A propulsion unit includes a housing supported on a vessel. A propeller shaft extends in the housing. The propeller shaft is rotatably supported with a first bearing and a second bearing. A propeller is attached to at least one end of the propeller shaft. The first bearing includes a first radial bearing and a first thrust bearing. The first radial bearing is a sliding bearing positioned axially inside the first thrust bearing. The first bearing is positioned at the first end of the housing and the second bearing being positioned at the second end of the housing or vice a versa.

A boat and a propeller assembly for a boat. The propeller assembly includes a propeller and a thrust bearing, and the thrust bearing is made of a harder material than the propeller. The boat may also include a hull, a drive shaft, and a motor. The motor may be positioned within the hull and configured to rotate the drive shaft. The drive shaft may extend through a hull bottom of the hull and the propeller assembly may be positioned forward of a transom of the hull and beneath the hull bottom. The propeller may include a central hub having a hole capable of having the drive shaft inserted therethrough. The thrust bearing may be located in the hole of the central hub and secured to the propeller such that the thrust bearing and the propeller form a unified assembly.

A thrust bearing configured to support axial loads that act on a rotating body includes a thrust shaft rotatably supportable in a bearing housing, a thrust collar, and a retainer connected to the thrust shaft and configured to support a plurality of thrust pieces. The thrust pieces each have a front sliding surface in sliding contact with the thrust collar, and the retainer includes a disk having a central opening and an outer circumference and a plurality of radial incisions extending radially inwardly from the outer circumference which incisions have inner ends radially spaced from the central opening. The radial incisions define circumferentially adjacent spring sections each of the which is individually axially flexible against and away from the bearing housing to open and close a spring gap between each of the spring sections and the bearing housing.

An electrically driven propulsion system for a watercraft comprises an electric motor, a pulse inverter, a thrust bearing, and a transmission is presented. The pulse inverter can be electrically coupled to the electric motor and adapted to provide an electrical supply power of at least 50 kW to the electric motor. The electrically driven propulsion system further comprises a common waterproof housing. An external section of the transmission can be arranged outside of the common waterproof housing. The transmission can be adapted to rotationally couple the external section of the transmission to the electric motor. The thrust bearing can be mechanically coupled to the rotary shaft of said transmission and to the common waterproof housing. The thrust bearing can be adapted to transfer a force applied to the transmission along an axial direction of said rotary shaft of the transmission to the common waterproof housing.

A propulsion unit includes a housing supported on a vessel. A propeller shaft extends in the housing. The propeller shaft is rotatably supported with a first bearing and a second bearing. A propeller is attached to at least one end of the propeller shaft. The first bearing includes a first radial bearing and a first thrust bearing. The first radial bearing is a sliding bearing positioned axially inside the first thrust bearing. The first bearing is positioned at the first end of the housing and the second bearing being positioned at the second end of the housing or vice a versa.

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.

A thrust bearing configured to support axial loads that act on a rotating body includes a thrust shaft rotatably supportable in a bearing housing, a thrust collar, and a retainer connected to the thrust shaft and configured to support a plurality of thrust pieces. The thrust pieces each have a front sliding surface in sliding contact with the thrust collar, and the retainer includes a disk having a central opening and an outer circumference and a plurality of radial incisions extending radially inwardly from the outer circumference which incisions have inner ends radially spaced from the central opening. The radial incisions define circumferentially adjacent spring sections each of the which is individually axially flexible against and away from the bearing housing to open and close a spring gap between each of the spring sections and the bearing housing.

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.

A propulsion unit including a housing supported with a support arm on a hull, a propeller shaft. The propeller shaft has an axis of rotation and is rotatably supported with a first bearing and with a second bearing. The first bearing including a thrust bearing positioned and supported in a bearing house, and a radial bearing that is a sliding bearing. The first bearing including a collar. Opposite side surfaces of the collar is rotatably supported in the bearing house on elastic biasing means loaded slide pieces of the thrust bearing. The radial bearing is positioned and supported in the bearing house, and the radial bearing is positioned axially at least partly between the elastic biasing means loaded slide pieces.