A coaxial contra-rotating circumferential thruster includes: an input end, a one-way commutator, a two-way deflector, a steering support and two output ends. The input end is connected to a power device. The one-way commutator converts one rotation into two rotations having the same rotation speed and opposite rotation directions. The two-way deflector respectively indirectly connects two shafts of a contra-rotating sleeve shaft to two output shafts thereof by means of two bevel gear pair. Two unidirectional deflecting torques respectively generated by the two bevel gear pairs have the same magnitude and opposite directions. By transferring by means of a bracket or an output sleeve shaft, the two unidirectional deflecting torques cancel each other. The two output ends are respectively connected to two propellers (or rotors). A turnaround control device controls the steering support to be turned around, the control torque required for co-rotating and contra-rotating is the same.

A system for adjusting the rotational timing between driveshafts rotated by an output shaft. The system includes a flange coupler configured to be coupled to a first of the driveshafts to prevent rotation therebetween. The flange coupler defines openings therein. A coupler input gear defines openings therein and is configured to rotatably mesh with a second input gear coupled to a second of the driveshafts. Fasteners are configured to the extend through the openings in the flange coupler and the openings in the coupler input gear to rotationally fix the flange coupler and the coupler input gear, which are fixable at multiple rotational orientations therebetween. The rotational timing between the driveshafts is adjustable by rotating the coupler input gear into different orientations of the multiple rotational orientations relative to the flange coupler prior to fixing the flange coupler to the coupler input gear.

A marine propulsion system, supported by a strut, which comprises an inner propeller shaft supporting a first propeller adjacent a trailing end thereof, and the inner propeller shaft is connected to the drive shaft for receiving and supplying a first portion of torque to the first propeller as well as transfer thrust, generated by the first propeller, along the inner propeller shaft back to the drive shaft. An outer propeller shaft supports a second propeller adjacent a trailing end thereof, and the outer propeller shaft surrounds the inner propeller shaft. A planetary gear assembly receives a second portion of the torque and supplies the torque to the outer propeller shaft so that the second propeller rotates in an opposite direction to the first propeller. A portion of the planetary gear assembly is accommodated vertically above a flat end face of the strut for reducing hydrodynamic drag of the strut.

The present innovation relates generally to propulsion mechanisms for propeller-driven vehicles and vessels, and, more particularly, to gear-driven transmissions for airboats.

A strut mounted gear box for counter rotating propellers. The gear box is strut mounted for securement to the hull of a boat. A main input shaft is coupled to a propulsion component of a boat with a distal end secured to an idler gear cage assembly located within the gear box. The main input shaft transfers torque and rotation from the propulsion component to an idler gear cage assembly. An inner tail shaft is coupled to the main input shaft and arranged to rotate the inner tail shaft in a first direction. A counter shaft is coupled to the idler gear cage assembly and arranged to rotate the counter shaft in a second direction. A first propeller is secured to the inner tail shaft providing rotation in the first direction; and a second propeller is secured to the counter shaft allowing rotation in the second direction.

A strut mounted gear box for counter rotating propellers. The gear box is strut mounted for securement to the hull of a boat. A main input shaft is coupled to a propulsion component of a boat with a distal end secured to an idler gear cage assembly located within the gear box. The main input shaft transfers torque and rotation from the propulsion component to an idler gear cage assembly. An inner tail shaft is coupled to the main input shaft and arranged to rotate the inner tail shaft in a first direction. A counter shaft is coupled to the idler gear cage assembly and arranged to rotate the counter shaft in a second direction. A first propeller is secured to the inner tail shaft providing rotation in the first direction; and a second propeller is secured to the counter shaft allowing rotation in the second direction.

The present innovation relates generally to propulsion mechanisms for propeller-driven vehicles and vessels, and, more particularly, to gear-driven transmissions for airboats.

A system for providing marine propulsion is provided including an input shaft driven by a prime mover, a pinion gear coupled to the input shaft, a plurality of planet gears coupled to the pinion gear, a planet carrier having the plurality of planet gears rotationally mounted thereto, and a ring gear surrounding the planet gears and coupled thereto. The planet carrier and ring gear are coupled to internal and external output shafts that are coaxially aligned, which are coupled to aft and forward propulsor elements. The ring gear and planet carrier rotate in opposite directions to provide contra-rotating forward and aft propulsor elements. The ring gear and planet gear are each coupled to rotation altering devices that, when at least one is activated, the rotation of both the planet carrier and ring gear will be altered, thereby altering the rotation of the propulsor elements.

A computer implemented diagnostics system for a marine propeller drive unit is provided. The diagnostics system comprising processing circuitry connected to a speed sensor system and to a control unit associated with the electric machine. The speed sensor system is arranged in connection to the differential arrangement to provide propeller speed data to the processing circuitry indicative of a speed of rotation of at least one of the propeller axles of the self-balancing propeller drive unit. The control unit is arranged to provide motor current data to the processing circuitry indicative of a motor current drawn by the electric machine. The processing circuitry is arranged to monitor the motor current data from the control unit, and the propeller speed data from the speed sensor system, and to classify a state of the self-balancing propeller drive unit into a pre-determined number of states comprising one or more fault states, based on the motor current data and on the propeller speed data. The processing circuitry is arranged to trigger an action by the diagnostics system in case the state of the self-balancing propeller drive unit is classified as a fault state.

Disclosed are a propulsion system for a ship, a method of assembling the same, and a method of disassembling the same. The propulsion system for the ship includes: a rear propeller fixed to a rotary shaft; a front propeller that is rotatably supported on the rotary shaft in front of the rear propeller; a contra-rotating device that is mounted in an installation space at a rear end of a hull so as to reverse the rotation of the rotary shaft and transmit the reversed rotation to the front propeller; a propeller connecting member that connects the contra-rotating device and the front propeller to transmit a rotational force; and a thrust supporting device that is provided between the contra-rotating device and the propeller connection member to support thrust of the front propeller.