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.

A transmission for an outboard motor, the transmission having an input shaft with an input gear. A countershaft has a countershaft driven gear and a reverse driving gear, where the countershaft driven gear meshes with the input gear. An output shaft has first and second driven gears. First and second driving gears mesh with the first and second driven gears. A reverse idler gear meshes with the reverse driving gear and also with a reverse driven gear. A plurality of clutches includes first, second, third, and reverse clutches. The first and second clutches selectively rotate the first and second driving gears with the countershaft in first and second modes in forward rotation, respectively. The third clutch selectively rotates the second driving gear with the input shaft in a third mode in forward rotation. The reverse clutch selectively rotates the output shaft with the reverse driven gear in reverse rotation.

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 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 transmission (1) with a main driveshaft (3), a first intermediate shaft (4) and a drive output shaft (6), by way of which at least one propeller (21) can be driven. The marine transmission (1) has an electric machine (7), as an additional drive, a second intermediate shaft (5) and a planetary gear assembly (8). The electric machine (7) can be connected to the second intermediate shaft (5) by way of the planetary gear assembly (8). Also a drive arrangement for a marine transmission with a main drive motor (2) and with a marine transmission (1) of that type are disclosed.

A reverse gear includes an input shaft, a forward clutch, a reverse clutch, an output shaft, a reduction mechanism, and a relay shaft. The input shaft receives rotational power of a main engine. The forward clutch transmits the rotational power of the input shaft as forward output. The reverse clutch transmits the rotational power of the input shaft as reverse output. The output shaft outputs the rotational power transmitted via the forward clutch and the reverse clutch. The reduction mechanism reduces the rotational power of the output shaft and transmits the reduced rotational power to the propeller shaft. The relay shaft intersects the input shaft and relays the rotational power from the forward clutch and the reverse clutch toward the output shaft. The relay shaft and the output shaft are coupled to each other via a pair of intersecting-shaft gears to be able to transmit power.

A propeller drive arrangement includes a propeller shaft, a planetary gear comprising a first planetary gear member, a second planetary gear member and a third planetary gear member which are drivingly connected, and an outer shaft arranged coaxially with and radially outside of the propeller shaft. The outer shaft is drivingly connected to one or more propeller blades for varying the pitch angle, and the propeller shaft is drivingly fixed to one of the planetary gear members and another one of the planetary gear members is arranged to drive the outer shaft by a driving torque exerted on the propeller shaft. The propeller drive arrangement has a pitch controlling member for varying the pitch angle of the one or more propeller blades, in a first state, to rotationally fix the third planetary gear member to the second planetary gear member so that the propeller shaft and the outer shaft are arranged to rotate with the same rotational speed, and, in a second state, to engage the third planetary gear member to a housing so that the third planetary gear member is rotationally fixed with respect to the housing.

A main drive device of a planocentric set for three armed forces, including inner ring, outer ring, rolling column between the inner and outer rings at a side closer to the inner ring, and rolling pin shaft pairs installed between the inner and outer rings at a side closer to the outer ring; the inner ring is installed on an eccentric shaft and rotates driven by the eccentric shaft; the eccentric shaft is driven by a prime mover; when the rolling column is in contact with the inner ring, it contacts one of the two neighboring rolling pin shaft pairs to transmit power to the rolling pin shaft pairs in clockwise and counter-clockwise rotation; the rolling pin shaft pair drives the outer ring to rotate; the outer ring drives a planet wheel spoke to rotate, to drive a planocentric set planet wheel, and implement drive of a planocentric set.

Provided is a ship propelling apparatus including a rotation shaft on which a rear propeller is fixed; a front propeller rotatably supported on the rotation shaft in front of the rear propeller; and a counter-rotating device through which the rotation shaft passes, which includes a gear box including therein a plurality of gears configured to reverse rotation of the rotation shaft and transfer the reversed rotation to the front propeller, and which is installed in an installation space formed at the rear of a ship. The rotation shaft includes a measurement hole formed to pass through a center of the rotation shaft for centering of the counter-rotating device installed in the installation space; and an individual lubricant path separated from the measurement hole.

Transmission systems and methods are for a marine propulsion device having an internal combustion engine that drives a propulsor. An input shaft is driven into rotation at a non-zero first rotational speed by the internal combustion engine. An output shaft drives the propulsor into rotation at a non-zero second rotational speed. A planetary gearset transfers power from the input shaft to the output shaft. A band brake is on the planetary gearset. Actuation of the band brake effects a gear change in the planetary gearset. A band brake actuator actuates the band brake to effect the gear change. A controller controls the band brake actuator. Based upon one or more operational characteristics of the marine propulsion device the controller is programmed to control the band brake actuator so that the second rotational speed is less than the first rotational speed.