Abstract: The present invention provides a wet type multi-plate clutch comprising a first friction engaging element coaxially arranged within a clutch housing, a second friction engaging element alternately disposed with the first friction engaging element and a piston for applying an axial load to engage the first and second friction engaging elements with each other and wherein a projection protruding toward the piston is provided on the clutch housing and a recessed portion is provided in the piston so that a relative rotation between the clutch housing and the piston is prevented by engaging the projection with the recessed portion.

Abstract: A method of manufacturing a clutch housing which accommodates therein a plurality of clutch plates adapted to be engaged together so as to transmit a torque, wherein a drum portion and a boss portion can be integrally formed from a plate material so as to form a thick portion having a thickness of not less than approximately 1.3 times as large as that of the plate material and a thin portion having a thickness of not greater than approximately ½ of that of the plate material.

Abstract: A clutch hub provided with a side wall at an end of a cylindrical portion. The cylindrical portion is formed to have convexed and concaved portions to serve as a spline and an oil passage is formed on a tooth of the spline. An oil dam is formed by plastic deformation on the inner peripheral surface of the tooth of the spline with the oil passage formed thereon at a position separated from an open end by a predetermined distance, concaved grooves are formed on the outer peripheral surface of the spline with the oil dam formed thereon.

Abstract: A supporting structure of a multiple-plate clutch is constructed by a clutch drum having an outer cylindrical portion in which a spline is formed on an inner periphery, an inner cylindrical portion, and a bottom-wall portion formed at one end of the axial direction, a hub in which a spline is formed on an outer periphery, and a piston for pressing, in the axial direction, a first frictional engaging element which is spline-fitted to the inner periphery of the outer cylindrical portion and a second frictional engaging element which is spline-fitted to the hub. Both sides of the axial direction of a position of a center of gravity of the multiple-plate clutch are bearing-supported.

Abstract: A hydraulic pressure control valve for use in a hydraulic multiplate clutch assembly includes a valve plate having a ridge-shaped, elevated portion formed in a proximity of at least a part of the valve plate, where a deformation is to take place in a staking step to be performed upon assembly of the hydraulic pressure control valve. The ridge-shaped, elevated portion serves to prevent the deformation from spreading to a closing part of the valve plate for an associated oil leak hole.

Abstract: A method of manufacturing a member having a toothed portion, comprises a first step of cutting a work piece into predetermined dimensions and then deburring the same, and a second step, in succession with the first step, of pressing an axially end face of a portion to be toothed with a predetermined load, and simultaneously drawing the work piece so as to form the toothed portion.

Abstract: The present invention provides a wet type multi-plate clutch comprising a first friction engaging element coaxially arranged within a clutch housing, a second friction engaging element alternately disposed with the first friction engaging element and a piston for applying an axial load to engage the first and second friction engaging elements with each other and wherein a projection protruding toward the piston is provided on the clutch housing and a recessed portion is provided in the piston so that a relative rotation between the clutch housing and the piston is prevented by engaging the projection with the recessed portion.

Abstract: The present invention provides a multi-plate type friction engaging apparatus for transmitting a power by engagement of a plurality of plural friction elements housed in a housing, which comprises a hub provided on an inner periphery of the housing and a bush interposed between the hub and a shaft on which the hub is slid, and wherein a groove extending in an axial direction is formed in an outer peripheral surface of the bush.

Abstract: There is disclosed a hub for a wet multi-plate clutch which is provided with an outer cylindrical portion having splines formed on the outer periphery thereof and oil holes formed through from the inner periphery to the outer periphery thereof. A stop ring is provided on the inner periphery of the outer cylindrical portion of the hub and a weir is constituted by this stop ring.

Abstract: A clutch hub provided with a side wall at an end of a cylindrical portion. The cylindrical portion is formed to have convexed and concaved portions to serve as a spline and an oil passage is formed on a tooth of the spline. An oil dam is formed by plastic deformation on the inner peripheral surface of the tooth of the spline with the oil passage formed thereon at a position separated from an open end by a predetermined distance, concaved grooves are formed on the outer peripheral surface of the spline with the oil dam formed thereon.

Abstract: A method of manufacturing a clutch housing which accommodates therein a plurality of clutch plates adapted to be engaged together so as to transmit a torque, wherein a drum portion and a boss portion can be integrally formed from a plate material so as to form a thick portion having a thickness of not less than approximately 1.3 times as large as that of the plate material and a thin portion having a thickness of not greater than approximately ½ of that of the plate material.

Abstract: A method of manufacturing a member having a toothed portion, comprises a first step of cutting a work piece into predetermined dimensions and then deburring the same, and a second step, in succession with the first step, of pressing an axially end face of a portion to be toothed with a predetermined load, and simultaneously drawing the work piece so as to form the toothed portion,

Abstract: A hydraulic clutch has an operating hydraulic chamber, an operational member pushed in an axial direction thereof by a hydraulic fluid supplied from the operating hydraulic chamber so as to transmit torque by engaging frictional engaging elements, a non-operational member that defines the operating hydraulic chamber with the operational member, the non-operational member having a seal member setting portion thereon and a seal member provided in the seal member setting portion of the non-operational member. A bottom surface of the seal member setting portion is inclined so as to gradually shallow towards a direction that the operational member is pushed.

Abstract: A supporting structure of a multiple-plate clutch is constructed by a clutch drum having an outer cylindrical portion in which a spline is formed on an inner periphery, an inner cylindrical portion, and a bottom-wall portion formed at one end of the axial direction, a hub in which a spline is formed on an outer periphery, and a piston for pressing, in the axial direction, a first frictional engaging element which is spline-fitted to the inner periphery of the outer cylindrical portion and a second frictional engaging element which is spline-fitted to the hub. Both sides of the axial direction of a position of a center of gravity of the multiple-plate clutch are bearing-supported.

Abstract: A multiplate clutch is provided with a clutch case, friction plates and separator plates alternately arranged within the clutch case, and a piston arranged within the clutch case to apply a load on the friction plates and separator plates. At least one of bent portions with which a component of the multiplate clutch, for example, the clutch case is provided has an inner circumferential cross-sectional shape comprising at least two circular arc parts, preferably at least one straight-line part and at least two circular arc parts.

Abstract: A multiplate clutch is provided with a clutch case and a sleeve fitted in an inner circumferential wall of the clutch case with their piston oilways registered with each other. The sleeve is provided in an outer circumference thereof with at least one notch. The inner circumferential wall of the clutch case has been crimped at a portion thereof into each notch such that a crimped portion is formed to fixedly secure the sleeve on the inner circumferential wall of the clutch case. Preferably, the crimped portion can be formed such that a front surface of the crimped portion is shallower on a side of the sleeve and deeper on a side of the clutch case. The front surface may desirably have an inclination of from 5 to 15°. Desirably, the sleeve can be provided with two or more notches.

Abstract: The present invention provides a rotational element for an automatic transmission having at least one kind of grooves that are deeper from the outer diameter side to the inner diameter side, grooves that are deeper toward a rotational direction, and grooves that are deeper from the outer diameter side to the inner diameter side, and toward the rotational direction.

Abstract: A multiplate clutch is provided with a clutch case and a sleeve fitted in an inner circumferential wall of the clutch case with their piston oilways registered with each other. The sleeve is provided in an outer circumference thereof with at least one notch. The inner circumferential wall of the clutch case has been crimped at a portion thereof into each notch such that a crimped portion is formed to fixedly secure the sleeve on the inner circumferential wall of the clutch case. Preferably, the crimped portion can be formed such that a front surface of the crimped portion is shallower on a side of the sleeve and deeper on a side of the clutch case. The front surface may desirably have an inclination of from 5 to 15°. Desirably, the sleeve can be provided with two or more notches.