Motor assembly with compact gear drive

Patent metadata

Field	Value
Publication number	US-10230284-B2
Application number	US-201715433923-A
Country	US
Kind code	B2
Filing date	Feb 15, 2017
Priority date	Feb 15, 2016
Publication date	Mar 12, 2019
Grant date	Mar 12, 2019

Abstract

An electric motor assembly includes a rotor, a stator, and a gear assembly. The gear assembly includes a drive gear, a ring gear, and an intermediate gear disposed between and engaging each of the drive gear and the ring gear. The gear assembly further includes a carrier supporting the intermediate gear and being fixed relative to the stator so as to be stationary relative thereto. The ring gear is rotatable relative to the carrier and the stator.

First claim

What is claimed is:

1. An electric motor assembly comprising:
a rotor rotatable about a rotor axis;
a stator;
a gear assembly including—
a drive gear,
a ring gear at least substantially circumscribing the drive gear,
an intermediate gear disposed between and engaging each of the drive gear and the ring gear, and
a carrier supporting the intermediate gear,
said carrier being fixed relative to the stator so as to be stationary relative thereto,
said ring gear being rotatable relative to the carrier and the stator,

said rotor including a flywheel,
said rotor further including a shaft,
said shaft including axially opposed shaft ends,
said flywheel being disposed axially between the shaft ends.

2. The electric motor assembly of claim 1 ,
said assembly further comprising a housing defining a motor chamber at least substantially receiving the rotor and the stator,
said stator and said carrier being fixed relative to the housing.

3. The electric motor assembly of claim 2 ,
said housing at least in part circumscribing the carrier.

4. The electric motor assembly of claim 2 ,
said housing including an endshield rotatably supporting the shaft,
said carrier being fixed directly to said endshield.

5. The electric motor assembly of claim 4 ,
said stator at least substantially circumscribing said rotor.

6. The electric motor assembly of claim 4 ,
said housing further including a support structure at least in part disposed axially between the stator and the endshield,
said endshield and said stator each being fixed directly to said support structure.

7. The electric motor assembly of claim 6 ,
said rotor at least substantially circumscribing said stator.

8. The electric motor assembly of claim 1 ,
said carrier defining a gear chamber at least in part receiving the intermediate gear.

9. The electric motor assembly of claim 1 ,
said ring gear including a plurality of teeth presenting a toothed surface and configured to intermesh with complementary structure defined by the intermediate gear.

10. The electric motor assembly of claim 1 ,
said electric motor assembly further comprising a wheel fixed relative to the ring gear to rotate therewith.

11. The electric motor assembly of claim 10 ,
said wheel presenting a wheel axis of rotation that is coaxial with the rotor axis.

12. The electric motor assembly of claim 10 ,
said electric motor assembly further comprising a hub fixed to said wheel, with the hub being provided by the ring gear.

13. The electric motor assembly of claim 1 ,
said carrier being at least substantially coaxial with the stator.

14. The electric motor assembly of claim 1 ,
said shaft presenting the drive gear.

15. The electric motor assembly of claim 1 ,
said gear assembly including three of said intermediate gears.

16. The electric motor assembly of claim 1 ,
said gear assembly having a 9:1 gear ratio.

17. The electric motor assembly of claim 1 ,
said rotor further including a rotor core,
said flywheel being disposed axially between the rotor core and the gear assembly.

18. The electric motor assembly of claim 17 ,
said flywheel being integrally formed with the shaft.

19. An electric motor assembly comprising:
a rotor rotatable about a rotor axis;
a stator;
a gear assembly including—
a drive gear,
a ring gear at least substantially circumscribing the drive gear,
an intermediate gear disposed between and engaging each of the drive gear and the ring gear, and
a carrier supporting the intermediate gear,
said carrier being fixed relative to the stator so as to be stationary relative thereto,
said ring gear being rotatable relative to the carrier and the stator,

said ring gear including a plurality of teeth presenting a toothed surface and configured to intermesh with complementary structure defined by the intermediate gear,
said electric motor assembly further comprising a first bearing rotatably supporting the ring gear on the carrier,
said ring gear presenting a first mounting surface engaging the first bearing.

20. The electric motor assembly of claim 19 ,
said electric motor assembly further comprising a second bearing rotatably supporting the ring gear on the carrier,
said ring gear presenting a second mounting surface engaging the second bearing.

21. The electric motor assembly of claim 20 ,
said toothed surface being disposed axially between said first and second mounting surfaces.

22. The electric motor assembly of claim 19 ,
said ring gear including discrete first and second components respectively presenting the toothed surface and the first mounting surface.

23. The electric motor assembly of claim 19 ,
said rotor including a flywheel.

24. An electric motor assembly comprising:
a rotor rotatable about a rotor axis;
a stator;
a gear assembly including—
a drive gear,
a ring gear at least substantially circumscribing the drive gear,
an intermediate gear disposed between and engaging each of the drive gear and the ring gear, and
a carrier supporting the intermediate gear,
said carrier being fixed relative to the stator so as to be stationary relative thereto,
said ring gear being rotatable relative to the carrier and the stator,

said rotor including a flywheel,
said rotor further including a shaft,
said flywheel being integrally formed with the shaft.

25. The electric motor assembly of claim 24 ,
said shaft including axially opposed shaft ends,
said flywheel being disposed axially between the shaft ends.

26. The electric motor assembly of claim 24 ,
said rotor further including a rotor core,
said flywheel being disposed axially between the rotor core and the gear assembly.

27. An electric motor assembly comprising:
a rotor rotatable about a rotor axis;
a stator;
a gear assembly including—
a drive gear,
a ring gear at least substantially circumscribing the drive gear,
an intermediate gear disposed between and engaging each of the drive gear and the ring gear, and
a carrier supporting the intermediate gear,
said carrier being fixed relative to the stator so as to be stationary relative thereto,
said ring gear being rotatable relative to the carrier and the stator,

said rotor including a flywheel,
said rotor further including a rotor core,
said flywheel being disposed axially between the rotor core and the gear assembly.

Assignees

• Nidec Motor Corp

Inventors

• Moore William D
• Biro Joshua M
• Fadler Richard J
• Allen Matthew D
• Johnson Philip S
• Moore Michael E
• Tucker John M

Classifications

• H02K7/116 Primary

  with gears · CPC title

• H02K7/08

  Structural association with bearings · CPC title

• F16H57/02

  Gearboxes; Mounting gearing therein · CPC title

• F16H1/28

  with gears having orbital motion · CPC title

• F16H2057/02034

  Gearboxes combined or connected with electric machines · CPC title