Claims
- 1. A method of controlling slot vibration or other motor related tonal vibration in a direct current motor having field and armature windings comprising the steps of(a) passing a current through a winding of said motor, (b) modulating said current in response to a control signal, (c) sensing said tonal vibration to provide a feedback signal, and (d) adjusting said control signal in response to said feedback signal by means of an adaptive control system, thereby reducing said tonal vibration.
- 2. A method as in claim 1 wherein said current is passed through the field winding of said motor and is a direct current.
- 3. A method as in claim 1 wherein said current is passed through the armature winding of said motor.
- 4. An active noise control system for controlling motor induced vibration in a direct current motor having field and armature windings, said system comprising(a) frequency measuring means to detect the rotational speed of the motor and thus its slot rate, (b) means to supply current to a winding of said motor, (c) circuit means for modulating the current supplied to a winding of said motor at the slot rate thereof in response to a control signal, (d) sensing means providing a feed back signal related to said vibration, and (e) controller means for adjusting said control signal in response to said feedback signal and said slot rate, whereby said tonal vibration is reduced.
- 5. A system as in claim 4 wherein the control circuit is connected in series with a coil of said motor.
- 6. A system as in claim 4 wherein the control circuit is connected in parallel with a coil of said motor.
- 7. A system as in claim 4 wherein the control is a manual control operating loop on the armature.
- 8. A system as in claim 4 wherein the control is an automatic controller operating closed loop on the armature.
- 9. A system as in claim 4 whereby vibration reduction is point reduction on the motor or motor mounting plate.
- 10. A system as in claim 4 wherein the tonals are multiples of line frequency and said frequency measuring is off the line supplying the motor.
- 11. A system as in claim 4 wherein the current is supplied to the field winding of said DC motor.
- 12. A system as in claim 4 wherein the current is supplied to the armature winding of said DC motor.
- 13. A system as in claim 4 wherein said sensing means is an optical scanner.
- 14. A system as in claim 4 wherein said sensing means is a magnetic pickup.
- 15. A system as in claim 4 wherein said circuit means includes an SCR controller which delivers a direct current RMS output from an alternating current source.
- 16. A system as in claim 4 wherein the control is a manual controller operating open loop on the field.
- 17. A system as in claim 4 wherein the control is an automatic controller operating closed loop on the field.
- 18. A system as in claim 4 wherein the control is an automatic controller operating closed loop on the field and armature and is interacting in that only the tonal vibration is canceled not the control signal.
- 19. A system as in claim 4 whereby vibration reduction is global reduction on the motor or motor mounting plate.
- 20. An active noise cancellation system for controlling the motor induced vibration in a DC motor having field and armature windings a slot rate, said system comprising a sensing means to detect motor related tonals,means to supply current through a winding of said DC motor at the slot rate thereof, circuit means for producing anti-noise signals to be applied to the field and/or armature windings to counter the slot tonals vibration and thereby lessen the slot induced vibration of said motor.
Parent Case Info
This is a continuation-in-part of Ser. No. 08/302,744, filed Sep. 9, 1994.
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5568557 |
Ross et al. |
Oct 1996 |
|
5692054 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
08/302744 |
Sep 1994 |
US |
Child |
08/733462 |
|
US |