Abstract: A gear position of a multi-position transmission, which shifts and drives a vehicle according to a turn motion of a shift drum, is detected by a plurality of sensors. An end portion of the shift drum is fitted with an end portion of an elongated shaft rotated coaxially with the shift drum. A first sensor which is fitted to other end portion of the elongated shaft detects a turn position of the elongated shaft. A second sensor which is located outside in a radial direction of the elongated shaft between the one end portion and the other end portion of the elongated shaft detects that the elongated shaft is located at a specified turn position. The first sensor and the second sensor are fitted from the outside of a transmission case of the multi-position transmission and are exposed to the outside of the transmission case.

Abstract: A gear position of a multi-position transmission, which shifts and drives a vehicle according to a turn motion of a shift drum, is detected by a plurality of sensors. An end portion of the shift drum is fitted with an end portion of an elongated shaft rotated coaxially with the shift drum. A first sensor which is fitted to other end portion of the elongated shaft detects a turn position of the elongated shaft. A second sensor which is located outside in a radial direction of the elongated shaft between the one end portion and the other end portion of the elongated shaft detects that the elongated shaft is located at a specified turn position. The first sensor and the second sensor are fitted from the outside of a transmission case of the multi-position transmission and are exposed to the outside of the transmission case.

Abstract: A power transmission device includes an input rotary member having a pressing portion, and an output rotary member having a receiving portion to be pressed by the pressing portion. The input rotary member forces the output rotary member to rotate when resilient members disposed between the input rotary member and the output rotary member are deformed by predetermined amounts.

Abstract: A power transmission device includes an input rotary member having a pressing portion, and an output rotary member having a receiving portion to be pressed by the pressing portion. The input rotary member forces the output rotary member to rotate when resilient members disposed between the input rotary member and the output rotary member are deformed by predetermined amounts.

Abstract: An overhead-camshaft internal combustion engine having an outer wall of a crankcase provided adjacent a crankshaft, with a spiral-surfaced opening through which the crankshaft is passed. The outer crankcase wall is integrally provided with a loop guide engaging recess formed thereon. The loop guide engaging recess supports a base end portion of a loop guide for guiding an endless chain. A loop-retaining member for preventing the timing endless chain from dropping is arranged at a position on the lower side of a loop drive sprocket integrally formed at an end portion of the crankshaft.

Abstract: A power unit includes a shaft member rotatably supported by the crankcase and a torsional coil spring, disposed at one end of the shaft member, biasing a swing arm in one rotational direction. An oil strainer is fixed to the crankcase through a strainer support bracket extending vertically relative to a strainer element. The torsional coil spring includes a coil portion wound around the shaft member, one end portion retained on the side of the shaft member, and the other end portion retained by a retaining portion formed integrally with the strainer support bracket.

Abstract: A breather structure for internal combustion engine, the structure making a breather chamber smaller and thus making an internal combustion engine as a whole smaller. A breather chamber and a small chamber are formed. The breather chamber includes a first side face cover. The first side face cover is joined to a case to cover a first one of the right and left side faces of the case. Inside the first side face cover, an auxiliary apparatus chamber is formed. The auxiliary apparatus chamber houses a clutch mechanism connecting or disconnecting the power transmission route. Additionally, formed inside a housing are an external communication port communicating to the outside of the housing, and the small chamber communicating to a crank chamber and to the auxiliary apparatus chamber. Moreover, the auxiliary apparatus chamber communicates to the breather chamber.

Abstract: An internal combustion engine including a transmission for transmitting power from a crankshaft to an output shaft through speed change, with the speed change in the transmission being performed by the driving of a speed change electric motor through a speed change drive mechanism, wherein power transmission control means for controlling the transmission of power from the crankshaft to the transmission is provided at one end of the crankshaft, and at least a part of the speed change electric motor and the speed change drive mechanism is disposed on the outside of the power transmission control means. This configuration of the internal combustion engine is reduced in size because of the layout of the speed change drive mechanism and the speed change electric motor.

Abstract: A gearshift position detector, for a transmission component of a powertrain unit including an engine and a transmission, includes first and second actuator arms for cooperatively interacting with neutral and reverse indicator switches. The neutral and reverse indicator switches are mounted to a crankcase or a crankcase cover of the engine. The acutator arms are selectively operable to trip the respective switches, and thereby, to generate signals for alerting a vehicle operator that the transmission is in neutral or reverse. The actuator arms are operatively attached to a shift drum skip-turn-prevention plate which, in turn, is secured to an axial end surface of a shift drum. The indicator switches are, respectively, capable of being energized upon interaction between the corresponding actuator arm and the switch. In this configuration, the main components of the detector are housed within the crankcase, thereby saving space in the vicinity of the engine.

Abstract: An overhead-camshaft internal combustion engine having an outer wall of a crankcase provided adjacent a crankshaft, with a spiral-surfaced opening through which the crankshaft is passed. The outer crankcase wall is integrally provided with a loop guide engaging recess formed thereon. The loop guide engaging recess supports a base end portion of a loop guide for guiding an endless chain. A loop-retaining member for preventing the timing endless chain from dropping is arranged at a position on the lower side of a loop drive sprocket integrally formed at an end portion of the crankshaft.

Abstract: A breather structure for internal combustion engine, the structure making a breather chamber smaller and thus making an internal combustion engine as a whole smaller. A breather chamber and a small chamber are formed. The breather chamber includes a first side face cover. The first side face cover is joined to a case to cover a first one of the right and left side faces of the case. Inside the first side face cover, an auxiliary apparatus chamber is formed. The auxiliary apparatus chamber houses a clutch mechanism connecting or disconnecting the power transmission route. Additionally, formed inside a housing are an external communication port communicating to the outside of the housing, and the small chamber communicating to a crank chamber and to the auxiliary apparatus chamber. Moreover, the auxiliary apparatus chamber communicates to the breather chamber.

Abstract: A power unit includes a shaft member rotatably supported by the crankcase and a torsional coil spring, disposed at one end of the shaft member, biasing a swing arm in one rotational direction. An oil strainer is fixed to the crankcase through a strainer support bracket extending vertically relative to a strainer element. The torsional coil spring includes a coil portion wound around the shaft member, one end portion retained on the side of the shaft member, and the other end portion retained by a retaining portion formed integrally with the strainer support bracket.

Abstract: An internal combustion engine including a transmission for transmitting power from a crankshaft to an output shaft through speed change, with the speed change in the transmission being performed by the driving of a speed change electric motor through a speed change drive mechanism, wherein power transmission control means for controlling the transmission of power from the crankshaft to the transmission is provided at one end of the crankshaft, and at least a part of the speed change electric motor and the speed change drive mechanism is disposed on the outside of the power transmission control means. This configuration of the internal combustion engine is reduced in size because of the layout of the speed change drive mechanism and the speed change electric motor.

Abstract: A power unit for a vehicle with an internal combustion engine including a cylinder block and a crankshaft. A speed change drive shaft is disposed at a position on the upper side of a static oil hydraulic type non-stage transmission and in parallel to the axis of the transmission. A plane connecting the axis of the speed change drive shaft and the axis of the transmission does not intersect with the axis of the crankshaft, and intersects with the axis of the cylinder center axis of the cylinder block at a position on the lower side of the axis of the crankshaft while making an acute angle with the axis of the cylinder center axis of the cylinder block.

Abstract: A shift position detection apparatus for a variable speed gear wherein a shift shaft is moved in an axial direction to perform a speed changing operation. A variable speed gear includes a clutch sleeve disposed for movement in an axial direction on a counter shaft with a shift shaft disposed so as to extend in parallel to the counter shaft. A shift fork is coupled and attached to the shift shaft and has an end engaged with the clutch sleeve. The clutch sleeve is moved in the axial direction through the shift fork to select a shift position. A shift position detection apparatus includes F, R and N shift detection portions provided on the shift fork. The F shift detection portion and the R shift detection portion are spaced by approximately 60 degrees in a circumferential direction on substantially the same plane perpendicular to the axis of a cylindrical portion.

Abstract: A gearshift position detector, for a transmission component of a powertrain unit including an engine and a transmission, includes first and second actuator arms for cooperatively interacting with neutral and reverse indicator switches. The neutral and reverse indicator switches are mounted to a crankcase or a crankcase cover of the engine. The acutator arms are selectively operable to trip the respective switches, and thereby, to generate signals for alerting a vehicle operator that the transmission is in neutral or reverse. The actuator arms are operatively attached to a shift drum skip-turn-prevention plate which, in turn, is secured to an axial end surface of a shift drum. The indicator switches are, respectively, capable of being energized upon interaction between the corresponding actuator arm and the switch. In this configuration, the main components of the detector are housed within the crankcase, thereby saving space in the vicinity of the engine.

Abstract: A shift position detection apparatus for a variable speed gear wherein a shift shaft is moved in an axial direction to perform a speed changing operation. A variable speed gear includes a clutch sleeve disposed for movement in an axial direction on a counter shaft with a shift shaft disposed so as to extend in parallel to the counter shaft. A shift fork is coupled and attached to the shift shaft and has an end engaged with the clutch sleeve. The clutch sleeve is moved in the axial direction through the shift fork to select a shift position. A shift position detection apparatus includes F, R and N shift detection portions provided on the shift fork. The F shift detection portion and the R shift detection portion are spaced by approximately 60 degrees in a circumferential direction on substantially the same plane perpendicular to the axis of a cylindrical portion.

Abstract: A power unit for a vehicle with an internal combustion engine including a cylinder block and a crankshaft. A speed change drive shaft is disposed at a position on the upper side of a static oil hydraulic type non-stage transmission and in parallel to the axis of the transmission. A plane connecting the axis of the speed change drive shaft and the axis of the transmission does not intersect with the axis of the crankshaft, and intersects with the axis of the cylinder center axis of the cylinder block at a position on the lower side of the axis of the crankshaft while making an acute angle with the axis of the cylinder center axis of the cylinder block.