Provided is a frictional engagement device capable of preventing a momentum of oil supplied to a frictional engagement element from becoming excessive even when an outer diameter of the frictional engagement device (a clutch) is large or a rotation speed thereof becomes high due to a centrifugal force in accordance with rotation. When a piston moves toward the engagement position, a canceller spring cover is elastically deformed by a pressing force of the piston acting via a return spring, a contact portion of the canceller spring cover comes into contact with the contacted portion of a clutch hub, and thus an opening/closing portion of a first cooling oil path provided between the contact portion and the contacted portion is closed. Accordingly, the first cooling oil path can be closed through which the oil supplied to a frictional engagement portion flows in accordance with an engagement operation of the clutch.

A clutch arrangement having multiple pressure lines, connected to pressure chambers provided in a clutch housing, a first pressure chamber exerts load on a clutch piston and a second pressure chamber accommodates a clutch element and feeds fluid for cooling the at least one clutch element. The two pressure chambers are separated from one another in a pressure-tight fashion in the region of the clutch piston. The clutch piston and/or a component assigned to the clutch piston is designed such that, when at least one pressure chamber is connected to at least two pressure lines, a flow connection between the two pressure chambers is prevented, whereas, when each pressure chamber is connected to only one pressure line, a flow connection can be produced between the two pressure chambers by virtue of the clutch piston, and/or the component assigned to the clutch piston, being formed with a passage.

A clutch arrangement having multiple pressure lines, connected to pressure chambers provided in a clutch housing, a first pressure chamber exerts load on a clutch piston and a second pressure chamber accommodates a clutch element and feeds fluid for cooling the at least one clutch element. The two pressure chambers are separated from one another in a pressure-tight fashion in the region of the clutch piston. The clutch piston and/or a component assigned to the clutch piston is designed such that, when at least one pressure chamber is connected to at least two pressure lines, a flow connection between the two pressure chambers is prevented, whereas, when each pressure chamber is connected to only one pressure line, a flow connection can be produced between the two pressure chambers by virtue of the clutch piston, and/or the component assigned to the clutch piston, being formed with a passage.

The present disclosure includes: a creep control unit configured to perform a creep control including bringing one of a first clutch and a second clutch into a half-clutch state and bringing the other into a disengaged state, so as to transmit a predetermined torque from a drive source to a transmission mechanism via a clutch device; and a clutch switching control unit configured to, when a vehicle stops during the performing of the creep control, perform a clutch switching control including, on the basis of the heat-generating state of the one clutch that is maintained in the half-clutch state from the stop of the vehicle, switching the one clutch from the half-clutch state to the disengaged state and switching the other clutch from the disengaged state to the half-clutch state.

A method for forming a rotor hub that includes a sheet metal cylinder including spline teeth including angularly spaced crests and valleys, a tube surrounding the cylinder, secured to the crests and supporting a rotor thereon, a hub secured to the cylinder and supported for rotation, a torque converter, and a flex plate secured to the hub and the torque converter.

A method for forming a rotor hub that includes a sheet metal cylinder including spline teeth including angularly spaced crests and valleys, a tube surrounding the cylinder, secured to the crests and supporting a rotor thereon, a hub secured to the cylinder and supported for rotation, a torque converter, and a flex plate secured to the hub and the torque converter.

A clutch-release control for a motorcycle includes a post having an aperture on a first end that telescopically receives a biased piston. The piston includes a cap at a distal end and a flange spaced therefrom. The piston is movable between a retracted position, where the cap is proximal the first end of the post, and an extended position, where the cap engages a clutch-release arm on a motorcycle. To use the device, a rider releases a latch to thrust the cap into engagement with the clutch-release arm. When the rider fully opens the throttle and releases the clutch, the piston applies a predetermined amount of resistance to the arm, preventing the clutch from suddenly engaging the motor.

A method for controlling an engine clutch includes steps of controlling the hydraulic pressure transmitted from a master cylinder, driven by a motor, to a concentric slave cylinder using a controller outputting a motor control command for controlling an engine clutch so as to switch the engine clutch to a target state, driving the engine clutch using the concentric slave cylinder, after the step of controlling hydraulic pressure, detecting a position of a piston of the master cylinder using a first travel sensor and detecting a position of a piston of the concentric slave cylinder using a second travel sensor, and performing compensation control with respect to the motor based on the positions of the pistons detected by the first travel sensor and the second travel sensor using the controller so that the engine clutch is switched to the target state.

A method for controlling an engine clutch includes steps of controlling the hydraulic pressure transmitted from a master cylinder, driven by a motor, to a concentric slave cylinder using a controller outputting a motor control command for controlling an engine clutch so as to switch the engine clutch to a target state, driving the engine clutch using the concentric slave cylinder, after the step of controlling hydraulic pressure, detecting a position of a piston of the master cylinder using a first travel sensor and detecting a position of a piston of the concentric slave cylinder using a second travel sensor, and performing compensation control with respect to the motor based on the positions of the pistons detected by the first travel sensor and the second travel sensor using the controller so that the engine clutch is switched to the target state.

Components for an automatic motor vehicle transmission including a band brake drum, a clutch housing or hub having a seal surface or a clutch housing or hub utilized in a friction clutch assembly having a spline set. All of these components are fabricated of aluminum and the outer surface of the band brake drum, the housing or hub sealing surface and the area of the spline set includes a thin coating of a thermally sprayed steel material. The thermally sprayed steel material may be a low carbon steel such as SAE 1008 or 1010, a similar alloy, iron or other metal. The resulting components thus exhibit the weight saving of aluminum while providing excellent service life due to the enhanced strength and wear resistance provided by the thermally sprayed steel coating.