquid-tight state therebetween for suppressing leakage of oil to the other axial side (the side of the rotary electrical machine MG). That is, the pump drive shaft 10 is supported on the pump body 90 (pump case 8) via the first bearing 51. Note that the pump case 8 is fixed to the case 2 as described above. Thus, the pump drive shaft 10 is supported on the case 2 via the first bearing 51 and the pump case 8. The first bearing 51 is disposed in a state of, as illustrated in FIG. 2, abutting the one axial end face of the axially projecting portion 46 from the one axial side.

Note that the pump drive shaft 10 is formed integrally with the one-side radially extending portion 45 forming the clutch case CH as described above, it can be said that the one-side radially extending portion 45 is supported on the pump body 90 (pump case 8) via the first bearing 51. That is, the first bearing 51 supports the one-side radially extending portion 45 forming the clutch case CH so as to be relatively rotatable with respect to the pump case 8, which is a non-rotating member, and the case 2 to which the pump case 8 is fixed.

In this embodiment, the first bearing 51 is a bearing (rolling bearing) having an outer wheel 51a, an inner wheel 51b, and rolling elements 51c intervening between the outer wheel 51a and the inner wheel 51b (see FIG. 3). Specifically, the first bearing 51 is a ball bearing with the rolling elements being balls, and is structured to be capable of receiving both of a radial load and an axial load. That is, the hybrid drive apparatus 1 according to this embodiment includes the first bearing 51 supporting the clutch case CH at one axial side in the radial direction and the axial direction on the case 2. As described above, in this example, the clutch case CH is supported in the radial direction and the axial direction on the case 2 at both sides in the axial direction by the first bearing 51 and the second bearing 52. Then, both the first bearing 51 and the second bearing 52 are a rolling bearing (ball bearing in this example) having an outer wheel, an inner wheel, and rolling elements. Thus, in this structure, it is possible to support the clutch case CH precisely in the radial direction, and it is easy to suppress displacement in the radial direction of the outer peripheral face of the pump drive shaft 10 provided in the clutch case CH within a relatively narrow range.

Note that the outer wheel 51 a of the first bearing 51 is fitted with an inner peripheral face of the axially projecting portion 90b (an interference fit by press fitting in this example) to be fixed in position in the radial direction, and the inner wheel 51b is fitted with the outer peripheral face of the pump drive shaft 10 (an interference fit with a smaller interference compared to the fitting of the outer wheel 51a or a free running fit in this example) to be fixed in position in the radial direction. Further, as illustrated in FIG. 2, the first bearing 51 is arranged to overlap with the one-side radially extending portion 45 (specifically, the radially outer portion of the one-side radially extending portion 45) in the axial direction. In other words, the first bearing 51 is arranged to overlap with the one-side radially extending portion 45 (specifically, the radially outer portion of the one-side radially extending portion 45) when it is seen from the radial direction. The first bearing 51 may be one at least capable of supporting the clutch case CH at the one axial side in the radial direction, and may be a bearing other than the ball bearing. For example, the first bearing 51 may be a roller bearing with the rolling elements being rollers.

Further, the one-side radially extending portion 45 is coupled to a portion of one axial side of the axially extending portion 49 in the vicinity of the radially outer end portion. Specifically, as illustrated in FIG. 2, the one-side radially extending portion 45 is joined thereto by welding in a state of being fitted (an interference fit by press fitting in this example) with the second abutting portion 49b of the axially extending portion 49. That is, the one-side radially extending portion 45 and the axially extending portion 49 are joined by welding and integrated. Note that the welding is performed from one axial side on an abutting part of the inner peripheral face of the axially extending portion 49 (second abutting portion 49b) and the outer peripheral face of the one-side radially extending portion 45, and thus a joining part 85 by welding is formed around the same radial position as the second abutting portion 49b. As described above, the second abutting portion 49b is located on the radially outer side with respect to the first abutting portion 49a abutting and supporting the inner peripheral face of the rotor Ro from the radially inner side. Thus, the joining part 85 is located on a radially outer side with respect to the inner peripheral face of the rotor Ro. Accordingly, the joining part 85 by welding can be at a position apart in the radial direction from the pump drive shaft 10, thereby suppressing deformation of the pump drive shaft 10 and the one-side radially extending portion 45, on which the pump drive shaft 10 is provided on the radially inner end portion, by heat during the welding.

Moreover, in this embodiment, as illustrated in FIG. 2, the radially outer portion of the one-side radially extending portion 45 and one axial side portion of the axially extending portion 49 are joined by welding in a state that both of faces facing each other in the radial direction and faces facing each other in the axial direction abut each other. Accordingly, heat during the welding is suppressed from being transmitted intensively to one member of the one-side radially extending portion 45 and the axially extending portion 49, and temperatures of the one-side radially extending portion 45 and the axially extending portion 49 are suppressed from increasing excessively and causing deformation. Note that the heat capacity of the axially extending portion 49 is favorably formed larger than the heat capacity of the one-side radially extending portion 45 because a large quantity of heat during the welding can escape to the axially extending portion 49.

Note that in this embodiment, the clutch drum 26 is formed integrally with this one-side radially extending portion 45. More specifically, in the vicinity of the radially outer end portion of the one-side radially extending portion 45, the cylindrical clutch drum 26 is integrally formed to extend from the one-side radially extending portion 45 toward the other axial side. Further, in this embodiment, the operating oil chamber 37 is formed between the radially inner portion of the one-side radially extending portion 45 and the piston 36. Moreover, in the one-side radially extending portion 45, the communication oil passage 48 extending in the radial direction in its entirety while slightly inclining toward the other axial side with respect to the radial direction, so as to communicate the supply oil passage 15 with the operating oil chamber 37, is formed in the axially projecting portion 46.

In the space formed in the clutch case CH, the space occupying a major part excluding the operating oil chamber 37 is the previously described circulation oil chamber 38. Then, in this embodiment, oil discharged by the oil pump 18 and adjusted to a predetermined oil pressure is supplied to the circulation oil chamber 38 via the circulation oil passage 47 formed to extend in the pump drive shaft 10 and the axially projecting portion 46 in the axial direction. In this embodiment, the fifth bearing 55 disposed between the axially projecting portion 42 formed in the another-side radially extending portion 41 and the input shaft I is a bearing with a seal function (here, a needle bearing with sealing) structured to be capable of ensuring a certain degree of liquid-tightness. Moreover, the one-side radially extending portion 45 (axially projecting portion 46) has its inner peripheral face of the radially inner end portion abutting the outer peripheral face of the intermediate shaft M across the entire circumferential direction. Accordingly, by supplying oil to the circulation oil chamber 38 via the circulation oil passage 47, the circulation oil chamber 38 in the clutch case CH is basically in a state of being constantly filled with the oil.

Note that although basically the state of being constantly filled with oil is maintained, the oil flows in the circulation oil chamber 38. This flow is shown with dashed arrows in FIG. 2. That is, the oil supplied from the circulation oil passage 47 to the circulation oil chamber 38 first flows between the one-side radially extending portion 45 and the flange portion 11 and between the piston 36 and the clutch hub 21 toward the radially outer side, so as to cool the plural friction plates 31. Then, the oil which cooled the plural friction plates 31 flows between the clutch hub 21 and the flange portion 11 and the another-side radially extending portion 41 toward a radially inner side, and reaches a base end portion of the flange portion 11. Thereafter, the oil is discharged from the circulation oil chamber 38. Thus, in the hybrid drive apparatus 1 according to this embodiment, it is possible to effectively cool the plural friction plates 31 provided in the clutch CL with the large amount of oil which is filled constantly in the circulation oil chamber 38.

Moreover, although detailed descriptions are omitted, in this embodiment, in order to efficiently introduce oil supplied from a radially inner side to gaps between the friction plates 31, a through hole 23 (slit-shaped through hole in this example) penetrating in the radial direction is formed in the cylindrical portion 22 of the clutch hub 21. Further, in order to properly discharge the oil introduced to the gaps between the friction plates 31 from these gaps, a through hole 27 (slit-shaped through hole in this example) penetrating in the radial direction is formed in the clutch drum 26. Accordingly, the oil supplied from the radially inner side is introduced efficiently to the gaps between the friction plates 31, and thereby it is possible to improve the cooling efficiency of the plural friction plates 31. Note that it is of course possible that the oil may flow in the circumferential direction at the same time, but the main flow of the oil is as described above.

As illustrated in FIG. 2, in this example, a discharge route of oil from the circulation oil chamber 38 is separated into two systems. A first discharge route is via a communication hole in the radial direction opening in the outer peripheral face of the input shaft I and the discharged oil passage 16 formed in the inner diameter portion of the intermediate shaft M. In this embodiment, the outer diameter of the other axial end portion of the intermediate shaft M is formed to be slightly smaller than the inner diameter of the shaft end hole portion 12 of the input shaft I, and a predetermined gap is formed between an end face on the other axial side of the intermediate shaft M and a face defining a bottom portion in the axial direction in the shaft end portion 12 of the input shaft I. Accordingly, the oil discharged from the circulation oil chamber 38 via the through hole in the radial direction formed in the input shaft I can be properly guided to the discharged oil passage 16 via the gap in the radial direction and the gap in the axial direction formed between the intermediate shaft M and the shaft end hole portion 12 of the input shaft I. A second discharge route is targeted at oil leaking in the axial direction from the fifth bearing 55, and is via the discharged oil passage 72 in the oil passage forming member 71 attached to the first support wall 4. Such a second discharge route is defined by the third seal member 63 disposed between the input shaft I and the first support wall 4 and the second seal member 62 disposed between the axially projecting portion 42 of the clutch case CH and the axially projecting portion 5 of the first support wall 4. Thus, the oil leaking in the axial direction from the fifth bearing 55 can be guided properly to the discharged oil passage 72.

As illustrated in FIG. 2, the rotary electrical machine MG is arranged coaxially with the intermediate shaft M on a radially outer side of the clutch case CH. The rotary electrical machine MG has the stator St fixed to the case 2 and the rotor Ro supported rotatably on a radially inner side of the stator St. That is, the rotary electrical machine MG has the rotor Ro on the radially inner side with respect to the stator St. The stator St has a stator core formed as a stacked structure, in which plural electromagnetic steel sheets having an annular plate shape are stacked, and fixed on the first support wall 4, and a coil wound on the stator core. Note that in the coil, portions projecting in both sides in the axial direction of the stator core are coil end portions Ce. The rotor Ro of the rotary electrical machine MG has a rotor core formed as a stacked structure, in which plural electromagnetic steel sheets having an annular plate shape are stacked, and a permanent magnet embedded in the rotor core.

In this embodiment, the rotary electrical machine MG is arranged coaxially with the clutch case CH to overlap with the clutch case CH in the axial direction. That is, the rotary electrical machine MG is arranged to overlap with the clutch case CH when it is seen from the radial direction. In this example, particularly the rotor Ro of the rotary electrical machine MG is fixed to an outer peripheral portion of the axially extending portion 49 forming the clutch case CH. Specifically, the rotor Ro of the rotary electrical machine MG is fixed to the above-described first abutting portion 49a provided on the axially extending portion 49. That is, respective inner peripheral faces of the plural electromagnetic steel plates forming the rotor core of the rotor Ro are fixed in a state of contacting the outer peripheral face (first abutting portion 49a) of the axially extending portion 49. Accordingly, the clutch case CH also functions as a rotor support member supporting the rotor Ro, and in this embodiment, the clutch case CH and the rotor support member are formed in common. Note that as described above, the clutch case CH is supported in the radial direction and the axial direction on the case 2 at both sides in the axial direction by the first bearing 51 and the second bearing 52. Moreover, both the first bearing 51 and the second bearing 52 are a rolling bearing (ball bearing in this example) having an outer wheel, an inner wheel, and rolling elements. Accordingly, it is possible to support the rotor Ro of the rotary electrical machine MG with high precision. Then, as described above, the clutch drum 26 is thus formed integrally with the clutch case CH which integrally rotates with the rotor Ro of the rotary electrical machine MG That is, the rotary electrical machine MG is drive-coupled to the clutch drum 26 which is an output side member of the clutch CL via the clutch case CH.

Further, in this embodiment, the damper D is arranged at a predetermined space apart on the other axial side of the first support wall 4. The damper D is arranged in a space, which retreats toward the one axial side when it is seen from the other axial side, of the first support wall 4 formed to have a shape curving in a dish form which protrudes toward the one axial side. In this example, moreover, the damper D is arranged in a radially inner side of the coil end portion Ce of another axial side (the side of the internal combustion engine E) of the stator St of the rotary electrical machine MG to overlap with the coil end portion Ce in the axial direction. That is, the damper D is arranged to overlap with the coil end portion Ce when it is seen from the radial direction.

Then, the resolver 19 (one example of a rotation sensor) which is a sensor for detecting the rotation angle (rotation phase) of the rotor Ro with respect to the stator St of the rotary electrical machine MG is arranged in the case 2. In this embodiment, as illustrated in FIG. 2, the resolver 19 is arranged adjacent to both the second support wall 7 of the case 2 and the one-side radially extending portion 45 on one axial side of the clutch case CH. In this example, the resolver 19 is an outer rotor type resolver having a sensor stator on a radially inner side with respect to a sensor rotor. Then, the sensor stator of the resolver 19 is fixed to the cylindrical portion 7a provided in the second support wall 7, and the sensor rotor of the resolver 19 is fixed to an inner peripheral face of one axial end portion of the axially extending portion 49.

3. Leakage Suppressing Structure for Oil from the Pump Chamber

As described above, the first bearing 51 supporting the clutch case CH at one axial side in the radial direction (the radial direction and the axial direction in this example) is supplied with oil leaking to another axial side through the space between the pump body 90 and the pump drive shaft 10 from the pump chamber 18a. In the present invention, it is possible to limit the amount of oil leaking from the pump chamber 18a to the other axial side without arranging a dedicated member (seal member or the like) for limiting leakage of oil. Here, a leakage suppressing structure for oil from the pump chamber 18a according to this embodiment will be described in detail based on FIG. 3.

As illustrated in FIG. 3, the pump case 8 (pump body 90 in this example) includes a partition wall 90a partitioning the first bearing 51 and the inner rotor 18b. That is, another axial side of the pump chamber 18a is sectioned by the partition wall 90a.

Further, one axial side of the pump chamber 18a is sectioned by a section wall 91a provided in the pump case 8 (pump cover 91 in this example). The section wall 91a is arranged on the opposite of the inner rotor 18b from the partition wall 90a in the axial direction. The partition wall 90a includes a drive shaft insertion hole 90c through which the pump drive shaft 10 is inserted. Here, a diameter of an inner peripheral face of the drive shaft insertion hole 90c is “Φc”. Then, a gap between the outer peripheral face of the pump drive shaft 10 and the inner peripheral face of the drive shaft insertion hole 90c is designated as a distribution passage L for oil flowing from the pump chamber 18a to the first bearing 51. That is, the distribution passage L is a flow passage of oil leaking from the pump chamber 18a to the other axial side along the outer peripheral face of the pump drive shaft 10.

In this embodiment, as illustrated in FIG. 3, the pump drive shaft 10 is formed in a stepped shape with one axial side being a small diameter portion 10a and another axial side being a large diameter portion 10b, so as to reduce a dragging distance when the first bearing 51 is assembled with the pump drive shaft 10 from the one axial side. Here, a diameter of an outer peripheral face of the small diameter portion 10a is “Φa”, and a diameter of an outer peripheral face of the large diameter portion 10b is “Φb”. In one axial end portion of the small diameter portion 10a, the key grooves 10d are formed, which engage with the keys 18d provided on the inner rotor 18b. Then, the pump drive shaft 10 is arranged so that an inner peripheral face of the drive shaft insertion hole 90c faces the outer peripheral face of the small diameter portion 10a. Further, the first bearing 51 is arranged in contact with the outer peripheral face of the large diameter portion 10b.

Now, to allow rotation of the inner rotor 18b and the outer rotor 18c in the pump chamber 18a, axial widths of the inner rotor 18b and the outer rotor 18c are set slightly smaller than an axial width of the pump chamber 18a. Thus, as illustrated in FIG. 3, gaps exist between the inner rotor 18b and the outer rotor 18c and the walls sectioning the pump chamber 18a (the partition wall 90a and the section wall 91a). Accordingly, not all of the oil increased in pressure in the pump chamber 18a is discharged via the discharge chamber (not-illustrated), and part thereof flows through these gaps to a lower pressure part in the pump chamber 18a. That is, such gaps form pump flow passages, which are flow passages of oil in the pump chamber 18a.

Here, a pump flow passage formed by the gap between the partition wall 90a and the inner rotor 18b is designated as a first pump flow passage L1. Further, a pump flow passage formed by the gap between the section wall 91a and the inner rotor 18b is designated as a second pump flow passage L2. As illustrated in FIG. 3, the first pump flow passage L1 has an axial width “δ” and communicates at its radially inner end portion with the distribution passage L. Note that in this embodiment, the first pump flow passage L1 also communicates with a space formed on a radially inner side with respect to the inner peripheral face of the inner rotor 18b (hereinafter referred to as a “target space”). This target space is a low pressure space relative to the first pump flow passage L1 located at a position closer to a discharge port (discharge chamber) which is not shown, and thus as illustrated in FIG. 3 a distribution route of oil from the first pump flow passage L1 toward the distribution passage L via the target space is formed. In this embodiment, the first pump flow passage L1 functions as an “pump flow passage” in the present invention.

Further, the second pump flow passage L2 communicates with a space formed in one axial side of the pump drive shaft 10 (space denoted by a symbol L3 in FIG. 3). This space is formed in an annular shape and, as illustrated in FIG. 2, communicates with the circulation oil passage 47. That is, this space is a communication passage L3 communicating the second pump flow passage L2 with the circulation oil passage 47. In other words, the second pump flow passage L2 communicates with the circulation oil passage 47 via the communication passage L3. Note that the communication passage L3 is a low pressure space relative to the second pump flow passage L2 located at a position closer to the discharge port (discharge chamber) which is not shown, and thus as illustrated in FIG. 3, a distribution route of oil from the second pump flow passage L2 toward the communication passage L3 and a distribution route of oil from the communication passage L3 toward the circulation oil passage 47 (see FIG. 2) are formed. Thus, the circulation oil passage 47 is basically supplied with the pressure oil discharged by the oil pump 18 and adjusted to a predetermined pressure by the hydraulic control device (not-illustrated), and is structured to be supplied also with the oil leaking from the pump chamber 18a. In this embodiment, the second pump flow passage L2 functions as a “section wall side pump flow passage” in the present invention.

Note that the axial widths of the first pump flow passage L1 and the second pump flow passage L2 change according to the axial position of the inner rotor 18b in the pump chamber 18a. Then, the inner rotor 18b may be at a position displaced on an axially outer side from the axial center position of the pump chamber 18a depending on the structures of the suction chamber 92 and the discharge chamber (not-illustrated), but in a stationary state, it is located at a position close to the axial center position of the pump chamber 18a. Thus, the axial width of the second pump flow passage L2 is a value which is the same as or close to the axial width δ of the first pump flow passage L1.

Then, a distribution passage diameter difference, which is a difference between the diameter of the outer peripheral face of the pump drive shaft 10 and the diameter of the inner peripheral face of the drive shaft insertion hole 90c in the distribution passage L, is set so that the distribution passage L functions as a narrowed portion which limits a flow rate of oil. Note that in this embodiment, since the small diameter portion 10a of the pump drive shaft 10 faces the inner peripheral face Of the drive shaft insertion hole 90c, the outer peripheral face of the pump drive shaft 10 in the distribution passage L is the outer peripheral face of the small diameter portion 10a. Thus, in this embodiment, the distribution passage diameter difference is “Φc-Φa”.

Specifically, a difference between the diameter of the large diameter portion 10b of the pump drive shaft 10 and the diameter of the small diameter portion 10a is designated as a pump shaft step width, and the distribution passage diameter difference can be set to a value smaller than the pump shaft step width. For example, the distribution passage diameter difference can be set to a value which is one-half or one-fourth of the pump shaft step width. Note that the pump shaft step width is represented as “Φb-Φa”, and thus “Φc-Φa” (distribution passage diameter difference) is set smaller than “Φb- Φa” (pump shaft step width). That is, the distribution passage diameter difference is set so as to satisfy the relation of “Φb>Φc>Φa”.

Moreover, in this embodiment, the distribution passage diameter difference is set so that a flow passage sectional area of the distribution passage L is smaller than a flow passage sectional area of the first pump flow passage L1. For example, the flow passage sectional area of the distribution passage L can be set to a value which is one-half or one-fourth of the flow passage sectional area of the first pump flow passage L1. Here, as illustrated in FIG. 3, when a diameter of an inner peripheral face of another axial side portion with respect to the key 18d in the inner rotor 18b is “Φd”, the flow passage sectional area of the first pump flow passage L1 can be regarded in a simplified manner as the area “π×Φd×δ” of a cylinder face whose diameter is “Φd” and axial width is “δ”. Further, the flow passage sectional area of the distribution passage L can be regarded in a simplified manner as an axial center orthogonal cross-sectional area “π×Φc×Φc/4−π×Φa×Φa/4” of a cylinder whose inner diameter is “Φa” and outer diameter is “Φc”. Thus, in this example, the distribution passage diameter difference is set so that “π×Φc×Φc/4−π×Φa×Φa/4” is smaller than “π×Φd×δ”. By thus setting the flow passage sectional area of the distribution passage L smaller than the flow passage sectional area of the first pump flow passage L1, the distribution passage L functions properly as the narrowed portion, and in this structure it is possible to guide into the distribution passage L only part of oil which is not discharged from the discharge chamber but flows through the first pump flow passage L1. That is, the amount of oil leaking in the axial direction along the outer peripheral face of the pump drive shaft 10 from the pump chamber 18a can be limited, and the amount of oil discharged via the discharge chamber (not-illustrated) from the pump chamber 18a can be secured properly.

Note that as described above, on the opposite side of the inner rotor 18b from the first pump flow passage L1 in the axial direction, the second pump flow passage L2 is formed. Then, the first pump flow passage L1 and the second pump flow passage L2 communicate with each other via a gap between outer teeth of the inner rotor 18b and inner teeth of the outer rotor 18c. Further, the above-described target space and the communication passage L3 communicate with each other via gaps between the inner rotor 18b and the pump drive shaft 10 (such as a gap between the keys 18d and the key grooves 10d). Accordingly, when oil which is not discharged to the distribution passage L due to that the distribution passage L functions as the narrowed portion flows to the communication passage L3 via the second pump flow passage L2 and the above-described gap, and is supplied to the circulation oil passage 47. Thus, in this structure, the oil which is not discharged to the distribution passage L due to that the distribution passage L functions as the narrowed portion can be actively guided to the circulation oil passage 47 for supplying oil to the clutch CL.

Further, the distribution passage diameter difference (Φc-Φa) is set larger than a maximum value of an allowance of displacement in the radial direction of the pump drive shaft 10 supported by the first bearing 51. For example, the distribution passage diameter difference can be set to substantially the same value as this maximum value, or can be set to the value which is double the maximum value. Thus, a contact between the outer peripheral face of the pump drive shaft 10 and the inner peripheral face of the drive shaft insertion hole 90c is suppressed. Note that the displacement amount (sway amount) in the radial direction of the pump drive shaft 10 is decided according to at least a radial gap of the first bearing 51 in a state of being fixed between the large diameter portion 10b of the pump drive shaft 10 and the axially projecting portion 90b of the pump body 90. Note that the radial gap of the first bearing 51 is a relative displacement amount in the radial direction between the outer wheel 51a and the inner wheel 51b allowed by a clearance existing in the first bearing 51.

Further, the displacement amount in the radial direction of the pump drive shaft 10 also depends on an allowance of displacement in the radial direction of the first bearing 51 itself. For example, displacement in the radial direction of the first bearing 51 itself is allowed by a gap between an outer peripheral face of the outer wheel 51 a of the first bearing 51 and the inner peripheral face of the axially projecting portion 90b fitting with and supporting this outer wheel 51a as well as a gap between an inner peripheral face of the inner wheel 51b of the first bearing 51 and the outer peripheral face of the large diameter portion 10b fitting with and supporting this inner wheel 51b. Note that the degrees of these respective factors, which are factors of displacement in the radial direction of the pump drive shaft 10, are decided according to dimensional tolerances and attaching position tolerances of respective members, and the like.

Note that in this embodiment, as described above, the clutch case CH is supported in the radial direction and the axial direction on the case 2 at both sides in the axial direction by the first bearing 51 and the second bearing 52. Then, both the first bearing 51 and the second bearing 52 are a rolling bearing (a ball bearing in this example) having an outer wheel, an inner wheel, and rolling elements. Thus, in this structure, it is possible to precisely support the clutch case CH in the radial direction, and it is easy to suppress the maximum value of the allowance of displacement in the radial direction of the pump drive shaft 10 supported by the first bearing 51, which is an amount for determining a lower limit value of the distribution passage diameter difference, to a low value of a degree which is decided by the above-described factors. That is, in this structure, while suppressing a contact between the outer peripheral face of the pump drive shaft 10 and the inner peripheral face of the drive shaft insertion hole 90c, it is easy to set the distribution passage diameter difference to a minimal value so that the distribution passage L functions properly as the narrowed portion.

4. Other Embodiments

At last, other embodiments of the hybrid drive apparatus according to the present invention will be described. Note that characteristic structures disclosed in each of the following embodiments are not only applied in the embodiment, but may also be applied in combination with characteristic structures disclosed in the other embodiments as long as no inconsistency occurs.

• (1) In the above-described embodiment, the case where the distribution passage diameter difference is set to a value smaller than the pump shaft step width, and the flow passage sectional area of the distribution passage L is set smaller than the flow passage sectional area of the first pump flow passage L1, is described as an example. However, the embodiment of the present invention is not limited to this, and it is possible to change the distribution passage diameter difference appropriately according to the amount of oil needed for lubricating the first bearing 51, and the like. For example, it is possible to set the distribution passage diameter difference to a value smaller than the pump shaft step width, and set the distribution passage diameter difference so that the flow passage sectional area of the distribution passage L is larger than the flow passage sectional area of the first pump flow passage L1. Further, it is possible to set the distribution passage diameter difference to a value larger than the pump shaft step width, and set the distribution passage diameter difference so that the flow passage sectional area of the distribution passage L is smaller than the flow passage sectional area of the first pump flow passage L1. Moreover, it is possible to set the distribution passage diameter difference to a value larger than the pump shaft step width, and set the distribution passage diameter difference so that the flow passage sectional area of the distribution passage L is larger than the flow passage sectional area of the first pump flow passage L1.
• (2) In the above-described embodiment, the case where the distribution passage diameter difference is set larger than the maximum value of the allowance of displacement in the radial direction of the pump drive shaft 10 supported by the first bearing 51 is described as an example. However, the embodiment of the present invention is not limited to this, and the distribution passage diameter difference can be changed appropriately according to the amount of oil needed for lubricating the first bearing 51, a tendency of the radial position of the pump drive shaft 10 when the hybrid drive apparatus 1 is in use, and the like. For example, it is also possible to set the distribution passage diameter difference smaller than the maximum value of the allowance of displacement in the radial direction of the pump drive shaft 10 supported by the first bearing 51. For example, the distribution passage diameter difference can be set to a value which is one-half or one-fourth of the maximum value of the allowance of displacement in the radial direction of the pump drive shaft 10 supported by the first bearing 51.
• (3) In the above-described embodiment, the case where the pump drive shaft 10 is formed in a stepped shape, with one axial side being the small diameter portion 10a and another axial side being the large diameter portion 10b, is described as an example. However, the embodiment of the present invention is not limited to this, and it is possible to have a structure such that the pump drive shaft 10 is formed to have the size of an outer diameter which is even in the axial direction. In this case, a portion of the pump drive shaft 10 abutting the first bearing 51 from the radially inner side and a portion of the pump drive shaft 10 defining a radially inner side of the distribution passage L are located at the same radial position.
• (4) In the above-described embodiment, the case where basically the circulation oil chamber 38, which is a space occupying the major part excluding the operating oil chamber 37 in the space formed inside the clutch case CH, is constantly in a state of being filled with oil is described as an example. However, the embodiment of the present invention is not limited to this, and in another preferred embodiment of the present invention, the space excluding the operating oil chamber 37 in the clutch case CH is structured as a space which is supplied with oil but not necessarily filled with the oil. In this case, the space excluding the operating oil chamber 37 in the clutch case CH is need not necessarily be sectioned in an oil-tight state.
• (5) In the above-described embodiment, the case where the second pump flow passage L2 communicates with the circulation oil passage 47 is described as an example. However, the embodiment of the present invention is not limited to this, and it is possible to have a structure such that the second pump flow passage L2 communicates with an oil passage other than the circulation oil passage 47, or a structure such that the second pump flow passage L2 does not communicate with the circulation oil passage 47 but is sealed or discharged to a drain.
• (6) In the above-described embodiment, the case where the joining part 85 by welding is located on the radially outer side with respect to the inner peripheral face of the rotor Ro is described as an example. However, the embodiment of the present invention is not limited to this, and it is possible to have a structure such that the joining part 85 is located on a radially inner side with respect to the inner peripheral face of the rotor Ro. Further, in the above-described embodiment, the case where the one-side radially extending portion 45 and the axially extending portion 49 are joined by welding and integrated is described as an example, but it is possible to have a structure such that the one-side radially extending portion 45 and the axially extending portion 49 are integrated by a fixing method other than welding (fixing by fastening with fastening members, fixing with a caulking structure, or the like).
• (7) In the above-described embodiment, the case where the clutch case CH is drive-coupled to the intermediate shaft M out of the input shaft I and the intermediate shaft M is described as an example, but it is possible to have a structure such that the clutch case CH is drive-coupled to the input shaft I out of the input shaft I and the intermediate shaft M. In this case, the clutch drum 26 which integrally rotates with the clutch case CH is the input side member of the clutch CL, and the clutch hub 21 drive-coupled to the intermediate shaft M is the output side member of the clutch CL.
• (8) In the above-described embodiment, the case where the oil pump 18 is an inscribed type gear pump is described as an example. However, the embodiment of the present invention is not limited to this, and the oil pump 18 may be an oil pump of a structure other than the inscribed type gear pump, such as a circumscribed type gear pump or a vane pump. Also in these cases, it can be structured such that a rotor is arranged coaxially with the intermediate shaft M in a pump chamber of the oil pump, and this rotor is the “pump rotor” in the present invention.
• (9) In the above-described embodiment, the case where the rotor Ro of the rotary electrical machine MG is fixed in contact with the outer peripheral face of the axially extending portion 49 is described as an example, but it is possible to have a structure such that the rotor Ro of the rotary electrical machine MG is supported by any other member forming the clutch case CH (namely, the one-side radially extending portion 45 or the another-side radially extending portion 41).
• (10) Regarding other structures, the embodiment disclosed in this specification is an example in all respects, and the embodiment of the present invention is not limited thereto. That is, as long as the structures described in the claims of the present application and structures equivalent thereto are included, a structure in which part of the structure which is not described in the claims is appropriately changed belongs of course to the technical scope of the present invention.

The present invention can be preferably used for a hybrid drive apparatus including a first shaft drive-coupled to an internal combustion engine, a second shaft drive-coupled to a speed change mechanism, a clutch drive-coupled selectively to the first shaft and the second shaft, a rotary electrical machine, and a case housing the clutch and the rotary electrical machine.

Claims

1. A hybrid drive apparatus, comprising:

a first shaft drive-coupled to an internal combustion engine;

a second shaft drive-coupled to a speed change mechanism;

a clutch drive-coupled selectively to the first shaft and the second shaft;

a rotary electrical machine;

a case housing the clutch and the rotary electrical machine;

a clutch case drive-coupled to one of the first shaft and the second shaft and housing the clutch;

an oil pump comprising a pump case fixed to the case and forming a pump chamber inside and a pump rotor arranged rotatably in the pump chamber, the oil pump being arranged coaxially with the clutch case on one axial side with respect to the clutch case;

a first bearing supporting the clutch case at one axial side in a radial direction on the case; and

a second bearing supporting the clutch case at another axial side in the radial direction on the case, wherein

a rotor of the rotary electrical machine is supported by the clutch case,

the first bearing comprises an outer wheel, an inner wheel, and rolling elements intervening between the outer wheel and the inner wheel,

the clutch case comprises a pump drive shaft which extends toward one axial side and is drive-coupled to the pump rotor,

the pump drive shaft is supported on the case via the first bearing and the pump case,

the pump case comprises a partition wall partitioning the first bearing and the pump rotor,

the partition wall comprises a drive shaft insertion hole through which the pump drive shaft is inserted,

a gap between an outer peripheral face of the pump drive shaft and an inner peripheral face of the drive shaft insertion hole is a distribution passage of oil flowing from the pump chamber to the first bearing, and

a distribution passage diameter difference, which is a difference between a diameter of the outer peripheral face of the pump drive shaft and a diameter of the inner peripheral face of the drive shaft insertion hole in the distribution passage, is set so that the distribution passage functions as a narrowed portion which limits a flow rate of oil.

2. The hybrid drive apparatus according to claim 1, wherein

the distribution passage diameter difference is set larger than a maximum value of an allowance of displacement in the radial direction of the pump drive shaft supported by the first bearing, and

the distribution passage diameter difference is set so that a flow passage sectional area of the distribution passage is smaller than a flow passage sectional area of a pump flow passage which is formed by a gap between the partition wall and the pump rotor and communicates with the distribution passage.

3. The hybrid drive apparatus according to claim 1, wherein

the pump drive shaft is formed in a stepped shape with one axial side being a small diameter portion and another axial side being a large diameter portion, and is arranged so that the inner peripheral face of the drive shaft insertion hole faces an outer peripheral face of the small diameter portion,

the first bearing is arranged in contact with an outer peripheral face of the large diameter portion,

a difference between a diameter of the large diameter portion and a diameter of the small diameter portion is designated as a pump shaft step width, and

the distribution passage diameter difference is set to a value larger than a maximum value of an allowance of displacement in the radial direction of the pump drive shaft supported by the first bearing and smaller than the pump shaft step width.

4. The hybrid drive apparatus according to claim 1, wherein

the pump drive shaft comprises a supply oil passage inside that supplies oil to the clutch,

the pump case comprises a section wall which is arranged on the opposite side of the pump rotor from the partition wall in the axial direction and sections one axial side of the pump chamber, and

a section wall side pump flow passage formed by a gap between the section wall and the pump rotor communicates with the supply oil passage.

5. The hybrid drive apparatus according to claim 1, wherein

the clutch case comprises a one-side radially extending portion arranged on one axial side of the clutch to extend in the radial direction and having a radially inner end portion on which the pump drive shaft is provided, an another-side radially extending portion arranged on another axial side of the clutch to extend in the radial direction, and a cylindrical axially extending portion arranged on a radially outer side of the clutch to extend in the axial direction,

the rotary electrical machine is arranged coaxially with the clutch case and the rotor of the rotary electrical machine is fixed in contact with an outer peripheral face of the axially extending portion,

the another-side radially extending portion and the axially extending portion are formed integrally,

the one-side radially extending portion and the axially extending portion are joined by welding and integrated, and

a joining part by welding is located on a radially outer side with respect to an inner peripheral face of the rotor.