Yamaha Hatsudoki Kabushiki Kaisha

Tatsuo Niiyama

Masahiro Uchida

Kenichi Sakurai

Kazuo Shimada

Tetsushi Saito

Minoru Yonezawa

An improved compact oil pump drive arrangement for an internal combustion engine having an auxiliary shaft that is driven by the crankshaft. The oil pump is driven by an oil pump drive shaft that is disposed between the auxiliary shaft and the crankshaft by a helical gear arrangement. The auxiliary drive shaft is also driven by a helical gear arrangement, and the helical gears on the auxiliary drive shaft are of appropriate hands so as to balance the axial thrusts on the auxiliary drive shaft.

Oil pump drive for engine

A two-stage cam shaft drive arrangement for an internal combustion engine employing a pair of flexible transmitters. The two-stage mechanism is driven by an intermediate shaft that is driven off of the crankshaft at a point between its ends. Flexible transmitter tensioners are engaged with the flexible transmitters on the side away from the cylinder block for ease of accessibility and to maintain a more compact engine configuration.

Engine cam shaft drive arrangement

A compact arrangement for an inline multiple-cylinder engine for driving a pair of twin overhead camshafts. The camshafts are driven by a drive that includes an intermediate shaft and at least a portion of the drive and the intermediate shaft is accessible through one or more openings formed in the side of the engine body. A manifold is also provided on this side of the engine and is configured so that it does not substantially obstruct the openings.

Timing case cover for engine

An improved camshaft and accessory drive arrangement for a V type engine wherein pairs of overhead cams are driven from the crankshaft by means of intermediate shafts that are directly driven by the crankshaft. The axis of rotation of the intermediate shafts is disposed closer to the axis of rotation of the crankshaft than the axes of rotation of the camshafts. An accessory is positioned in the valley of the V and is also driven by the crankshaft but is spaced further from the crankshaft axis of rotation than the intermediate shafts. This accessory is a water pump and an oil pump is also driven by the crankshaft at the same end of the engine.

Camshaft and accessory drive arrangement for engine

A camshaft drive arrangement for a V type engine having a pair of flexible transmitters that drive intermediate shafts which, in turn, drive respective camshafts associated with the respective cylinder banks. A combined flexible transmitter and guide member is disposed between the flexible transmitters that drive the intermediate shafts for tensioning one of these flexible transmitters and acting as a guide for the other of them.

Growing community of inventors

Iwata, Japan

Tatsuo Niiyama