Yamaha Hatsudoki Kabushiki Kaisha

Sanshin Kogyo Kabushiki Kaisha

Kenji Yukishima

Kimitaka Saruwatari

Makoto Mizutani

Hiroyuki Suzuki

Toshio Suzuki

Noriyuki Natsume

Akihiro Noma

Hiroyuki Tsunekawa

Yuki Ikegaya

Junya Onoue

Yu Wakamizu

Koma Ariga

Manabu Yamamoto

Shunsuke Yukawa

Isao Tateishi

Ryo Nakanishi

An outboard motor includes a drive shaft, a coupling to connect a first shaft and a second shaft of the drive shaft together, and a transmission including a dog clutch to transmit a rotation of the drive shaft to a propeller shaft. The coupling includes a first portion attached to the first shaft, a second portion attached to the second shaft, and a damper. The first portion includes first claws arranged along a rotation direction of the drive shaft. The second portion includes second claws between adjacent ones of the first claws in the rotation direction. The damper includes an elastic portion interposed between adjacent ones of the first claws and the second claws in the rotation direction.

Outboard motor

A marine propulsion device includes an engine, an exhaust pipe to allow exhaust gas of the engine to pass through the exhaust pipe, and a cooling water supply passage to supply cooling water for the engine into the exhaust pipe toward a downstream side in a flow direction of the exhaust gas and cause the cooling water to flow circumferentially along an inner peripheral surface of the exhaust pipe.

Marine propulsion device and marine vessel

An outboard motor includes a shaft including a second spline that upwardly extends from a housing. The second spline is meshed with a first spline disposed inside either an engine cowl or an upper housing. The second spline includes a distal end and a body. The distal end is provided on an upper end of the shaft. The body is provided below the distal end. In the second spline, a groove width in the circumferential direction at the distal end is larger than a groove width in the circumferential direction at the body.

Outboard motor and method of manufacturing shaft for outboard motor

In an outboard motor, a damper includes a bushing fixed to a periphery of a propeller shaft. The damper includes a second pressing surface that presses a first pressing surface of an inner surface of a cylinder in a circumferential direction, an elastic member disposed around a portion of the bushing different from the second pressing surface of the bushing, and a reinforcer disposed between the first pressing surface and the second pressing surface.

Outboard motor and damper for propeller unit

A boat propulsion system includes a drive bevel gear fixed on a lower end of a drive shaft, a forwarding bevel gear and a reversing bevel gear rotatably fitted on a propeller shaft and meshing together with the drive bevel gear, and a dog clutch mounted on the propeller shaft and rotatable with the propeller shaft, moves in an axial direction of the propeller shaft, and meshes together with the forwarding bevel gear or the reversing bevel gear to rotate the propeller shaft, in which the propeller shaft comes in contact with the forwarding bevel gear via a forwarding side buffer member having a disc spring as a component member. The boat propulsion system prevents and minimizes sound and impact even when variations in thrust force occur.

Boat propulsion system

An exhaust system for an outboard motor includes an improved construction that can be compact enough for the limited space afforded within a powerhead of an outboard motor. The outboard motor includes an engine and a support member arranged to support the engine. The engine includes a cylinder block that defines a plurality of cylinder bores. The cylinder bores extend generally horizontally and spaced apart vertically from each other to form a cylinder bank extending generally vertically. At least two exhaust manifolds extend generally vertically aside and along the cylinder bank. Pistons reciprocate within the cylinder bores. A cylinder head closes ends of the cylinder bores to define combustion chambers together with the cylinder bores and the pistons. The cylinder head further defines at least one exhaust port per each one of the combustion chambers. Exhaust passages communicate with the exhaust ports. The exhaust passages are coupled with the exhaust manifolds so that at least one of the exhaust passages is allotted to each one of the exhaust manifolds.

Exhaust system for outboard motor

An engine decompression device includes an improved construction to release at an exceedingly slow engine speed. The engine has a camshaft that actuates at least one exhaust valve and extends generally vertically. The decompression device has an actuator mounted on the camshaft for pivotal movement about a pivot axis extending generally normal to an axis of the camshaft. The actuator includes a cam section that holds the exhaust valve in an open position and a sinker section that moves with centrifugal force produced by relatively slow rotation of the camshaft so as to release the cam section from holding the exhaust valve open.

Growing community of inventors

Shizuoka, Japan

Kenji Yukishima