Hydromechanical Transmission and Assemblies
A motor vehicle 10 includes a hydromechanical powersplit transmission 11, a prime mover 13, an engine drive shaft 14, drive wheels 15, a differential 16, a differential drive shaft 17, and frame rails 18. The transmission 11 includes a connecting plate 25 having a hydraulic side 25a with a pressurized hydraulic chamber 36 filled with hydraulic fluid and a gear set side 25b with an atmospheric pressure gear side chamber 37 partially filled with lubricating oil. The connecting plate 25 provides a hydraulic manifold. A prime mover input shaft 41, 62 extends through the hydraulic chamber 36 and connecting plate 25 and is drivingly connected to one of the planetary gear components 71. Hydraulic pump motor units 42, 43 include hydraulic pump motor unit drive shafts 44, 45 that extend through connecting plate 25 and are drivingly connected to planetary gear components 71.
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The present patent application is a continuation of PCT/US2013/023048, filed on Jan. 25, 2013 which claims the benefit of U.S. Provisional Patent Application Ser. No. 61/641,467 filed May 2, 2012, the disclosures of which are incorporated herein by reference in entirety.
The present patent application also cross references related patent applications filed of even date herewith by the assignee of the present patent application and titled “Hydromechanical Transmission With Double Sump Gear Unit Housing,” and “Method of Assembly for Hydromechanical Transmission.”
TECHNICAL FIELDThis invention relates generally to a hydromechanical transmission, and more specifically to a hydromechanical powersplit transmission for a hydraulic hybrid vehicle, and to components and assemblies and methods that may be used with such transmissions and elsewhere.
Hydromechanical transmissions, including hydromechanical powersplit transmissions, are used in hydraulic hybrid vehicles. Such vehicles may include a vehicle prime mover such as an internal combustion engine, at least one hydraulic pump motor unit, a gear set such as a planetary gear set, and an output shaft connecting the planetary gear set to a drive shaft of the vehicle. The internal combustion engine and the hydraulic pump motor unit are connected to the gear set, and the gear set splits power from the internal combustion engine and from the hydraulic pump motor unit in a motoring mode to rotate the drive shaft and propel the vehicle. The pump motor unit may also be used in a pumping mode to capture energy under certain conditions such as braking the vehicle, and the captured energy may be stored in an energy storage device such as a hydraulic accumulator to power the hydraulic pump motor unit in the motoring mode.
Various prior art configurations for hydromechanical powersplit vehicle transmissions may be used in off-highway vehicle applications such as agricultural tractors and wheel loaders or in on-highway applications such as delivery trucks. The ability of the powersplit transmission to provide infinitely variable speed allows the engine to run at its optimum efficiency conditions, while transmission of most power through the mechanical power path rather than through the hydraulic power path may result in relatively high transmission efficiency when hydraulic power is limited or not being used. Smooth and seamless control with uninterrupted transfer of torque from the prime mover and/or the hydraulic pump motor unit to the vehicle drive shaft may result in good performance when compared to manual and automatic transmissions having discrete gear ratios, white elimination of a hydrodynamic torque converter may help achieve efficiency when compared to automatic transmissions.
In transmissions of this type, and in hydromechanical components and assemblies and methods for use in such transmissions and elsewhere, technical problems include difficulties with system complexity, efficiency, size, weight, flexibility, lubrication of components, sump oil fill levels and heat build-up, assembly, repair, transmission of forces and torque in relatively large weight vehicles, and parking lock requirements. More specifically, these technical problems include alignment with other components of a vehicle such as the prime mover engine and the differential, ease of assembly, ease of installation in a vehicle and removal from the vehicle, space availability of the vehicle, space requirements of the transmission and within the transmission, weight of the transmission, smooth operation, transmission control, ease of disassembly and repair, and flexibility to change for use in a variety of different vehicles and different applications. Still more specifically, these technical problems include difficulty assembling and attaching and integrating the hydraulic components, including the hydraulic pump motor units and the controls and drive shafts for the hydraulic pump motor units and the hydraulic flow passages and ports for the hydraulic pump motor units, with the planetary gear set, including the drive gears and planetary gear set components, and assembling those components to the prime mover and differential of the vehicle. Further technical problems include lubrication of gear components, including size and complexity and efficiency of lubrication fluid pumps, and assembly and alignment of spline connections. Further technical problems include complexity of, and forces and stresses imposed on, parking lock mechanisms in relatively large weight vehicles.
SUMMARY OF THE INVENTIONThe present invention addresses the certain of the aforementioned technical problems and provides a hydromechanical vehicle transmission and assemblies for use in such transmissions and elsewhere. The transmission and assemblies according to the present invention may be used in a motor vehicle in place of a conventional manual or automatic transmission, connected directly to a conventional vehicle prime mover engine drive shaft and differential drive shaft, and situated between typical vehicle frame rails, while providing a configuration that is modular, compact, and capable of kinetic brake energy recovery, with good efficiency.
Still more specifically, the invention provides a hydromechanical transmission and assemblies that integrate hydraulic components with gear set components in an integral assembly. Still more specifically, the invention provides a connecting assembly for a hydromechanical transmission that includes a connecting plate having a hydraulic unit side and a gear unit side. Mechanical drive and hydraulic drive openings extend longitudinally through the connecting plate, and the connecting plate and hydraulic components and gear unit components are connected as an integral assembly. The connecting plate provides a hydraulic fluid manifold for the hydraulic components.
At least one embodiment of the invention provides a hybrid vehicle hydromechanical or hydromechanical powersplit transmission including a hydraulic unit housing having a sealed internal chamber and a gear unit housing having a separate internal chamber sealed from the hydraulic unit housing internal chamber. The hydraulic unit housing may be connected to the gear unit housing in longitudinally aligned relationship. The hydraulic unit housing may have a prime mover input shaft opening at its input end and at least one and preferably two variable displacement hydraulic pump motor units with pump motor unit drive shafts disposed within the hydraulic unit housing interior chamber in laterally offset relation to the prime mover input shaft opening. The variable displacement hydraulic pump motor units and their pump motor unit drive shafts may be in circumferentially spaced relation and in axially spaced relation to one another. The gear unit housing may have an output drive shaft opening at its output end extending longitudinally from the gear unit housing interior chamber and a gear unit having gear unit components. An input shaft may be disposed in the input shaft opening, and an output shaft may be disposed in the output shaft opening. The input shaft and the hydraulic pump motor unit drive shaft(s) and the output shaft may each be drivingly connected to one of the gear components. The input shaft opening, input shaft, output shaft opening and output shaft may be substantially coaxial, so that the transmission may be connected to a conventional vehicle prime mover engine and a conventional vehicle drive wheel differential. The gear unit may include a planetary gear set having planetary gear components. Various different hydraulic components may be used with various different gear set components, to provide flexibility for use in a wide variety of applications and vehicles.
At feast one embodiment of the invention further provides a connecting plate intermediate the hydraulic unit housing and the gear unit housing. One side of the connecting plate may provide a wall of the hydraulic unit housing interior chamber, and the other side of the connecting plate may provide a wall of the gear unit housing interior chamber. The hydraulic pump motor units and the gear set may be mounted on and carried by the connecting plate. The connecting plate may also provide a hydraulic manifold having fluid flow passages in fluid communication with each pump motor unit, and the connecting plate may include bearings for supporting rotating shafts including the pump motor unit drive shafts. One type of fluid may be disposed within the hydraulic unit housing interior chamber to provide a hydraulic fluid reservoir, and a different type of fluid with a different fluid level may be disposed within the planetary gear unit housing interior chamber to provide gear lubrication. Components of the hydraulic unit extend into the gear unit and provide integral portions of the gear unit, while portions of the gear unit provide integral portions of the hydraulic unit.
At least one embodiment of the invention further provides a motor vehicle having two laterally spaced apart longitudinally extending frame rails, and the hydromechanical powersplit transmission is disposed between the frame rails. The motor vehicle includes a drive shaft and a prime mover having a prime mover shaft, the drive shaft is axially aligned with and drivingly connected to the output shaft, and the prime mover shaft is axially aligned and drivingly connected to the input shaft.
The invention further provides the combinations set out in the accompanying claims. This Summary is not intended to identify key features or essential features of the claimed subject matter, and these and other features of the invention are more fully described and particularly pointed out in the description and claims set out below. The following description and claims and the annexed drawings set forth in detail certain illustrative embodiments of the invention, and these embodiments indicate but a few of the various ways in which the principles of the invention may be used.
Embodiments of this invention will now be described in further detail with reference to the accompanying drawings, in which:
Referring now to the drawings in greater detail,
Headings are provided in the description below to assist the reader. However descriptions under all headings relate to the descriptions under each individual heading, so that the complete description below is to be used to understand the description under each individual heading.
Overall Structure and OperationThe object 10 can be any object that uses a transmission for transmitting energy or converting energy to rotational movement. In the preferred embodiment described below, the object 10 is a wheeled land vehicle such as an on-highway truck. The vehicle 10 includes a prime mover 13, which in the preferred embodiment is a conventional internal combustion engine such as a gasoline or diesel or natural gas engine, and an engine drive shaft 14. The vehicle 10 further includes drive wheels 15, a differential 16, and a differential drive shaft 17. The vehicle 10 also includes frame rails 18, which are longitudinally extending beams, which may be steel or other suitable structural material, to which the body (not shown), prime mover 13, drive shaft 14, vehicle suspension components (not shown), differential 16 and other components of the vehicle 10 are mounted in a conventional well know manner.
As best shown in
The hydraulic unit housing 26 includes a longitudinally extending prime mover input shaft or mechanical drive shaft 41 connected to engine drive shaft 14 through a suitable torsional vibration dampening coupling 14a. Input shaft 41 (
As best illustrated in
As illustrated schematically in
More specifically, as illustrated in
Referring to
Referring now to
The connecting plate 25 of the connecting assembly 84 provides a hydraulic manifold and further includes fluid flow passages that include high pressure fluid flow passages 89a and 89b and pilot signal passages 90. The high pressure fluid outlet side of each hydraulic pump motor unit 42 and 43 includes a high pressure fluid outlet or flow tube 91 (
In this manner, the connecting plate 25 is a component of a connecting assembly 84 and provides a mounting platform for the pump motor units 42 and 43 and for the valves 52, 53, 54, and 55; provides support and bearings for the pump motor unit shafts 44 and 45; provides bearings for the transfer shaft 62 and support for the transfer shaft 62 and input shaft 41; provides a mounting platform for the planetary gear components 71; provides a wall for the hydraulic unit internal chamber 36 and for the planetary gear unit internal chamber 37; combines the hydraulic unit 23 and the planetary gear unit 24 into an integral unit; and provides a high pressure hydraulic manifold for the fluid connections between and among the high pressure accumulator 46, valves 52, 53, 54, and 55, setting pistons 48, 49, 50 and 51, and pump motor units 42 and 43 and their associated rotating piston groups and high pressure flow tubes 91, 92. The illustrated components in the hydraulic unit 23, such as for example the pump motor units 42 and 43, may be replaced with different components and used with the gear unit 24 or with a different gear unit. Similarly, the illustrated components in the gear unit 24, such as for example the planetary gear components 71 and drive gears, may be replaced with different components and used with the hydraulic unit 23 or with a different hydraulic unit. This enables the transmission 11 to be used in a wide variety of vehicles and applications.
As best illustrated in
Once the transmission 11 is assembled in the configuration illustrated in the drawings and described above, the transmission 11 is installed in the vehicle 10 in the lateral space between the frame rails 18 and in the longitudinal space between the prime mover drive shaft 14 and the differential drive shaft 17 (
Turning now the operation of the transmission 11, the transmission 11 operates in various modes under a wide variety of conditions. For example, the transmission 11 operates in various modes in response to vehicle operator accelerator pedal input to transmit power from the prime mover 13 and/or from stored energy in the high pressure accumulator 46 to the differential drive shaft 17 to propel the vehicle 10. Further, the transmission 11 operates in various modes in response to vehicle operator brake pedal input to capture energy from the vehicle 16 during braking of the vehicle 10 and to transmit the captured energy to the high pressure accumulator storage device 46 for later use. Still further, the transmission 11 operates in response to vehicle operator input to start the prime mover 13 using stored energy in the accumulator storage device 46 when the vehicle 10 is stationary.
To select among a virtually infinite array of the above described operating modes of the transmission 11, the displacement and pump or motor operating mode of pump motor units 42 and 43 may be changed and the isolation valves 54 and 55 may be opened or closed. For example, when the secondary unit 43 is to be used in a pumping mode during braking to charge the accumulator 46, an input provided to the pilot valve 55a may allow the isolation valve 55 to close. In this mode of operation, the isolation valve 55 for the secondary pump motor unit 43 may act as a check valve, so that the isolation valve 55 opens when pressure in the outlet tube 92 exceeds the pressure in the high pressure accumulator 46 to allow pressure from unit 43 to charge accumulator 46. The isolation valve 54 for the primary pump motor unit 42 may be generally opened when the vehicle 10 is moving, except closed when the secondary unit 43 is pumping during braking to prevent supply of fluid from the secondary unit 43 to the primary unit 42.
When the vehicle 10 is stationary, the isolation valve 54 for the primary unit 42 may be closed, to prevent unintended flow to the secondary unit 43 and unintended movement of the vehicle 10. The transmission 11 may also be used to start the engine 13, to eliminate the need for a conventional starter. For this mode, hydraulic fluid from accumulator 46 is supplied to primary pump motor unit 42 and isolated from secondary pump motor unit 43, so that unit 43 and its drive shaft 44 rotate to rotate gears 76, 77, 72 and 74 to rotate planet carrier 75 and transfer shaft 62 and input shaft 41 and drive shaft 14 to rotate and start prime mover engine 13 (
Further, the proportional control valves 52 and 53 adjust the displacement of the units 42 and 43 during both pumping and motoring modes. For example, when movement of vehicle 10 is initially started from a stopped position, fluid is supplied from accumulator 46 to secondary unit 43 and displacement of unit 43 is gradually increased to accelerate vehicle 10. As speed of the vehicle 10 increases and displacement of unit 43 increases, fluid pressure from accumulator 46 decreases and less stored energy is available to unit 43 to continue to drive vehicle 10. As the speed of the vehicle further increases, more power is transmitted mechanically directly from the engine 13 to driveshaft 17 through the planetary gearset 71, while less power is transmitted by the hydraulic pump motor units. By reducing the hydraulic power transmitted at higher vehicle speeds, the overall transmission efficiency is increased. Additionally, the displacements of pump motors 42 and 43 are steplessly adjusted to achieve a desired output shaft speed for a given input prime mover input shaft speed. The adjusting of displacement provides for an infinitely variable or stepless transmission ratio, which allows the prime mover 13 to be operated at its most efficient operating speed regardless of output shaft speed. Additionally, since there is no gear shifting, there is no interruption in power. Under this condition, displacement of units 42 and 43 may be set to zero, to minimize any drag or inefficiency caused by units 42 and 43. When vehicle 10 is to brake, secondary unit 43 is operated in a pumping mode and displacement of unit 43 is increased to pump more fluid into accumulator 46 and cause further braking resistance to the drive wheels 15 until the desired slower speed or stopped condition for the vehicle 10 is achieved. During operation of the transmission 11, the sealed hydraulic unit chamber 36 is maintained at a positive pressure of at least about 2 bar and preferably in the range of about 2 bar to about 6 bar, to prevent cavitation in the pump motor units 42 and/or 43 during pumping, while the sealed gear unit chamber 37 is maintained at about atmospheric pressure. Because the pump motor units 42 and 43 are disposed in chamber 36 which is the low pressure reservoir, separate low pressure conduits and connections between the low pressure reservoir and the pump motor units 42 and 43 are not required.
In this manner, the transmission 11 provides a hydromechanical powersplit transmission that captures and stores energy as high pressure fluid in accumulator 46 during vehicle braking and that uses that stored energy to propel the vehicle 10 or to start engine 13. Further, when the vehicle 10 is to be propelled when stored energy in accumulator 46 is depleted, a direct variable speed mechanical connection is provided from engine 14, through hydraulic unit 23 but without pumping or motoring displacement of the units 42 and 43, through the planetary gear set 71 and to the drive wheels 15.
Gear Unit Double SumpReferring now to FIGS. 1 and 7-9, the planetary gear unit housing 29 includes a front gear unit housing 29a and a rear gear unit housing 29b. The sealed interior chamber or sump 37 of the planetary gear unit 24 includes a front chamber or front sump 37a and a rear chamber or rear sump 37b. The primary hydraulic pump motor unit drive shaft 44 extends from the hydraulic side 25a, through the connecting plate 25, to the front chamber 37a, where its associated gear 76 is drivingly connected to the sun gear 72 through gear 77 (
Gear unit front housing 29a includes a longitudinally extending housing portion or wall 93 and a laterally extending generally planar housing portion or wall 94. Housing portion 94 provides a wall that separates sumps 37a and 37b and provides a common or shared wall for each sump 37a and 37b. An output drive shaft opening 95 extends longitudinally through housing portion or wall 94, and a bearing 96 in opening 95 supports output drive shaft 63. Gear unit rear housing 29b includes a longitudinally extending housing portion or wall 97 and a laterally extending generally planar housing portion or wall 98. The output drive shaft opening 63a extends longitudinally through housing portion or wail 98, and a bearing 100 in opening 63a supports output drive shaft 63.
When the motor vehicle 10 is not moving, the output shaft 63 and gears 79 and 78 and secondary pump motor unit drive shaft 45 are in a stationary condition and are not rotating, in this condition, the fluid level in the chambers or sumps 37a and 37b is approximately at a level indicated by dotted line 101a in
Referring now to
As illustrated in
As illustrated in
As illustrated in
Accordingly, the walls 93 and 94 of the front or first housing 29a define the front or first sump 37a. The rear or second housing 29b is connected to the first housing 29a and includes walls 97 and 98 that cooperate with the common wall 94 of the first housing 29a to define the rear or second sump 37b. A first set of rotatable gears 71 is disposed in the first sump 37a and has a stationary condition and a rotating condition. A second set of rotatable gears 78, 79 is disposed in the second sump 37b and has a stationary condition and a rotating condition. An input drive shaft 62 extends longitudinally into the first sump 37a and is rotatably connected to the first set of rotatable gears. An output drive shaft 63 extends longitudinally out of the second sump 37b and is rotatably connected to the second set of gears. The longitudinal axes 22 of the input and output drive shafts are substantially coaxial. A first hydraulic pump motor unit drive shaft 44 extends into the first sump 37a and is driving connected with the first set of rotatable gears. A second hydraulic pump motor unit drive shaft 45 extends longitudinally from end to end through the first sump 37a and into the second sump 37b and is drivingly connected with the second set of rotatable gears. The first and second hydraulic pump motor unit drive shafts are supported by bearings in wails 25, 94 and 98. Openings 102 and 103 extend between and establish a fluid flow path between the first sump 37a and the second sump 37b, and the openings 102 and 103 extend to the channel 104 to pump lubricating liquid from the second sump 37b to the first sump 37a when the second set of gears is rotating.
Method of Assembly and DisassemblyTurning now to FIGS. 14 and 22-33, various steps in a method 140 of assembling and disassembling and repairing a transmission according to the present invention and various subassemblies or assemblies according to the present invention are illustrated. The method 140 and the assemblies provide a hydromechanical powersplit transmission 11 illustrated in the other Figures and described elsewhere in this description. The method 140 may be practiced in the step by step order described below, in a different order, or in a reverse order, and the steps may be combined or broken into sub-steps, to assemble and disassemble (in which case the term assemble will be understand to mean disassemble) and repair according to the present invention.
The method of assembly 140 includes step 140a illustrated in
The method of assembly 140 further includes step 140b illustrated in
The method of assembly 140 further includes step 140c illustrated in
The method of assembly 140 further includes step 140d illustrated in
The method of assembly 140 further includes step 140e illustrated in
The method of assembly 140 further includes step 140f illustrated in
The method of assembly 140 further includes step 140g illustrated in
The method of assembly 140 further includes step 140h illustrated in
The method of assembly 140 further includes step 140i illustrated in
The method of assembly 140 further includes step 140j illustrated in
Using the method 140 of assembly according to the present invention, a hydraulic unit 23 and a planetary gear unit 24 are assembled using a central connecting plate 25. The hydraulic components are assembled on the hydraulic side 25a of the connecting plate 25, and a hydraulic unit housing 26 is assembled over the hydraulic components and in sealing engagement with the hydraulic side 25a to provide a sealed chamber 36 that is pressurized during operation of the transmission 11. The planetary gear components are assembled on the planetary gear side 25b of the connecting plate 25, and planetary gear housings 29a and 29b are assembled over the planetary gear components to provide sealed chambers 37a and 37b that are isolated from chamber 36. After assembly of the transmission 11, the transmission 11 is assembled onto the vehicle 10 in the position described above.
If it becomes necessary to repair the transmission 11, the transmission 11 is removed from the vehicle 10. For repairs to the planetary gear unit 24, the planetary gear unit housings 29b and, if necessary, 29a, are removed to access the planetary gear unit components as illustrated in
Referring now to FIGS. 7 and 13-17, additional structure and features of the planetary gear set 71, planet carrier 75, planet gears 74 and lubrication system for the moving components within the front sump 37a are illustrated, with
To assemble the splash gear 112 onto the planet carrier 75, the splash gear 112 is assembled in the longitudinal direction onto the radially outer peripheral surface 75a of a circumferentially extending longitudinally projecting annular lip 75b on a lateral end face or lateral wall 75c of planet carrier 75. The notches 112c of the splash gear 112 are aligned with the shafts 113 so that the shafts 113 project longitudinally through the notches 112c, and this position of the splash gear 112 is a partially assembled position. The splash gear 112 is then rotated about 5 to 10 degrees (clockwise as viewed in
The planet carrier 75 further includes a longitudinally extending central opening 75e. The central opening 75e includes an internal spline connector 75f. When the planet carrier 75 is assembled onto the transfer drive shaft 62 (
Each planet gear shaft 113 also includes a central bore or lubricating liquid flow passage 113c. Each flow passage 113c extends into the shaft 113 from the lateral wall 75c in the longitudinal direction to the left as viewed in the drawings. A lateral cross bore or radial passage 113d (
When the planet carrier 74 and lateral wall 74c are in a rotating condition about longitudinal axis 71a within the front sump 36a, the splash gear 112 rotates with the planet carrier 74 and lateral wall 74c about axis 71a. The teeth 112a of the splash gear 112 rotate into and out of the lubricating oil in the lower portion of the front sump 37a below the fluid level 101a. This splashes lubricating liquid within the front sump 37a and creates a lubricating liquid suspension or droplets within the upper portion of the sump 37a above the lubricating liquid level 101a. Some of this splashed lubricating liquid enters the space between the trough wall 117b and the connecting plate gear side 25b, and this oil flows by gravity to lubricate bearing 86. Some of the splashed lubricating liquid engages and accumulates on the rotating lateral wall 75c of the planet carrier 75 to at least partially coat the lateral wall 75c with lubricating oil. When this liquid is deposited in this manner on the lateral wall 75c, the liquid begins to rotate with the lateral wall 75c. The lubricating liquid immediately adjacent the wall 75c will rotate substantially at the same rotational velocity as the wall 75c, and the liquid farther away from the wall 75c will rotate at a slightly lesser rotational velocity than the wall 75c.
As this lubricating liquid on the lateral wall 75c rotates with the lateral wall 75c, the liquid is acted upon by centrifugal force and moved by centrifugal force laterally or radially outwardly against an annular radially inwardly facing catch wall 75g of the lip 75b. The catch wall 75g is substantially adjacent each flow passage 113c and is at least partially radially outward from each flow passage 113c. The lubricating liquid begins to accumulate at or flood the catch wall 75g, and the thickness or depth of the lubricating liquid increases at the location of the catch wall 75g. Due to the centrifugal force acting on the lubricating liquid, coupled with the relative rotational movement between the lateral wail 75c and the liquid and between the catch wall 75g and the liquid, the accumulating lubricating liquid flows circumferentially along the rotating catch wall 75g. This flow will be in a direction opposite the direction of rotation of the lateral wall 75c and catch wall 75g and toward and along the inwardly facing catch wall 113f of each associated planet gear shaft 113. A portion of this accumulating liquid then flows longitudinally through the passages 113c and then radially through the passages 113d to lubricate outer peripheral surfaces 113g of planet gear shafts 113 and bearings 74a and planet gears 74. To facilitate this flow of oil, inwardly facing catch wall 113f of each planet gear shaft 113 is generally laterally and circumferentially aligned with the inwardly facing catch wail 75g so that the surfaces 75g and 113f provide a generally smooth generally annular catch wall. The catch wall 75g extends longitudinally from the lateral wall 75c in the opposite direction to the flow passages 113c (that is, to the right as viewed in the drawings). As the planet carrier 75 rotates about axis 71a, centrifugal force acting on each planet gear 74 urges each planet gear 74 radially outward away from axis 71a. This unloads the bearings 74a at the location of the passages 113d, to facilitate flow of lubricating liquid from the passages 113d to the bearings 74a and to prevent the holes 113d from damaging the bearings 74a.
The annular catch wall 75g includes catch wall portions 75h adjacent each of the flow passages 113c, extending circumferentially in the direction of rotation of the lateral wall 75c and catch wail 75g. Lubricating liquid accumulating on each of these catch wall portions 75h will flow to an adjacent flow passage 113g, while lubricating liquid accumulating on the catch wall 75g on the other side of a flow passage 113g will flow to the next flow passage 113g or will flood over the catch wall 75g and contribute to the splash lubricating suspension or droplets. Each of the catch wall portions 75h has a sufficient circumferential extent to catch lubricating oil to feed its adjacent flow passage 113c. In the preferred embodiment, this circumferential extent is at least about 10 degrees. Also, in the preferred embodiment, the catch wail portions 75h are each generally semicircular and are joined to form the continuous annular catch wall 75g. As used herein, the term circumferential extending in relation to the catch wall portions 75h describes both curved surfaces and straight surfaces, so that, for example, the catch wall portions 75h could alternatively be straight wall portions. Also, while the catch wall portions 75h in the preferred embodiment are joined together to provide the continuous catch wall 75g, the catch wall portions 75h could alternatively be separated from one another. Further, the catch wail 75g and its catch wall portions 75h may extend perpendicular to the lateral wall 75c (in which case they extend only in the longitudinal direction) or at another angle relative to the lateral wall 75c (in which case they would extend in both the longitudinal and the lateral or radial direction). Also, the lateral wall 75c may be disposed in a plane that is perpendicular to the longitudinal axis 71a (in which case it extends only in the lateral direction) or in a plane at another angle relative to the longitudinal axis 71a (in which case it would extend in both the lateral and the longitudinal direction).
In this manner, lubricating oil from rear sump 37b is pumped through channel 104 to front sump 37a to reduce the fluid level in rear sump 37b, and lubricating oil in the front sump or chamber 37a is distributed to the moving components and bearings within the chamber 37a. This distribution is accomplished using the splash gear 112 and the planet carrier 75 and lateral wall 74c and catch walls 75g, 75h and 113f and flow passages 113c and 113d and planet gear shafts 113, to eliminate a need for a conventional lubrication pump and to minimize the size and weight and complexity of the transmission 11. The lubricating system could alternatively secure a rotating splash gear and rotating lateral wall with catch walls to a different rotating planetary gear set component, such as for example a rotating ring gear, or could alternatively be used with other types of gear sets or in other applications.
Park Pawl AssemblyReferring now to FIGS. 1 and 17-21, the transmission 11 further includes a park pawl assembly 120. The park pawl assembly 120 locks the output drive shaft 63 (and the gears 79 and 73 and the ring gear 73) against rotation to prevent unwanted movement of the vehicle 10 such as when the vehicle 10 is parked. This is accomplished by the park pawl assembly 120 locking the drive shaft 63 to the stationary rear planetary housing 29. As described more fully below, the park pawl assembly 120 is moveable between an engaged or locked position illustrated in
The park pawl assembly 120 includes a park hub 121 (
As shown in
The park pawl 127 is free floating with the bushing 129 and bore in which the bushing 129 is disposed. A locking spring 132 pushes or biases the free floating park pawl actuator 127 toward the locked position illustrated in
A release arm 133 and a release lever 134 are secured to a release shaft 135, and the components 133, 134 and 135 rotate or pivot together as a unit about the longitudinal axis or release arm pivot axis 135a of the release shaft 135. The release arm pivot axis and the park pawl pivot axis and the path of the park pawl actuator 127 are substantially perpendicular to one another. To move the park pawl assembly 120 from its locked position to its unlocked position against the bias of locking spring 132 to release the park pawl 122 from its locked position, the release lever 134 is rotated about the release pivot axis 135a from its locked position illustrated in
The hub 121 includes several teeth on its outer peripheral surface, and the profile of each tooth is involute. The profile of the oppositely facing surfaces of the pawl locking finger 125 that engage the teeth is substantially flat. When the park pawl assembly 120 is in its locked position with the finger 125 engaging a tooth of the hub 121 and the vehicle is parked on a hill, the involute profile of the tooth acting against the substantially fiat profile of the finger 125 urges the finger 125 out of engagement with the tooth to assure unlocking. When the park pawl assembly 120 is in its unlocked position and the park pawl actuator 127 is moved to allow spring 132 to urge the finger 125 toward its locked position, the involute profile of the teeth and the substantially flat profile of the finger 125 prevent the finger 125 from fully entering the space between the teeth and locking against a tooth of the hub 121 until the vehicle has slowed to an acceptable slow speed, for example one mile per hour or less, or has stopped.
The park pawl assembly 120 therefore includes the park pawl 122, the park pawl actuator 127, and the release arm 133. The park pawl actuator 127 is a generally cylindrical plunger and moves with its cam surface 123 along a substantially straight line path from an unlocked position to a locked position by operation of the locking spring 132 in response to rotational movement of the release arm 133 to its locked position. This substantially straight line movement of the actuator 127 is substantially perpendicular to the direction of movement of the locking surface 126 and locking finger 125 of the park pawl 122 and causes movement of the park pawl 122 to its locked position. The release arm 133 rotates about its pivot axis back to its unlocked position, and this rotational movement of the release arm 133 causes substantially straight line movement of the park pawl actuator 127 against the bias of the locking spring 132 back to its unlocked position, to return the park pawl 122 to its unlocked position.
Spline ConnectionsThe gears and shafts described above are preferably secured together using a spline connection 160 illustrated in
The spline connection 160 includes an internal spline connector 161 on the gear 76 and a mating external spline connector 162 on the shaft 44. As best shown in
As best shown in
Continued movement of the gear 76 onto the shaft 44 to a second partially assembled position or configuration illustrated in
In this manner, the spline connection 161 includes an internal spline connector 161 and an external spline connector 162. At least one of the spline connectors 161 or 162, and preferably both, include a spline portion and a smooth centering portion. During assembly, the smooth centering portion of one of the spline connectors 161 or 162 cooperates with the spline portion of the other spline connector to align the connectors 161 and 162 while permitting rotating movement between the spline connectors 161 and 162. In the fully assembled configuration, the smooth centering portion of the one spline connector moves into registry with the smooth centering portion of the other spline connector to continue to maintain alignment and reduce relative movement between the spline connectors.
ConclusionThe principles, embodiments and operation of the present invention are described in detail herein with reference to the accompanying drawings but are not to be construed as being limited to the particular illustrative forms disclosed. It will thus become apparent to those skilled in the art that various modifications of the principles, embodiments and operation herein can be made without departing from the spirit or scope of the invention.
Claims
1. A connecting assembly for a hydromechanical transmission, comprising,
- a connecting plate having a hydraulic unit wall and a gear set unit wall,
- a hydraulic unit housing which is connected to the hydraulic unit wail to provide a sealed hydraulic chamber which contains a hydraulic fluid,
- a gear set unit housing which is connected to the gear set unit wall to provide a sealed gear set chamber,
- first and second hydraulic pump motor units disposed in the sealed hydraulic chamber and arranged so that hydraulic fluid can flow between each of the pump motor units and the sealed hydraulic chamber so as to permit exchange of fluid between the pump motor units, and
- a gear set disposed in the sealed gear set chamber.
2. A connecting assembly as set forth in claim 1, wherein the connecting plate includes fluid flow passages, and the hydraulic pump motor unit includes a fluid outlet in fluid communication with one of the passages.
3. A connecting assembly as set forth in claim 1, including a mechanical drive opening that extends longitudinally through the connecting plate from the sealed hydraulic chamber to the sealed gear set chamber, and a mechanical drive shaft extends longitudinally from end to end through the sealed hydraulic chamber and through the mechanical drive opening and into the sealed gear set chamber.
4. A connecting assembly as set forth in claim 1 including a hydraulic drive opening that extends longitudinally through the connecting plate from the sealed hydraulic chamber to the sealed gear set chamber, a hydraulic pump motor unit drive shaft drivingly connected to the hydraulic pump motor unit, and the hydraulic pump motor unit drive shaft extends longitudinally through the hydraulic drive opening.
5. A connecting assembly as set forth in claim 4, in which the hydraulic drive openings are in laterally offset relation to the mechanical drive opening and are in circumferentially spaced relation to one another.
6. A connecting assembly as set forth in claim 1, in which the gear set includes a plurality of gear components, the mechanical drive shaft is connected to one of the gear components, and each hydraulic pump motor unit drive shaft is connected to another of the gear components.
7. A connecting assembly for a hydromechanical transmission, comprising:
- a connecting plate having a hydraulic unit wall and a gear set unit wall,
- a hydraulic unit housing which is connected to the hydraulic unit wall to provide a sealed hydraulic chamber,
- a gear set unit housing which is connected to the gear set unit wall to provide a seated gear set chamber,
- a hydraulic pump motor unit disposed in the sealed hydraulic chamber, having a hydraulic pump motor unit drive shaft drivingly connected to it,
- a gear set disposed in the sealed gear set chamber and including a plurality of gear components, the hydraulic pump motor unit drive shaft extending through a hydraulic drive opening in the connecting plate from the hydraulic unit housing chamber into the gear set unit housing chamber where it is connected to a first one of the gear components,
- a mechanical drive shaft for connection to a prime mover, which extends from the prime mover into the hydraulic unit housing, extending without interruption through the hydraulic unit housing chamber and out of the chamber through a mechanical drive opening in the connecting plate into the gear set unit housing chamber where it is connected to a second one of the gear components, the mechanical drive shaft being offset laterally from the hydraulic pump motor unit drive shaft.
8. A connecting assembly as set forth in claim 7, in which the connecting plate includes fluid flow passages, and the hydraulic pump motor unit includes a fluid outlet in fluid communication with one of the passages.
9. A connecting assembly as set forth in claim 7, which includes a second hydraulic pump motor unit disposed in the sealed hydraulic chamber having a second hydraulic pump motor unit drive shaft drivingly connected to it, the second hydraulic pump motor unit drive shaft extends longitudinally through a second hydraulic drive opening in the connecting plate.
10. A hydromechanical transmission comprising a hydraulic unit having a hydraulic unit housing, a gear unit having a gear unit housing,
- the hydraulic unit housing having a vehicle prime mover input end and an output end, the gear unit housing having an input end and a vehicle drive shaft output end, the hydraulic unit housing and the gear unit housing each having an exterior surface and an interior surface, each interior surface defining an interior chamber, each of the interior chambers being sealed from the other interior chamber,
- the hydraulic unit housing having a longitudinally extending prime mover input shaft opening at its input end extending longitudinally into the hydraulic unit housing interior chamber, at least one variable displacement hydraulic pump motor unit disposed within the hydraulic unit housing interior chamber, a hydraulic pump motor unit drive shaft within the hydraulic unit housing interior chamber, the hydraulic pump motor unit drive shaft being drivingly connected to the hydraulic pump motor unit,
- the gear unit housing having an output drive shaft opening at its output end extending longitudinally from the gear unit housing interior chamber, a gear unit disposed within the gear unit housing interior chamber, the gear unit having gear components,
- the hydraulic pump motor unit drive shaft being drivingly connected to one of the gear components, and
- the hydraulic unit housing output end being connected to the gear unit housing input end, with the hydraulic unit housing interior chamber and the gear unit interior chamber being in longitudinally aligned relationship to one another.
11. A hydromechanical transmission as set forth in claim 10, wherein the hydraulic pump motor unit drive shaft extends from the hydraulic unit housing interior chamber to the gear unit housing interior chamber
12. A hydromechanical transmission as set forth in claim 10, including a connecting plate having longitudinally opposite sides, the connecting plate is intermediate the hydraulic unit housing interior chamber and the gear unit interior chamber, one side of the connecting plate is adjacent the hydraulic unit output end, and the other side of the connecting plate is adjacent the gear unit input end.
13. A hydromechanical transmission as set forth in claim 12, wherein the hydraulic unit housing includes another hydraulic pump motor unit and another hydraulic pump motor unit drive shaft connected to the other hydraulic pump motor unit, the other pump motor unit drive shaft extends from the hydraulic unit housing interior chamber to the gear unit housing interior chamber, each hydraulic pump motor unit and each hydraulic pump motor unit drive shaft is disposed in laterally offset relation to the input shaft opening, each hydraulic pump motor unit drive shaft is drivingly connected to one of the gear unit components, and the input shaft opening and output shaft opening are substantially axially aligned.
14. A hydromechanical transmission as set forth in claim 13, wherein the transmission is a powersplit transmission, each hydraulic pump motor unit is in circumferentially spaced relation to the other, each hydraulic pump motor unit drive shaft is in circumferentially spaced in relation to the other, the gear unit is a planetary gear unit having planetary gear components including a sun gear and a ring gear and a planet gear carrier.
15. A hydromechanical transmission as set forth in claim 13, wherein each hydraulic pump motor unit is in longitudinally spaced relation to the other.
16. A hydromechanical transmission as set forth in claim 13, including a prime mover input shaft extending longitudinally through the prime mover input shaft opening, an output shaft extending longitudinally through the output shaft opening, one of the sides of the connecting plate provides a wall of the hydraulic unit housing interior chamber, the other of the sides of the connecting plate provides a wall of the gear unit housing interior chamber, and the connecting plate includes bearings for supporting the input shaft and each hydraulic pump motor unit drive shaft.
17. A hydromechanical transmission as set forth in claim 13, wherein one side of the connecting plate provides a wall of the hydraulic unit housing interior chamber, another side of the connecting plate provides a wall of the gear unit interior chamber, and the hydraulic unit housing and the planetary gear unit housing are each removably attached to the connecting plate.
18. A hydromechanical transmission as set forth in claim 13, wherein the connecting plate is a hydraulic manifold having fluid flow passages in fluid communication with the pump motor unit.
19. A hydromechanical transmission as set forth in claim 16, wherein each pump motor unit is a bent axis variable displacement pump motor unit, the variable displacement pump motor units each include a pumping mode high pressure hydraulic fluid outlet and a displacement control mechanism, and different ones of the fluid flow passages in the connecting plate are in fluid communication with the pumping mode high pressure hydraulic fluid outlet and with the displacement control mechanism of each pump motor unit.
20. A hydromechanical transmission as set forth in claim 13, including a displacement control valve associated with each pump motor unit, each displacement control valve is in fluid communication with the fluid flow passages that are in fluid communication with the displacement control mechanism.
21. A hydromechanical transmission as set forth in claim 20, wherein each of the displacement control valves is mounted on the connecting plate.
22. A hydromechanical transmission as set forth in claim 13, including an isolation valve associated with each pump motor unit, the isolation valves include a high pressure port, each isolation valve has a closed position isolating the high pressure port from its associated pump motor unit.
23. A hydromechanical transmission as set forth in claim 22, wherein each isolation valve is mounted on the connecting plate.
24. A hydromechanical transmission as set forth in claim 23, wherein the isolation valves are disposed in a single isolation valve housing, the isolation valve high pressure port is disposed in the isolation valve housing, the isolation valve housing includes passages connecting the isolation valve high pressure port with a connecting plate high pressure port and with each of the isolation valves.
25. A hydromechanical transmission as set forth in claim 22, wherein the connecting plate includes passages connecting each of the isolation valves with an associated one of the pump motor units.
26. A hydromechanical transmission as set forth in claim 16, wherein the input shaft is connected to the planet gear carrier, the first mentioned hydraulic pump motor unit drive shaft is connected to the sun gear, and the second mentioned hydraulic pump motor unit drive shaft and the output shaft are each connected to the ring gear.
27. A hydromechanical transmission as set forth in claim 16, including a transfer shaft extending longitudinally intermediate the input shaft and the output shaft, the transfer shaft is drivingly connected to the input shaft and to one of the planetary gear components, the connecting plate includes a bearing supporting the transfer shaft, and the transfer shaft is axially aligned with the input shaft and with the output shaft.
28. A hydromechanical transmission as set forth in claim 26, including a bearing rotatably supporting the transfer shaft within one end of the output shaft.
29. A hydromechanical transmission as set forth in claim 16, wherein the connecting plate includes a bearing rotatably supporting each pump motor unit drive shaft.
30. A hydromechanical transmission as set forth in claim 29, wherein the planetary gear unit housing includes a bearing rotatably supporting each pump motor unit drive shaft.
31. A hydromechanical transmission as set forth in claim 30, including a gear fixed to each pump motor unit drive shaft intermediate the bearings, and the gear is rotatably connected to one of the planetary gear components.
32. A hydromechanical transmission as set forth in claim 16, wherein the connecting plate includes bearings rotatably supporting each of the pump motor unit drive shafts and seals preventing fluid leakage between the pump motor unit drive shafts and the connecting plate, the planetary gear unit housing includes bearings rotatably supporting each pump motor unit drive shaft, a gear is fixed to each of the pump motor unit drive shafts intermediate the bearings, the gears are each rotatably connected to one of the planetary gear components, and the input shaft and the output shafts are substantially axially aligned.
33. A hydromechanical transmission as set forth in claim 32, wherein the bearings in the connecting plate are radial and axial thrust bearings.
34. A hydromechanical transmission as set forth in claim 10, including one type of fluid disposed within the hydraulic unit housing interior chamber and a different type of fluid disposed within the planetary gear unit housing interior chamber.
35. A hydromechanical transmission as set forth in claim 34, wherein the hydraulic unit housing interior chamber is substantially completely filled with the one type of fluid and is at a positive pressure of at least about 2 bar, and the planetary gear unit housing is substantially less than half filled with the different type of fluid at about atmospheric pressure.
36. A hydromechanical transmission as set forth in claim 35, wherein each of the hydraulic pump motor units is fully immersed in the one type of fluid within the hydraulic unit interior chamber.
37. A hydromechanical transmission as set forth in claim 36, wherein the first mentioned hydraulic pump motor unit discharges fluid into the hydraulic unit housing interior chamber when in a motoring mode, and the other hydraulic pump motor unit inputs fluid from the first mentioned hydraulic pump motor unit through the hydraulic unit housing interior chamber when in a pumping mode.
38. A hydromechanical transmission as set forth in claim 10, including a motor vehicle having two laterally spaced apart longitudinally extending frame rails, and the hydromechanical transmission is disposed between the frame rails.
39. A hydromechanical transmission as set forth in claim 38, wherein the motor vehicle includes a vehicle drive shaft and a prime mover having a prime mover shaft, the output shaft opening is axially aligned with the vehicle drive shaft, and the input shaft opening is axially aligned with the prime mover shaft.
40. A hydromechanical transmission as set forth in claim 33, wherein the motor vehicle includes a high pressure accumulator and the high pressure accumulator is connected with each hydraulic pump motor unit during various modes of operation of the motor vehicle.
Type: Application
Filed: Oct 31, 2014
Publication Date: Feb 19, 2015
Applicant: PARKER-HANNIFIN CORPORATION (Cleveland, OH)
Inventors: Joseph Kovach (Aurora, OH), Matthew Simon (Paw Paw, MI), Stephen Horsfall (Auckland), Brian Ralph (Grove City, OH), Thomas Finsel (Kalamazoo, MI), Christopher Phillips (Marcellus, MI), John Loeffler (Olive Branch, MS)
Application Number: 14/529,210
International Classification: F16H 47/04 (20060101); F16H 61/44 (20060101);