Abstract: A variable capacity swash plate compressor includes a plurality of pistons slidably received in a plurality of cylinder bores, respectively, a rotating member rigidly fitted on the drive shaft, for rotation in unison with the drive shaft, a swash plate mounted on the drive shaft in a manner tilted with respect to an imaginary plane perpendicular to the drive shaft and axially slidable along the drive shaft, and a linkage interposed between the rotating member and the swash plate, for tiltably connecting the swash plate to the rotating member to cause the swash plate to rotate in unison with the rotating member. The link member is offset by a predetermined amount from a boundary between a compressing piston-side area which receives compression reaction forces from ones of the pistons during the compression stroke and a suction piston-side area which receives tensile reaction forces from ones of the pistons during the suction stroke, toward the compressing piston-side area.

Abstract: A hydrostatic axial piston machine with a swash plate achieves a high power with a compact and simple construction. Two cylinder drums are at some axial distance from one another and are in synchronous rotation. Each drum contains a group of concentric cylindrical borings, between which, and at an angle with respect to the axis of rotation of the axial piston machine there is a rotationally locked circular ring-shaped eccentric disc. The pistons are guided against the disc so that they can move longitudinally in the cylinder bores. Each piston consists of two piston segments having the same diameter oriented coaxially to one another and at some distance from one another. The segments are inserted in cylinder bores which are located opposite one another and are connected to one another by a bridge segment. Two support bodies, one on either side of the eccentric disc, are provided for movement on the eccentric disc along a track.

Abstract: A swash plate type compressor having a cylinder block with cylinder bores disposed parallel to the axis of the cylinder block. A rotary shaft rotatably mounted within the cylinder block carries an aluminum swash plate. The swash plate is fixed in the rotary shaft and has two facial surfaces and an end surface. The swash plate has a coating preferably between 0.8 to 2.5 microns, of a tin/cobalt coating of at least 0.2 wt% cobalt and the balance being tin. A piston reciprocally fitted within the cylinder bore contains shoes which slideably intervene between the piston and the swash plate facial surfaces and reciprocate the piston and the swash plate facial surfaces and reciprocate the pistons by rotation of the swash plate. The coating on the swash plate permits the use of low silicon alloy aluminum without the need of metal plating or high finish polishing.

Abstract: In a shoe 5 for a swash plate compressor, the conical tapered surface 13 is formed between the spherical surface 10 and the rounded edge 14 to converge toward the spherical surface 10 inside an imaginary spherical surface 15 including the spherical surface 10. The conical tapered surface 13 forms a relatively large arcuate gap 23 between the hemispherical concavity 7 and the conical tapered surface 13. The arcuate gap 23 serves to reserve necessary amount of lubricant oil which may be supplied to sliding portions between the spherical surface 10 of the convex surface 11 and hemispherical concavity 7 of the piston 2. In addition, upon manufacture of the shoe 5, it can easily be removed from a metallic mold 52 due to existence of the arcuate gap 23 which prevents tight fit of the shoe 5 in the mold 52.

Abstract: A swash plate assembly for use in connection with a hydrostatic transmission. The swash plate assembly comprises a thrust bearing and a swash plate formed as a net shaped part from a plastic material adapted to carry the thrust bearing wherein the swash plate has an elongated aperture for allowing a shaft to pass therethrough and a plurality of acoustical cavities formed in the underside thereof generally arranged around the elongated aperture and proximate to the thrust bearing.

Abstract: A control plate (1) of a hydraulic machine having a core (2) is disclosed, which at least on its upper side (O), lying in operation against a cylinder drum, is covered with a layer of friction-reducing plastics material (3). The plastics material (3) is joined to the core (2) by means of a connecting element (8) which, as a result of interlocking engagement with the plastics material (3) and/or the core (2), takes up tensile forces substantially at right angles to the upper side (O).

Abstract: A pressure transformer is provided having a housing, with a rotating group disposed therein, an adjustable port plate is disposed between a barrel of the rotating group and a head portion of the housing. The barrel has a plurality of pistons slideably disposed in cylinders defined in the barrel. The cylinders each define a cylinder port that is in intimate contact with the port plate. Each cylinder port has a predetermined circumferential length. The port plate has three arcuate slots defined therein and spaced from one another along a predetermined circumference. Each arcuate slot has a leading edge and a trailing edge. Likewise each of the cylinder ports has a leading edge and a trailing edge. The shape and orientation of the leading edges and trailing edges of the cylinder ports and the arcuate slots are the same. The circumferential length of the space between adjacent ones of the arcuate slots is less than the circumferential length of the respective cylinder ports.

Abstract: A swash plate which is made of an iron-based or aluminum-based material and is used in a single-side compression type swash-plate compressor. A flame-sprayed copper-based alloy layer is formed on at least a sliding surface with a first shoe in a compression space side. The flame-sprayed copper-based alloy layer contains in total, by weight percentage, not less than 0.5% and not more than 50% of one or more kinds selected from not more than 40% of lead, not more than 30% of tin, not more than 0.5% of phosphorus, not more than 15% of aluminum, not more than 10% of silver, not more than 5% of silicon, not more than 5% of manganese, not more than 5% of chromium, not more than 20% of nickel, and not more than 30% of zinc and the balance essentially copper and impurities. Electrolytic plating, electroless plating, lubricant coating, phophatizing or hardening is applied on at least a second sliding surface with a second shoe in the side opposite to the compression space.

Abstract: A variable displacement axial piston pump (11) having a tiltable swashplate (33) to vary pump displacement by a manual input lever (43). The pump includes a neutral centering device (45) in which a cam member (57) is fixed to the end of one trunnion member (35). The cam member (57) defines three cam surfaces (65), each having a minimum displacement portion (67) and at least one maximum displacement portion (69). In engagement with each of the cam surfaces (65) is a follower element (79) supported by a cam follower holder (73), both of which are biased by a set of Belleville washers (75), toward the cam member (57). The present invention provides a neutral centering device which is balanced and simple to assemble, not requiring any special fixtures or holders for preloading a biasing spring, but which is able to provide a substantially constant return torque.

Abstract: In a piston pump/motor of swash plate type which comprises: a cylinder block disposed in a casing to be rotatable jointly with a shaft therein; a plurality of pistons slidably inserted in the cylinder block parallel to the shaft; and a swash plate swingably attached to the casing for guiding the plurality of pistons on a front surface thereof and changing a displacement of each of the pistons by changing an inclination thereof, there is provided a swash plate angle changing apparatus in which the swash plate has a rear surface formed with a first contact surface and a second contact surface which make an angle between them. The casing has a swash plate support surface which is perpendicular to the shaft and with which the first contact surface and the second contact surface are each adapted to contact.

Abstract: A swash plate type axial piston pump improved in respect to wear or abrasion-resistant capability of sliding members of the pump adapted to rotate relative to each other for protecting them from rapid wearing even upon high rotation of the pump. The axial piston pump includes a housing (1), a rotatable shaft (3) supported rotatably within the housing (1), an axial piston pump including a cylinder block (15) mounted on the shaft (3) axially slideably therealong and co-rotatably therewith and a plurality of pistons (21) accommodated axially reciprocatively within a corresponding number of cylinders, respectively, which extend axially, being arrayed around the rotatable shaft (3), a swash plate (23) disposed for moving reciprocatively the pistons (21) in axial direction as the shaft (3) is rotated, and a plurality of sliding members which are incorporated slideably relative to one another for constituting parts of the pump.

Abstract: A pressure-applying arrangement in a hydraulic axial piston machine is disclosed, having a pressure plate (7) and a piston (9) that is axially displaceable in a cylinder body (3), is biased by a spring (10) and acts against the pressure plate (7). It should also be possible to use such a pressure-applying arrangement when the axial piston machine is operated with a hydraulic fluid that has no or only very little lubricating property, for example, water. For that purpose, the piston (9) is formed from a high-strength thermoplastics material.

Abstract: Apparatus is disclosed for articulating and correcting the trajectory of a piston in a volumetric machine with a plurality of pistons in a plurality of corresponding curved cylinders. The apparatus includes a piston seal ring positioned in a plane inclined to a plane of rotation of the pistons, with the inclined plane being different for each of the pistons and an intersection point of the axis of rotation of the pistons and an axis of rotation of the cylinders, a position compensation element permitting movement of the selected piston tangential to an instantaneous trajectory of that piston, and a piston support in radial contact with that piston to compensate centrifugal forces acting on that piston.

Abstract: A positive displacement pump including a plurality of pistons reciprocally driven in respective cylinders by a swashplate assembly to expel fluid during the pressure stroke of the piston from a chamber in communication with each piston. Oppositely disposed magnets are located respectively in an upper pressure face of each piston and in a check valve housing adjacent each cylinder to produce a magnetic force circuit accelerating movement of each piston toward and in continual contact with a cluster bearing associated with the swashplate assembly during the suction stroke of each piston. Like poles of each magnet face each other to produce a permanent levitating force on each piston.

Abstract: In a swash plate type axial piston pump, a swash plate 23 is fixed and supported in a cabinet while being inclined with respect to the center axial line of a rotary shaft 3. A cylinder block 15 having a plurality of cylinders 13 is attached to the rotary shaft 3 so that the cylinder block 15 slides of the rotary shaft 3 in the axial direction thereof and is rotated integrally therewith. Each one end of a plurality of pistons 21 is slidingly engaged with the cylinder 13 and the other end thereof is abutted against the swash plate 23 through a shoe 25. A valve plate 31 having a suction port 33 and a discharge port 35 is disposed so as to be abutted against the inner surface of the cabinet 1 and the bottom the cylinder block 15 so that a suction path 39 and a discharge path 41 in the cabinet 1 are selectively communicated with a pump chamber 14 in each cylinder through the suction port 33 and the discharge port 35.

Abstract: An improved apparatus for retaining slipper holddown pins radially in a hydraulic unit includes a cylinder block having a plurality of holes therein for respectively receiving a corresponding plurality of elongated slipper holddown pins, each having a maximum transverse width. The holes are adjacent to and communicate with a center bore of the cylinder block to form respective throats. The throats have a maximum width that is less than the maximum transverse width of the pins such that the pins cannot be radially displaced through the respective throats. Each hole has a side wall that extends more than 180.degree. around its central axis. The side wall defines the throat between the hole and the center bore. The shaft can be inserted into driving engagement with the center bore of the cylinder block. The slipper holddown pin has a maximum transverse width greater than the maximum width of the throat.

Abstract: A hydraulic pump is disclosed having an adjusting member for varying yoke angle. The present adjusting member includes a control piston for displacing the yoke so as to define a desired yoke angle. A stop member is provided having threads and retained within the control piston. An adjusting screw for rotational motion is provided and includes an O-ring and a back up ring for sealing between the screw and the pump housing. The screw also includes a threaded portion for engaging the threads of the stop member. Rotation of the screw advances the threads while remaining stationary, displacing the control piston to limit the maximum inclination of the yoke.

Abstract: A hydraulic axial piston machine is disclosed, having a cylinder drum, which has at least one cylinder in which a piston is arranged to move back and forth, which piston bears by way of a slide shoe against a swash plate, wherein the cylinder drum and the swash plate are rotatable relative to one another, and a pressure plate, which holds the slide shoe in contact with the swash plate, is joined, articulated, to the cylinder drum by way of a ball-and-socket joint having a convexly spherical bearing surface. It is desirable for manufacture of such a machine to be simplified. To that end, the bearing surface is formed by a friction-reducing plastics material.

Abstract: A hydraulic axial piston motor (1) is disclosed, having a cylinder drum (4) which is connected, so that it is non-movable axially, to a shaft (3) and so that they rotate together, and which has at least one cylinder (5), for each cylinder a piston (6) arranged in the cylinder, which piston bears at its end projecting from the cylinder drum (4) against a swash plate (8) via the intermediary of a slider shoe (7), a pressure-applying arrangement (9) for holding at least one slider shoe (7) against the swash plate and a control plate (12) with control kidneys. It is desirable for such a motor to be reliably operable even when the shaft is provided with axial play. Leakages in particular are to be avoided. For that purpose, the pressure-applying device (9) is mounted so as to e axially movable relative to the cylinder drum (4).

Abstract: Two synchronous hydraulic polyphase motor-generators with axial cylinders are connected by rigid or flexible pipes. One functions as a generator, the other as a motor to transmit torque and power. Sinusoidal piston motion is developed without the use of cams. The pistons cause columns of fluid to alternate between motor and generator, producing synchronous rotation. Apparatus for synchronizing, coupling and decoupling the motive force are disclosed.

Abstract: An axial piston machine includes a housing and a rotary shaft is mounted in the housing. A plurality of radially spaced cylindrical bores are arranged concentrically around the shaft and a reciprocal piston is located in each bore. A plate is located at an angle of inclination with respect to the rotary shaft. Each piston is connected to the plate by a support body locator and first and second support bodies are located in the support body locator and are in contact with the opposed surfaces of the plate.

Abstract: A hydraulic axial piston machine (1) is disclosed, having a cylinder drum (2), which has at least one cylinder (5) in which a piston (9) is arranged to move back and forth, and having a control plate (3), which on rotation of the cylinder drum (2) and control plate (3) relative to one another connects the cylinder (5), in dependence on its position, to a fluid inlet and a fluid outlet (4), a pressure plate (6) being arranged between the cylinder drum (2) and the control plate (3) and having for each cylinder (5) a fluid path (14) between the control plate (3) and the cylinder drum (2). It is desirable for such a machine to be capable of operation also with a hydraulic fluid that has no or only slight lubricating properties. To that end, the cylinder (5) is lined with a bushing (10) of a friction-reducing plastics material which projects from the cylinder drum (2) and is inserted in the pressure plate (6).

Abstract: A hydraulic axial piston motor is disclosed, having a rotatable cylinder drum, in which several work pistons, each provided at one end with a slider shoe, are arranged in work cylinders so as to be axially movable, having a control plate, a swash plate, against which the slider shoes bear, a pressure plate which holds the slider shoes on the swash plate, and a pressure-applying unit, which acts on the pressure plate and comprises a hydraulic piston-cylinder arrangement. Using such a motor it is desirable for an adequate contact pressure to be produced using simple means. For that purpose, the piston-cylinder arrangement is arranged between the cylinder drum and the control plate.

Abstract: A retaining device for axial piston machines embodies a shoe plate with a plurality of openings radially disposed in it. On each side of each opening a substantially flat portion exists to maintain a tangential line of radial contact with the shoes. The shoe plate has a force transferring portion made up of a plurality of raised surfaces. The raised surfaces are arranged to apply two areas of axial contact on each shoe. The two areas of axial contact are generally diametrically opposed which keeps the shoes in sliding contact with the swash plate and thus substantially eliminates tipping of the shoes.

Abstract: An improved axial-piston energy converting device is provided by utilizing a thin ceramic wear plate insert, having a typical thickness of only about 0.005 to 0.040 inches in thickness, as a cam surface secured by atmospheric pressure to an underlying support surface of a steel cam plate support structure. Attachment of the wear plate to the cam plate supporting surface is accomplished by polishing both a supporting surface of the cam plate, and a mating surface of the wear plate to a very smooth finish, and wiping a thin film of a fluid such as oil onto one of the polished surfaces prior to placing the wear plate onto the supporting surface. The highly polished, together with the light film of oil, result in a joint that is essentially air tight. Atmospheric pressure acting on the cam surface of the wear plate serves to hold the wear plate tightly in place on the support surface in the same manner that a pair of Johansson blocks are held together if their highly polished surfaces are mated.

Abstract: A variable displacement type compressor having a rotary shaft, a swash plate with a through hole into which the rotary shaft is inserted for inclining movement of the swash plate, a lug plate mounted on the rotary shaft, a hinge mechanism between the lug plate and the swash plate for guiding the inclining movement of the swash plate. The displacement of the compressor varies by adjusting the inclined angle of the swash plate. The swash plate is connected through the hinge mechanism to the rotary shaft on two points and directly contacts the rotary shaft at a single contact point located on the inner periphery of the through hole.

Abstract: A variable displacement pump has a fluid passageway formed through a swash plate fluidly communicating a piston chamber with a drive shaft chamber not later than when the piston chamber comes into open fluid communication with a valve blcok resident inlet port to prevent erosion of the swash plate and the valve block about the inlet port. Secondary port portions of reduced flow area per unit rotation communicate with and circumferentially lead primary port portions of greater flow area per unit rotation.

Abstract: A hydraulic pump is disclosed which uses a side-discharge valve plate. The present valve plate includes a valve plate body having front and back surfaces with a side defining the peripheral surface therebetween. First and second fluid passages are formed on at least one of said front and back surfaces for respectively defining a fluid inlet for supplying hydraulic fluid to a piston and a fluid outlet for receiving pressurized hydraulic fluid from a piston. At least one fluid access is formed in the side of the valve plate body, connecting with at least one of said fluid passages to define a fluid pathway therewith. The design of the present invention thereby permits a pump design have shorter axial length, permitting a smaller size pump which offers improved space considerations. Also, the present valve plate also has few contact surfaces, thereby reducing leakage and improving pump efficiency.

Abstract: A hydraulic axial piston machine is disclosed, having a cylinder drum which is mounted for rotation relative to a housing (1), with a bearing (3) having a slide face (4) being arranged between the circumference of the cylinder drum and the housing (1). It is desired that such a machine shall be capable of operating also with fluids that are not such good lubricants as hydraulic oil. For that purpose the slide face (4) is formed by a friction-reducing plastics material and has at least one recess (5, 6, 7) communicating with at least one end edge of the slide face (4).

Abstract: A hydraulic helm pump used for vessel steering has a housing, a barrel rotating in the housing, and one or more cylindrical pistons reciprocating in the barrel. The barrel has a separate abutment surface at the end of each piston bore and spaced from each respective piston. The pistons are solid, not hollow. A compression spring is interposed between each respective piston and the abutment surface and the spring outside diameter is about equal to the maximum diameter of the piston. When each piston is in its forward position, its forward end is very close to the abutment surface, thereby reducing unswept volume. And each piston return spring occupies most of the remaining otherwise-unswept volume between the piston and its bore. The pistons are random-fitted to their bores and include resilient piston-and-bore seal members.

Abstract: The hinge unit K of a variable capacity swash plate type compressor has support arms protruded to the back side of a rotor on the rotating drive shaft, and guide pins, one end of which is fixed to a rotatable and wobbling swash plate. The support arms have guide holes (guide surfaces) which extend in a predetermined direction having an angle .alpha. with respect to an axis perpendicular to the axis of rotation of the drive shaft. Sections perpendicular to the center lines L.sub.1 of the guide holes are formed into at least a partial circle. A spherical elements of the guide pins are slidably and rotatably engaged with the guide holes of the support arms to be in line contact with the guide surface of the guide holes. The angle .alpha. is set so that the top clearance TC of the respective pistons at both maximum and minimum compression capacities of the compressor is equivalent.

Abstract: A hydraulic piston machine is proposed, with a cylinder body (1), which comprises at least one cylinder (2) with a piston (3) movable therein, and a control counter-plate (7) which engages the cylinder body (1) by way of a contact surface (6) and, on relative movement between the cylinder body and the control counter-plate parallel to the contact surface, connects the cylinder in dependence upon its position with inlet and outlet channels (11, 12) respectively, the control counter-plate (7) and/or the cylinder body (1) being provided, at least in the region of the contact surface (6, 9), with a friction-reducing layer (13). A machine of that kind should be inexpensive to manufacture yet should operate reliably even when the hydraulic fluid has no or only slight lubricating properties. For that purpose the friction-reducing layer (13) is in the form of an injection-moulded part.

Abstract: A pump apparatus includes an outer cylindrical housing having end plates, and a power conversion assembly supported for rotation within the outer housing. A torque input shaft provided on one of the end plates has a "primary" gear on its free end. The inner housing includes a crank case within which cylinders are arranged at spaced radial locations. Double-acting pistons are housed within the cylinders. Crank members supported by the crank case for rotation are coupled to the pistons via force transmitting elements to drive the pistons with reciprocating motion in the cylinders. Each of the crank members includes a "secondary" gear engaged with the primary gear. Each crank member includes a linkage coupled with a piston rod so that the pistons are driven in reciprocating motion in the cylinders.

Abstract: A hydraulic axial piston machine (1) is disclosed, having a cylinder drum (2) which is mounted rotatably in a housing and comprises at least one cylinder (3) which, on rotation of the cylinder drum (2), passes over control kidneys (15) in a control face. In order to be able to operate such a machine even with hydraulic fluid that has no or only slight lubricating properties, such as, for example, water, and in order to be able to manufacture the machine with few manufacturing steps, the control face is located on the rear flange (9) of the housing, and the control kidneys (15) are formed in a plastics material insert (10) which is arranged in the rear flange (9) of the machine (1).

Abstract: A hydraulic axial piston machine is disclosed, having an inclined plate (7), on which a slider shoe (9) of at least one piston slides on relative movement between a cylinder body (2) receiving the piston and the inclined plate (7), and a pressure plate (10) articulated on the cylinder body (2) and holding the slider shoe (9) in engagement with the inclined plate. It is desirable for such a machine also to be operable with a hydraulic fluid that has no lubricating properties. For that purpose, between the pressure plate (10) and the cylinder body (2) there is arranged a bearing element (18) with a bearing surface (19) of plastics material, which slides with low friction on a counterpart (15) made of metal lying against the bearing surface (19).

Abstract: A hydraulic axial piston machine is disclosed, with a cylinder drum (2), which has at least one cylinder (3), in which a piston (6) is mounted so as to be axially displaceable, and with a control counter-plate (11 ) which, on rotation of the cylinder drum (2) and the control counter-plate (11 ) relative to one another, connects the cylinder (3) in dependence upon its position with a fluid inlet (14) and a fluid outlet (15). With a machine of that kind, it is desirable to improve balancing out of the forces necessary for effecting a seal between the cylinder drum (3) and the control counter-plate (11). For that purpose, between the cylinder drum (2) and the control counter-plate (11 ) there is arranged a pressure plate (17) which engages the cylinder drum (2) via the intermediary of a spring element (21), the pressure plate (17) having a through-opening (20) associated with the cylinder (3), which through-opening is connected to the cylinder (3) in a fluid-tight manner.

Abstract: A variable displacement axial piston pump has a plurality of piston bores each connected to an inwardly angled fill port. The fill ports extend from the piston bores inwardly to the working face of the barrel to reduce the diameter of the fill circle of a pump. This decreases the velocity that must be attained by incoming fluid to thereby increase the operating speed at which the pump may be driven where the pump is filled at atmospheric pressure.

Abstract: An improved hydrostatic transmission which is compact, reliable and economical to manufacture, including a novel apparatus for reducing the speed of the input to the transaxle using both hydraulics and mechanical gearing; an improved differential which is stronger and less complicated than prior art designs; a more effective and efficient apparatus for braking the transaxle, an improved apparatus for hydraulically bypassing the hydrostatic transmission and a unique check valve arrangement for maintaining oil pressure within the hydrostatic transmission. Also, an apparatus is provided for diverting the hydraulic fluid to a sump by lifting a cylinder block from a running surface of the hydrostatic transmission to quickly drain the fluid.

Abstract: A continuously variable hydrostatic transmission includes an input shaft connected to drive a hydraulic pump unit, a grounded hydraulic motor unit, and an output shaft. A wedge-shaped swashplate is pivotally mounted to the output shaft in driving connection to receive output torque resulting from the exchange of pressurized hydraulic fluid between the pump and motor units through specially configured ports in the swashplate. A hydraulically actuated ratio controller is pivotally linked to the swashplate to selectively adjust the swashplate angle relative to the output shaft axis and thereby change transmission ratio.

Abstract: An axle driving apparatus has in a housing a hydrostatic transmission with a variable displacement type hydraulic system having a slantingly movable swash plate. In one embodiment, the movable swash plate is manually slantingly operable. A leg member integrally extends from an inner wall of the housing, a lid for closing an opening of the housing, or a center section. The leg member has a support portion for supporting a shaft provided on an axis of rotation of the movable swash plate. Accordingly, the movable swash plate is suspended in the housing for slanting or pivoting movement.

Abstract: An axle driving apparatus which is so constructed that an input pulley for engine power is set lower in mounting position with respect to the axis of a driving axle so as to enable the platform of a vehicle to be lowered. The engine position lowers to promote miniaturization, a lower center of gravity and running stability of the vehicle. For maintenance of the transmission for driving the axle, the entire axle driving apparatus need not be removed from the frame of the vehicle. A bearing for supporting the axle to the casing is held with exact dimensional precision so as not to cause a backlash on the axle, to thereby prolong the life span of the bearing. The axle is ensured to be sealed, the number of mounting bolts for the casing need not be increased in order to improve rigidity, and the casing is strong so that the assembly time for the axle driving apparatus is minimized.

Abstract: An improved hydrostatic transmission for use in a transaxle comprising a means for mechanically diverting hydraulic fluid from the hydraulic transmission to a sump to enable the vehicle to be moved with minimal resistance from the hydraulic fluid by unseating at least one of the hydraulic displacement units from its running surface to allow the fluid to drain quickly from the transmission to the sump, and an improved check valve mechanism on the center section of the transmission.

Abstract: A follow up mechanism for maintaining a timed positional relationship between a bearing cage of an arcuate roller bearing assembly and a swashplate supported by the bearing assembly includes a flexural elastic link pivotally connected to the bearing cage and having first and second ends slidably disposed within a first bore in a pump housing and a second bore in the swashplate, respectively. The bores are in axial alignment with each other when the swashplate is in the equivalent of its centered position thereby allowing blind assembly of the follow up mechanism thereby eliminating the need for an access opening in the side of the pump housing and the associated cover, gasket and bolts.

Abstract: Arcuate bearings are useful, for example, in pivotally supporting a cradle swashplate of axial piston variable displacement hydraulic devices. The bearings of known hydraulic devices have either been a pair of laterally spaced roller bearings assembly or a pair of laterally spaced sleeve bearings. The subject hydraulic device includes a roller bearing assembly positioned between the swashplate and the housing at the side of the swashplate subjected to high loads and a less expensive sleeve bearing positioned between the swashplate and the housing at the other side of the swashplate subjected to low loads. By using this combination of bearings, the overall cost of the hydraulic device is reduced without impairing the operation of the hydraulic device.

Abstract: A swash-plate, plunger-type hydraulic pressure apparatus, which may operate as a hydraulic pump or motor, includes a cylinder block, an annular array of plungers slidably held in the cylinder block, a swash plate, a plurality of shoes angularly movably coupled respectively to the ends of the plungers, and a retainer plate mounted adjacent the swash plate and holding the shoes in slidable contact with the sliding surface. The shoes have respective annular grooves defined in the outer cylindrical surfaces thereof. The retainer plate has a plurality of shoe holding holes defined therein and a like plurality of cutout openings extending from the holes. The shoe holding holes communicate with one of outer and inner circumferential edges of the retainer plate through the cutout openings, respectively. The cutout openings have a width slightly larger than the outside diameter of the annular grooves, whereby the annular grooves can be inserted into the shoe holding holes, respectively, through the cutout openings.

Abstract: An axle driving apparatus which is so constructed that an input pulley for engine power is set lower in mounting position with respect to the axis of a driving axle so s to enable the platform of a vehicle to be lowered. The engine position lowers to promote miniaturization, a lower center of gravity and running stability of the vehicle. For maintenance of the transmission for driving the axle, the entire axle driving apparatus need not be removed from the frame of the vehicle. A bearing for supporting the axle to the casing is held with exact dimensional precision so as not to cause a backlash on the axle, to thereby prolong the life span of the bearing. The axle is ensured to be sealed, the number of mounting bolts for the casing need not be increased in order to improve rigidity, and the casing is strong so that the assembly time for the axle driving apparatus is minimized.

Abstract: A swash-plate plunger-type hydraulic device has a cylinder block with a plurality of plungers slidably fitted in cylinder bores, a swash plate confronting one end of the cylinder block, and a distribution valve plate slidably held against the other end of the cylinder block. The cylinder block has an odd number of circularly arrayed connecting ports communicating with the cylinder bores and opening at the other end thereof. The distribution valve plate has inlet and outlet ports. The cylinder block is rotatable through an angular displacement .theta.1 in which the hydraulic pressure in one connecting port between the inlet and outlet ports increases from a lower pressure to a higher pressure, through an angular displacement .theta.2 in which the hydraulic pressure in one connecting port between the inlet and output ports decreases from the higher pressure to the lower pressure, and through an angular displacement .theta.

Abstract: A swash-plate plunger-type hydraulic device has a cylinder block with a plurality of plungers slidably fitted in cylinder bores, a swash plate confronting one end of the cylinder block, and a distribution valve plate slidably held against the other end of the cylinder block. The cylinder block has an even number of circularly arrayed connecting ports communicating with the cylinder bores and opening at the other end thereof. The distribution valve plate has inlet and outlet ports. The cylinder block is rotatable through an angular displacement .theta.1 in which the hydraulic pressure in one connecting port between the inlet and outlet ports increases from a lower pressure to a higher pressure, through an angular displacement .theta.2 in which the hydraulic pressure in one connecting port between the inlet and output ports decreases from the higher pressure to the lower pressure, and through an angular displacement .theta.

Abstract: A rotary shock absorber suitable for use in a suspension system of a vehicle. The shock absorber is provided with a housing and a rotary shaft supported by the housing for relative rotation thereto. A pressure chamber is formed in the housing and a rotor having a pair of blades is received within the pressure chamber. Further, a pair of partition walls are formed within the pressure chamber to define first and second chambers at both sides of each blade, and the first and second chambers are communicated with each other through throttles. When the rotary shaft is rotated, a high viscous fluid filled within the first and second chambers flows therebetween through the throttles. Due to the flow resistances of the throttles, pressures are generated in the first or second chambers. This pressure generation is used to generate a damping force.

Abstract: A differential rotation control device with a hydraulic assembly includes two torque transmission assemblies. Each assembly has a first rotor with a pump-driven arrangement secured to a drive shaft which is common to both of the torque transmission assemblies, and a second rotor with a torque-receiving arrangement rotatably supported on the drive shaft. The torque-receiving arrangement is rotated when hydraulic power is applied to the pump-driven arrangement so that the rotation speed ratio between the first and second rotors can be variably set. The two pump assemblies each have a pump-driving arrangement assembled to the first rotor for constituting a circular route together with the pump-driven arrangement for circulating fluid. A pump-regulating arrangement controls fluid supplied to the pump-driven arrangement when the drive shaft is rotated relative to a pump-stator to which the pump-regulating arrangement is secured.