A parallel or redundant hybrid drive of a marine drivetrain of a propulsion unit includes an input shaft, which is configured to be driven by a primary drive source; a clutch unit attached to the input shaft with which rotation of the input shaft can be either connected, reversed, or disconnected; a countershaft transverse to the input shaft and driven by the input shaft via a gear; and a secondary drive source arranged via an interconnected clutch at an end of the countershaft, so that upon driving of the input shaft by the primary drive source, the secondary drive source drives the countershaft either on its own or in cooperation with the primary drive source.

A marine propeller propulsion unit has a compound planetary gear for driving a propeller, a propulsion motor for driving the compound planetary gear, and a housing for enclosing the propulsion motor and the compound planetary gear. The compound planetary gear comprises a sun gear, a ring gear, a planet carrier, a first planet gear and a second planet gear. The radius of the second planet gear exceeds the radius of the first planet gear and the first and second planet gears are rotationally fixed to one another. The ring gear meshes with the first planet gear and the sun gear meshes with the second planet gear. The sun gear is adapted to be connected to the propulsion motor and the ring gear is adapted to be connected to the propeller.

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.

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.

The planetary gearset has different areas of use. Transmissions are intended for example for marine propulsion device. A main planetary gearset that connects the input shaft to the output shaft so as to drive the output shaft into forward rotation. A complementary planetary gearset together with the main planetary gearset that connect the input shaft to the output shaft so as to drive the output shaft into reverse rotation. A forward brake engages the main planetary gearset in a forward gear wherein the main planetary gearset drives the output shaft into the forward rotation. A reverse brake engages the complementary planetary gearset in a reverse gear wherein the complementary planetary gearset together with the main planetary gearset drive the output shaft into the reverse rotation.

A drive unit for a marine vessel has an elongated drive unit body arranged to support a propeller shaft at a lower end and a motor interface at an upper end of the drive unit body, where the propeller shaft extends in a center plane of the drive unit. A drive shaft is arranged extending from the motor interface through the drive unit body to a bevel gear arrangement arranged to rotatably connect the drive shaft to the propeller shaft. The bevel gear arrangement has a first bevel gear arranged on the drive shaft and a second bevel gear arranged on the propeller shaft to cooperate with the first bevel gear. The drive unit has an oil channel with an aperture arranged to steer a flow of oil to flow away from the propeller shaft upwards through the drive unit body.