Abstract: A straddle type vehicle is provided with a body frame of a vehicle, a bar handle provided in a front portion of the vehicle body frame, a steering shaft transmitting a turning operation of the bar handle to a pair of right and left front wheels, and an electric power steering apparatus mounted in an intermediate portion of the steering shaft for assisting a steering motion of the bar handle. The electric power steering apparatus includes, in a state of the vehicle capable of being traveled, an electric power steering main body including an electric motor, a gear unit, an input shaft and an output shaft, an upper steering shaft in which the bar handle is attached to an upper end portion and an upper end of the input shaft is connected to a lower end portion, and a support member supporting the upper steering shaft.

Abstract: A straddle type vehicle with an electric power steering apparatus includes a vehicle body frame, a bar handle disposed in a front portion of the vehicle body frame, a steering shaft transmitting a turning operation of the bar handle to a pair of right and left front wheels, an electric power steering apparatus mounted in an intermediate portion of the steering shaft for assisting a steering motion of the bar handle, and an engine unit mounted in a center lower portion of the vehicle body frame in rear of the steering shaft. The electric power steering apparatus includes an electric motor arranged in front of the steering shaft.

Abstract: A straddle type vehicle with an electric power steering apparatus includes a vehicle body frame, a bar handle disposed in a front portion of the vehicle body frame, a steering shaft transmitting a turning operation of the bar handle to a pair of right and left front wheels, an electric power steering apparatus mounted in an intermediate portion of the steering shaft for assisting a steering motion of the bar handle, and an engine unit mounted in a center lower portion of the vehicle body frame in rear of the steering shaft. The electric power steering apparatus includes an electric motor arranged in front of the steering shaft.

Abstract: A straddle type vehicle is provided with a body frame of a vehicle, a bar handle provided in a front portion of the vehicle body frame, a steering shaft transmitting a turning operation of the bar handle to a pair of right and left front wheels, and an electric power steering apparatus mounted in an intermediate portion of the steering shaft for assisting a steering motion of the bar handle. The electric power steering apparatus includes, in a state of the vehicle capable of being traveled, an electric power steering main body including an electric motor, a gear unit, an input shaft and an output shaft, an upper steering shaft in which the bar handle is attached to an upper end portion and an upper end of the input shaft is connected to a lower end portion, and a support member supporting the upper steering shaft.

Abstract: In a motorcycle, a crankshaft and a balancer shaft are supported on a matching surface between a cylinder block and a crankcase, the balancer shaft is arranged above a crankshaft, auxiliary devices of a engine unit are placed in front of and behind the balancer shaft, the auxiliary devices with smaller outer diameters among the auxiliary devices are arranged in front of the balancer shaft, the auxiliary devices with larger outer diameters are arranged behind the balancer shaft, and an oil filter is provided in a lower portion of the cylinder block.

Abstract: An engine unit for a vehicle comprises an engine case in which a crankshaft and a counter shaft are rotatably supported and an oil pump is provided so that rotation of the crankshaft is transmitted to the counter shaft. The counter shaft serves as a driving shaft of the oil pump arranged to be coaxial with the counter shaft. The oil pump has a pump case, which is provided with a tubular engaging member concentrically surrounding the counter shaft to extend in an axial direction thereof and with a discharge passage extending so as to be apart from the counter shaft in the axial direction thereof. The tubular engaging member is fitted into a fitting hole for a counter shaft bearing and the discharge passage having an end portion fitted into an oil supply port formed in the engine case.

Abstract: An engine unit of a motorcycle generally include a cylinder head, a cylinder block formed with a cylinder bore therein, a crankcase and a rear case sequentially assembled in this order from a front side of a motorcycle body. A crankshaft is pivoted to a mating face between the cylinder block and the crankcase, a counter shaft which is rotated with the crankshaft in an interlocking manner is pivoted to a mating face between the crankcase and the rear case. These two mating faces lie in planes parallel to each other so as to be substantially perpendicular to a center axis of the cylinder bore of the cylinder block.

Abstract: In a motorcycle in which an engine unit is mounted to a motorcycle body and a power transmission unit coupled to the engine unit is arranged to the motorcycle body to be swingable through a pivot shaft, a rear wheel suspension system is formed so as to include the power transmission unit, a pair of arm members disposed to lateral side portions of the motorcycle body in parallel to each other, and connection members connecting both end portions of the arm members. One of the arm members constitutes the power transmission unit which has an inner hollow portion in which a power transmission member is accommodated and has a structure dividable into lateral two parts forming an arm base section and a cover section.

Abstract: A power unit of the motorcycle is provided with an engine unit in which a counter shaft is pivoted to a rear portion in a casing of an engine body provided with a crankshaft disposed along a motorcycle body width direction and a bracket having a fitting hole extending rearward so as to pass through in the width direction is formed in a rear portion outside the casing, a transmission unit and a bevel unit which are pivoted in a manner to be independent from the engine unit. One side surface of a front portion of the transmission unit is fixed to one side surface of a rear portion of the casing in the engine unit so as to connect the counter shaft to the input shaft to be integrally rotatable, the same side surface of the rear portion in the transmission unit is fitted and fixed to one side surface of the bracket so as to fit and fix the bevel unit to another side surface of the bracket. Thus, the output shaft is connected to a bevel input shaft to be integrally rotatable.

Abstract: An engine unit for a vehicle comprises an engine case in which a crankshaft and a counter shaft are rotatably supported and an oil pump is provided so that rotation of the crankshaft is transmitted to the counter shaft. The counter shaft serves as a driving shaft of the oil pump arranged to be coaxial with the counter shaft. The oil pump has a pump case, which is provided with a tubular engaging member concentrically surrounding the counter shaft to extend in an axial direction thereof and with a discharge passage extending so as to be apart from the counter shaft in the axial direction thereof. The tubular engaging member is fitted into a fitting hole for a counter shaft bearing and the discharge passage having an end portion fitted into an oil supply port formed in the engine case.

Abstract: In a motorcycle in which an engine unit is mounted to a motorcycle body and a power transmission unit coupled to the engine unit is arranged to the motorcycle body to be swingable through a pivot shaft, a rear wheel suspension system is formed so as to include the power transmission unit, a pair of arm members disposed to lateral side portions of the motorcycle body in parallel to each other, and connection members connecting both end portions of the arm members. One of the arm members constitutes the power transmission unit which has an inner hollow portion in which a power transmission member is accommodated and has a structure dividable into lateral two parts forming an arm base section and a cover section.

Abstract: In a motorcycle, a crankshaft and a balancer shaft are supported on a matching surface between a cylinder block and a crankcase, the balancer shaft is arranged above a crankshaft, auxiliary devices of a engine unit are placed in front of and behind the balancer shaft, the auxiliary devices with smaller outer diameters among the auxiliary devices are arranged in front of the balancer shaft, the auxiliary devices with larger outer diameters are arranged behind the balancer shaft, and an oil filter is provided in a lower portion of the cylinder block.

Abstract: An engine unit of a motorcycle generally comprises a cylinder head, a cylinder block formed with a cylinder bore therein, a crankcase and a rear case sequentially assembled in this order from a front side of a motorcycle body. A crankshaft is pivoted to a mating face between the cylinder block and the crankcase, a counter shaft which is rotated with the crankshaft in an interlocking manner is pivoted to a mating face between the crankcase and the rear case. These two mating faces lie in planes parallel to each other so as to be substantially perpendicular to a center axis of the cylinder bore of the cylinder block.

Abstract: A power unit of the motorcycle is provided with an engine unit in which a counter shaft is pivoted to a rear portion in a casing of an engine body provided with a crankshaft disposed along a motorcycle body width direction and a bracket having a fitting hole extending rearward so as to pass through in the width direction is formed in a rear portion outside the casing, a transmission unit and a bevel unit which are pivoted in a manner to be independent from the engine unit. One side surface of a front portion of the transmission unit is fixed to one side surface of a rear portion of the casing in the engine unit so as to connect the counter shaft to the input shaft to be integrally rotatable, the same side surface of the rear portion in the transmission unit is fitted and fixed to one side surface of the bracket so as to fit and fix the bevel unit to another side surface of the bracket. Thus, the output shaft is connected to a bevel input shaft to be integrally rotatable.

Abstract: A power assist bicycle includes a front wheel and a rear wheel, a bicycle body frame supporting the front and rear wheels to be rotatable, a saddle mounted to the bicycle body frame on which a rider rides, and a pair of pedals which are operatively connected to each other through a crank shaft, and the bicycle body frame includes a head pipe supporting the front wheel, a main pipe extending obliquely downward in a rearward direction from the head pipe, and a saddle pipe supporting the saddle at an upper end portion thereof in a standing attitude of the bicycle.

Abstract: A power assist apparatus of a power assisted bicycle comprises a crank shaft to be driven for rotation by a pedaling force, an electric motor for generating an assisting power, a force composition device for composing the pedaling force and the assisting power to output a composed force thereof to a driving wheel side and at the same time for generating two thrust component forces having magnitude proportional to pedaling force and assisting power, a thrust component force magnitude difference detector for detecting the difference in magnitude between the two thrust component forces, and a controller for controlling an output of the electric motor so as to bring the difference in magnitude between the two thrust component forces to "0" and to an optional magnitude difference based on an input from the thrust component force magnitude difference detector.

Abstract: A two-and-four-wheel drive shifting system of the type not including a differential gear unit comprises a pair of output shafts extending opposedly from each other and mounted rotatably independently of each other, an input member mounted concentrically and rotatably on one end of one of the pair of output shafts, and a sliding clutch mounted operatively on the other of the pair of output shafts. The sliding clutch having an engagement claw adapted to commonly engage with claws provided on one output shaft and on an input member in such a manner that the sliding clutch may be shifted in sliding motion in the axial direction along the other output shaft so as to selectively engage and disengage with either of the output shafts and the input member so that either the two-wheel or four-wheel drive position can be selected.

Abstract: An improved power transmission system for use with a light saddle-type vehicle with an internal combustion engine of cross-mounted type has an improved construction such that there are provided a split type crank case adapted to be split generally centrally into two counterparts in the vertical way, an output shaft mounted on the bottom of and extending along a splitting line of the crank case, and a bevel gear transmission disposed intermediate the output shaft and a secondary drive shaft so that the driving power on the secondary drive shaft from the engine may be transmitted operatively to the output shaft through the bevel gear transmission, and/or that there is provided an auxiliary transission mounted outwardly of an outer bearing means of the transmission housed in the case, and adapted to provide a substantially large overall gear ratio making an increased stage of gear shifting available in the operation of the vehicle, whereby the maneuverability of the vehicle can be improved substantially.

Abstract: An off-road vehicle is equipped with an endless articulated steel band drive system including a drive wheel, a plurality of idle wheels and an endless belt extending around the drive wheel and the idle wheel. A back slider plate extends along the inner surface of the endless belt to urge the ground contact surface of the endless belt against the ground. The leading portion of the back plate rises upwardly at an angle of with respect to the ground. One of the idle wheels is rotatably mounted to the rear end of the back plate and the back plate is mounted to the vehicle frame by a leaf spring.

Abstract: A steering apparatus for a four-wheel motorcar of the saddle-ride type having two front wheels and two rear wheels, each wheel being fitted with a balloon tire, a front axle steerably supporting the front wheels, a car body connected together in an integral manner by a support frame, a steering shaft connected to the front wheels through a linkage mechanism, and a bearing portion in a head pipe rotatably supporting the upper end portion of the steering shaft integral with said support frame, the lower end portion of the steering shaft being rotatably supported by the front axle.