Provided herein is a marine propulsion apparatus including a prime mover having a drive shaft, a cowling enclosing the prime mover, first and second struts affixed to the cowling, where each of the struts have a leading portion, an interior belt void, and a trailing portion. The apparatus further includes a lower unit coupled to the distal ends of the struts, a sprocket rotatably disposed within the lower unit, a shaft rotatably coupled to the sprocket, a belt rotatably coupling the drive shaft to the sprocket, such that a first portion of the belt is disposed within the interior belt void of the first strut and a second portion of the belt is disposed within the interior belt void of the second strut. The apparatus further includes a thermal circuit (having a heat transfer fluid) extending from the cowling, through each of the struts, and into the lower unit.

Provided herein is a marine propulsion apparatus including a prime mover having a drive shaft, a cowling enclosing the prime mover, first and second struts affixed to the cowling, where each of the struts have a leading portion, an interior belt void, and a trailing portion. The apparatus further includes a lower unit coupled to the distal ends of the struts, a sprocket rotatably disposed within the lower unit, a shaft rotatably coupled to the sprocket, a belt rotatably coupling the drive shaft to the sprocket, such that a first portion of the belt is disposed within the interior belt void of the first strut and a second portion of the belt is disposed within the interior belt void of the second strut. The apparatus further includes a thermal circuit (having a heat transfer fluid) extending from the cowling, through each of the struts, and into the lower unit.

An outboard motor for a marine vessel application, and related methods of making and operating same, are disclosed herein. In at least one embodiment, the outboard motor includes a horizontal-crankshaft engine in an upper portion of the outboard motor, positioned substantially positioned above a trimming axis of the outboard motor. In at least another embodiment, first, second and third transmission devices are employed to transmit rotational power from the engine to one or more propellers at a lower portion of the outboard motor. In at least a further embodiment, the outboard motor is made to include a rigid interior assembly formed by the engine, multiple transmission devices, and a further structural component. In further embodiments, the outboard motor includes numerous cooling, exhaust, and/or oil system components, as well as other transmission features.

An outboard motor for a marine vessel application, and related methods of making and operating same, are disclosed herein. In at least one embodiment, the outboard motor includes a horizontal-crankshaft engine in an upper portion of the outboard motor, positioned substantially positioned above a trimming axis of the outboard motor. In at least another embodiment, first, second and third transmission devices are employed to transmit rotational power from the engine to one or more propellers at a lower portion of the outboard motor. In at least a further embodiment, the outboard motor is made to include a rigid interior assembly formed by the engine, multiple transmission devices, and a further structural component. In further embodiments, the outboard motor includes numerous cooling, exhaust, and/or oil system components, as well as other transmission features.

A lower unit for a marine propulsion device includes a gearcase housing defined along a longitudinal center axis between a fore end and an aft end. A propulsor shaft extends through the gearcase housing along the longitudinal axis. A driveshaft extends non-parallel to the propulsor shaft and rotates in a direction of rotation when powered by an engine. The driveshaft is coupled in torque-transmitting relationship with the propulsor shaft. A skeg projects from a bottom surface of the gearcase housing proximate at least the aft end thereof. The skeg or the gearcase housing is cambered such that a moment acting in a direction opposite the driveshaft's direction of rotation is induced on the skeg or the gearcase housing as the lower unit moves through water. A marine propulsion device is also disclosed.

The present device relates to boatbuilding, and more particularly to screw propellers with safety couplings, intended for use in outboard motors and/or marine screw propellers. A screw propeller with a safety coupling comprises a screw propeller body-cum-hub, a drive coupling, a driven coupling, and a dowel pin. The driven coupling is disposed for rotation on a spacer bushing, said spacer bushing being a tail bushing of the driving coupling. The driven coupling is partially or completely disposed in an opening in the screw propeller body-cum-hub and transmits torque to the screw propeller body-cum-hub by means of a longitudinal dowel pin and/or longitudinal grooves and a spline coupling. A common opening for the dowel pin in the driving and/or the driven coupling is configured as a through opening, and/or the blind end of the opening for the dowel pin is connected by a transverse opening to the outside surface.

The present device relates to boatbuilding, and more particularly to screw propellers with safety couplings, intended for use in outboard motors and/or marine screw propellers. A screw propeller with a safety coupling comprises a screw propeller body-cum-hub, a drive coupling, a driven coupling, and a dowel pin. The driven coupling is disposed for rotation on a spacer bushing, said spacer bushing being a tail bushing of the driving coupling. The driven coupling is partially or completely disposed in an opening in the screw propeller body-cum-hub and transmits torque to the screw propeller body-cum-hub by means of a longitudinal dowel pin and/or longitudinal grooves and a spline coupling. A common opening for the dowel pin in the driving and/or the driven coupling is configured as a through opening, and/or the blind end of the opening for the dowel pin is connected by a transverse opening to the outside surface.

An outboard motor includes an outboard-motor main-body, an anti-ventilation plate, and a foreign-matter collection apparatus. The anti-ventilation plate is provided on the outboard-motor main-body. The foreign-matter collection apparatus is provided above the anti-ventilation plate and outside the outboard-motor main-body and located at a height such that a water intake is submerged under water when a ship to which the outboard-motor main-body has been attached is in a pre-planing state.

A vertical-input outboard-motor angled-drive lower unit apparatus and method for improved operations in shallow, muddy, marshy water or water choked with vegetation or obstacles. Vertically applied single-direction rotational power from an outboard motor engine is transferred to operator-controlled forward and reverse rotational power applied at an acute angle to the horizontal water surface. The apparatus is cooled by an external flow of water without being taken into any port which might become blocked. A thrust redirection plate reflects otherwise wasted propeller thrust, especially when operating in reverse, for more efficient operation and reduced churning of the water surface. An angled skeg and the angled orientation of the output shaft and housing deflect obstructions.

A vertical-input outboard-motor angled-drive lower unit apparatus and method for improved operations in shallow, muddy, marshy water or water choked with vegetation or obstacles. Vertically applied single-direction rotational power from an outboard motor engine is transferred to operator-controlled forward and reverse rotational power applied at an acute angle to the horizontal water surface. The apparatus is cooled by an external flow of water without being taken into any port which might become blocked. A thrust redirection plate reflects otherwise wasted propeller thrust, especially when operating in reverse, for more efficient operation and reduced churning of the water surface. An angled skeg and the angled orientation of the output shaft and housing deflect obstructions.