A duo propeller disclosed having a forward propeller having increased loading distribution and high swirl near the tip. The duo propeller has an aft propeller with a more optimal loading distribution that can cancel the high tip swirl from the forward propeller. The duo-propeller an enhanced ability for the aft propeller to capture the energy lost to the swirling flow of the forward propeller's outflow.

The present invention relates to rotating equipment, and more specifically, to high efficiency rotating equipment which generates thrust through contra-rotating or produces electricity. The rotating equipment includes: a plurality of propeller modules (10, 20) including a plurality of blades (11, 21) installed inside along a circumferential direction; and a rotary module (40) which rotates the plurality of propeller modules (10, 20) or is rotated.

The present invention relates to rotating equipment, and more specifically, to high efficiency rotating equipment which generates thrust through contra-rotating or produces electricity. The rotating equipment includes: a plurality of propeller modules (10, 20) including a plurality of blades (11, 21) installed inside along a circumferential direction; and a rotary module (40) which rotates the plurality of propeller modules (10, 20) or is rotated.

Disclosed herein is an inventive dual propeller assembly that can be manually or automatively assembled and includes a leading propeller, a torsion bushing, a thrust washer, a drive sleeve, and a trailing propeller. The propellers were coupled with an alignment system that did not require welding of the two propellers. The leading propeller includes a cylindrical hub and a plurality of blades that extend from an outer surface of the cylindrical hub. The trailing propeller includes a first cylindrical hub having a plurality of grooves, a second cylindrical hub having a cylindrical mount ring, and a conical profile formed between the first cylindrical hub and the second cylindrical hub. The outer surface of the first cylindrical hub is designed to mate with the inner surface of the cylindrical hub of the leading propeller. The trailing propeller is secured and aligned coaxially with the leading propeller. The trailing propeller can be effectively and consistently used with existing propellers.

Disclosed herein is an inventive dual propeller assembly that can be manually or automatively assembled and includes a leading propeller, a torsion bushing, a thrust washer, a drive sleeve, and a trailing propeller. The propellers were coupled with an alignment system that did not require welding of the two propellers. The leading propeller includes a cylindrical hub and a plurality of blades that extend from an outer surface of the cylindrical hub. The trailing propeller includes a first cylindrical hub having a plurality of grooves, a second cylindrical hub having a cylindrical mount ring, and a conical profile formed between the first cylindrical hub and the second cylindrical hub. The outer surface of the first cylindrical hub is designed to mate with the inner surface of the cylindrical hub of the leading propeller. The trailing propeller is secured and aligned coaxially with the leading propeller. The trailing propeller can be effectively and consistently used with existing propellers.

A drive train in a marine vessel includes a marine pod drive unit and an inboard engine operatively connected by a driveshaft. To protectively enclose the driveshaft, a guard sleeve having a tubular configuration is disposed around the driveshaft and extends between the marine pod drive unit and the inboard engine. The first sleeve end of the guard sleeve is coupled to a first coupling collar on the marine pod drive unit using a first annular packing and the second sleeve end is coupled to a second coupling collar on the inboard engine using a second annular packing. The first and second annular packings enable relative angular displacement between the guard sleeve and the marine pod drive unit or the inboard engine.

A radial flux synchronous machine includes a stator in a cylindrical shape provided with a plurality of magnetic poles, an inner rotor disposed radially inward of the stator and having an inner armature opposing the magnetic pole from radially inward, and an outer rotor disposed radially outward of the stator and having an outer armature opposing the magnetic pole (from radially outward.

A radial flux synchronous machine includes a stator in a cylindrical shape provided with a plurality of magnetic poles, an inner rotor disposed radially inward of the stator and having an inner armature opposing the magnetic pole from radially inward, and an outer rotor disposed radially outward of the stator and having an outer armature opposing the magnetic pole (from radially outward.

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.