A ship propulsion unit includes: an engine including a crankshaft extending in a front-rear direction of a ship; a propeller shaft; a power transmission mechanism configured to couple the crankshaft and the propeller shaft; an upper case; and a lower case accommodating the propeller shaft and connected to the upper case. The power transmission mechanism includes a drive shaft extending from the upper case toward the lower case. The upper case and the engine are fixed to a ship body. A connection portion between the upper case and the lower case is provided with a rotation mechanism configured to rotate the lower case around an axis of the drive shaft.

Hydraulic pump-accessory assemblies are provided for engines. The assemblies may include: an accessory pulley or gear configured to engage a drive belt or chain of an engine; and a hydraulic pump operatively engaging the pulley or gear to be driven by the engine. Engines are provided that can include: a crankshaft pulley or gear operably engaging a belt or chain to convey power to one or more accessories; an accessory pulley or gear operably engaged by the belt or chain; and a hydraulic pump operatively engaging the accessory pulley or gear to receive power from the belt or chain. Methods for modifying an engine are also provided. The methods can include operatively engaging a hydraulic motor to the pulley or gear of an accessory configured to be operably engaged with a belt or chain of the engine.

A linking drive system comprises a first drive shaft of the first drivetrain connected between a first prime mover and a first propulsor. The linking drive system comprises a second drive shaft of the second drivetrain connected between a second prime mover and a second propulsor. The linking drive system further comprises a linking drive clutch, which comprises at least a first clutch part and a second clutch part. The first clutch part and the second clutch part are engageable with each other and can transmit rotation therebetween. At least one flexible drive link is coupled between the linking drive clutch and the first and/or second drive shafts. Rotation from one of the first and second drive shafts is transferred to the other of the first and second drive shafts when the linking drive clutch is engaged thereby linking the first and second drivetrains.

A propulsion system (102) for an aquatic vessel (100) is provided. The propulsion system includes a plurality of Magnus-type rotors (108) and a drive arrangement (147) for rotating the plurality of Magnus-type rotors. The plurality of Magnus-type rotors are operable to rotate about corresponding substantially upright axes. The propulsion system also includes a control arrangement (150) for controlling the drive arrangement to vary rates of rotations of the plurality of Magnus-type rotors. Each of the plurality of Magnus-type rotors includes a hollow region (116) therein. Each of the Magnus-type rotors is rotationally supported onto a support arrangement (118) which extends into the hollow region. The drive arrangement includes at least one motor (148) disposed in the hollow region and located outside the support arrangement such that the at least one motor is accessible for maintenance. Furthermore, the at least one Magnus-type rotor includes a ventilation aperture arrangement (132) for enabling an upward movement of air to occur in operation within the at least one Magnus-type rotor for ventilating and cooling the drive arrangement and/or other internal components.

A ship propulsion unit includes: an engine including a crankshaft extending in a front-rear direction of a ship; a propeller shaft; a power transmission mechanism configured to couple the crankshaft and the propeller shaft; an upper case; and a lower case accommodating the propeller shaft and connected to the upper case. The power transmission mechanism includes a drive shaft extending from the upper case toward the lower case. The upper case and the engine are fixed to a ship body. A connection portion between the upper case and the lower case is provided with a rotation mechanism configured to rotate the lower case around an axis of the drive shaft.

A marine propulsion apparatus includes a first drive shaft, a lifting plate fixed relative to the first drive shaft, a midsection top collar. The apparatus includes a lower unit attached to the midsection top collar, the lower unit having a second drive shaft, wherein the midsection top collar is fixed relative to the second drive shaft. The apparatus includes a power transmission component rotatably coupling the first drive shaft to the second drive shaft, wherein the power transmission component is continuously disposed over the first drive shaft and the second drive shaft and configured to rotate about the first and second drive shafts. The apparatus includes one or more lifting screws coupling the lifting plate to the midsection top collar, wherein adjusting the one or more lifting screws changes a distance between the lifting plate and the midsection top collar, thereby adjusting a tension of the power transmission component.

The portable pedal system for kayaks and other watercraft is a propulsion device. The portable pedal system for kayaks and other watercraft removably attaches to a vessel. The portable pedal system for kayaks and other watercraft is manually powered. The portable pedal system for kayaks and other watercraft comprises a belt drive, a transmission structure, and a vessel. The belt drive and the transmission structure removably attach to the vessel. The belt drive attaches to the transmission structure. A client manually powers the rotation of the belt drive. The rotation of the belt drive rotates the transmission structure which propels the vessel through the water.

A transmission for a human-powered vehicle. The transmission has a primary system that includes a transmission case, a crankshaft with cog, a pair of receiver cranks, a pair of connecting rods, a pair of oscillating driver cranks, and a pair of pedals. A secondary biasing system is engaged with the primary system to provide a favorable torque around dead centers of the primary system. The transmission 150 may be configured to transmit power by driveshaft, chain, or belt to drive a wheel or propeller. In a watercraft application, an operator alternatingly applies force to a pair of pedals while seated close to the floor of a kayak 145. Power from the transmission is transmitted through a steerable lower gear case 134 via a propeller to propel the craft. The operator maneuvers the craft by means of a control lever 135 operably connected to the lower gear case by cables 136.

An outboard drive device (10) comprising a motor (11) having a crankshaft (16), wherein said outboard drive device (10) further comprises a propeller shaft (12) with a propeller which propeller is below the hull (13) of a boat when said outboard drive device (10) is operated, and a power coupling system for transferring power from the motor (11) to the propeller shaft (12). The motor (11) is an automotive motor or an industrial base engine, wherein the crankshaft (16) is substantially horizontal and substantially parallel to the propeller shaft (12) when said outboard drive device (10) is operated. The power coupling system comprises a power transfer device (17), a transmission (18) and a transmission drive shaft (19). The power transfer device (17) connects the crankshaft (16) with the transmission drive shaft (19) for transferring the output power from the crankshaft (16) to the transmission drive shaft (19). The transmission (18) comprises a forward gear (23) and a reverse gear (24), so that the output power is reversible.

An improved human powered watercraft propulsion device and mounting frame for attachment to existing pontoon watercraft. The propulsion device is light weight, self-contained, portable, has few moving parts made from corrosive resistant materials, and is propeller driven for quiet, efficient, and environmentally friendly underwater propulsion. Having a simple twisted belt configuration with an open structural design, all of the components are easily viewed and maintained by the user, as well as continuously cleaned, cooled, and lubricated by the water during operation, without the need for a sealed waterproof housing and internal oil bath. Hand knobs provide belt tensioning during operation and the device is adapted for operation by pedal, friction wheel, or direct chain drive. The device is adjustable on the attachment frame to fit the operator, pivots when beaching or striking an underwater object, and components such as pulleys and the propeller are changeable to achieve different power ratios.