Abstract: In a power transmission apparatus, a second clutch includes a divider dividing driving clutch plates and driven clutch plates in an axial direction such that a first region adjacent to a clutch pressure plate and a second region adjacent to a centrifugal clutch are defined. The second clutch presses the driving clutch plates and the driven clutch plates in the first region and the second region against each other during operation of the centrifugal clutch, and presses the driving clutch plates and the driven clutch plates in the first region against each other during operation of a back torque transmission cam.

Abstract: A power unit for a motorcycle includes an internal combustion engine with a transmission having an input shaft and an output shaft. A clutch with a hydraulic cylinder is provided for changing over the connection/disconnection of power transmission between a crankshaft and the input shaft. A cylinder support member, mounted on the engine body, includes a cylindrical case portion where a portion of the hydraulic cylinder is housed. The power unit can be miniaturized by suppressing the projection of the hydraulic cylinder from the engine body in the axial direction. A cover member is mounted on the engine body for covering and surrounding a projecting end portion of an output shaft from an engine body. A cylinder support member is mounted on the engine body such that a portion of a case portion is arranged in an opening portion formed by cutting away a portion of the cover member.

Abstract: A novel adjustable slave cylinder is disclosed. The improved slave cylinder is particularly well suited for use with a clutch incorporating an expanding friction disk. The adjustable slave cylinder provides a means for adjusting a clutch pressure plate's position via an adjustment mechanism external to the inside of an engine.

Abstract: A slave cylinder and a release system, the slave cylinder being configured in particular as a CSC for a hydraulic system of a motor vehicle. While maintaining the axial extension of the working space of the piston axially moveable in the slave cylinder, the force for actuating the clutch is increased in that the pressure chamber is sealed by two sealing elements having different diameters, and in that at least one energy accumulator is disposed in the pressure chamber of the slave cylinder, the energy accumulator generating a preload on the clutch release bearing operative connected to the slave cylinder.

Abstract: A clutch hydraulic mechanism wherein the positional relationship between two cylinders is not varied, and a compact structure can be achieved. A see-saw member for transmitting motive power is provided between a second release cylinder and a first master cylinder and the first master cylinder and the second release cylinder are formed in the same cylinder block. This eliminates the need for adjusting the positions of the first master cylinder and the second release cylinder. In addition, it is possible to dispose the first master cylinder and the second release cylinder close to each other.

Abstract: A clutch device is configured to include a clutch mechanism, a clutch actuator operatively engaging and disengaging the clutch mechanism, a clutch lever, and an assist pressure generator which generates assist hydraulic pressure by driving an electric motor. The assist hydraulic pressure is supplied to the clutch actuator to operatively engage and disengage the clutch mechanism. The clutch device further includes a first turning angle sensor which detects the turn operation angle of the clutch lever, a control unit which controllably drives the electric motor based on the turning operation amount of the clutch lever and adjusts the driving force generating gain characteristic of the electric motor, and a gain adjustment knob which variably sets the gain characteristic. The clutch device makes it possible to changeably set the magnitude of an assist force of an assist device according to a rider's preference.

Abstract: A clutch structure, constructed without a one-way clutch, remains engaged until the input side rotational speed becomes relatively low. A pressure plate presses a group of plates directly or indirectly by moving in the direction of an axis, bringing the group of plates into a press contact state. An input side press body turns around the axis with the rotation of a clutch housing, presses the pressure plate to the side of the group of plates by centrifugal force generated during the turning, and moves in a direction away from the axis. A roller retainer presses the group of plates directly or indirectly by moving in the direction of the axis, bringing the group of plates into a press contact state. An output side press body turns around the axis with the rotation of an output side clutch member, presses the roller retainer to the side of the group of plates by centrifugal force generated during the turning, and moves in a direction away from the axis.

Abstract: A clutch hydraulic system for a vehicle wherein it is possible to independently operate two systems, to increase the degree of freedom in designing, and to achieve a reduction in cost. A seesaw member for transmitting motive power is provided between a second release cylinder and a first master cylinder, the first master cylinder and a second hydraulic oil pipe communicate with each other through a large diameter hole and a small diameter hole provided as communicating passages through which oil flows. A reservoir tank is provided for reserving the oil for controlling the amounts of the oil in the hydraulic oil passage on the side of the first master cylinder and the amount of the oil in the hydraulic oil passage on the side of the second release cylinder is connected to a second master cylinder.

Abstract: An automatic change gear control device for a motorcycle having a manually operated clutch operation member achieves both easy clutch operation and secure freedom of drive. A clutch is connected and disconnected to change gears in a transmission capable of freely changing gears in plural stages. A clutch actuator drives the clutch. A clutch operation unit has a manually-operated clutch lever. An ECU controls the clutch actuator based on driver operation of the clutch lever.

Abstract: A clutch operation mechanism wherein when a clutch is disengaged and engaged by manual operation or by operation of an actuator the one operation does not affect the other operation. The clutch operation mechanism includes a lever side lost mechanism which is disposed between a clutch lever and a turn-operating force transmitting member for interrupting, from the clutch lever side, an operated-force applied from the turn-operating force transmitting member by driving the electric motor when the clutch lever is not operated. A motor side lost mechanism is disposed between the electric motor and the turn-operating force transmitting member and interrupts, from the side of the electric motor, the operated-force applied from the turn-operating force transmitting member by operating the clutch lever when the electric motor is not operated.

Abstract: A marine transmission provides a cylindrical spool valve that is disposed within the gear case of the transmission and has a movable portion that is axially movable in a vertical direction to select forward, neutral, and reverse gear positions of the transmission. A piston assembly provides a primary piston and two auxiliary pistons which cooperate with each other to provide appropriate hydraulic forces which move a dog clutch into engagement with forward or reverse gears or toward a location in non-engagement with neither the forward nor reverse gears. The spool valve is generally cylindrical and disposed within a narrow column portion of the gear case of a marine propulsion system.

Abstract: A clutch-manipulation assist mechanism of a vehicle clutch mechanism is capable of disconnecting power of an engine and is provided to a power transmission path which transmits the power of the engine to a rear wheel. The clutch-manipulation assist mechanism includes a push rod member which is arranged near the clutch mechanism and which is movable in the axial direction interlockingly with a power cutoff of the clutch mechanism due to the manipulation of a clutch lever by a rider. An axial movement of the push rod member is assisted by an actuator in response to a detection of the clutch lever manipulation by the rider using a stroke sensor, thus reducing a manipulation force of the clutch lever. A detection lug of the stroke sensor detects a movement quantity of a shaft end of the push rod member.

Abstract: A hydraulic clutch for utilization with an engine of a motorcycle is disclosed herein. The hydraulic clutch includes a hydraulic clutch adjuster assembly, a clutch basket, a cover plate, first clutch plates, second clutch plates and a dynamic expansion ring assembly having cam members. The dynamic expansion ring assembly imparts substantially equal expansion forces in opposite directions. A gap is present when the engine is at an idle speed and cam members are positioned radially inward, and the gap is not present when the engine is operating faster than idle and the cam members are positioned radially outward by centrifugal force.

Abstract: A clutch actuator comprises a motor having a motor shaft. A worm shaft is formed with a threaded section. A worm wheel meshes with the threaded section of the worm shaft. An output rod reciprocates in an axial direction to disengage and engage a clutch. A crank shaft converts rotational motion of the worm wheel to reciprocating motion of the output rod. The motor shaft and the worm shaft are coupled by a spline connection.