Electric Machine Comprising Axial Thrust Bearings
An electric machine has a stator with N posts. A rotor is mounted on bearings for rotary movement about an axis relative to the stator with an air gap between the rotor and stator. The bearings are pre-loaded axial thrust bearings or pre-loaded angular bearings. The pre-load forces are provided at least in part by magnetic attraction between the stator and rotor. The rotor has M poles. The values for N and M have the property that the greatest common divisor of N and M is four or more.
1 - 21 . (canceled)
22 . An electric machine, comprising: a stator; a rotor mounted on bearings for rotary movement about an axis relative to the stator with an air gap between the rotor and stator, the bearings being pre-loaded angular bearings, in which pre-load forces are provided at least in part by magnetic attraction between the stator and rotor.
23 . The electric machine of claim 22 , wherein stator has N posts, the rotor has M poles; and N and M having the property that the greatest common divisor of N and M is four or more.
24 . The electric machine of claim 23 in which the posts are divided into sections with a common phase of electrical excitation in conductors around the posts in each section and/or there is an even number of posts in each section.
25 . The electric machine of claim 24 in which the posts are divided into at least three sections.
26 . The electric machine of claim 23 in which both N and M are 60 or more.
27 . The electric machine of claim 24 in which the conductors on the stators further comprise multiphase wiring configurations.
28 . The electric machine of claim 27 in which each of the three or more sections comprises a number of wired posts, and in which the number of wired posts for each of the three or more sections is the same.
29 . The electric machine of claim 28 in which the three or more sections further comprise two or more equally arrayed sections per phase.
30 . The electric machine of claim 29 in which the three or more sections further comprise four or more equally arrayed sections per phase.
31 . The electric machine of claim 30 in which the three or more section further comprise six or more equally arrayed sections per phase.
32 . The electric machine of claim 30 in which the three or more sections further comprise exactly four equally arrayed sections for each of the respective phases.
33 . The electric machine of claim 22 , wherein the rotor comprises a plurality of inner flux restrictors positioned radially inward from the angular bearings.
34 . The electric machine of claim 33 , wherein the inner flux restrictors are blind holes.
35 . The electric machine of claim 33 , wherein the inner flux restrictors are through holes.
36 . The electric machine of claim 22 , wherein the electric machine is a radial flux motor.
37 . The electric machine of claim 22 , further comprising pre-loaded axial thrust bearings between the rotor and stator.
38 . The electric machine of claim 22 , wherein the rotor contains permanent magnets and further wherein the permanent magnets are tapered in a direction toward the stator.
39 . The electric machine of claim 22 , wherein the rotor contains posts and further wherein the posts are tapered in a direction away from the stator.