Yamaha Hatsudoki Kabushiki Kaisha

Yamaha Marine Kabushiki Kaisha

Tadatsugu Yamamura

Yasuhiko Henmi

Tatsuya Yoshida

An impeller for a jet propulsion device includes at least one fluid channel formed on each impeller blade. During impeller rotation, a fluid back-flow is generated through the fluid channels. The back-flow advantageously sweeps cavitation bubbles away from the impeller blades and inhibit their implosion on the blade surfaces and/or inner housing surface which lies adjacent the blade tips. This desirably reduces erosion and provides a long-life and efficient propulsion device.

Impeller for marine propulsion device

An exhaust system for a watercraft includes a water trap arranged on a first side of a hull tunnel, a discharge port arranged on a second side of the hull tunnel, and a chamber branched from and communicating with an exhaust passage connecting the watertrap with the discharge port.

Growing community of inventors

Shizuoka, Japan

Tadatsugu Yamamura