Abstract: An electric bicycle includes a motor that includes a stator and a rotor and that is driven by a battery, a reduction gear, an output shaft configured to output power of the motor, a sprocket fixed to the output shaft, a housing, and a water jacket configured to cool the motor. The water jacket includes a flange section protruding outward in a radial direction of the stator, the flange section being formed in the water jacket at a side opposite to the reduction gear in a vehicle width direction.

Abstract: An internal combustion engine which can be miniaturized, even where it includes an oil filter between a hydraulic clutch and an oil pump, without significantly increasing the length of an oil passage for the hydraulic clutch, the oil pump and a hydraulic pressure adjustment apparatus. A second oil filter is provided on an oil pan at a lower portion of the internal combustion engine so as to be disposed at a position at which the second oil filter does not overlap with any of a controlling oil pump and a hydraulic pressure adjustment apparatus as viewed in side elevation and which is lower than those of the oil pump and the hydraulic pressure adjustment apparatus.

Abstract: A multiplate friction clutch includes: a pressure plate having a boss portion which penetrates a clutch center; a clutch lifter plate joined to the boss portion and receiving a drive force in a axial direction at a time of disconnection between a friction plate and a clutch plate; and a spring sandwiched between the clutch lifter plate and the clutch center, and capable of generating an elastic force in a direction that the friction plate and the clutch plate are pressed to each other. A position restricting portion is provided on the clutch lifter plate, the position restricting portion being brought into contact with the boss portion from an outside in a radial direction of the clutch lifter plate so as to restrict a position of the clutch lifter plate with respect to the pressure plate.

Abstract: An electric bicycle includes a motor that includes a stator and a rotor and that is driven by a battery, a reduction gear, an output shaft configured to output power of the motor, a sprocket fixed to the output shaft, a housing, and a water jacket configured to cool the motor. The water jacket includes a flange section protruding outward in a radial direction of the stator, the flange section being formed in the water jacket at a side opposite to the reduction gear in a vehicle width direction.

Abstract: A transmission for a vehicle has a main shaft and a counter shaft, which are supported in a transmission case by bearings. Gears on the main shaft and gears on the counter shaft include: shifter gears which are not rotatable but axially movable relative to the shaft, and fixed gears which are rotatable but not axially movable relative to the shaft. Dog clutches are provided between the shifter gears and the fixed gears, and outer races of the bearings supporting the main and counter shafts are affixed to the transmission case. Vibration-absorbing elastic members are pressed against the outer races from axially outside and are set to have a volume of 50% or more of the volume of the outer races. With such configuration, the vibration of the bearings supporting both the main and counter shafts of the transmission is attenuated, and striking noise caused by shifting is reduced.

Abstract: A power unit for a vehicle includes an engine that is a power source, a gear shift apparatus, a twin clutch type transmission that intermittently switches power transmission between the engine and the gear shift apparatus, and a clutch actuator that controls intermittent switching of the twin clutch type transmission, the engine includes a crankcase and a pair of cylinders installed on the crankcase so that a V-bank is formed therebetween, and the clutch actuator is installed on the cylinders so that the clutch actuator overlaps a region of the V-bank.

Abstract: An oil supply structure for a power unit includes a working oil pump, a lubrication oil pump, an oil storage section, a working oil pressure detection part and a lubrication hydraulic pressure detection part, the oil storage section including a lubrication oil storage chamber in which a suction section of the lubrication oil pump is opened, and a working oil storage chamber in which a suction section of the working oil pump is opened, and oil overflowed from the working oil storage chamber being stored in the lubrication oil storage chamber.

Abstract: A multiplate friction clutch includes: a pressure plate having a boss portion which penetrates a clutch center; a clutch lifter plate joined to the boss portion and receiving a drive force in a axial direction at a time of disconnection between a friction plate and a clutch plate; and a spring sandwiched between the clutch lifter plate and the clutch center, and capable of generating an elastic force in a direction that the friction plate and the clutch plate are pressed to each other. A position restricting portion is provided on the clutch lifter plate, the position restricting portion being brought into contact with the boss portion from an outside in a radial direction of the clutch lifter plate so as to restrict a position of the clutch lifter plate with respect to the pressure plate.

Abstract: A clutch actuator structure provided for an internal combustion engine and a hydraulic clutch mechanism for transmitting a rotational driving force of a crankshaft of said engine includes a clutch actuator for controlling an oil pressure for engaging and disengaging the hydraulic clutch mechanism. The clutch actuator structure ensures that noises generated at the times of operation of the clutch actuator for actuating a hydraulic clutch are prevented from being transmitted to the exterior. The clutch actuator structure includes an oil sump part for reserving oil provided in the periphery of a clutch actuator. The clutch actuator is disposed in the oil sump part.

Abstract: A power unit for a vehicle includes an engine that is a power source, a gear shift apparatus, a twin clutch type transmission that intermittently switches power transmission between the engine and the gear shift apparatus, and a clutch actuator that controls intermittent switching of the twin clutch type transmission, the engine includes a crankcase and a pair of cylinders installed on the crankcase so that a V-bank is formed therebetween, and the clutch actuator is installed on the cylinders so that the clutch actuator overlaps a region of the V-bank.

Abstract: A transmission that reduces the difference of rotational speed when engaging a main shaft-side sprocket and a main shaft-outer shaft, in a low-speed traveling mode. When shifting from first gear to neutral in the transmission, a dog on a drive gear is engaged with a dog hole in a main shaft-side sprocket, engagement between a dog on a driven gear for first gear and a dog hole in a driven gear is released, and then a first clutch and a second clutch are disconnected with the drive gear and the main shaft-side sprocket being engaged.

Abstract: A gear-shifting mechanism driving device for allowing a speedy and accurate gear-shifting operation has a light weight even in the case where a shift spindle is short. The gear-shifting mechanism driving device includes a transmission for selectively establishing a gear combination by the turning of a shift spindle for turning a master arm, and an actuator as a power source for turning the shift spindle, in which the gear-shifting mechanism driving device includes a reduction gear shaft provided in a power transmission path between the actuator and the shift spindle, a first gear provided on one end side of the reduction gear shaft to receive power from the actuator side, and a second gear provided on another end side of the reduction gear shaft to transmit power to the shift spindle side. The reduction gear shaft is made of a torsion bar.

Abstract: A transmission of an internal combustion engine in which the shaft length of a main shaft can be shortened to eliminate a supporting wall around a reduction gear while a thrust load is received. Around a main shaft of a transmission of an internal combustion engine, a primary bearing is fastened to an inside of a primary driven gear, and is disposed between the primary driven gear and the main shaft. A collar member is disposed between the primary bearing and a main bearing. A step portion, in contact with the main bearing, is formed on the main shaft on an opposite side of the main bearing from the collar member. A cylindrical portion, an inner race of the primary bearing, the collar member, and an inner race of the main bearing are fastened to the side of the step portion.

Abstract: A variable speed drive wherein an impact to be transmitted to an inputting mechanism is absorbed. A shift spindle has an input side end portion to which an inputting mechanism is connected and an output side end portion supported for rotation at a transmission side supporting portion provided on a transmission case. A master arm is positioned between the input side end portion and the output side end portion in an axial direction of the shift spindle. An extension collar member is fixed integrally to the master arm. The extension collar member connects the master arm and a connection portion provided at a location of the shift spindle rather near to the input side end portion than the output side end portion. The extension collar member extends from the connection portion toward the master arm with a gap left from an outer circumferential face of the shift spindle.

Abstract: The clutch device includes, a right pressure flange that brings clutch discs provided on a clutch outer and clutch plates provided on a clutch inner into pressure contact with one another. A pressure ring that moves the right pressure flange with an external force and a clutch spring transmits the force toward a clutch connected position, from the pressure ring to the right pressure flange. Further, a return spring between the clutch inner and the right pressure flange urges the right pressure flange toward a clutch disconnected position. The clutch spring and the return spring are disposed parallel to a clutch axial direction, their respective positions overlapping each other in the clutch axial direction.

Abstract: A saddle-type vehicle that allows common use of a handle switch with a vehicle having no advancing-backing function and can suppress increase in the number of switches and the lowering of the layout efficiency of the switches. A saddle-type vehicle has a reverse mode setting input part that sets a reverse mode in which backing driving of the saddle-type vehicle is permitted and a control system that disables shift operation of a transmission by a shift-down switch and a shift-up switch and causes the saddle-type vehicle to advance through operation of the shift-down switch and to back through operation of the shift-up switch when the reverse mode is set.

Abstract: An internal combustion engine which can be miniaturized, even where it includes an oil filter between a hydraulic clutch and an oil pump, without significantly increasing the length of an oil passage for the hydraulic clutch, the oil pump and a hydraulic pressure adjustment apparatus. A second oil filter is provided on an oil pan at a lower portion of the internal combustion engine so as to be disposed at a position at which the second oil filter does not overlap with any of a controlling oil pump and a hydraulic pressure adjustment apparatus as viewed in side elevation and which is lower than those of the oil pump and the hydraulic pressure adjustment apparatus.

Abstract: A transmission for a vehicle has a main shaft and a counter shaft, which are supported in a transmission case by bearings. Gears on the main shaft and gears on the counter shaft include: shifter gears which are not rotatable but axially movable relative to the shaft, and fixed gears which are rotatable but not axially movable relative to the shaft. Dog clutches are provided between the shifter gears and the fixed gears, and outer races of the bearings supporting the main and counter shafts are affixed to the transmission case. Vibration-absorbing elastic members are pressed against the outer races from axially outside and are set to have a volume of 50% or more of the volume of the outer races. With such configuration, the vibration of the bearings supporting both the main and counter shafts of the transmission is attenuated, and striking noise caused by shifting is reduced.

Abstract: A saddle-riding type vehicle wherein an electric power transmission apparatus is rendered compact and a clearance is kept between a front wheel and a shift motor in a structure wherein a change mechanism and the shift motor are disposed in a forward direction of a power unit. A change mechanism for selectively establishing a gear stage of a transmission and a shift motor for supplying rotational power to the change mechanism are disposed in a forward direction of a power unit. A speed reducer gear mechanism for reducing the speed of the rotational power from the shift motor is disposed in a forward direction of a transmission compartment. The shift motor is disposed such that a main motor body thereof is positioned rearwardly of the speed reducer gear mechanism.

Abstract: A main shaft side sprocket wheel and a countershaft side sprocket wheel are provided for relative rotation on the shafts with a chain wrapped around and extended between the sprocket wheels. One of the driven gears is a floating gear provided for relative rotation on the countershaft. The countershaft side sprocket wheel is provided for integral rotation with the floating gear. The main shaft includes a main shaft inner shaft which includes the main shaft side sprocket wheel, and an outer pipe disposed coaxially on the outer side of the main shaft inner shaft in a diametrical direction and capable of being placed into and out of integral rotation with the main shaft side sprocket wheel. A reverse transmission gear for meshing with a driven gear is provided on the outer pipe. A reduction gear ratio by the floating gear or the reverse transmission gear is set higher than 1.