Yamaha Hatsudoki Kabushiki Kaisha

Nobuaki Karaki

Hidetoshi Kageyama

Junichi Mitani

A balancer of an engine includes a rod and a balancer piston. A first end portion of the rod includes a joining portion which is arranged to be joined to a crankshaft of the engine at a position that is eccentric relative to a rotation axis of the crankshaft. A second end portion of the rod is arranged to reciprocate inside a cylinder according to a rotation of the crankshaft. The balancer piston is fixed to the second end portion of the rod. The balancer piston is arranged to reciprocate inside the cylinder, while rocking between a contact state in which the balancer piston is in contact with an inner wall surface of the cylinder and a non-contact state in which the balancer piston is separated from the inner wall surface. The balancer piston includes a cylindrical outer peripheral portion that is curved so as to swell toward the inner wall surface. The outer peripheral portion is arranged such that lines of intersection with planes perpendicular or substantially perpendicular to a central axis of the balancer piston define circles. The outer peripheral portion includes a contact start portion which is arranged to come into contact first with the inner wall surface when the balancer piston switches from the non-contact state to the contact state. A distance from a center of a maximum outer diameter circle with the largest radius among the circles to the contact start portion is larger than the radius of the maximum outer diameter circle.

Balancer of engine, engine, and outboard motor

A compact supercharged internal combustion engine, wherein the supercharger is mounted above the twin overhead cam cylinder head of the engine but is readily detachable from it. The drive for the pumping elements of the supercharger including counter rotating shafts to which balance masses are added so as to assist in engine balancing. In addition to supplying compressed air to the combustion chambers of the engine for combustion, the supercharger also supplies air to an air injection system that cooperates with the exhaust system for reducing the emissions of undesirable pollutants to the atmosphere.

Growing community of inventors

Shizuoka, Japan

Nobuaki Karaki