DYNAMOELECTRIC MACHINE WITH REDUCED VIBRATION

• US 20040021392A1
• Filed: 11/26/2002
• Published: 02/05/2004
• Est. Priority Date: 03/11/2002
• Status: Active Grant

• Current Assignee: Edward Clarence Labrush
• Original Assignee: Edward Clarence Labrush
• Inventors: LaBrush, Edward Clarence
• Granted Patent: US 6,747,379 B2
• Time in Patent Office: Days
• US Class Current: 310/216
• CPC Class Codes: H02K 1/04 characterised by the material used for insulating the magnetic circuit or parts thereof
• CPC Class Codes: H02K 1/146 consisting of a generally annular yoke with salient poles
• CPC Class Codes: H02K 1/185 to outer stators

Abstract

A method and structural means are provided to mechanically modify the electromagnetic structure of a dynamoelectric machine for suppression of the vibration and noise otherwise occurring during machine operation. In doing so, the electrical performance of said modified dynamoelectric machine need not be significantly degraded.

Claims

1. A method to reduce vibration and noise during operation of a dynamoelectric machine comprising the steps of:

(a) determine the overall receptance for the electromagnetic structure in said machine at natural frequencies to the magnetic force being applied at said natural frequencies during machine operation,

(b) modify the mechanical features of said electromagnetic structure to reduce the overall receptance of said modified electromagnetic structure to said applied magnetic force,

(c) further modify adjacent stator laminations in said electromagnetic structure to provide slip damping therebetween due to having dissimilar receptance.

2. The method of claim 1 wherein the natural frequencies and corresponding mode shapes of the electromagnetic structure are determined by mathematical calculation.

3. The method of claim 1 wherein the natural frequencies and corresponding mode shapes of the electromagnetic structure are determined by experimental evaluation.

4. The method of claim 1 wherein the spatial distribution of the magnetic force on the electromagnetic structure is determined by mathematical calculation.

5. The method of claim 1 wherein the time waveform of the magnetic force acting upon receptance sites in the electromagnetic structure is determined by mathematical calculation.

6. The method of claim 5 wherein the corresponding magnetic force frequency spectrum is determined by mathematical calculation.

7. The method of claim 1 wherein the spatial distribution of the magnetic force acting on the electromagnetic structure is determined by experimental evaluation.

8. The method of claim 1 wherein the time waveform of the magnetic force acting upon receptance sites in the electromagnetic structure is determined by experimental evaluation.

9. The method of claim 8 wherein the corresponding magnetic force frequency spectrum is determined by experimental evaluation.

10. The method of claim 2 performed by mathematical modeling calculation.

11. The method of claim 4 performed by mathematical modeling calculation.

12. The method of claim 5 performed by mathematical modeling calculation.

13. The method of claim 6 performed by mathematical modeling calculation.

14. The method of claim 1 wherein the amount of vibration noise during machine operation depends upon the spatial distribution of the applied magnetic force, structural receptances of the electromagnetic structure and the proximity of coincidence between the magnetic force frequencies and the natural frequencies of the electromagnetic structure.

15. The method of claim 1 wherein receptance of the electromagnetic structure is its vibrating response at a natural frequency to the magnetic force being applied at the same frequency for specific physical sites in said electromagnetic structure.

16. The method of claim 15 wherein the receptance of said electromagnetic structure corresponds to the mode shape of the structure at that natural frequency.

17. The method of claim 2 wherein the mode shape is a graphical representation of relative amplitudes of vibration for the electromagnetic structure at a particular natural frequency.

18. The method of claim 1 wherein the maximum receptance sites in the electromagnetic structure at a natural frequency are the antinode sites of the corresponding mode shape.

19. The method of claim 1 wherein the minimum receptance sites in the electromagnetic structure at a natural frequency are the node sites of the corresponding mode shape.

20. The method of claim 1 wherein maximum vibration of the electromagnetic structure occurs when the frequency of the magnetic force coincides with a natural frequency of the electromagnetic structure and the spatial distribution of the magnetic force coincides with the maximum receptance sites in the electromagnetic structure at that natural frequency.

21. The method of claim 1 wherein said dynamoelectric machine is an electric motor.

22. The method of claim 1 wherein said dynamoelectric machine is an electric generator.

23. The method of claim 1 wherein modifying structural features in said electromagnetic structure includes modification of the stator physical dimensions.

24. The method of claim 1 wherein modifying structural features in said electromagnetic structure includes modified stator slots.

25. The method of claim 1 wherein modifying the structural features in said electromagnetic structure includes modified stator poles.

26. The method of claim 1 wherein modifying the structural features in said electromagnetic structure includes modified stator teeth.

27. The method of claim 1 wherein modifying structural features in said electromagnetic structure includes a modified stator core.

28. The method of claim 1 wherein modifying structural features in said electromagnetic structure further includes modification of the machine rotor.

29. The method of claim 28 wherein modification of said structural features includes modifying the operative cooperation between the stator and rotor.

30. Vibration noise suppression means for dynamoelectric machine operation which comprises a mechanically modified electromagnetic structure reducing the overall receptance of said modified electromagnetic structure to the applied magnetic force in operative association with adjacent laminations in said electromagnetic structure having slip damping therebetween.

31. Vibration noise suppression means of claim 30 wherein mechanical modification of the electromagnetic structure is made dependent upon the spatial distribution of the applied magnetic force, the structural receptances of the electromagnetic structure and the proximity of coincidence between the magnetic force frequencies and the natural frequencies of the electromagnetic structure.

32. Vibration noise suppression means of claim 30 wherein mechanical modification of the electromagnetic structure is made dependent upon receptance of the electromagnetic structure at a natural frequency to the magnetic force being applied at the same frequency.

33. Vibration noise suppression means of claim 32 wherein receptance of said electromagnetic structure corresponds to the mode shape of the structure at that natural frequency.

34. Vibration noise suppression means of claim 33 wherein the mode shape is a graphical representation of relative amplitudes of vibration for the electromagnetic structure at a particular natural frequency.

35. Vibration noise suppression means of claim 32 wherein the maximum receptance sites in the electromagnetic structure at a natural frequency are the antinode sites of the corresponding mode shape.

36. Vibration noise suppression means of claim 32 wherein the minimum receptance sites in the electromagnetic structure at a natural frequency are the mode sites of the corresponding mode shape.

37. Vibration noise suppression means of claim 30 wherein said dynamoelectric machine is an electric motor.

38. Vibratory noise suppression means of claim 30 wherein said dynamoelectric machine is an electric generator.

39. Vibratory noise suppression means of claim 30 wherein modifying structural features in said electromagnetic structure includes modification of the physical dimensions.

40. Vibratory noise suppression means of claim 30 wherein modifying structural features in said electromagnetic structure includes modified slots.

41. Vibratory noise suppression means of claim 30 wherein modifying the structural features in said electromagnetic structure includes modified teeth.

42. Vibratory noise suppression means of claim 30 wherein modifying the structural features in said electromagnetic structure includes modified poles.

43. Vibratory noise suppression means of claim 30 wherein modifying structural features in said electromagnetic structure includes a modified core.

44. Vibratory noise suppression means of claim 30 wherein modifying structural features in said electromagnetic structure includes modification of the machine stator.

45. Vibratory noise suppression means of claim 30 wherein modification of said structural features includes modifying the operative cooperation between the stator and rotor.

46. A dynamoelectric machine exhibiting reduced vibratory noise which includes a rotor and stator component having relative motion therebetween during operation, said stator component including an electromagnetic structure which is mechanically modified to reduce the overall receptance to the magnetic force being applied during machine operation while further being modified with slip damping means being disposed between adjacent laminations.

47. A dynamoelectric machine exhibiting reduced vibratory noise which comprises:

(a) a stator mounted in a stationary housing having a bore therethrough which includes a mechanically modified electromagnetic structure having a laminated ferromagnetic core ring containing a plurality of poles disposed therein upon teeth elements spaced apart in slot openings, said electromagnetic structure having been mechanically modified to reduce the overall receptance of said modified electromagnetic structure to the magnetic force being applied during machine operation while further being modified with slip damping means being disposed between adjacent stator laminations, and

(b) a rotor being movably mounted with respect to said stator.

48. The dynamoelectric machine of claim 47 wherein mechanical modification of the electromagnetic structure is made dependent upon the spatial distribution of the applied magnetic force, the structural receptances of the electromagnetic structure and the proximity of coincidence between the magnetic force frequencies and the natural frequencies of the electromagnetic structure.

49. The dynamoelectric machine of claim 47 wherein mechanical modification of the electromagnetic structure is made dependent upon receptance of the electromagnetic structure at a natural frequency in response to the magnetic force being applied at nearly the same frequency.

50. The dynamoelectric machine of claim 49 wherein receptance of said electromagnetic structure corresponds to the mode shape of the structure at that natural frequency.

51. The dynamoelectric machine of claim 49 wherein the mode shape is a graphical representation of relative amplitudes of vibration for the electromagnetic structure at a particular natural frequency.

52. The dynamoelectric machine of claim 50 wherein the maximum receptance sites in the electromagnetic structure at a natural frequency are the antinode sites of the corresponding mode shape.

53. The dynamoelectric machine of claim 49 wherein the minimum receptance sites in the electromagnetic structure at a natural frequency are the node sites of the corresponding mode shape.

54. The dynamoelectric machine of claim 47 wherein said dynamoelectric machine is an electric motor.

55. The dynamoelectric machine of claim 47 wherein said dynamoelectric machine is an electric generator.

56. The dynamoelectric machine claim 47 wherein modifying structural features in said electromagnetic structure includes modification of the stator physical dimensions.

57. The dynamoelectric machine of claim 47 wherein modifying structural features in said electromagnetic structure includes modified stator slots.

58. The dynamoelectric machine of claim 47 wherein modifying the structural features in said electromagnetic structure includes modified stator poles.

59. The dynamoelectric machine of claim 47 wherein modifying the structural features in said electromagnetic structure includes modified stator teeth.

60. The dynamoelectric machine of claim 47 wherein modifying the structural features in said electromagnetic structure includes a modified stator core.

61. The dynamoelectric machine of claim 47 wherein modifying structural features in said electromagnetic structure further includes modification of the machine rotor.

62. The dynamoelectric machine of claim 47 wherein modification of said structural features includes modifying the operative cooperation between the stator and rotor.