Abstract: A vehicle includes an engine that generates drive torque and a power transfer device that selectively transfers the drive torque to a driveline. The power transfer device includes an input shaft, an output shaft and a torque biasing system. The torque biasing system has a clutch pack and an actuator that regulates engagement of the clutch pack. An on-demand lubrication system supplies a lubricating fluid flow through the clutch pack based on a control signal generated by a control system. A passively actuated positive displacement pump supplies the lubricating fluid flow through the clutch pack based on a speed differential between the input shaft and the output shaft.

Abstract: The present invention provides a friction plate with features to provide additional cooling for use within a wet clutch system. The friction plate has a core plate with a friction facing layer affixed to each face of the core plate. The first friction facing layer has a plurality of radially oriented lubrication grooves formed by a plurality of friction pads having porosity. Additionally, the second friction facing layer has a plurality of friction pads formed by radially oriented lubrication grooves whose centerline is coincident with the radial centerline of the friction pads of the first friction facing layer. Each of the lubrication grooves has at least one hole provided therein to introduce fluid to effect cooling of the friction pad opposite the groove. Additionally, the present invention provides a method of enhancing the performance of a wet clutch system.

Abstract: A coolant distribution device for a wet-running clutch device and comprising several coolant distribution surfaces along which coolant is conveyed outwards in the radial direction. In order to increase the service lifetime of a wet-running clutch device the coolant distribution surfaces are implemented so that the coolant conveyed outwards in the radial direction has different axial coolant spray-off points and/or coolant spray-off devices.

Abstract: The object of the present invention is to provide an optimizing method for a groove structure of a friction disk of a wet-type friction engaging element, which can reduce drag torque by increasing outgoing flow of lubricating oil on the friction surface and increasing the content of air in the lubricating oil.

Abstract: A clutch arrangement for a motor vehicle has a clutch housing that is filled with pumped medium in the form of fluid, a first friction element being rotatable in common with the clutch housing. Further, a second friction element is provided which is rotatable in common with a driven member and which can be brought into an operative connection with the at least one first friction element for producing a frictional interaction. At least one first friction element and at least one second friction element are each provided with a support component that can be provided for receiving at least one friction lining. The support components have support component segments which are arranged successively in circumferential direction and which are provided at a circumference-side terminating edge, respectively, with fluid delivery surfaces for generating a fluid circulation and are constructed in the form of friction lining segments to produce the frictional interaction with friction linings.

Abstract: A high performance clutch pack for use in the high gear clutch of a POWERGLIDE transmission is disclosed. The present clutch pack is disposed in a modified clutch drum including fluid exhaust vents to reduce piston drag and weight reduction features for accommodating up to ten friction disks and eleven steel disks representing a 150 percent increase in holding force in comparison to the stock POWERGLIDE clutch pack, which typically provides only four friction disks and five steel disks. In one embodiment the steel disks include elliptically shaped holes at predetermined locations for imparting turbulence to the flow of transmission fluid within the clutch pack and also feature anti-drag spacers for reducing parasitic drag during freewheeling. The clutch pack is actuated by a modified clutch piston having an increased stroke correlated to the increased number of friction disks delivering maximum holding force with minimal increase in rotating mass.

Abstract: A coupling device (11) including a housing (13, 15) defining a clutch cavity (39) and at least one window (55, 57) extending through the housing adjacent the clutch cavity. A clutch assembly (29) is disposed within the clutch cavity and includes a first clutch disc (31) having ears (63) to limit rotation relative to the housing. The housing defines a plurality of fluid passages (67) extending axially from the window to the clutch cavity, the housing defining a plurality of axial recesses (61), each of which receives one of the ears of each disc. Each of the fluid passages (67) is in fluid communication with one of the axial recesses (61), and receives fluid as the window passes through a reservoir of fluid (F).

Abstract: A vehicle includes an engine that generates drive torque and a power transfer device that selectively transfers the drive torque to a driveline. The power transfer device includes an input shaft, an output shaft and a torque biasing system. The torque biasing system has a clutch pack and an actuator that regulates engagement of the clutch pack. An on-demand lubrication system supplies a lubricating fluid flow through the clutch pack based on a control signal generated by a control system. A passively actuated positive displacement pump supplies the lubricating fluid flow through the clutch pack based on a speed differential between the input shaft and the output shaft.

Abstract: A friction plate for a wet type multiplate clutch has a substantially ring-shaped core plate and a friction member attached to the core plate. The friction member has a surface which includes a passage formed on a surface of the friction member, the passage extending from an inner peripheral edge of the friction member to an outer peripheral edge of the friction member, and a groove having an opened end which opens to the inner peripheral edge of the friction member and a closed end which is closed at a middle of the surface of the friction member. A width of the groove decreases towards a direction to the outer peripheral edge from the inner peripheral edge of the friction member.

Abstract: A wet-type segmented friction material has a tape-like friction material substrate which is passed through and pressed between a roller having a dent at a center and a flat roller. At the same time, the friction material substrate is heated from an inside and an outside of the rollers so as to carry out a heat press compression processing. Then, a processed friction material substrate has a predetermined cross-section. The processed friction material substrate is cut into segment pieces each having a segment shape by a rotary push cutter having a sharp cutting edge. A cut position of the segment piece is selected such that two straight lines at two lateral sides of the segment shape is located within an area of a compressed portion of the processed friction material substrate. That is, a stepped or sunken compressed portion is provided on both sides of the segment piece.

Abstract: A clutch assembly includes a hub with a hub friction surface and an inner surface that cooperate to define a cavity. A damper member is situated within the cavity and is in contact with the hub friction surface. The damper member is rotatable with respect to the hub so that relative movement between the damper ring and the hub friction surface results in energy absorption and dissipation to minimize unwanted clutch vibration. The damper ring is located inside the clutch hub so that it does not adversely affect transmission packaging. The clutch assembly preferably includes a member configured to direct lubricant along an inner diameter of the damper member so that it subsequently flows between the damper ring and the hub friction surface and through holes in the hub to lubricate clutch plates.

Abstract: A clutch unit has an oil pump which is powered by the input shaft and an oil pump which is powered by the output shaft. The oil pump powered by the input shaft pumps oil in both a clockwise and counterclockwise rotation of the input shaft. The oil flow is controlled by a unique bi-directional check valve which automatically selects the passage through which oil is being pumped. The oil pump powered by the output shaft provides oil to the friction plates of the clutch only when the clutch is engaged.

Abstract: The invention relates to a clutch arrangement, in particular for a motor vehicle, comprising a housing arrangement which is filled or can be filled with fluid, at least one first friction member which is coupled with the housing arrangement for commonly rotating, at least one second friction member which is coupled or can be coupled with a driven shaft for commonly rotating, a fluid supply area for introducing fluid into a delimited area of said housing arrangement, in which the first and second friction members operate, a fluid discharge area for evacuating the fluid from the delimited area, as well as an energy accumulator, by means of which the first and second friction members are prestressed in friction interaction.

Abstract: A method and device for operating a clutch between an internal combustion engine and at least one driven wheel of a vehicle, a torque being transmitted between the internal combustion engine and the driven wheel by pressing the clutch together via an application force or an application pressure, and the application force or the application pressure being controlled or regulated as a function of the temperature of the clutch.

Abstract: A plate (1) for a multiple-plate clutch has at least one friction surface (4) for transmitting a torque, in particular for a wet-running switchable multiple disk clutch. The plate (1) has at least one friction surface (4) which has grooves (7.1, 7.2, 10.1, 10.2) with an inside bordering edge (6) and an outside bordering edge (5), and at least one groove (7.1, 7.2, 10.1, 10.2) that runs from the inside bordering edge (6) to the outside bordering edge (5). The at least one groove (7.1, 7.2, 10.1, 10.2) has at least one bending point (8.1, 8.2, 9.1, 9.2, 11.1, 11.2, 12.1, 12.2) at which the at least one groove (7.1, 7.2, 10.1, 10.2) is bent at an angle (?1, ?2, ?3, ?4).

Abstract: A power takeoff having an output shaft, an output gear and a connect-disconnect clutch mechanism for connecting the output gear to the output shaft, the clutch mechanism, including a clutch hub, a disc stack slidably mounted between the output gear and the clutch hub and a piston for compressing the disc stack-thereby to bring the output shaft into rotatable engagement with the transmission of an engine; in which the clutch hub is normally biased by a spring away from the piston but is confined by snap rings to limit the hub's movement along the output shaft in such a manner so that substantially no operational force is placed on the snap rings during compression of the disc stack.

Abstract: A dry multi-disc clutch includes a plurality of friction discs interposed between a drive-side clutch outer and a driven-side clutch center and power is transmitted from the clutch outer to the clutch center by pushing these friction discs using a pressure plate. Fins which enhance a flow of air are formed on the clutch outer and the pressure plate and, at the same time, passages which allow the communication of air are formed in the clutch outer and the pressure plate. With such a clutch structure it is possible to efficiently radiate the friction heat, which is generated when the clutch is connected, and the heat transmitted from the engine and, at the same time, it is possible to discharge the wear powder that is generated when the clutch is connected. As a result, it is possible to stabilize the clutch performance.

Abstract: A hydraulic coupling system includes a pump, a controller, a clutch assembly, and a valve. The clutch assembly includes an actuator and a multi-disk clutch pack coupled to the actuator. Under the direction of the controller, the pump pressurizes a fluid in the actuator to engage the clutch pack and pumps the fluid through the clutch pack to cool the clutch pack. The valve maintains the fluid pumped to the actuator at a higher pressure than the pressure of the fluid pumped through the clutch pack to cool the clutch.

Abstract: A multiple disc clutch apparatus, comprises a plurality of externally splined annular friction plates, to one side surface only of each externally splined annular friction plate being fixed a friction material, and each externally splined annular friction plate being formed with engagement teeth at an outer periphery, a plurality of internally splined annular friction plates, to one side surface only of each internally splined annular friction plate being fixed a friction material, and each internally splined annular friction plate being formed with engagement teeth at an inner periphery. The externally splined friction plate and the internally splined friction plate are alternately arranged in a direction in which the frictional materials are not overlapped each other.

Abstract: An interleaved friction plate braking device having a multiplicity of confined curved or slanted vanes on the outside diameter of the rotating driven plates to impact a stationary fluid reservoir and impart inward flow thru passages to more completely cool and lubricate the sliding surfaces.

Abstract: A friction member for engagement in a torque-transmitting mechanism includes an outer layer comprising a first material. The outer layer has a friction surface for sliding contact with an opposing reaction member in the torque-transmitting mechanism. An inner layer is connected to the outer layer opposite the friction surface and comprises a second material. The inner layer is characterized by a first modulus of elasticity and the outer layer is characterized by a second modulus of elasticity greater than the first modulus of elasticity.

Abstract: A clutch system includes a clutch arrangement between a drive unit and a transmission, a pump arrangement which supplies pressure medium to the clutch arrangement at a pressure and rate of flow, and an operating medium supply arrangement which supplies an operating medium to the clutch arrangement at a pressure which is less than the pressure of the pressure medium and a rate of flow which is greater than the rate of flow of the pressure medium. The operating medium supply arrangement includes a pressure receiving element which is movable in a housing and has at least one pressure receiving surface which is exposed to the pressure medium, and an interaction element which is coupled to move with the pressure receiving element and has at least one interaction surface which interacts with the operating medium to produce a flow of the operating medium.

Abstract: A system and method are shown for reducing material in a core which receives a plurality of segments. The invention may further include a plurality of segmented pieces that are arranged to provide a plurality of gaps that lie in a predetermined sweep angle and that may comprise a scoop for facilitating channeling fluid into a gap between adjacent material segments. Various manufacturing approaches are also disclosed for manufacturing and assembling a ring for use in a traditional transmission or clutch plate manufacturing and assembly system.

Abstract: This invention describes a control method for a hydraulic coupling system that includes pressurizing a fluid in an actuator coupled to a multi-disk clutch pack to engage the clutch pack, pumping the fluid through the clutch pack to cool the clutch pack, and controlling one or more valve actuators and one or more pump-motors with a controller. The control method may incorporate pulse width modulation of the actuators, such as the actuators for the pump-motor and valve.

Abstract: An automatic transmission apparatus comprising, a first member rotating integrally with an input shaft and including a first cylindrical portion having an inner spline at an inner peripheral surface, a second member including a second cylindrical portion having an outer spline for engaging with the inner spline of the first member and a depressed portion formed on the second member and a clearance, which establishes a communication between an inner portion surrounded by the first and the second members and an outer portion of the first and the second members, is formed between the depressed portion of the second member and the inner surface of the first member.

Abstract: In the starting clutch, an electrical pump or an engine pump is omitted and a substitutive pump mechanism is obtained with a simple construction thereby to circulate lubricating oil within the starting clutch. There is provided a starting clutch in which lubricating oil supplied form a drive shaft side is circulated within the clutch and input side elements and output side elements are tightened by an axial load to transmit a power and wherein a non-electrically operated pump mechanism is provided within the starting clutch.

Abstract: A wet-type friction engaging apparatus 10 comprises a friction disk 30 which is fitted by spline with a hub 20 and a mating plate 40 which is fitted by spline with a drum D. The friction disk 30 and the mating plate 40 are arranged alternately, and torque is transmitted when the friction disk 30 and the mating plate 40 are engaged with each other. The inner surface of the hub 20 is in a stepped taper shape in order to let lubricating oil B leak from an opening end 26 of the hub 20, and an oil bore 24 is provided in each step in a radial direction of the hub 20. A periphery of an inlet of each oil bore 24 is in a concave shape. During low-speed rotation when centrifugal force is relatively small, the lubricating oil B leaks from the opening end 26 of the hub 20 and drag torque is reduced, and during high-speed rotation when centrifugal force is relatively large, lubricating oil which splashes from a shaft is securely concentrated and then be drained through the oil bore 24.

Abstract: A lubricating structure of a friction engaging device including a rotating drum which is a cylindrical rotating body, around a perimeter of which there is provided a friction member, and which is engaged with/disengaged from a predetermined coupling member via the friction member; and a ring gear which is spline-coupled to an inner surface of the rotating drum and which is positioned while contacting an inward flange that is integrally provided with the rotating drum. In the lubricating structure, a centrifugal oil passage which is formed between the ring gear and the inward flange, and which introduces lubricating oil inside the rotating drum to a spline-coupled portion of the ring gear and the rotating drum by centrifugal force, and a plurality of through holes which are formed in the rotating drum and through which the lubricating oil, that has flowed into the spline-coupled portion, flows to an outside of the rotating drum where the friction member is provided are formed.

Abstract: Wet clutch (100) or friction plate brake has an essentially hollow cylindrical shaped balance piston (14) that is coaxial to a clutch hub (2) and is rigidly connected with an apply piston support device (12), an essentially ring shaped spring support (14.1), and an essentially cylinder shaped wall (14.3) that has an essentially cylinder shaped contact surface (14.4). The cylinder shaped contact surface (14.4) is axially (ax) displaceable and is bordered by an essentially cylinder shaped contact surface (8.5) of an apply piston (8) so as to form an equalizing space (16). The contact or support surfaces (14.4, 8.5) of the balance piston (14) and the apply piston (8) are provided coaxial between the clutch hub (2) and the apply piston support device (12).

Abstract: A start-up element for an automatic transmission, comprising a start-up clutch arranged within a cover, which is flanged to a pump for the operating fluid, whereby a front pump support and gear seal are integrated in the cover.

Abstract: A fluid clutch includes a housing having an interior that can be filled with fluid, an output element that can be rotated relative to the housing, a first friction surface arrangement coupled to the housing, a second friction surface arrangement coupled to the output element, and means for bringing the first and second friction surface arrangements into frictional engagement. A fluid circulation arrangement in the housing causes fluid to circulate around the friction surfaces without requiring a simultaneous exchange of fluid to and from the interior.

Abstract: A friction clutch has a plurality of iron inner clutch plates and a plurality of iron outer clutch plates. Both the clutch plates have sliding surfaces which are friction-engaged each other. A thin carbon film in a diamond form, which functions as a solid lubricant, is formed on each of the sliding surfaces of the outer clutch plates by a known method such as the Chemical Vapor Deposition method. A known nitride treatment or quenching and tempering treatment is applied to the sliding surfaces of the inner clutch plates. A coupling device has a pilot clutch mechanism with the friction clutch and an electromagnetic actuator. As a result, the friction clutch is resistant to wear and the coupling device is excellent in durability.

Abstract: A clutch arrangement, especially for a motor vehicle, comprising a housing arrangement (12) which is filled or which can be filled with fluid, at least one first friction element (22) which can be jointly rotated with the housing arrangement (12) and at least one second friction organ (24) which can be jointly rotated with an output element (18) and which can be brought to rest against the at least one first friction element (22) in order to produce at least one interactive friction effect. At least one friction element (22, 24) is embodied in such a way that fluid can circulate around at least certain areas of the friction elements (22, 24).

Abstract: A system and method for supplying cooling fluid for frictional elements, for example multiple disc clutches and multiple disc brakes, in automatic transmissions. The cooling fluid flows through the multiple disc clutch or brake in a predefined manner radially inward or outward, whereby a defined flow through the clutch or brake packet is ensured through a defined pressure difference in the cooling fluid between the cooling fluid supply and the discharge of the cooling fluid. A preferred embodiment of device for supplying the cooling fluid is designed as a ring-shaped channel that partially or fully encloses the clutch or the brake.

Abstract: In order to manufacture a friction plate for a wet clutch including a core plate and a friction member bonded to at least one of annular flat surfaces of the core plate, each friction member including friction member segments, an oil groove being provided between adjacent friction member segments, there is adopted a method including: a step of making a plurality of cuts in at least one band-shaped friction member material in a lengthwise direction to form a plurality of friction member strips; a step of retaining the friction member strips with distances corresponding to the oil grooves being formed between adjacent friction member strips; a step of cutting off a portion of a tip end of at least one of the friction member strips which are located at opposite ends to thereby secure the oil grooves between the friction member segments on the annular flat surface; and a step of superposing friction member segment correspondence portions forming the tip ends of the plurality of friction member strips to the annul

Abstract: An electronic controlled coupling including a wet-type multiple disc clutch, a coupling case, a hydraulic chamber, an oil pump, an electric motor, an electric control unit, and a supply passage for supplying hydraulic pressure. The coupling case accommodates the wet-type multiple disc clutch and contains oil. The oil pump driven by the electric motor is connected to the coupling case. The outlet of the oil pump is connected to the hydraulic chamber of the wet-type multiple disc clutch with the supply passage therebetween. The electric control unit controls the speed of rotation of the electric motor through a motor driver so that the pump discharge pressure is equal to an operating pressure required for the wet-type multiple disc clutch. The electronic controlled coupling performs a complete coupling mechanism increasing the durability as a coupling and a compact and simple structure enhancing the flexibility in designing.

Abstract: A friction device (10, 110) having a drive member (12, 112) and a driven member (14, 114) which define a clutch housing (16, 116) therebetween. A clutch pack (24, 124) is interposed between the drive and driven members and is operable to connect and disconnect the drive and driven members for transferring and interrupting torque therebetween. A control valve (74, 174) is supported in the clutch housing (16, 116) and is moveable between open and closed positions. The control valve (74, 174) is operable to control the flow of cooling fluid from the source to the clutch pack (24, 124).

Abstract: The invention relates to a clutch arrangement, in particular for a motor vehicle, comprising a housing arrangement (12) which is filled or can be filled with fluid, at least one first friction member (22) which is coupled with the housing arrangement (12) for commonly rotating, at least one second friction member (26) which is coupled or can be coupled with a driven shaft (32) for commonly rotating, a fluid supply area for introducing fluid into a delimited area (34) of said housing arrangement (12), in which the first and second friction members (22. 26) operate, a fluid discharge area for evacuating the fluid from the delimited area (34), as well as an energy accumulator (60), by means of which said first and second friction members (22, 26) are prestressed in friction interaction.

Abstract: A hydrodynamic clutch arrangement is provided with at least a pump wheel and a turbine wheel to form a hydrodynamic circuit in a clutch housing, the drive-side wall of the housing being connected on the side facing the drive unit, such as an internal combustion engine, to the drive unit, a clutch device being provided to bring the housing into or out of working connection with the pump wheel. The clutch device is located inside the clutch housing.

Abstract: A dry multi-disc clutch includes a plurality of friction discs interposed between a drive-side clutch outer and a driven-side clutch center and power is transmitted from the clutch outer to the clutch center by pushing these friction discs using a pressure plate. Fins which enhance a flow of air are formed on the clutch outer and the pressure plate and, at the same time, passages which allow the communication of air are formed in the clutch outer and the pressure plate. With such a clutch structure it is possible to efficiently radiate the friction heat, which is generated when the clutch is connected, and the heat transmitted from the engine and, at the same time, it is possible to discharge the wear powder that is generated when the clutch is connected. As a result, it is possible to stabilize the clutch performance.

Abstract: A clutch arrangement, especially for a motor vehicle, comprises a housing arrangement which can be filled with fluid; at least one first friction element connected to the housing arrangement for rotation in common around an axis of rotation; and at least one second friction element connected to a power takeoff element for rotation in common around the axis of rotation (A), which second element can be brought into contact with at least one first friction element to produce a frictional interaction. The at least one first friction element or the at least one second friction element has a friction lining carrier which carries a friction lining arrangement on each frictionally active axial side of the friction element. At least in the case of one friction element with a friction lining carrier carrying a friction lining arrangement an arrangement of fluid transport surfaces is provided to produce a circulation of fluid which flows around at least certain areas of the friction elements.

Abstract: A hydraulic clutch assembly is equipped with a spring-drive hydraulic clutch, which includes a gear rotatably mounted on a transmission shaft and a clutch cylinder fixedly mounted on the transmission shaft, first and second friction elements respectively supported on the gear and the clutch cylinder in such a manner as to be slidable along an axis of the clutch (hereinafter sometimes referred to a clutch axis) and relatively non-rotatable thereto, a pressure disk disposed opposite to the friction elements, and a spring for moving the pressure disk towards the friction elements to bring the first friction element into engagement with the second friction element, in which the pressure disk is moved away from the friction elements by an effect of hydraulic pressure, thereby withdrawing the friction elements from engagement with each other.

Abstract: A lubricating structure of a hydraulic clutch including a drum-shaped clutch housing connected to an input shaft, and a clutch hub connected to an output shaft coaxial with the input shaft. The clutch hub has a cylindrical portion and a flange formed integrally with the cylindrical portion near one end of the cylindrical portion. The lubricating structure of the hydraulic clutch further includes a clutch piston for making pressure contact of first and second clutch plates respectively mounded to the clutch housing and the clutch hub and a hydraulic pump provided on the opposite side of the first and second clutch plates with respect to the clutch piston. The cylindrical portion of the clutch hub is formed with a plurality of first lubricating oil passages passing through the cylindrical portion, and the flange of the clutch hub is formed with a plurality of second lubricating oil passages passing through the flange.

Abstract: A reaction plate for a transmission clutch pack includes first and second steel disks each having a contact surface facing the other of the two steel disks and having inner and outer peripheral edges. Each contact surface has grooves formed therein to carry cooling fluid from the inner peripheral edge to the outer peripheral edge to enhance cooling.

Abstract: This invention describes a control method for a hydraulic coupling system that includes pressurizing a fluid in an actuator coupled to a multi-disk clutch pack to engage the clutch pack, pumping the fluid through the clutch pack to cool the clutch pack, and controlling one or more valve actuators and one or more pump-motors with a controller. The control method may incorporate pulse width modulation of the actuators, such as the actuators for the pump-motor and valve.

Abstract: A lubricating structure of a friction engaging device including a rotating drum which is a cylindrical rotating body, around a perimeter of which there is provided a friction member, and which is engaged with/disengaged from a predetermined coupling member via the friction member; and a ring gear which is spline-coupled to an inner surface of the rotating drum and which is positioned while contacting an inward flange that is integrally provided with the rotating drum. In the lubricating structure, a centrifugal oil passage which is formed between the ring gear and the inward flange, and which introduces lubricating oil inside the rotating drum to a spline-coupled portion of the ring gear and the rotating drum by centrifugal force, and a plurality of through holes which are formed in the rotating drum and through which the lubricating oil, that has flowed into the spline-coupled portion, flows to an outside of the rotating drum where the friction member is provided are formed.

Abstract: A friction device (10, 110) having a drive member (12, 112) and a driven member (14, 114) which define a clutch housing (16, 116) therebetween. A clutch pack (24, 124) is interposed between the drive and driven members and is operable to connect and disconnect the drive and driven members for transferring and interrupting torque therebetween. A control valve (74, 174) is supported in the clutch housing (16, 116) and is moveable between open and closed positions. The control valve (74, 174) is operable to control the flow of cooling fluid from the source to the clutch pack (24, 124).

Abstract: A wet-type friction clutch plate which keeps lubricant on a frictional slide face, stabilizes frictional torque transmission and suppresses shuddering noise. The wet-type friction clutch plate has the frictional slide face on which a grid of grooves is formed. The frictional slide face frictionally engages with an opposite clutch plate. At least one of the sectional shape and plan shape of each of the grooves is configured to provide the frictional slide face with a &mgr;-v characteristic such that &mgr; increases with an increase in v to prevent self-excited vibration during frictional engagement of the wet-type friction clutch plate with the opposite clutch plate, wherein &mgr; is a coefficient of friction on the frictional slide face and v is a relative rotational speed of the wet-type friction clutch plate relative to the opposite clutch plate.

Abstract: A dual clutch comprises two clutch areas, each with a pressure plate which can be moved by a force-exerting arrangement toward an abutment arrangement, where the abutment arrangement is to be connected by a connecting plate arrangement to a drive element, also comprising a starter gear ring connected to the abutment arrangement for rotation in common, where the starter gear ring has a first connecting area for connection to the abutment arrangement and a second connecting area for connection to the connecting plate arrangement

Abstract: A housing arrangement for a friction clutch, especially for a multi-disk clutch, where the housing arrangement is designed approximately in the shape of a cup and is provided with a bottom area and an edge area for connection to a flywheel. At least one air through-opening is provided in the bottom area, each opening being bounded by a front edge and a rear edge with respect to the direction of rotation, the front edge being axially offset toward the interior of the housing with respect to said rear edge.