Electric motor assemblies including stator and/or rotor cooling

Patent metadata

Field	Value
Publication number	US-9917486-B2
Application number	US-201514629254-A
Country	US
Kind code	B2
Filing date	Feb 23, 2015
Priority date	Jun 21, 2010
Publication date	Mar 13, 2018
Grant date	Mar 13, 2018

Abstract

An electric motor assembly including a stator having a stator core and windings around the stator core is disclosed. The stator core has opposing ends and an outer surface extending between the opposing ends. The electric motor assembly also includes a housing having an inner surface enclosing at least a portion of the stator, and at least one fluid passage between the outer surface of the stator core and the inner surface of the housing. The fluid passage permits a coolant in the fluid passage to contact one or more portions of the outer surface of the stator core to remove heat from the stator core during operation of the electric motor assembly. Additional motor assemblies including stator and/or rotor cooling features are disclosed.

First claim

The invention claimed is:

1. An electric motor assembly capable of being cooled with a coolant, said motor assembly comprising:
a rotor rotatable about an axis;
a stator including a stator core and windings wound about the stator core,
said stator core including opposite first and second ends spaced along the axis,
said stator core presenting an outer surface extending between the ends,
said windings including end turns positioned at the first end of the stator core;
a housing enclosing at least a portion of the stator,
said housing including an inner surface that cooperates with the outer surface of the stator core to define a stator cooling passage through which coolant flows to remove heat from the stator core during operation of the assembly; and
at least one orifice for directing coolant onto the end turns for removing heat from the end turns during operation of the assembly,
said at least one orifice being in fluid communication with the stator-cooling passage,
said windings including a second set of end turns positioned at the second end of the stator core,
said housing inner surface cooperating with the outer surface of the stator core to define a second stator-cooling passage through which coolant flows to remove heat from the stator core during operation of the assembly,
said assembly defining at least one second orifice for directing coolant onto the second end turns for removing heat from the second end turns during operation of the assembly,
said at least one second orifice being in fluid communication with the second stator-cooling passage.

2. The electric motor assembly as claimed in claim 1 ,
said stator-cooling passage and said second stator cooling passage each at least in part circumscribing the core,
said stator-cooling passage and said second stator cooling passage extending in generally opposite circumferential directions.

3. The electric motor assembly as claimed in claim 1 ,
said stator-cooling passage including a plurality of fluidly interconnected, at least substantially S-shaped portions.

4. The electric motor assembly as claimed in claim 1 ,
said stator-cooling passage directing coolant in alternating first and second circumferential directions,
said first circumferential direction being opposite the second circumferential direction.

5. The electric motor assembly as claimed in claim 1 ,
said stator-cooling passage at least in part circumscribing the core.

6. The electric motor assembly as claimed in claim 1 ,
said end turns presenting a radially outer side,
said at least one orifice directing coolant onto the radially outer side.

7. The electric motor assembly as claimed in claim 1 ,
said at least one orifice configured to be downstream of the stator-cooling passage, such that coolant first flows through the stator-cooling passage to remove heat from the stator core and is then directed through the at least one orifice to remove heat from the end turns.

8. The electric motor assembly as claimed in claim 7 ,
said assembly including a chamber extending between and fluidly interconnecting the stator-cooling passage and the at least one orifice.

9. The electric motor assembly as claimed in claim 8 ,
said chamber extending generally circumferentially.

10. The electric motor assembly as claimed in claim 9 ,
said chamber being generally toroidal.

11. The electric motor assembly as claimed in claim 8 ,
said housing at least in part defining the chamber.

12. The electric motor assembly as claimed in claim 11 ,
said chamber in part defined by a wall-like structure positioned between the housing and the stator,
said wall-like structure defining the at least one orifice.

13. The electric motor assembly as claimed in claim 12 ,
said housing including a recessed portion in part constituting the chamber,
said wall-like structure at least substantially enclosing the recessed portion of the housing.

14. The electric motor assembly as claimed in claim 13 ,
said wall-like structure being positioned between the housing and the first end of the stator.

15. The electric motor assembly as claimed in claim 14 ,
said housing having an axial end,
said wall-like structure being positioned axially between the axial end of the housing and the first end of the stator.

16. The electric motor assembly as claimed in claim 13 ,
said housing including an endshield defining the recessed portion.

17. The electric motor assembly as claimed in claim 12 ,
said assembly including a plurality of said orifices for directing coolant onto the end turns during operation of the assembly,
said wall-like structure defining the orifices.

18. The electric motor assembly as claimed in claim 17 ,
said orifices being arcuately spaced apart.

19. The electric motor assembly as claimed in claim 17 ,
said wall-like structure being contoured to direct coolant via the orifices onto different portions of the end turns.

20. The electric motor assembly as claimed in claim 8 ,
said assembly including a transfer port extending between and fluidly interconnecting the stator-cooling passage and the chamber,
said stator-cooling passage, said transfer port, and said chamber configured such that coolant is directed exclusively from the stator-cooling passage to the transfer port and exclusively from the transfer port to the chamber.

21. The electric motor assembly as claimed in claim 20 ,
said housing defining the transfer port.

22. The electric motor assembly as claimed in claim 8 ,
said assembly including an inlet, a fluid collection area, and an outlet,
said inlet, said stator-cooling passage, said at least one orifice, said fluid collection area, and said outlet being sequentially fluidly interconnected and configured such that coolant flows from the inlet into the stator-cooling passage and thereafter to the at least one orifice, is directed onto the end turns via the at least one orifice and thereafter collects in the fluid collection area, and drains from the fluid collection area to and through the outlet.

23. The electric motor assembly as claimed in claim 1 ,
said housing inner surface defining a recessed channel that at least in part constitutes the stator-cooling passage.

Assignees

• Nidec Motor Corp

Inventors

• Kirkley Jr Thomas E
• Wittman Lawrence J
• Poag Andrew F
• Randall Steven P

Classifications

• H02K9/19

  for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil · CPC title

• H02K1/2766

  having a flux concentration effect · CPC title

• H02K7/083

  radially supporting the rotary shaft at both ends of the rotor (H02K7/086, H02K7/09 take precedence) · CPC title

• H02K1/32 Primary

  with channels or ducts for flow of cooling medium · CPC title

• H02K5/20 Primary

  with channels or ducts for flow of cooling medium · CPC title