Electric motor and brush retaining assembly

• US 20040084992A1
• Filed: 10/25/2003
• Published: 05/06/2004
• Est. Priority Date: 10/01/2001
• Status: Active Grant

• Current Assignee: Ametek Incorporated
• Original Assignee: Ametek Incorporated
• Inventors: Finkenbinder, David B., Wu, Huanbo, Marsden, Jeffrey D., Miller, R. Craig
• Granted Patent: US 7,132,777 B2
• Time in Patent Office: Days
• US Class Current: 310/239
• CPC Class Codes: F04D 25/06 the pump being electrically driven F04D25/08 takes precedence
• CPC Class Codes: H02K 5/148 Slidably supported brushes
• CPC Class Codes: H02K 7/14 Structural association with mechanical loads, e.g. with hand-held machine tools or fans with fan or impeller for cooling the machine H02K9/06
• CPC Class Codes: H02K 9/28 Cooling of commutators, slip-rings or brushes e.g. by ventilating

Abstract

The present invention generally provides a motor-fan unit including a motor assembly having a shaft, a commutator supported on the shaft, and a pair of brushes in electrical contact with the commutator, a fan assembly having an impeller coupled to the shaft, an end plate assembly located between the impeller and the motor assembly, said end plate assembly including a plate portion defining an opening throughwhich the shaft passes, wherein said commutator is located near the opening, and a pair of brush retainers adapted to receive the brushes formed on the plate portion adjacent said commutator, the brush retainers opening toward the fan assembly.

Claims

1. A motor-fan unit comprising:

a motor assembly having a shaft, a commutator supported on said shaft, and a pair of brushes in electrical contact with said commutator;

a fan assembly having fan coupled to said shaft;

an end plate assembly located between said fan and said motor assembly, said end plate assembly including a plate portion defining an opening throughwhich said shaft passes, wherein said commutator is located near said opening; and

a pair of brush retainers adapted to receive said brushes formed on said plate portion adjacent said commutator, said brush retainers opening toward said fan assembly.

2. The motor-fan unit of claim 1, further comprising a plurality of resilient fasteners formed on any of said motor assembly, end plate assembly and said diffuser assembly and corresponding receivers formed on adjacent assemblies to effect tool free attachment thereof.

3. The motor-fan unit of claim 1, further comprising a pair of dividers extending axially from said plate portion toward said fan assembly, said dividers being located on either side of said brush retainers.

4. The motor-fan unit of claim 1, wherein said brush retainer is generally U-shaped having a first member extending axially toward said motor, a second member extending outward from said first member and a third member extending axially toward said fan assembly from said second member.

5. The motor-fan unit of claim 3, further comprising a notch formed between said plate portion and said third member, said notch extending radially along at least a portion of said portion of said third member such that said third member terminates short of said plate portion such that said brush retainer opens laterally of said brush.

6. The motor-fan unit of claim 4, further comprising a support member extending from said end plate portion toward said motor assembly adjacent said third wall and in supporting relation thereto.

7. The motor fan unit of claim 1, further comprising a spring assembly in operative contact with said brush, whereby said spring assembly urges said brush toward said commutator.

8. The motor fan unit of claim 6, further comprising a spring holder extending from said end plate assembly receiving said spring.

9. The motor fan unit of claim 7, wherein said spring has a first leg and a second leg, said spring holder including a first projection retaining said first leg, where in said second leg urges said brush toward said commutator.

10. The motor fan unit of claim 8, further comprising a second projection formed on said end plate assembly near said brush retainer, whereby said second leg of said spring is receivable against said second projection to insert or remove said brush assembly.

11. The motor-fan unit of claim 1, further comprising a diffuser located between said end plate assembly and said fan assembly, said diffuser having an opening in fluid communication with said fan assembly and throughwhich said shaft is received, said diffuser further having a pair of brush cap assemblies corresponding to said mouth of said brush retainers, said brush cap assemblies adapted to be at least partially received within said brush retainers.

12. The motor-fan unit of claim 11, wherein said brush cap assemblies each define a channel in fluid communication with said fan assembly and open toward said brushes.

13. The motor-fan unit of claim 11, wherein said channel extends radially substantially along the entire length of said brush.

14. The motor-fan unit of claim 11, wherein said diffuser assembly further comprises at least one channeling member extending axially toward said motor assembly, wherein at least a portion of said projections extend axially toward said motor assembly beyond said channeling members.

15. The motor-fan unit of claim 14, wherein said brush cap assemblies are located adjacent a channeling member and wherein said a channel of said brush cap assemblies is in fluid communication with said opening, said brushes, and channeling member, whereby air from the fan flows through said opening into said channel across said brushes and out of said channel where it is redirected by said channeling member.

16. The motor-fan unit of claim 11, wherein said brush retainer and said end plate assembly define a notch adjacent said plate portion and wherein said brush cap assembly has raised edge receivable within said notch.

17. The motor-fan unit of claim 16, wherein said raised edge is formed on said portion of said brush cap assembly extending into said brush retainers.

18. The motor-fan unit of claim 17, wherein said raised edge extends the length of said brush cap assembly.

19. The motor-fan unit of claim 11, further comprising a projecting surface carried on said brush cap assemblies adapted to engage a surface on said end plate adjacent said brush retainer upon assembly such that said end plate assembly and said diffuser are axially coupled.

20. The motor fan unit of claim 19, wherein said projecting surface extend radially inward from said brush cap assemblies adjacent said opening;

and

a commutator receiver formed on said end plate coaxially aligned with said opening, said commutator receiver defining at least one notch corresponding to said brush cap assemblies and adapted to receive said projecting surface, said notch having a surface that lockingly engages said projecting surface upon insertion.

21. An end plate assembly in a motor-fan unit comprising:

a plate portion and a bracket portion adapted to be attached to the motor, said plate portion having a commutator receiver formed thereon, said commutator receiver defining a well that at least partially receives said commutator.

22. The end plate assembly of claim 21, further comprising a brush retainer integrally formed on said plate portion, said brush retainer defining a mouth opening toward the fan of the motor-fan unit.

23. The end plate assembly of claim 21, wherein said brush retainer includes a generally U-shaped member extending axially toward the motor from the plate portion about said mouth.

24. The end plate assembly of claim 23, wherein said brush assembly includes a first member extending axially toward the motor from said end plate a second member cantilevered from said first member forming the base of said U and a third member extending axially toward the fan from said second member, wherein said third member terminates short of said plate portion to define a notch therebetween.

25. The end plate assembly of claim 21 further comprising at least one notch formed in said commutator receiver adapted to receive a snap locking projecting surface.

26. A diffuser in a motor-fan unit having a motor assembly and a fan assembly, the diffuser comprising:

a plurality of channeling members spaced about a central bore, and a pair of brush cap assemblies extending axially toward the motor assembly.

27. The diffuser assembly of claim 26, wherein said assemblies define a channel for receiving air from the fan assembly in the motor-fan unit.

28. The diffuser assembly of claim 26, wherein said brush cap assemblies include a projecting surface adapted to engage a surface on an end plate assembly in a snap lock fashion to couple said end plate assembly to the diffuser.

29. A combination diffuser assembly and end plate assembly in a motor-fan unit having a motor assembly and a fan assembly comprising:

an end plate assembly having a plate portion;

a pair of brush retainers extending axially toward the motor assembly from said plate portion defining a mouth that opens toward the diffuser assembly;

a pair of brush cap assemblies formed on the diffuser assembly corresponding to said brush retainers and at least partially extending into said mouth.

30. The combination diffuser assembly and end plate assembly of claim 29, further comprising a channel formed in each of said brush cap assemblies.

31. The combination diffuser assembly and end plate assembly of claim 29, wherein said diffuser assembly and said end plate assembly are attached by one or more resilient fastening assemblies.

32. The combination diffuser assembly and end plate assembly of claim 31, wherein said resilient fastening assemblies include a projecting surface extending radially inward from said brush cap assemblies adapted to engage a receiving surface formed on said end plate assembly adjacent said brush retainers in a snap-locking fashion.

33. The combination diffuser assembly and end plate assembly of claim 30, said end plate assembly further comprising, a pair of dividers located on either side of said each mouth.