Abstract: An engine is disposed with a crankshaft axially oriented in the longitudinal direction of the vehicle body. A camshaft and an exhaust port in a cylinder head are disposed parallel to the crankshaft. The exhaust port is open at the front surface of the cylinder head, and discharges exhaust gases through an exhaust pipe. Hoses extend from a radiator in front of the engine to the front surface of the engine. A valve case is disposed on a left side of a cylinder block in the vicinity of the exhaust port to which the exhaust pipe is connected, and is connected to an air cleaner behind the engine by a substantially straight secondary air pipe.

Abstract: A compact transmission for an internal combustion engine in a saddle ride type vehicle for operating on wasteland that effectively utilizes space and enables members to be laid out freely. A transmission for internal combustion engine, includes a crankshaft disposed in parallel to the operating direction of a vehicle body. A forward-running/backward-running changeover mechanism is provided wherein the supply sources of a working oil and a lubricating oil for an automatic transmission are arranged concentratedly on the side of a front crankcase cover. The changeover mechanism is provided between a rear crankcase and a rear crankcase cover. A forward-running/backward-running changeover shift drum is disposed on the upper side of a plane containing the axis of a main shaft and the axis of a counter shaft of the transmission. One end portion of a shift spindle projects from the rear crankcase cover at a position on a lateral side of the shift drum.

Abstract: A hydraulic clutch and a torque converter, a crank web or an alternator provided in separate locations, except opposite positions, for avoiding interference. A crankcase is provided in a transmission for transmitting the revolution of the torque converter to a crankshaft to a main shaft via a gear. Shifting speed in three steps is achieved by a gear provided on the main shaft and a counter shaft and the hydraulic clutch for connecting or disconnecting the gear. One hydraulic clutch is arranged on a main shaft outside a pair of supports for supporting the main shaft, two gears are fixed to the main shaft inside the supports for supporting the main shaft and on both sides close to the support. The two gears engaged with the two gears and hydraulic clutches for connecting or disconnecting each gear are arranged between the two gears.

Abstract: To provide a lubricating oil supply structure for an internal combustion engine, which requires no lubricating oil passage to be defined in a crankshaft, is capable of ejecting lubricating oil to a lubrication object, is free of limitations on the layout of the generator and peripheral devices, is capable of cooling generating coils of the generator, and allows the area of the lubrication object to which the lubricating oil is applied to be set with large freedom. A lubricating oil supply structure for an internal combustion engine has a generator having a stator with generating coils and a rotor. A one-way clutch is disposed opposite to the stator across the rotor. The lubricating oil supply structure includes a first nozzle disposed on a stator support of a generator cover for continuously ejecting lubricating oil. The lubricating oil is ejected from the first nozzle to the one-way clutch through holes which are disposed in a position confronting the one-way clutch in an ejected direction.

Abstract: In an engine with a torque converter for a saddle seat or buggy-type vehicle, a crankshaft and a shift drum placed approximately in parallel to a longitudinal direction of a vehicle are rotatably supported by a crankcase. The torque converter is provided on one end of an extension section of the crankshaft at an outer section of the crankcase. A double rotor type oil pump and a water pump are installed on the engine without enlarging a width of the engine. The lengths of piping to an oil cooler or radiator arranged in a front section of a vehicle body is made shortest. A part of the oil pump is overlapped with the shift drum and the torque converter, when viewed from the front of the engine. The oil pump is driven by chains from the crankshaft and is arranged in a space between an outer surface of the crankcase and the torque converter in a longitudinal direction.

Abstract: An internal combustion engine including a torque converter on a crankshaft, and a single oil passage provided in the crankshaft for supplying, in common, both a working oil for the torque converter and a lubricating oil for the engine. A pump impeller of the torque converter is fixed to the crankshaft, and a clutch for connection and disconnection of engine output is provided on the side of a transmission.

Abstract: To enhance productivity and maintainability of an internal combustion engine for a vehicle with a torque converter. An internal combustion engine with a torque converter includes a single feed pump for supplying both a working oil for a torque converter and a lubricating oil for the engine with an oil filter in communication with a discharge port of the feed pump being fitted to a crankcase cover. An outlet oil passage of the oil filter is branched into a low-pressure oil passage provided with an orifice and an oil passage for supplying a high-pressure control oil to changeover valves of a transmission. The high-pressure oil passage is provided concentratedly in the crankcase cover.

Abstract: A compact transmission for an internal combustion engine in a saddle ride type vehicle for operating on wasteland that effectively utilizes space and enables members to be laid out freely. A transmission for internal combustion engine, includes a crankshaft disposed in parallel to the operating direction of a vehicle body. A forward-running/backward-running changeover mechanism is provided wherein the supply sources of a working oil and a lubricating oil for an automatic transmission are arranged concentratedly on the side of a front crankcase cover. The changeover mechanism is provided between a rear crankcase and a rear crankcase cover. A forward-running/backward-running changeover shift drum is disposed on the upper side of a plane containing the axis of a main shaft and the axis of a counter shaft of the transmission. One end portion of a shift spindle projects from the rear crankcase cover at a position on a lateral side of the shift drum.

Abstract: Supplying fluids different in pressure from one end of a revolving shaft without providing a diagonal hole in the revolving shaft for supply holes for feeding hydraulic fluid and lubricating oil. The time for manufacturing and the cost of providing a hydraulic fluid feeder to the revolving shaft is reduced. A hydraulic fluid feeder includes a central hole provided on the centerline of the revolving shaft. Hollow tubes having a smaller outside diameter than the inside diameter of the central hole are concentrically inserted into the central hole and the central hole is partitioned. Either of the passages formed by partitioning functions as a hydraulic fluid supply passage for the hydraulic equipment and the other functions as a hydraulic fluid supply passage for another piece of hydraulic equipment or a lubricating oil supply passage for a bearing provided on the revolving shaft.

Abstract: A transmission of an internal combustion engine is used in a saddle-type vehicle (buggy) for running on rough terrain. A crankshaft of the vehicle is arranged so that it is parallel with the traveling direction of the body. The transmission includes a mechanism for switching a gear for forward travel and a gear for backward travel. At least a part of the mechanism for switching the gear for forward travel and the gear for backward travel is provided between a crankcase and a crankcase cover. At least one of shafts forming the switching mechanism is partially overlapped with a main shaft or a counter shaft in the axial direction.

Abstract: An output shaft structure enabling easy and secure positioning of an output shaft for a shaft driven vehicle having an internal combustion engine. The output shaft structure provides first and second cases which mutually connect on a face perpendicular to a crankshaft and form a crankcase, a case cover attached to the outside of the first case and the output shaft arranged in the crankcases and supported by a first bearing provided to the case cover and a second bearing provided to the first case. Also provided is an input gear for the output shaft arranged so that it touches the outside face of the second bearing. Further, the output shaft is provided with a first large diameter part positioned by touching the inside face of the first bearing, and a second large diameter part positioned by touching the outside face of the input gear.

Abstract: A hydraulic clutch and a torque converter, a crank web or an alternator provided in separate locations, except opposite positions, for avoiding interference. A crankcase is provided in a transmission for transmitting the revolution of the torque converter to a crankshaft to a main shaft via a gear. Shifting speed in three steps is achieved by a gear provided on the main shaft and a counter shaft and the hydraulic clutch for connecting or disconnecting the gear. One hydraulic clutch is arranged on a main shaft outside a pair of supports for supporting the main shaft, two gears are fixed to the main shaft inside the supports for supporting the main shaft and on both sides close to the support. The two gears engaged with the two gears and hydraulic clutches for connecting or disconnecting each gear are arranged between the two gears.

Abstract: In an oil passage structure in a rotary shaft, including two systems of oil passages different in pressure that are provided extending from both ends of the shaft, the rotary shaft is provided with oil supply holes in the radial direction of the shaft for connection between a center hole in the shaft and locations to be supplied with oil. The oil supply holes are bored from the outside of the shaft. At this time, burrs are generated at end portions of the oil supply holes on the side fronting on the center hole. Where the depth of the shaft center hole is a dead end, removal of the burrs is not easy. The shaft center hole is used as an oil passage wherein burrs, if any, in the hole can be easily removed. The two oil passages are in communication with each other through a communication passage smaller than the oil passages in diameter. The smaller-diameter communication passage is closed by pressing a steel ball therein, thereby making both of the oil passages independent from each other.

Abstract: To provide a lubricating oil supply structure for an internal combustion engine, which requires no lubricating oil passage to be defined in a crankshaft, is capable of ejecting lubricating oil to a lubrication object, is free of limitations on the layout of the generator and peripheral devices, is capable of cooling generating coils of the generator, and allows the area of the lubrication object to which the lubricating oil is applied to be set with large freedom. A lubricating oil supply structure for an internal combustion engine has a generator having a stator with generating coils and a rotor. A one-way clutch is disposed opposite to the stator across the rotor. The lubricating oil supply structure includes a first nozzle disposed on a stator support of a generator cover for continuously ejecting lubricating oil. The lubricating oil is ejected from the first nozzle to the one-way clutch through holes which are disposed in a position confronting the one-way clutch in an ejected direction.

Abstract: A dry-sump lubrication unit for an internal combustion engine for a vehicle. A crankshaft of the vehicle is disposed so as to be parallel with the direction of travel of the vehicle, and in a position offset from a center of the vehicle when viewed from the front or back of the vehicle. A transmission shaft is disposed on the other side thereof. An oil tank is disposed in a crankcase located substantially at the lower center of the crankcase when viewed from the front or back of the vehicle on the rear side with respect to the traveling direction, and/or in a space between the crankcase and a rear case cover. Oil pumps are disposed forwardly of the oil tank. An oil injection pipe extends from the oil tank toward the side surface thereof on the transmission side. The resulting configuration prevents variations in liquid surface of lubricating oil of the vehicle internal combustion engine due to shaking of the vehicle body, and makes it possible to downsize the entire power unit.

Abstract: To provide a motive-power transmission device for a vehicle including a torque converter, a gearbox, and a clutch for cutting off the transmission of motive power between the input shaft of the gearbox and the turbine of the torque converter. The gearbox is accommodated in the crankcase, and the motive-power transmission device is compact in the axial direction of the crankshaft. A motive-power transmission device for a vehicle includes the crankshaft and the input shaft of the gearbox journaled freely rotatably in the crankcase, their axes being parallel to each other; the torque converter is mounted on one end portion of the crankshaft; and the clutch is separated along the axial direction of the crankshaft from the torque converter and so mounted on one end portion of the input shaft that part of the clutch overlaps the torque converter as seen in the axial direction of the crankshaft.

Abstract: In a power transmission apparatus for a vehicle having a gear transmission capable of transmitting power from a crankshaft of an engine to driving wheels by selectively establishing a plurality of shift stages of gear trains and a clutch for cutting power transmission from the crankshaft to the gear transmission in operating to shift the power transmission, when the clutch is operated to cut or connect in cooperation with the shift operation of the gear transmission, shift operability is promoted while avoiding an increase in weight. A gear transmission is shifted by a first actuator and a clutch is driven by a second actuator which is independent of the first actuator.

Abstract: An oil separating chamber for separating oil contained in blow-by gas is arranged outside a transmission member passage connecting a crank shaft with a cam shaft of a valve system and at an abutting surface between a cylinder block and a cylinder head. Partition walls perpendicular to the abutting surface for dividing the oil separating chamber into a plurality of small subchambers are alternatively arranged at the cylinder block and the cylinder head to form a labyrinth structure. The small subchamber at one end of the plurality of small subchambers is provided with a blow-by gas intake passage communicated with the transmission member passage. The small subchamber at the other end is provided with a blow-by gas exhaust passage for returning blow-by gas to an air cleaner. Each of the small subchambers not provided with the blow-by gas intake passage is provided with an oil return passage communicating with the transmission member passage.

Abstract: An engine crankshaft 2 and a wheel drive shaft 5 are connected through a static hydraulic infinitely variable transmission 3. The static hydraulic infinitely variable transmission 3 has a hydraulic pump 20 extending to an engine side of the transmission and a hydraulic motor 21 extending to a wheel drive shaft 5 side of the transmission and connected together using a closed hydraulic circuit. A control clutch 18 is fitted in the transmission system between the hydraulic motor 21 and the wheel drive shaft 5 so that the control clutch is disengaged when the engine is idling and when operation is suspended.

Abstract: To provide a power unit mounted for a vehicle, such as a motorcycle, wherein the power unit is attached to a transmission actuating device or attached to a clutch actuating device, or attached to both actuating units. A power unit for a vehicle having an internal combustion engine mounted in a condition where a crank shaft is oriented in the longitudinal direction of the vehicle body, and having a transmission arranged behind the internal combustion engine, wherein one or both of a transmission actuating electric motor for driving an transmission actuating device of the transmission and a clutch actuating electric motor for driving a clutch actuating device of a clutch are arranged in a rear section of said power unit.