Sanshin Kogyo Kabushiki Kaisha

Sanshin Industries Co., Ltd.

Yasushi Iriono

Hiroshi Harada

Yoshitsugu Sumino

Takashi Iwashita

Yoshitugu Sumino

Mitsunori Suzuki

A propulsion system includes an improved propeller design which increases the durability of the propeller for enhanced rotational vibration damping, while simplifying the structure of the propeller. A rubber coupling is placed within a space that is secured between a propeller hub and an inner member of the propeller. The rubber coupling resiliently couples the propeller hub to the inner member with only the inner member and the propeller hub maintaining the space in which the rubber coupling is placed. The substantially constant size of the space generally isolates the rubber coupling from cyclic tension and compression stresses in the axiel and radial directions as the propeller rotates to improve the durability of the rubber coupling.

Propulsion system for marine drive

A marine propulsion device improves the handling characteristics and the responsiveness of the watercraft on which it is used. The propulsion device includes a pair of counter-rotating propellers. At least the blades of the front propeller each have a mean camber line in cross-section which has a generally constant radius of curvature. This blade shape reduces cavitations and permits the rear propeller to be mounted closer to the front propeller, and consequently closer to the steering axis of the outboard drive. As a result, steering torque is reduced. The blades of the rear propeller also are not more than thirty percent smaller than the blades of the front propeller, and the average pitches of the propellers do not differ by more than one to four percent. These blade configurations of the front and rear propellers improve the stability of the watercraft when turning, thereby reducing chine walk, as well as improve the responsiveness of the watercraft.

Marine propulsion device

A propulsion unit for watercraft that employs a pair of counter-rotating propellers disposed one in front of the other in order to improve the performance upon acceleration, a cavitation effect is generated around at least one of the propellers at least during acceleration. Various ways in which this can be done employing the exhaust gases from the powering internal combustion engine for driving the propellers are illustrated.

Propulsion system for marine vessel

A tandem propeller assembly for use with a marine propulsion unit is disclosed wherein a single shock-absorber assembly is utilized to assure damping effects for both propellers so as to protect the propulsion system from being damaged when either propeller is obstructed by drifting wood or other debris. Each of the preferred embodiments disclosed provides a simple structure for absorbing impacts upon either propeller in a tandem propeller assembly while minimizing any increase in the surface area of contact with the water which would increase the propulsion resistance and would result in speed loss.

Growing community of inventors

Hamamatsu, Japan

Yasushi Iriono