Abstract: An electric machine, such as a motor or generator, is configured in a machine housing with a cup-shaped rotor attached to a shaft rotatively supported in the housing, an inner stator coaxial with and enclosed by the rotor, and an outer stator coaxial with and enclosing the rotor. The inner and outer portions of the machine are separated by a magnetic isolator that divides and supports inner and outer portions of the rotor. The magnetic isolator, which supports inner and outer sets of permanent magnets in one embodiment and inner and outer squirrel cage rotor assemblies in another embodiment is preferably made of non-magnetic stainless steel but may also be made of titanium, brass, aluminum, bronze or magnesium, or any material that provides magnetic isolation between the inner and outer portions of the machine.

Abstract: In a marine propulsor which includes an electric motor with a rotor, a bearing assembly supporting the rotor, and a plurality of propulsor blades and a blade assembly driven by the motor, improved cooling/lubricating system includes an inlet through which coolant/lubricant is supplied to the bearing assembly and the motor, a passage communicating with the inlet through which the coolant/lubricant flows, and an outlet located adjacent the trailing edge of the blade assembly through which the coolant/lubricant is expelled, whereby the expulsion of coolant/lubricant through the outlet provides additional forward thrust to the propulsor. The outlet may be located in the blade hub of the blade assembly or, alternatively, the outlet may comprise a plurality of holes located in the trailing edges of the blades of the blade assembly.

Abstract: An improved motor and bearing assembly is provided for use in an axial gap electric motor. The motor and bearing assembly includes a bearing support, bearing cones circumferentially mounted on the bearing support and a rotating bearing member. Each bearing cone has an axial conical surface at one end. The conical surfaces face each other to form a V-shaped cross-sectional groove. The rotating bearing member includes two rotating bearing rings abutting one another, each ring having an angularly disposed surface forming a V-shaped configuration complementary to the V-shaped groove of the bearing cones. The rotating bearing member provides axial and radial support of the rotor of the axial gap electric motor. Each of the bearing cones is axially movable relative to the bearing support, thereby permitting the stator-to-rotor gap and the bearing clearance to be adjusted after final assembly.

Abstract: A marine propulsor for submersible vessels or surface vessels powered by underwater propulsion units. A shaftless motor with disk-shaped rotor and stator(s) is mounted in the vessel structure with a blade hub mounted on the rotor, the hub including propeller blades extending beyond the circumference of the vessel housing. The motor is substantially iron-free with much of the rotor/stator volume being occupied by windings, thus providing sufficient power without taking up substantial space or adding burdensome weight. The rotor is journal mounted in the vessel and circumferential thrust bearing assemblies are provided around the rotor/blade hub assembly. A water cooling/lubricating system is provided for the bearings and rotor/stator(s). Power is supplied individually to two stators mounted on either side of the rotor to control electromagnetic forces on the rotor to offset thrust forces and to reduce the magnitude of propulsor induced structural vibration.