Abstract: A torque transmission system, particularly for a vehicle, includes a housing arrangement (26) with a hub region (36) which engages in a shaft opening (22) of the gearbox housing (16) and is rotatably supported so as to be substantially fluid-tight with respect to the gearbox housing (16) by means of a bearing/seal arrangement (42); at least one first fluid port (97) which opens toward an intermediate space region (98) formed between the housing arrangement (26) and the gearbox housing (16) is provided in the housing arrangement (26) in or in the vicinity of the hub region (36), and at least one second fluid port (104) which bypasses the bearing/seal arrangement (42) and opens toward the intermediate space region (98) is provided in the gearbox housing (16) and/or in the bearing/seal arrangement (42).

Abstract: The present disclosure relates to a dry-clutch transmission having various cooling techniques. Some techniques include forming different structural features on transmission components so as to create an organized air flow. The disclosed techniques are applicable to both opened and closed transmission housings.

Abstract: A clutch assembly includes a hub rotatable about an axis and at least partially surrounding a cavity, a damper ring within the cavity, able to revolve about the axis, rotatable relative to the hub, a spring, a friction disc, forced elastically by the spring into contact with the damper ring, and a second friction disc contacting the damper ring and providing a reaction to the force of the spring.

Abstract: A clutch assembly with a rotatable clutch hub which is connected rotationally fixedly to several inner plates which may be brought into friction connection with outer plates of an associated clutch basket and form a plate pack. The clutch hub has at least one bore which allows a throughflow of a fluid from the interior of the clutch to the plates, and an oil conduction device attached to the clutch hub at the at least one bore.

Abstract: A transmission clutch cooling system includes a clutch housing defined between a drive hub of a drive member and a clutch hub of a driven member and a clutch assembly housed in the clutch housing. The clutch hub includes a hub deck having a plurality of bores therethrough, an inner annulus extending axially from the hub deck, and an outer annulus extending axially from the hub deck, the outer annulus including a plurality of radial orifices therethrough and a lip flange extending from a distal end towards the inner annulus. The clutch assembly includes a plurality of clutch plates secured to the drive hub and a plurality of friction plates secured to the driven member. A piston assembly is provided for engaging or disengaging the plurality of friction plates against the plurality of clutch plates to cause or release integrated rotation of the drive member and the driven member.

Abstract: A braking system includes at least one rotating disc, and at least one brake disc having a front face and a rear face. The brake disc has at least four inner chambers disposed therein. Each of the at least four inner chambers has a liquid inlet and a liquid outlet and defines a liquid pathway. At least one biasing element is configured to move the front face of the at least one brake disc into contact with the at least one rotating disc.

Abstract: The invention relates to a method and a device for suppressing transmission noise from automatic transmissions, in particular for motor vehicles, the transmission having at least two alternating multi-disk clutches that control a power flow via a gearing mechanism through which oil flows to cool the clutches and to reduce wear and tear on them. To create a method and a device that are of simple design and that can operate without wear and tear, it is proposed that under defined operating conditions of the transmission, the throughput amount of oil is increased in such a way that a defined drag torque occurs at the multi-disk clutch that is opened.

Abstract: A fan drive system is provided having a housing connected with a pulley. A fan shaft is rotatably mounted to the housing by a clutch. A piston actuates the clutch. A pressure tube is provided for delivering pressure to the piston. A valve controls pressure against the piston. A fixed shaft rotatably supports the housing and the pulley and has passages extending through the pulley. A base connects the support shaft to a vehicle structure. An oil plate has inlets and outlets with the shaft passages. The oil plate circulates the hydraulic fluid. A coolant plate is juxtaposed between the oil plate and the structure supporting the support shaft. The coolant plate has inlets and outlets for coolant from a remote cooler.

Abstract: A segment-type friction material is composed of segment pieces. An outer circumference of the segment piece is away from an outer circumference of a core plate. A setback amount is about 2 mm. Then, a gap between the outer circumference of the segment piece and an inner peripheral part of an automatic transmission case becomes large. Thus, there is generated a part at which a gap between the segment pieces and a separator plate becomes large in a disengaged state.

Abstract: The present invention provides a starting clutch disposed between a transmission and an engine and having a wet type multi-plate clutch for transmitting a power, in which the wet type multi-plate clutch includes a plurality of friction plates housed for an axial sliding movement, a clutch drum for housing the friction plates, and a piston for urging a radial central region or therearound of the friction plate to engage the friction plates, and oil which has lubricated the wet type multi-plate clutch is temporarily trapped within the clutch drum and then is discharged.

Abstract: The present invention provides a friction plate having a friction surface formed by sticking an annular friction material to a substantially annular core plate and wherein the friction surface is provided with a first oil groove having an opening portion opened to an inner peripheral edge of the friction plate and an end terminating at a point between the inner peripheral edge and an outer peripheral edge, and a second oil groove having an opening portion opened to the outer peripheral edge of the friction plate and an end terminating at a point between the inner peripheral edge and the outer peripheral edge.

Abstract: A multi-plate clutch including a clutch hub having a cylindrical portion; a plurality of clutch plates splined to the outer periphery of the cylindrical portion of the clutch hub, and a plurality of spline teeth being formed on the outer periphery of the cylindrical portion of the clutch hub. A recessed portion is formed on the inner side of each spline tooth, and a weir portion is formed at one end of each recessed portion by depressing one portion of the spline tooth to the inner side on one end side of the cylindrical portion. Thus forming a depressed portion, and removing, with one portion of the depressed portion left behind, a portion of the cylindrical portion on the one end side of the one portion of the depressed portion.

Abstract: A lubricant composition comprising lubricating oil and a compound containing phosphorus and an amine of formula I: wherein R1 is a hydrocarbon group and at least one of R1 is selected from: —(C1-C20)alkyl, —(C1-C20)alkenyl, —(C5-C20)cycloalkyl; R is selected from: —(C4-C20)alkyl, —(C4-C20)alkenyl, —(C5-C20)cycloalkyl; and wherein R2, R3 and R4 are independently selected from: —H, —(C6-C36)alkyl, —(C6-C36)alkenyl, —(C6-C36)cycloalkyl, wherein at least one of R2, R3 and R4 is not H; X is O or S; Y1 and Y2 are selected from S and O; m is 1 or 2, n is 0 or 1, p is 1 or 2, provided that m+n+p=3 and q=0.8 to 1.2*p, wherein the compound provides at least 48 ppm of phosphorus and a molar ratio phosphorus to nitrogen (P/N) in the range of about 0.40 to about 1.50.

Abstract: The present invention provides a starting clutch disposed between a transmission and an engine and having a wet type multi-plate clutch for transmitting a power, in which the wet type multi-plate clutch includes a plurality of friction plates housed for an axial sliding movement, a clutch drum for housing the friction plates, and a piston for urging a radial central region or therearound of the friction plate to engage the friction plates, and oil which has lubricated the wet type multi-plate clutch is temporarily trapped within the clutch drum and then is discharged.

Abstract: Hydraulic fan drive system with oil flow system. A modular valve mechanism is provided with coaxial oil passages to circulating lubrication oil through the clutch and to and from a heat exchanger.

Abstract: An axle assembly comprises a power transmission device including a housing having a cylindrically shaped sidewall. The power transmission device selectively communicates rotatable motion from an input member to an output member. A frictional clutch is disposed in the housing and includes a drum. A first and a second axle shaft selectively drive a first and a second drive wheel, respectively. A differential selectively transfers drive torque from the output member to at least one of the first and second axle shafts. An electric motor comprising a coil and a plurality of magnets is provided on the axle assembly. In one example, the coil is disposed on the housing and the magnets are disposed on the drum. The coil is configured to selectively energize to provide one of a positive or negative torque input to the output member.

Abstract: Disclosed is a lock-up clutch operative to uniform temperatures on a multiple number of friction surfaces, thereby improving accuracy of a lock-up control and to prevent shudders of a vehicle from being generated. The lock-up clutch includes a front cover, a lock-up piston, a plurality of torque transmitting plates, and a plurality of friction materials formed on the torque transmitting plates and having three or more friction surfaces. The friction materials are constituted by a first friction material frictionally contactable with the front cover, a second friction material frictionally contactable with the lock-up piston, and third friction materials frictionally contactable with at least one of the plates. Three or more friction surfaces are constituted by outside friction surfaces formed on the first and second friction materials and each having a small area, and inside friction surfaces formed on the third friction materials and each having a large area.

Abstract: A wet clutch includes a rotatable hub and a rotatable drum having an aperture extending therethrough. A plurality of outer clutch plates are fixed for rotation with the drum. A plurality of inner clutch plates are fixed for rotation with the hub and interleaved with the outer clutch plates. A piston is moveable to apply a force to the inner and outer clutch plates to transfer torque between the hub and the drum. A cover is moveable relative to the drum between first and second positions. The cover selectively restricts a flow of fluid through the aperture in the drum when in the first position.

Abstract: A hydraulic clutch for preventing a drag of a clutch at the time of disengaging the clutch by decreasing an oil supply quantity between a plurality of clutch plates and a plurality of clutch discs thus decreasing a change hitting sound at the time of shifting. A hydraulic clutch is configured such that the superposition between an oil supply hole formed in a clutch pressure plate and an oil supply hole formed in a clutch center becomes maximum when the clutch is engaged.

Abstract: A clutch apparatus includes a clutch pack including a plurality of friction disks having friction surfaces. The clutch pack may include a plurality of cooling inlets. The clutch pack may selectively transfer torque from a torque supplying member to a torque receiving member. The clutch apparatus may include a rotating manifold having at least a first cooling port for directing a cooling fluid to the clutch pack and at least a portion of the rotating manifold may be coupled for rotation with at least a portion of the friction disks. A fluid-flow area of at least a subset of the plurality of cooling inlets may be dissimilar from other of the plurality of cooling inlets for enabling a desired fluid flow to the friction disks.

Abstract: A hydraulic disc coupling (4) for an AWD vehicle is provided with an actuator pump (17) for actuating its disc package (12). There is a separate lubrication pump (30) for the purpose of both supplying lubricating and cooling oil to the disc package (12) at normal operating conditions and supporting the actuator pump (17) in quickly engaging the coupling (4) after its disconnection and possible emptying of lubricating and cooling oil.

Abstract: The present invention relates to a multi-disc clutch for the transfer of torque between a first clutch part and a second clutch part, having at least one first and at least one second disc that engage on another and that are movable parallel to a rotational axis of the multi-disc clutch, and having a reset device for the receiprocal ventilation of adjacent discs. The first clutch part is connected in a rotationally secure fashion to the first disc and the second clutch part is connected in a rotationally secure fashion to the second disc. The reset device has at least two reset elements that are disposed eccentrically relative to the rotational axis and distributed in the circumferential direction.

Abstract: An estimating method for transmitting torque of a dry type clutch in a vehicle, may include a slip determining step of determining by a processor whether only one clutch slips between an engine and a transmission, a transmitting torque estimating step of estimating a current transmitting torque of the dry type clutch by using a torque observer when the only one clutch slips as a result of performing the slip determining step, and an updating step of reflecting the current transmitting torque of the dry type clutch estimated in the transmitting torque estimating step and an actuator torque in the transmitting torque estimating step to a T-S (Torque-Stroke) curve.

Abstract: The invention relates to a clutch assembly, particularly for use in force transmission devices for motor vehicle, comprising a housing arrangement that is or can be filled with a fluid, and a frictional arrangement that has a first frictional surface arrangement and a second frictional surface arrangement which can be effectively interconnected by means of an actuator. Each frictional surface arrangement is provided with at least one frictional surface-supporting element. A fluid flow can be generated in the housing arrangement for cooling the frictional surface arrangements. The invention is characterized in that means are provided for creating at least one circuit which repeatedly flows through at least one frictional surface-supporting element of the frictional arrangement and conducts the fluid flow when the rotational speed differs between the effectively interconnectable frictional surface-supporting elements of the different frictional surface arrangements.

Abstract: A wet clutch includes a rotatable hub and a rotatable drum having an aperture extending therethrough. A plurality of outer clutch plates are fixed for rotation with the drum. A plurality of inner clutch plates are fixed for rotation with the hub and interleaved with the outer clutch plates. A piston is moveable to apply a force to the inner and outer clutch plates to transfer torque between the hub and the drum. A cover is moveable relative to the drum between first and second positions. The cover selectively restricts a flow of fluid through the aperture in the drum when in the first position.

Abstract: A clutch for a manual or automatic transmission according to the present invention includes an axial fan or turbine disposed on a shaft extending between the clutch and the transmission. Air is supplied to the turbine through one or more radial passageways between the clutch and transmission housings and is provided through an annular passageway around the shaft. Air from the annular passageway is then dispersed generally radially between the clutch plates or disks and other clutch components to absorb and carry away heat generated during clutch operation.

Abstract: A clutch arrangement includes a housing filled with fluid, a first friction surface formation rotatable with the housing around an axis of rotation, a second friction surface formation rotatable with a driven element around the axis of rotation, a pressing element rotatable with the housing around the axis of rotation and which divides an interior space of the housing into a first spatial area and a second spatial area. Depending on fluid pressure in the first and fluid pressure in the second spatial areas, the pressing element is movable with respect to the housing for producing and canceling a frictional engagement between the and the second friction surface formations. A fluid supply system for the first spatial area and/or the second spatial area includes at least a first fluid flow path. The fluid can be supplied to the associated spatial area via at least one fluid flow path and fluid can be removed from the associated spatial area via at least one fluid flow path.

Abstract: A method for ascertaining a rotational speed parameter for determining a setpoint torque for driving a drivetrain. The drivetrain comprises a first and at least one second drive assembly for driving a hybrid vehicle. The first drive assembly can be coupled to the drivetrain by means of a clutch. The second drive assembly is mechanically coupled to the drivetrain. When the hybrid vehicle is being driven by means of at least the first drive assembly, the rotational speed parameter corresponds to the value of a shaft rotational speed. When the hybrid vehicle is being driven only by means of the second drive assembly, the rotational speed parameter corresponds to the value of a determined rotational speed.

Abstract: The present invention relates to a multiple clutch device having a first clutch which is assigned a first actuating piston with a first pressure chamber and a first pressure equalization chamber, and having a second clutch which is assigned a second actuating piston with a second pressure chamber and a second pressure equalization chamber, a first crossflow channel being provided for setting the hydraulic fluid column in the first pressure equalization chamber and a second crossflow channel being provided for setting the hydraulic fluid column in the second pressure equalization chamber. According to the invention, the first and second crossflow channels are arranged in such a way that both the oil which is discharged via the first crossflow channel and the oil which is discharged via the second crossflow channel can be fed to the first and second clutches.

Abstract: An embodiment of a multidisk oil-bath clutch having: a housing mounted to rotate; at least one hub mounted to rotate and housed inside and coaxially with the housing; a number of drive disks housed inside the housing and angularly integral with the housing or the hub; a number of driven disks housed inside the housing, alternating with the drive disks, and angularly integral with the hub or the housing; at least one oil inlet into the housing; and at least one oil outlet from the housing. Each drive disk has a number of first circulation channels extending radially from an inner edge of the drive disk; and each driven disk has a number of second circulation channels extending radially from an inner edge of the driven disk.

Abstract: A fan drive system is provided having a housing connected with a pulley. A fan shaft is rotatably mounted to the housing by a clutch. A piston actuates the clutch. A pressure tube is provided for delivering pressure to the piston. A valve controls pressure against the piston. A fixed shaft rotatably supports the housing and the pulley and has passages extending through the pulley. A base connects the support shaft to a vehicle structure. An oil plate has inlets and outlets with the shaft passages. The oil plate circulates the hydraulic fluid. A coolant plate is juxtaposed between the oil plate and the structure supporting the support shaft. The coolant plate has inlets and outlets for coolant from a remote cooler.

Abstract: The work vehicle includes a braking device, a lubricant feeding section, and a controlling section. The controlling section configured to execute a first control in which an amount of the lubricant fed to the braking device is controlled based on a temperature of a rotating member of the braking device. The controlling section sets the amount of the lubricant to a predetermined first feed amount when the braking device is in a braking state, calculates the temperature of the rotating member, and makes a decision in the first control, based on the calculated temperature of the rotating member, to change the amount of the lubricant from the first feed amount to a second feed amount, which is smaller than the first feed amount, when the braking device is switched from the braking state to a non-braking state.

Abstract: A hydraulically controlled fan drive system is provided including a housing containing a hydraulic fluid, a pulley connected to the housing a fan shaft rotatably mounted to the housing by a hydraulically actuated clutch, a piston mounted within a piston housing for actuating the clutch, a pitot tube for delivering pressurized hydraulic fluid from the housing to the piston housing, a valve for controlling the fluid pressure within the piston housing, a shaft rotationally supporting the housing having passages extending through the pulley, a base connected with the shaft connecting the shaft with a structure, the base having coolant inlet and outlet, and an oil cooler connected with the base on a side of said base generally axially opposite of the pulley.

Abstract: A wet clutch assembly has an inner housing configured for rotation with an input torque member to the clutch assembly. The inner housing has a series of splines to support a portion of the plates in a clutch pack. Each spline defines a single aperture in fluid communication with at least one plate of the clutch pack, and apertures on adjacent splines are offset to distribute cooling fluid nearly equally between friction surfaces. Uniform flow distribution ensures efficient use of cooling fluid and prevents overheating of plates receiving lesser fluid flow.

Abstract: A wet clutch includes a rotatable hub and a rotatable drum having an aperture extending therethrough. A plurality of outer clutch plates are fixed for rotation with the drum. A plurality of inner clutch plates are fixed for rotation with the hub and interleaved with the outer clutch plates. A piston is moveable to apply a force to the inner and outer clutch plates to transfer torque between the hub and the drum. A cover is moveable relative to the drum between first and second positions. The cover selectively restricts a flow of fluid through the aperture in the drum when in the first position.

Abstract: A hybrid drive train (1) has an electric machine (15) with a stator (16) fastened to a clutch housing (18) and a rotor (20) that can be rotated relative to the stator (16) with a radial gap (22) therebetween. The hybrid drive train (1) also has a wet-running multiple disk clutch device (8) with an outer multiple disk carrier (24) that has at least one oil passage opening (41). The radial gap (22) between the rotor (20) and the stator (16) is shielded from the oil passage opening (41) of the outer multiple disk carrier (24) by an oil shielding device (50).

Abstract: The lubricant-return holes are provided in the intermediate portion of the ring gear. Thus, the lubricant stagnating above the first oil sealing member can be easily discharged to the oil pan side via the lubricant-return holes even when the ring gear has stopped rotating in response to the starter motor being turned off after completion of the start of the internal combustion engine. As such, the level of the surface of lubricant stagnating between the ring gear and the outer race member does not rise, and therefore the lubricant surface virtually does not reach the outer race and the one-way clutch that are rotating while the internal combustion engine is running. Thus, bubbling of lubricant and production of sludge, which may otherwise be caused by agitation of the lubricant surface, can be prevented.

Abstract: A brake device lubrication device includes a lubricant supply unit and a control unit. The control unit includes a braking timer, a release timer and a storage unit. The control unit is configured to control the lubricant supply unit so as to supply a predetermined first supply amount of lubricant to a brake device when the brake device is in a braking state, to acquire a delay time corresponding to a braking time counted by the braking timer from a relationship of correspondence between the braking time and the delay time stored by the storage unit when the brake device is switched from the braking state to a released state, and to switch a supply amount of lubricant from the first supply amount to a second supply amount which is smaller than the first supply amount when the release time counted by the release timer reaches the acquired delay time.

Abstract: An embodiment of a multidisk oil-bath clutch having: a housing mounted to rotate about a longitudinal axis of rotation; at least one hub mounted to rotate about the longitudinal axis of rotation and housed inside and coaxially with the housing; a number of drive disks housed inside the housing and angularly integral with the housing or the hub; a number of driven disks housed inside the housing, alternating with the drive disks, and angularly integral with the hub or the housing; at least one oil inlet into the housing; and at least one oil outlet from the housing. Each drive disk has a number of first circulation channels equally spaced about the longitudinal axis of rotation and extending radially from an inner edge of the drive disk to an outer edge of the drive disk; and each driven disk has a number of second circulation channels equally spaced about the longitudinal axis of rotation and extending radially from an inner edge of the driven disk to an outer edge of the driven disk.

Abstract: A pressure plate for use in a friction clutch assembly comprises a substantially flat annular coupling face for frictional engagement with a coupling face of a clutch plate and one or more discontinuities formed in the coupling face of the pressure plate. The discontinuity(ies) decrease a greater relative proportion of the surface area closer to an inner radius of the coupling face of the pressure plate than an outer radius of the coupling face of the pressure plate to increase a mean effective radius of the surface area. The discontinuity(ies) include a generally circumferential groove around an inner portion of the coupling face of the pressure plate and, at each end of the generally circumferential groove, a wiper portion of the coupling face of the pressure plate extending inwardly toward an axis of rotation of the pressure plate(s).

Abstract: The present invention provides a starting clutch disposed between a transmission and an engine and having a wet type multi-plate clutch for transmitting a power, in which the wet type multi-plate clutch includes a plurality of friction plates housed for an axial sliding movement, a clutch drum for housing the friction plates, and a piston for urging a radial central region or therearound of the friction plate to engage the friction plates, and oil which has lubricated the wet type multi-plate clutch is temporarily trapped within the clutch drum and then is discharged.

Abstract: A dual clutch transmission has a driving plate defining concentric engagement surfaces, concentric friction plates, concentric pressure plates, and first and second clutch springs for operation of the pressure plates in clamping the friction plates against their respective engagement surface on the driving plate. The driving plate has a top hat type configuration, whereby the engagement surfaces are axially off set from one another. Cooling passages may be provided in the driving plate. The dct is preferably nested, wherein the outer pressure plate is in axial alignment with the radially inner portion of the driving plate, the inner pressure plate is in axial alignment with the radially outer portion of the driving plate, and the friction plates are arranged in axial alignment with one another.

Abstract: The present invention provides a friction plate having a friction surface formed by sticking an annular friction material to a substantially annular core plate and wherein the friction surface is provided with a first oil groove having an opening portion opened to an inner peripheral edge of the friction plate and an end terminating at a point between the inner peripheral edge and an outer peripheral edge, and a second oil groove having an opening portion opened to the outer peripheral edge of the friction plate and an end terminating at a point between the inner peripheral edge and the outer peripheral edge.

Abstract: A force transmission device having a hydrodynamic component, disposed between an input and an output, comprising at least a pump shell and a turbine shell, forming an operating cavity in combination, with an actuatable clutch device for at least partially bridging the hydrodynamic component, comprising a clutch component for at least partially bridging the hydrodynamic component, comprising a first clutch component connected with the input and a second clutch component at least indirectly connected to the output, which can be brought into operative engagement with one another through an actuation device, with a vibration absorber disposed in the force flow at least subsequent to the actuatable clutch device, with a housing coupled with the input or with an element coupled non-rotatably to the input and coupled with the pump shell.

Abstract: An embodiment of a multidisk oil-bath clutch having: a housing mounted to rotate; at least one hub mounted to rotate and housed inside and coaxially with the housing; a number of drive disks housed inside the housing and angularly integral with the housing or the hub; a number of driven disks housed inside the housing, alternating with the drive disks, and angularly integral with the hub or the housing; at least one oil inlet into the housing; and at least one oil outlet from the housing. Each drive disk has a number of first circulation channels extending radially from an inner edge of the drive disk; and each driven disk has a number of second circulation channels extending radially from an inner edge of the driven disk.

Abstract: In a frictional engagement apparatus that includes a clutch drum, separator plates, a clutch hub, and friction plates, a plurality of concave portions that dip inward in the plate thickness direction and a plurality of convex portions that protrude outward in the plate thickness direction are formed on an edge of the separator plates and/or a an edge of the friction plates, with each convex portion being arranged between two adjacent concave portions. Ridge lines of the concave portions and the convex portions pass through positions away from a center point of the separator plates and/or the friction plates.

Abstract: A clutch unit (1) including at least one wet clutch (28, 29) and a torsional vibration damper (12) which are accommodated in a housing (8) driven by the drive unit. In order to simplify assembly, pre-assembled modular units (3, 4, 5) are formed that are joined together during the final assembly process. Advantageously, a separation point is provided between two modular units in the torsional vibration damper, wherein one modular unit (3) includes the energy accumulators (11) captively accommodated in a housing part (6), while the other modular unit (4) includes the output part of the torsional vibration damper as an input part (13) of the at least one wet clutch.

Abstract: The lubricant-return holes are provided in the intermediate portion of the ring gear. Thus, the lubricant stagnating above the first oil sealing member can be easily discharged to the oil pan side via the lubricant-return holes even when the ring gear has stopped rotating in response to the starter motor being turned off after completion of the start of the internal combustion engine. As such, the level of the surface of lubricant stagnating between the ring gear and the outer race member does not rise, and therefore the lubricant surface virtually does not reach the outer race and the one-way clutch that are rotating while the internal combustion engine is running. Thus, bubbling of lubricant and production of sludge, which may otherwise be caused by agitation of the lubricant surface, can be prevented.

Abstract: A wet clutch comprising at least one friction disk (10) which is loaded by a piston (5) against an end disk (4). In order to run a forced pressure medium flow over the friction surfaces (11, 12) of the wet clutch, two pressures cavities (7, 8) having a connection in the region of the friction surfaces, are loaded with varying pressures. In order to improve such arrangements, the invention proposes that the leakage flow flowing over the supports of the friction disks is limited.

Abstract: A friction-plate lubricating device for an automatic transmission that includes a friction engagement element with a plurality of friction plates in which outer friction plates and inner friction plates are alternately disposed; a hub with splines engaged with teeth formed on an inner circumference of the inner friction plates, the hub having the splines on an outer circumference thereof and having uneven portions formed on an inner circumference thereof; and a nozzle that discharges lubricant to the uneven portions. Recesses of the uneven portions serve as oil reservoirs in which the lubricant gathers, and through-holes are formed in bottom surfaces of the recesses. The lubricant discharged from the nozzle is collected in the oil reservoirs formed by the recesses so as to be supplied to the plurality of friction plates of the friction engagement element through the through-holes.