Turning gear apparatus (10) for rotating a shaft (11) comprises a rotary drive arrangement (12) and a transmission system including a pivot arm (20). The rotary drive arrangement (12) is fixed, for example to a vessel hull (14), and the pivot arm (20) is pivotable between a first, shaft-disengaged, position and a second, shaft-engaged position where the rotary drive arrangement (12) is operably coupled to the shaft (11), thereby permitting control over rotation of the shaft (11) by the rotary drive arrangement (12).

The front sides of pinions are rotatably supported by a first case via first taper roller bearings, and the back sides of the pinions are rotatably supported by a second case via second taper roller bearings, and the back sides of input shafts are rotatably supported by a case cover via third taper roller bearings, and clutches and input gears are stored in the case cover, and sleeves are interposed between the first taper roller bearings and the front side of the pinions, and the pinions are configured to be inserted and extracted into/from the sleeves.

The front sides of pinions are rotatably supported by a first case via first taper roller bearings, and the back sides of the pinions are rotatably supported by a second case via second taper roller bearings, and the back sides of input shafts are rotatably supported by a case cover via third taper roller bearings, and clutches and input gears are stored in the case cover, and sleeves are interposed between the first taper roller bearings and the front side of the pinions, and the pinions are configured to be inserted and extracted into/from the sleeves.

A ship propulsion device (1) is adapted to rotate a propeller (20) to propel a ship (2). In a case where the rotating speed of the propeller (20) is less than a predetermined rotating speed, a low-output sub-motor (M2) is controlled and rotationally driven by a small-capacity general-purpose inverter (24), and the rotational driving is transmitted to the propeller (20) so as to rotate the propeller. In that case, in a drive system of a main motor (M1), rotation is not transmitted to a slip clutch (23) or an input shaft (7) by cutting off an on-off clutch (8). In a case where the rotating speed of the propeller (20) becomes equal to or more than the predetermined rotating speed, a driving source is switched from the sub-motor (M2) to the main motor (M1) so as to couple the on-off clutch (8), and the rotating speed of the main motor (M1) is controlled by the slip clutch (23) and transmitted to the propeller (20) so as to rotate the propeller (20).

A ship propulsion device (1) is adapted to rotate a propeller (20) to propel a ship (2). In a case where the rotating speed of the propeller (20) is less than a predetermined rotating speed, a low-output sub-motor (M2) is controlled and rotationally driven by a small-capacity general-purpose inverter (24), and the rotational driving is transmitted to the propeller (20) so as to rotate the propeller. In that case, in a drive system of a main motor (M1), rotation is not transmitted to a slip clutch (23) or an input shaft (7) by cutting off an on-off clutch (8). In a case where the rotating speed of the propeller (20) becomes equal to or more than the predetermined rotating speed, a driving source is switched from the sub-motor (M2) to the main motor (M1) so as to couple the on-off clutch (8), and the rotating speed of the main motor (M1) is controlled by the slip clutch (23) and transmitted to the propeller (20) so as to rotate the propeller (20).

A hybrid marine drive unit mounted to a transom. The drive unit includes a drive housing mounted on the transom, a propelling unit rotatable about a vertical axis and mounted to a lower surface of the drive housing, and a transmission with at least a vertical drive shaft located in the drive housing and extending into the propelling unit. The vertical drive shaft is arranged transmit drive torque from at least one of multiple sources of drive torque. The vertical drive shaft is operably connected to a first source of drive torque arranged within the drive housing, and the vertical drive shaft is operably connected to a horizontal output shaft extending into the drive housing through the transom. The horizontal output shaft is connectable to a second source of drive torque.

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.

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.

In a marine hybrid system which includes an engine, an electric motor, a thrust generation device, and a clutch mechanism configured to be able to switch connection states therebetween, if it is determined that the engine is in an overload condition, the clutch mechanism is controlled such that a load of the engine is reduced.