Yamaha Hatsudoki Kabushiki Kaisha

Kenichi Sakurai

Masahiro Uchida

Tatsuo Niiyama

Kazutoshi Ueda

Makoto Kawamura

Yuichi Suzuki

Kaoru Okui

Masato Nishigaki

Tateo Aoyama

Masami Wada

Yoshihide Takano

Shigeo Yamamoto

An induction system for a multi valve engine that facilitates operation in a lean burn mode over a large range of speeds and loads by employing a smaller cross sectional branch passages in several induction passages serving a common combustion chamber and a valve arrangement that progressively opens flow first through the branch passages and finally through both the main and branch passages so that maximum power can also be obtained.

Engine induction system

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 number of embodiments of V-type internal combustion engines having an induction system which provides variable length sections for serving each combustion chamber, with each section being tuned to provide optimum charging efficiency for a different engine running speed. In addition, a flow-controlling valve is provided in the induction passages adjacent the combustion chamber and is movable between a nonrestricting flow position and a position wherein the flow is redirected to generate turbulence in the combustion chamber. The induction system is designed so as to provide a compact assembly and yet permit efficient induction and combustion under a wide range of engine speed and load conditions.

Intake control system

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

An improved water pump drive arrangement for an internal combustion engine, having an intermediate shaft. The water pump is driven from one of the flexible transmitters of the camshaft drive and is located in such an arrangement so as to function as an idler for the flexible transmitter and also to permit the water pump to be mounted at the end of the engine, although the flexible transmitters are spaced from the engine end.

Engine water pump drive

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

A multi-valve manifold injected internal combustion engine. The fuel injector has a spray pattern that is directed primarily toward each of the intake valve seats. An air control system is incorporated, however, that directs the airflow primarily toward the center intake valve seat under some running conditions so as to improve fuel stratification.

Fuel injected multi-valve engine

An in-line type multi-cylinder, double overhead cam, internal combustion engine having a balancer shaft arrangement that is driven directly off the crankshaft at a point intermediate of the ends of the crankshaft. To permit a more compact engine assembly, the balancer shaft also functions as an accessory drive shaft for driving a number of accessories including the camshafts of the engine.

Engine balancer shaft drive

An internal combustion engine having an improved accessory drive arrangement. A number of the engine accessories is driven off of an intermediate shaft that is driven from the crankshaft between its ends and which permits the driving of accessories at points on this intermediate shaft that are spaced inwardly from the ends of the crankshaft to provide a more compact assembly. This facilitates mounting of the engine in transverse engine fashion in the engine compartment of a motor vehicle since the accessory drives do not increase the overall length of the engine, particularly at its upper end.

Accessory drive arrangement for engine

A fuel injection system for a multi-valve internal combustion engine that includes an arrangement for controlling the fuel spray in response to engine load and speed. As a result, it is possible to obtain stratification under low-speed, low-load conditions and a homogeneous mixture under high-speed, high-load conditions.

Fuel-injected engine

Several embodiments of variable camshaft timing means for twin overhead cam engines. There is provided a first timing altering means between the engine output shaft and one of the camshafts and a second timing altering means that is operative between the one camshaft and the other camshaft. Both timing altering means are operated by the same hydraulic pressure in several embodiments and a locking device is incorporated so as to avoid self-induced timing adjustment due to the change in driving loads.

Valve timing retarding system

A V type engine embodying an improved oil separator for its crankcase ventilation system. The oil separator is contained within the valley between the banks of cylinders and has a simplified but effective arrangement for achieving separation.

Cooling system for vehicle

A cooling system and crankcase ventilating system for a V type internal combustion engine wherein the crankcase ventilating system includes a crankcase ventilating chamber that is positioned in the valley of the V of the engine. The cooling system includes a main coolant gallery that extends through the valley of the engine and is disposed between the crankcase ventilating chamber and the crankcase for cooling the crankcase ventilating gases. The main gallery also partially encircles the main oil gallery for cooling the lubricant.

Growing community of inventors

Iwata, Japan

Kenichi Sakurai