Abstract: A twin clutch type transmission connected to an engine of a vehicle and the like in which an end portion of the main shaft is held in the secure and compact manner to contribute to efficient operation of the transmission. In the twin clutch type transmission, the first and second hydraulic disk clutches are coaxially provided to be adjacent with each other, and the inner and outer shafts of the main shaft as a coaxial dual structure are connected to the respective disk clutches coaxially. The ball bearing fixed to the transmission case with the holder plate pierces the left end portion of the inner shaft so as to be supported, and further to be tightened and fixed to the ball bearing with the locknut screwed with the leading end of the left end portion.

Abstract: A shift control device for a vehicle transmission is provided in which drive means for making a shift drum pivot is connected to the shift drum, wherein the drive means (112) includes a power source (113) disposed on at one end, in the axial direction, of the shift drum (104), and a transmission shaft (117) to which power from the power source (113) is transmitted at the one end, in the axial direction, of the shift drum (104), power from the transmission shaft (117) being transmitted to the other end, in the axial direction, of the shift drum (104). This enables an internal combustion engine to be made compact while avoiding a concentrated disposition of the drive means on one side, in the axial direction, of the shift drum.

Abstract: A gear shift device is used in a transmission of an engine, and includes: a shift drum that changes a speed change stage of the transmission according to a rotational position about an axis; an actuator having a driving shaft substantially orthogonal to this shift drum; a worm shaped barrel cam that is arranged parallel to the driving shaft of this actuator and that has a cam groove on an outer circumference; and a wheel gear that is coaxially fixed on the shift drum and that has a plurality of pins on an outer circumference. At least a pair of each pin of the wheel gear and the cam groove of the barrel cam is engaged with each other, and the shift drum is rotated by the actuator via the barrel cam and the wheel gear, to thereby change the speed change stage of the transmission.

Abstract: This twin-clutch apparatus for use in a transmission of an engine, including: a hydraulic first disk clutch and second disk clutch that exert a predetermined engagement force by pressure members displaced in an axial direction by the pressure of a supply oil from outside, the first disk clutch and the second disk clutch being coaxially arranged adjacent to each other, in which: clutch plates of the first disk clutch and clutch plates of the second disk clutch are different in thickness from each other.

Abstract: A transmission is provided in which gear trains for multiple shift stages are provided between a countershaft and a first main shaft and second main shaft running coaxially and relatively rotatably through the first main shaft so that the gear trains can be alternatively established, wherein a plurality of odd number stage gear trains (G1, G3, G5) are provided between the second main shaft (27) and the countershaft (28) so that the first speed gear train (G1) is disposed on the opposite side to the first and second clutches (37, 38), an end part of the second main shaft (27) on the first speed gear train (G1) side is rotatably supported on an engine main body via a main shaft side ball bearing (31) having a larger diameter than an outer diameter of a first speed drive gear (89) provided integrally with the second main shaft (27), and an outer race (31a) of the main shaft side ball bearing (31) is fixed to the engine main body via a fixing plate (95) engaging with an outer peripheral part of the outer race (31

Abstract: A speed change control device for a transmission of an internal combustion engine includes a driving means having an electric motor for rotatably driving a shift drum. The electric motor has a rotation axis orthogonal to an axis of a shift drum. A barrel cam having a cam groove rotates about an axis parallel to that of the electric motor. A transmission rotation member is interlocked and is coupled to the shift drum so as to be rotatable about the axis orthogonal to the rotation axis of the barrel cam. The transmission rotation member is provided with a plurality of engagement pins that selectively engages the cam groove. The resulting configuration allows the electric motor to be disposed inwardly with respect to an outermost side of the body of the internal combustion engine in the direction of the axis of a shift drum and improves the shift accuracy.

Abstract: A power unit for a motorcycle includes an internal combustion engine provided with a crankcase rotatably supporting a crankshaft with an axial line extending in a vehicle-width direction. An oil pump is mounted on the crankcase with a balancer rotatably supported by the crankcase. Rotational power from the crankshaft is transmitted to a pump driven member provided on a pump shall of the oil pump and to a balancer driven member coaxially interlinked with and connected to the balancer so as to transmit power to the balancer. The power unit is downsized by bringing a balancer and an oil pump into a close arrangement. The pump driven member and the balancer driven member are offset from each other in a vehicle-width direction and are located at such a position so as to at least partially overlap each other as viewed from the side of the vehicle-width direction.

Abstract: An internal combustion engine includes a continuously variable transmission chamber formed of a crank case and a cover member connected to the crank case to permit the use of oil different between the internal combustion engine and the continuously variable transmission. Thereafter, a sufficient amount of each oil is ensured to not reduce the lowest road clearance. A division wall divides an interior of an oil pan into an internal combustion engine side oil reservoir and a continuously variable transmission side oil reservoir that reserves oil for lubrication of a continuously variable transmission and for speed control thereof, and which is connected to a lower portion of a crank case. The continuously variable transmission side oil reservoir is formed in a width direction of the motorcycle wherein part of continuously variable transmission side oil reservoir expands more outwardly than a continuously variable transmission chamber.

Abstract: A power unit includes an engine having a crankshaft, and a continuously variable transmission having a drive pulley operatively connected with the crankshaft, a driven pulley, and a belt extended between and wrapped around the drive pulley and the driven pulley. The power unit further includes a transmission input clutch, which allows or interrupts the transmission of a rotational drive force of the crankshaft to the drive pulley, mounted on a drive pulley shaft; and a starter clutch, which allows or interrupts the transmission of a rotational drive force of the driven pulley to the drive wheel, mounted on a driven pulley shaft. The transmission input clutch and the starter clutch are arranged such that a continuously variable transmission is sandwiched therebetween.

Abstract: A power unit for a motorcycle includes an internal combustion engine having a crankcase rotatably supporting a crankshaft with an axis located on a split face between an upper case half body and a lower case half body and a continuously variable transmission having a belt. Two types of respective different oils for an internal combustion engine and for a continuously variable transmission are used while the rigidity of the crankcase is enhanced. A crankcase is provided with a partition wall that separates between a crank chamber housing a crankshaft and a continuously variable transmission chamber housing a continuously variable transmission. An axial line of the crankshaft and respective axial lines of the drive pulley and the driven pulley are each located at a corresponding one of apexes of an imaginary triangle on a view projected on a plane perpendicular to the axial line of the crankshaft.

Abstract: This twin-clutch apparatus for use in a transmission of an engine, including: a hydraulic first disk clutch and second disk clutch that exert a predetermined engagement force by pressure members displaced in an axial direction by the pressure of a supply oil from outside, the first disk clutch and the second disk clutch being coaxially arranged adjacent to each other, in which: clutch plates of the first disk clutch and clutch plates of the second disk clutch are different in thickness from each other.

Abstract: A motorcycle is provided with a compact, lightweight power unit that allows for increased maneuverability and increased bank angles while turning. The power unit includes an engine and transmission integrated into a single unit. Often, the balance and maneuverability of a motorcycle are influenced by the heaviest components of the vehicle, such as the engine or power unit. The present advantage is accomplished by providing the power unit with a water pump, oil pump and transmission which are balanced on the motorcycle, limiting the weight variations and protrusions from the motorcycle. This results in allowing the motorcycle to achieve greater bank angles for better turning speeds and maneuverability. It desirable to keep the vehicle center of gravity as low as possible in a motorcycle which is likely to lean steeply around corners. The present arrangement provides the vehicle with a lower center of gravity thereby increasing maneuverability.

Abstract: A gear shift device is used in a transmission of an engine, and includes: a shift drum that changes a speed change stage of the transmission according to a rotational position about an axis; an actuator having a driving shaft substantially orthogonal to this shift drum; a worm shaped barrel cam that is arranged parallel to the driving shaft of this actuator and that has a cam groove on an outer circumference; and a wheel gear that is coaxially fixed on the shift drum and that has a plurality of pins on an outer circumference. At least a pair of each pin of the wheel gear and the cam groove of the barrel cam is engaged with each other, and the shift drum is rotated by the actuator via the barrel cam and the wheel gear, to thereby change the speed change stage of the transmission.

Abstract: A shift control device for a vehicle transmission is provided in which drive means for making a shift drum pivot is connected to the shift drum, wherein the drive means (112) includes a power source (113) disposed on at one end, in the axial direction, of the shift drum (104), and a transmission shaft (117) to which power from the power source (113) is transmitted at the one end, in the axial direction, of the shift drum (104), power from the transmission shaft (117) being transmitted to the other end, in the axial direction, of the shift drum (104). This enables an internal combustion engine to be made compact while avoiding a concentrated disposition of the drive means on one side, in the axial direction, of the shift drum.

Abstract: A transmission is provided in which gear trains for multiple shift stages are provided between a countershaft and a first main shaft and second main shaft running coaxially and relatively rotatably through the first main shaft so that the gear trains can be alternatively established, wherein a plurality of odd number stage gear trains (G1, G3, G5) are provided between the second main shaft (27) and the countershaft (28) so that the first speed gear train (G1) is disposed on the opposite side to the first and second clutches (37, 38), an end part of the second main shaft (27) on the first speed gear train (G1) side is rotatably supported on an engine main body via a main shaft side ball bearing (31) having a larger diameter than an outer diameter of a first speed drive gear (89) provided integrally with the second main shaft (27), and an outer race (31a) of the main shaft side ball bearing (31) is fixed to the engine main body via a fixing plate (95) engaging with an outer peripheral part of the outer race (31

Abstract: A power unit for a motorcycle includes an internal combustion engine having a crankcase rotatably supporting a crankshaft with an axis located on a split face between an upper case half body and a lower case half body and a continuously variable transmission having a belt. Two types of respective different oils for an internal combustion engine and for a continuously variable transmission are used while the rigidity of the crankcase is enhanced. A crankcase is provided with a partition wall that separates between a crank chamber housing a crankshaft and a continuously variable transmission chamber housing a continuously variable transmission. An axial line of the crankshaft and respective axial lines of the drive pulley and the driven pulley are each located at a corresponding one of apexes of an imaginary triangle on a view projected on a plane perpendicular to the axial line of the crankshaft.

Abstract: A power unit for a motorcycle includes an internal combustion engine provided with a crankcase rotatably supporting a crankshaft with an axial line extending in a vehicle-width direction. An oil pump is mounted on the crankcase with a balancer rotatably supported by the crankcase. Rotational power from the crankshaft is transmitted to a pump driven member provided on a pump shall of the oil pump and to a balancer driven member coaxially interlinked with and connected to the balancer so as to transmit power to the balancer. The power unit is downsized by bringing a balancer and an oil pump into a close arrangement. The pump driven member and the balancer driven member are offset from each other in a vehicle-width direction and are located at such a position so as to at least partially overlap each other as viewed from the side of the vehicle-width direction.

Abstract: A motorcycle is provided with a compact, lightweight power unit that allows for increased maneuverability and increased bank angles while turning. The power unit includes an engine and transmission integrated into a single unit. Often, the balance and maneuverability of a motorcycle are influenced by the heaviest components of the vehicle, such as the engine or power unit. The present advantage is accomplished by providing the power unit with a water pump, oil pump and transmission which are balanced on the motorcycle, limiting the weight variations and protrusions from the motorcycle. This results in allowing the motorcycle to achieve greater bank angles for better turning speeds and maneuverability. It desirable to keep the vehicle center of gravity as low as possible in a motorcycle which is likely to lean steeply around corners. The present arrangement provides the vehicle with a lower center of gravity thereby increasing maneuverability.

Abstract: An internal combustion engine includes a continuously variable transmission chamber formed of a crank case and a cover member connected to the crank case to permit the use of oil different between the internal combustion engine and the continuously variable transmission. Thereafter, a sufficient amount of each oil is ensured to not reduce the lowest road clearance. A division wall divides an interior of an oil pan into an internal combustion engine side oil reservoir and a continuously variable transmission side oil reservoir that reserves oil for lubrication of a continuously variable transmission and for speed control thereof, and which is connected to a lower portion of a crank case. The continuously variable transmission side oil reservoir is formed in a width direction of the motorcycle wherein part of continuously variable transmission side oil reservoir expands more outwardly than a continuously variable transmission chamber.

Abstract: A power unit includes an engine having a crankshaft, and a continuously variable transmission having a drive pulley operatively connected with the crankshaft, a driven pulley, and a belt extended between and wrapped around the drive pulley and the driven pulley. The power unit further includes a transmission input clutch, which allows or interrupts the transmission of a rotational drive force of the crankshaft to the drive pulley, mounted on a drive pulley shaft; and a starter clutch, which allows or interrupts the transmission of a rotational drive force of the driven pulley to the drive wheel, mounted on a driven pulley shaft. The transmission input clutch and the starter clutch are arranged such that a continuously variable transmission is sandwiched therebetween.