Abstract: A bearing structure of a crankshaft in an internal combustion engine supports a crankshaft on a crankcase with rolling bearings includes a play absorbing device for absorbing the play in the radial direction generated between an outer race of the rolling bearing and a bearing hole of the crankcase. The play absorbing device includes a push plug which pushes an outer race of the ball bearing in the direction perpendicular to an axis of the crankshaft. The push plug is arranged in parallel to the crankshaft between the cylinder and the crankshaft. The outer race of the ball bearing is resiliently biased toward a side of the bearing hole of the crankcase which receives an explosion pressure. As a result, the generation of a hitting sound which is attributed to the above-mentioned “play” can be largely reduced even with respect to an internal combustion engine with a high explosion pressure.

Abstract: A bearing structure of a crankshaft in an internal combustion engine supports a crankshaft on a crankcase with rolling bearings includes a play absorbing device for absorbing the play in the radial direction generated between an outer race of the rolling bearing and a bearing hole of the crankcase. The play absorbing device includes a push plug which pushes an outer race of the ball bearing in the direction perpendicular to an axis of the crankshaft. The push plug is arranged in parallel to the crankshaft between the cylinder and the crankshaft. The outer race of the ball bearing is resiliently biased toward a side of the bearing hole of the crankcase which receives an explosion pressure. As a result, the generation of a hitting sound which is attributed to the above-mentioned “play” can be largely reduced even with respect to an internal combustion engine with a high explosion pressure.

Abstract: To provide a multi-cylinder engine for a vehicle, in which a pair of cylinder bore rows, each including a plurality of cylinder bores disposed in parallel to each other, are disposed in such a manner as to be perpendicular to a crank shaft disposed substantially in the horizontal direction. Accordingly, a relatively large space can be ensured under a cylinder head. Cam shafts corresponding to cylinder bore rows are disposed over a pair of planes containing the axial lines of cylinder bores constituting the cylinder bore rows, respectively.

Abstract: To provide a multi-cylinder engine for a vehicle, in which a pair of cylinder bore rows, each including a plurality of cylinder bores disposed in parallel to each other, are disposed in such a manner as to be perpendicular to a crank shaft disposed substantially in the horizontal direction. Accordingly, a relatively large space can be ensured under a cylinder head. Cam shafts corresponding to cylinder bore rows are disposed over a pair of planes containing the axial lines of cylinder bores constituting the cylinder bore rows, respectively.

Abstract: To provide a multi-cylinder engine for a vehicle, in which a pair of cylinder bore rows, each including a plurality of cylinder bores disposed in parallel to each other, are disposed in such a manner as to be perpendicular to a crank shaft disposed substantially in the horizontal direction. Accordingly, a relatively large space can be ensured under a cylinder head. Cam shafts corresponding to cylinder bore rows are disposed over a pair of planes containing the axial lines of cylinder bores constituting the cylinder bore rows, respectively.

Abstract: A multi-cylinder engine in which a transmission mechanism is provided between a cam shaft linked with intake valves and exhaust valves and a crank shaft rotatably supported by a crank case and a plurality of bearing caps, wherein the transmission mechanism is configured as a chain-type transmission mechanism for making the engine compact. The restriction on the rotatably supporting position of a chain tensioner is moderated and the length of the chain tensioner is set at a relatively large value. The transmission mechanism is configured such that an endless chain, is wound around a drive sprocket, fixed on a crank shaft and a driven sprocket, fixed on a cam shaft. One end portion in the longitudinal direction of a chain tensioner, extending in the running direction of the chain is rotatably supported on one of the plurality of bearing caps in such a manner as to be elastically, slidably in contact with the chain.

Abstract: A horizontally-opposed type engine for a motorcycle, in which a pair of left and right cylinder heads are connected to a pair of left and right cylinder blocks in such a manner that combustion chambers are formed between each of the cylinder blocks containing a plurality of cylinder bores disposed in parallel with the axial lines thereof extending substantially in the horizontal direction and pistons slidably fitted in the cylinder bores; a crank shaft is disposed in such a manner as to be perpendicular to the axial lines of the cylinder bores; and the engine is mounted on the motorcycle with the axial line of the crank shaft extending in the longitudinal direction, wherein the restriction to the bank angle of the motorcycle given by the exhaust pipes is made small and thereby the bank angle is easily ensured.

Abstract: Rocker arm clearance removing device wherein a hydraulic adjuster applies torque to a pressure bearing surface at right angles thereto on a curved outwardly extending pressure bearing arm of an eccentric cam which eccentrically supports the rocker arm. Rotation of the rocker arm resulting from the torque causes the rocker arm to come into pressure contact with a valve operating cam and an intake or exhaust valve. An engaging piece can be provided radially extending from the eccentric cam circumferentially spaced from the pressure bearing arm for engaging a swivel stop on the case of the hydraulic adjuster to limit swinging of the eccentric cam and rocker arm during assembly. An arm stopper can also be provided on the case of the hydraulic adjuster to prevent swinging of cam and rocker arm in the opposite direction during assembly.

Abstract: A valve train for an internal combustion engine includes a mounting member mounted on a cylinder head, and a pair of elongated rocker arms interposed between a camshaft and the mounting member. Each rocker arm has opposite first and second sides facing a camshaft and the mounting member, respectively. The rocker arm has opposite ends held respectively against the camshaft and a respective one of intake and exhaust valves at the first side of the rocker arm. A pair of hydraulic tappets are mounted on the mounting member. Each hydraulic tappet includes an axially-extensible elongated body, and a tubular boot of an elastic material mounted around the body to form an oil reservoir therebetween.

Abstract: A hydraulic lash adjuster of the closed-type including a closed cylinder with a plunger positioned therein defining a hydraulic chamber at the closed end of the cylinder. An annular diaphragm extending between the cylinder and the plunger as a reservoir. A passage provides communication between the reservoir and the hydraulic chamber with a check valve preventing flow from the hydraulic chamber to the reservoir. A passageway extends axially through the plunger and is closed off by means of a soft plug in an area of greater diameter intermediate the ends of the passageway. Retainers hold the annular diaphragm in place with the retainer associated with the plunger extending inwardly to the plunger within the diaphragm to conserve on axial length of the mechanism.