Motor designs having spline structure connecting motor shaft and stator structure

Patent metadata

Field	Value
Publication number	US-11539251-B2
Application number	US-202017071415-A
Country	US
Kind code	B2
Filing date	Oct 15, 2020
Priority date	Oct 15, 2020
Publication date	Dec 27, 2022
Grant date	Dec 27, 2022

Abstract

An electrical machine that is an outer runner motor having a rotor mounted rotatably about a machine axis, with the rotor rotatively attached to a shaft. A stator assembly having a stator core with a non-ferromagnetic material. An axial-flux yoke with an inner wall rigidly attached on an outer surface of a first edge wall of the stator core, or a radial-flux yoke with a continuous inner wall rigidly attached on a continuous outer wall of the stator core. Wherein the axial-flux yoke or the radial-flux yoke, include laminated sheets and slots. Windings can be positioned in the slots of either the axial-flux stator yoke or the radial-flux stator yoke. Wherein the stator core and the shaft include a spline coupling feature adapted to selectively couple and mate the stator core to the shaft.

First claim

What is claimed is:

1. An electrical machine that is an outer runner motor, comprising:
a rotor mounted rotatably about a machine axis, with the rotor rotatively attached to a shaft;
a stator assembly having a stator core with a non-ferromagnetic material, and including
an axial-flux yoke having an inner wall rigidly attached on an outer surface of a first edge wall of the stator core, or a radial-flux yoke having a continuous inner wall rigidly attached on a continuous outer wall of the stator core, wherein the axial-flux yoke or the radial-flux yoke, include laminated sheets and slots;
windings are positioned in the slots of either the axial-flux stator yoke or the radial-flux stator yoke, and
wherein the stator core and the shaft include a spline coupling feature adapted to selectively couple and mate the stator core to the shaft.

2. The electrical machine of claim 1 , wherein the spline coupling feature includes the stator core having an external spline structure and the shaft having a corresponding internal spline structure, such that the shaft is adapted to be inserted into or removed from the stator core.

3. The electrical machine of claim 2 , wherein the stator core external spline structure includes teeth on an inner surface of an inner wall of the stator core that engages with the corresponding internal spline structure that has grooves on an outer surface of the shaft, so that the stator core is attached to the shaft, of which the rotor rotates around the same shaft, in order to transmit a torque action so that the stator assembly is fixed to the shaft in order to transmit a torque action and maintain an angular correspondence, to produce a torque force.

4. The electric machine of claim 1 , wherein the windings includes a set of toroid-shaped multiphase windings configured within the slots of either an outer wall of the axial-flux stator yoke or the radial-flux stator yoke.

5. The electrical machine of claim 1 , wherein the windings are thermally connected to the shaft, such that the windings are positioned in the slots of the axial-flux stator yoke or the radial-flux stator yoke and forms a toroid-shaped stator assembly.

6. The electrical machine of claim 1 , wherein the windings are wrapped around an assembled stator yoke including either the axial-flux stator yoke or the radial-flux stator yoke, and the windings include a winding pattern having end turns which are termed toroidal windings, such that the toroidal windings reduces an amount of a length of the end turns, resulting in an increase in an amount of overall efficiency of the electrical machine, when compared with a similarly configured electric machine without the toroidal windings.

7. The electrical machine of claim 1 , wherein the windings are wrapped around an assembled stator yoke including either the axial-flux stator yoke or the radial-flux stator yoke, and the windings include multiple loops of magnetic copper wires and have three-phases along with a pole pair number.

8. The electrical machine to claim 1 , wherein the windings include a copper material and are wrapped around an assembled stator yoke including either the axial-flux stator yoke or the radial-flux stator yoke, and the windings include a winding pattern with end turns that are termed toroidal windings, such that the toroidal windings reduces an amount of a length of the end turns, resulting in a total amount of a motor's windings copper loss which improves a motor's overall efficiency.

9. The electric machine of claim 1 , wherein the laminated sheets of the radial-flux stator yoke and the first and the second axial-flux stator yokes include one of, a spiral-shaped electrical lamination, a stacked electrical lamination, a solid material or at least one power material formulated into the radial-flux stator yoke and the first and the second axial-flux stator yokes.

10. The electrical machine to claim 1 , wherein the non-ferromagnetic material of the stator core includes at least 85% of one or more non-ferromagnetic materials.

11. The electrical machine of claim 1 , wherein the non-ferromagnetic material of the stator core is a material that is one of plastic, carbon fiber reinforced polymer, fiberglass or an iron (ferrous) free material.

12. The electrical machine of claim 1 , wherein the non-ferromagnetic material of the stator core includes a level of an electrically conductive material and a level of mechanical stiffness associated with one of titanium, fiber glass or acetal homopolymer.

13. An electrical machine that is an axial-flux and radial-flux motor, comprising:
a rotor mounted rotatably about a machine axis, with the rotor rotatively attached to a shaft; and
a stator assembly having a stator core with a non-ferromagnetic material, and including
a radial-flux stator yoke including a continuous inner wall rigidly attached on a continuous outer wall of the stator core;
a first axial-flux stator yoke with an inner wall rigidly attached on an outer surface of a first edge wall of the stator core, and a second axial-flux stator yoke having an inner wall rigidly attached on an outer surface of a second edge wall of the stator core, wherein the radial-flux stator yoke and the first and the second axial-flux stator yokes, each include laminated sheets and slots;
windings are positioned in the slots of the radial-flux stator yoke and the first and the second axial-flux stator yokes; and
wherein the stator core and the shaft include a spline coupling feature adapted to selectively couple and mate the shaft to the stator assembly, such that the spline coupling feature includes the stator core having an external spline structure and the shaft having a corresponding internal spline structure, such that the shaft is adapted to be inserted into or removed from the stator core.

14. The electrical machine of claim 13 , wherein the shaft is a hollow stationary shaft with the rotor rotatively attached to the stationary shaft using bearings.

15. The electrical machine of claim 13 , further comprising:
a two axial-flux rotor assembly rotatively attached to the shaft via bearings, and engages with the first and second axial-flux stator yokes, each axial-flux rotor assembly having an axial-flux rotor housing rigidly attached to an outer race of bearings, an axial-flux rotor back-iron attached to the axial-flux rotor housing, and an axial-flux permanent magnet array attached to the axial-flux rotor back-iron.

16. The electrical machine of claim 15 , further comprising:
a radial-flux rotor assembly rigidly connected to each axial-flux rotor assembly axial-flux rotor housing of the two axial-flux rotor assembly, and rotatively engaged with the radial-flux stator yoke, wherein the radial-flux rotor assembly includes a radial-flux rotor housing rigidly attached to each axial-flux rotor assembly axial-flux rotor housing of the two axial-flux rotor assembly, a radial-flux rotor back-iron attached to the radial-flux rotor housing, and a radial-flux permanent magnet array attached to each axial-flux rotor assembly axial-flux rotor back-iron axial-flux rotor housing of the two axial-flux rotor assembly.

17. The electrical machine to claim 13 , wherein the non-ferromagnetic material of the stator core includes at least 90% of one or more non-ferromagnetic materials.

18. The electrical machine of claim 13 , wherein the non-ferromagnetic material of the stator core is a material that is one or more non-ferromagnetic metals obtained from sulfide, carbonate or silicate minerals, and is non-magnetic.

19. The electrical mach

Assignees

• Mitsubishi Electric Res Laboratories Inc

Inventors

• Wang Hongyu
• Zhou Lei
• Wang Bingnan

Classifications

• H02K21/24 Primary

  with magnets axially facing the armatures, e.g. hub-type cycle dynamos · CPC title

• H02K7/003

  Couplings; Details of shafts (means for mounting rotors on shafts H02K1/28) · CPC title

• H02K1/187 Primary

  to inner stators · CPC title

• H02K21/222

  Flywheel magnetos · CPC title

• H02K21/227

  having an annular armature coil · CPC title