A modular drive apparatus includes a gear box (16) with a rotatable internal transmission gear (60). The gear box includes a plurality of body openings (44). The openings may be selectively closed by the installation of cover plates (52, 54). With a cover plate removed, a drive coupler (32, 34, 58, 148) may be extended in the respective opening and mounted in operative connection with the gear box. In the mounted position of the drive coupler, an idler gear (72, 172) engages the ring gear of the gear box. Rotatable power devices such as pumps, motors and generators may be operatively rotatably engaged with the drive coupler.

A marine propulsion unit includes a stern drive mounted to a transom. The stern drive comprises an upper unit enclosed in a stern drive housing and a lower unit enclosed in a gearbox housing; wherein the gearbox housing contains a gearbox arranged to drive at least one propeller. The propulsion unit further comprises at least two electric motors arranged in the stern drive housing, which electric motors are mounted with vertical output shafts; a planetary gear set arranged between the at least two electric motors and the gearbox, and a vertical shaft that is attached to a ring gear of the planetary gear set at its upper end and is connected to the gearbox at its lower end; wherein the output shaft of each electric motor is connected to a planetary gear arranged in the planetary gear set to drive the ring gear and the vertical shaft connected to the gearbox.

A reduction reverse gear according to the invention of the present application includes: an input shaft to which rotational driving force from a main engine is input; a front-reverse housing accommodating forward-backward switching mechanisms with which the rotational driving force from the input shaft is switched among forward, neutral, and backward; an output shaft through which the rotational driving force from the forward-backward switching mechanisms is output; and a reduction housing accommodating a reduction mechanism with which the rotational driving force from the output shaft is reduced to be transmitted to a propeller shaft. The housings are detachably coupled to each other on front and rear sides in an axial direction. The input shaft and the output shaft are arranged on the same plane while facing each other.

An outboard motor includes an engine, a propeller shaft that rotates together with a propeller and extends in a forward-rearward direction, and a lower case that houses the propeller shaft. The lower case includes a front case and a rear case separate from the front case and positioned rearward of the front case, and the front case and the rear case are assembled to each other.

A transmission for an outboard motor, the transmission having an input shaft with an input gear non-rotatably fixed thereto and rotatable by an engine. A countershaft has a countershaft driven gear and a reverse driving gear non-rotatably fixed thereto, where the countershaft driven gear meshes with the input gear. An output shaft has first and second driven gears non-rotatably fixed thereto. First and second driving gears mesh with the first and second driven gears, a reverse idler gear meshes with the reverse driving gear, and a reverse driven gear meshes with the reverse idler gear. First and second clutches selectively rotate the first and second driving gears with the countershaft in first and second modes at first and second speeds in forward rotation, respectively, and a reverse clutch selectively rotates the output shaft with the reverse driven gear in a reverse mode with reverse rotation.

The present invention relates to a gearbox system for mounting on a waterborne vessel with a hydrofoil, the gearbox system comprising:

a housing having an interior surface defining an interior space of defined dimension;
a gearing system comprising a propeller shaft engagement portion, the gearing system located within the interior of the housing; and
an engine located within the interior space of the housing and in mechanical communication with the gear box;
wherein the housing is water-tight and wherein the gearing system and engine are in thermal contact with the interior surface of the housing.

Further provided is a hydrofoil system including such a gearbox system and a waterborne vessel including such a hydrofoil system.

A marine propulsion system, supported by a strut, which comprises an inner propeller shaft supporting a first propeller adjacent a trailing end thereof, and the inner propeller shaft is connected to the drive shaft for receiving and supplying a first portion of torque to the first propeller as well as transfer thrust, generated by the first propeller, along the inner propeller shaft back to the drive shaft. An outer propeller shaft supports a second propeller adjacent a trailing end thereof, and the outer propeller shaft surrounds the inner propeller shaft. A planetary gear assembly receives a second portion of the torque and supplies the torque to the outer propeller shaft so that the second propeller rotates in an opposite direction to the first propeller. A portion of the planetary gear assembly is accommodated vertically above a flat end face of the strut for reducing hydrodynamic drag of the strut.

An outboard motor includes: an upper case supported on a hull; a lower case pivotably supported on the upper case; a first drive source disposed within the upper case; a planetary gear mechanism connected to the first drive source via an upper drive shaft; a propeller shaft connected to the planetary gear mechanism via a lower drive shaft; and a second drive source that provides the lower case with a torque. The planetary gear mechanism includes a sun gear, a planetary carrier supporting planetary gears and connected to an upper end of the lower drive shaft, and an internal gear. One of the sun gear and the internal gear is connected to the lower end of the upper drive shaft, and the other is connected to the lower case to provide the lower case with a torque in a direction opposite to a rotation direction of the lower drive shaft.

A hybrid propulsion system for a marine vessel is described. The hybrid propulsion system includes a shaft coupled to a propeller, a planetary gear system configured to operate in a first configuration and a second configuration, and a motor-generator. The motor-generator is configured to selectively rotate with and provide torque to the shaft through the planetary gear system in the first configuration and to rotate independently from the shaft in the second configuration. The shaft extends from the propeller through the planetary gear system and the motor-generator to a torque producing device for the marine vessel.

A power transmission device for an outboard motor, comprising a drive shaft, an endless loop flexible drive coupling and a propeller shaft, wherein the endless loop flexible drive coupling operatively connects said drive shaft to said propeller shaft for transferring output power from the drive shaft to the propeller shaft. The power transmission device comprises a first drive shaft, a second drive shaft, a first endless loop flexible drive coupling, a second endless loop flexible drive coupling, a first propeller shaft and a second propeller shaft, wherein the first propeller shaft is connected to the first drive shaft through the first endless loop flexible drive coupling to rotate the first propeller shaft in a first direction, and wherein the second propeller shaft is connected to the second drive shaft through the second endless loop flexible drive coupling to rotate the second propeller shaft in a second direction opposite to the first direction.