Sanshin Kogyo Kabushiki Kaisha

Yamaha Hatsudoki Kabushiki Kaisha

Takashi Iwashita

Ryoji Nakahama

Hideo Suzuki

Hiroshi Ogino

Masafumi Sougawa

Hiroshi Harada

Shinya Atsumi

Yasushi Iriono

Tamotsu Suzuki

Toyoshi Suzuki

Yoshitugu Sumino

A propeller thrust transmission device includes a taper portion of a propeller shaft that is fitted in a spacer divided into a first half and a second half. A thrust force acting on a propeller is received by the taper portion of the propeller shaft through the spacer. The first half includes a taper hole having an inner surface which corresponds in shape to an outer surface of the taper portion and in which the taper portion is fitted. The second half has a smaller diameter portion extending from one side of a ring-shaped wall portion closer to the propeller and fitted in a hole of an attachment device spaced from the propeller shaft, and a larger diameter portion extending from the other side of the ring-shaped wall portion and fitted on an outer peripheral surface of the first half.

Propeller thrust transmission device for a watercraft propulsion device

An exhaust system for an marine drive discharges exhaust gases between front and rear propellers of a counter-rotating propeller system. The discharge of exhaust gases between the propellers produces a cavitation effect about the rear propeller when accelerating from low speeds. As a result, the drive of the propellers accelerates more rapidly. At high speeds, however, the velocity of the exhaust gases carries the gases over the rear propeller principally in the vicinity of the rear propeller hub. No substantial cavitation effect occurs about the blades of the rear propeller at high speeds. As a result, the discharge of exhaust gases between the propellers causes no significant loss of propulsion efficiency when traveling at high speeds.

Exhaust system for outboard drive

A lower unit of a marine outboard drive has a unique shape which inhibits boundary layer separation within the water flow stream over the lower unit regardless of the trim position of the lower unit. The lower unit includes a nacelle. The front nose of the nacelle blends smoothly into a supporting strut in a vertical direction to form a generally teardrop-like cross-sectional shape. The front end of the strut fairs the nacelle body from its sharp leading edge to give the lower unit a streamline shape at trim angles approaching a full trim up position of the lower unit. The leading edge of the strut also slopes rearward away from the front nose of the nacelle. The shape of this junction between the upper side of the nacelle and the strut front end gives the front end of the lower unit a generally constant streamline shape as the lower unit rotates through a range of trim angle positions.

Lower-unit for marine outboard drive

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 battery system for use in connection with a pair of marine propulsion units, one of which is powered by an internal combustion engine that drives a generator and the other of which is actuated by an electric motor. A pair of actuating batteries are in circuit with the electric motor and the generator and are adapted to selectively provide power to the electric motor or receive a charge from the generator in response to a main switch which is also used to control the starting of the internal combustion engine. A pair of contact relays, responsive to the main switch, are used to adjust the circuitry of the battery system so that the actuating batteries are either connected in parallel in the charging state or connected in series in the actuating state.

Battery system for marine propulsion unit

Embodiments of outboard motors incorporating improved exhaust gas systems for preventing the ingestion of water into the cylinders of an alternate firing multiple chamber internal combustion engine. The exhaust passages are provided with a restricted communication with each other at a point that is above the water under all running conditions so as to prevent water ingestion. In one embodiment, the exhaust passages communicate with an above the water exhaust gas discharge independently of each other and the restricted communication is provided between the passages by a restricted opening in an exhaust pipe. In another embodiment, the exhaust pipe forms an expansion chamber and the individual exhaust passages communicate with this expansion chamber at points close to each other through restricted openings for providing the communication.

Exhaust system for outboard motor

A tilt locking and shock absorbing arrangement for a marine outboard drive embodying a single cylinder and piston assembly for controlling the tilt and trim positions of the drive and for further absorbing shocks applied to it. An accumulator arrangement is provided having gas over oil and is valved into the system in such a way as to prevent passage of the gas into the shock absorbing device per se. In addition, an arrangement is provided whereby the drive may be manually positioned without necessitating the operator's use of one hand to operate the mechanism when the desired position is reached.

Tilt lock mechanism for marine propulsion device

Several embodiments of improved detent devices for elements such as dog clutches. In each embodiment, the detent includes a holding detent for holding the dog clutch in a neutral position and an accelerating detent for accelerating the dog clutch element to its engaged position. In each embodiment, the accelerating detent is effective before the holding detent has been fully released. In some embodiments, the dog clutch element is axially movable and in other embodiments it is rotatable.

Detent mechanism for clutches

A tilt locking and shock absorbing arrangement for a marine outboard drive embodying a single cylinder and piston assembly for controlling the tilt and trim positions of the drive and for further absorbing shocks applied to it. An arrangement is provided whereby the trim position may be manually controlled without necessitating the operator's use of one hand to operate the mechanism when the desired position is reached. Popping up action is permitted in either normal or shallow water conditions but inadvertent popping up under shallow water, reverse drive is precluded.

A tilt-lock mechanism for a vertically tiltable outboard stern drive on a marine vessel preferably includes a hydraulic cylinder device dampingly connecting the drive unit and the vessel. The mechanism preferably includes apparatus allowing the operator to selectively prevent or allow the drive unit to freely tilt under various operating conditions.

Growing community of inventors

Hamamatsu, Japan

Takashi Iwashita