Electric motor and control system

• US 4,264,854 A
• Filed: 06/28/1979
• Issued: 04/28/1981
• Est. Priority Date: 06/28/1979
• Status: Expired due to Term

• Current Assignee: James S. Hawtree
• Original Assignee: James S. Hawtree
• Inventors: Hawtree, James S.
• Primary Examiner(s): Dobeck, Benjamin
• Assistant Examiner(s): Moose, Richard M.
• Application Number:
  US06/052,853
• Time in Patent Office: 670 Days
• Field of Search: 318/731, 318/732, 318/716, 318/717, 318/720, 318/723, 318/724, 318/729, 318/737, 318/748, 318/775, 318/777, 318/809
• US Class Current: 318/809
• CPC Class Codes: G05B 19/42 Recording and playback systems, i.e. in which the programme is recorded from a cycle of operations, e.g. the cycle of operations being manually controlled, after which this record is played back on the same machine

Abstract

A control system regulates operation of an electrical motor having multiple stator and rotor coils by regulating the phase displacement (1) between the rotor and stator energizing signals, (2) between the signals passed to the individual rotor coils, and (3) between the signals passed to the individual stator coils. A recorder coupled to the lines over which the phase-regulating signals are supplied to the rotor and stator coils can record these signals for later application to the motor to repeat the initial movement. Additionally displacement of the motor shaft produces signals which can be recorded for later duplication of the original shaft displacement. The phase-regulating signals for the rotor and stator coils can be supplied from a variable frequency oscillator, or a data processor, or any other suitable source.

Claims

1. The combination of a motor and a control system, comprising:

an electrical motor, having a stator with a plurality of stator coils spaced at regular intervals, and a rotor mounted on a shaft and having a plurality of rotor coils spaced at regular intervals which may be different than the stator coil intervals;

means for providing electrical signals to the stator coils;

means for providing electrical signals to the rotor coils; and

a plurality of phase shift means, each of which is respectively coupled to one of said stator coils and one of said rotor coils, there being one stator coil and one rotor coil to which no phase shift means is coupled, to effect phase displacement of the signals applied to each coil with respect to the signal applied to the adjacent coils.

2. The combination defined in claim 1, in which each of said phase shift means is individually adjustable to vary the amount of the phase shift effected by that particular means.

3. The combination of claim 1, and further comprising a plurality of operational amplifiers, each of which is coupled in series with one of said phase shift means, and two additional operational amplifiers, coupled respectively to the stator coil and the rotor coil which are not coupled to any phase shift means.

4. The combination of claim 3, in which said phase shift means and operational amplifiers are mounted within the motor.

5. The combination of claim 1, in which said means for providing electrical signals to the stator coils and the rotor coils includes first and second cables, and further comprising a recorder coupled to both cables, said recorder being effective to record both the electrical signals provided to the stator coils and the electrical signals provided to the rotor coils.

6. The combination of claim 5, and further comprising a switch arrangement associated with the stator windings, operative when actuated both to interrupt the normal energization of said stator coils and to complete a signal path between one of said stator coils and the recorder, to facilitate recording to signals provided by the motor when the motor shaft is driven.

7. The combination of claim 1, and further comprising an overspeed protection circuit coupled to the means for providing electrical signals to the stator coils and to the rotor coils, operative to interrupt the transfer of said electrical signals when the phase difference between the stator coil signals and the rotor coil signals signifies the motor has reached a preset speed limit.

8. The combination of claim 7, in which the overspeed protection circuit includes a comparator stage which switches when a preset phase difference is sensed, and switching means connected for actuation by the comparator stage to interrupt the signal transfer.

9. The combination of claim 1, and further comprising a data processor connected to supply said electrical signals to the stator coils and to the rotor coils, which data processor includes a counter circuit having an input for receiving "jam" data to set the start-up condition of said counter circuit, thus setting the phase differences between adjacent coils of the rotor and stator.

10. The combination of claim 9, and further comprising a conditioning logic stage connected to receive digital signals from said counter circuit, and a digital-to-analog converter coupled between said conditioning logic stage and one of said coils, to drive said coil with an analog signal related to the output of said counter circuit.

11. The combination of a motor and a control system comprising:

an electrical motor, having a stator with a plurality of stator coils spaced at regular intervals, and a rotor mounted on a shaft and having a plurality of rotor coils spaced at regular intervals which may be different than the stator coil intervals;

means for providing electrical signals to the stator coils;

means for providing electrical signals to the rotor coils;

a plurality of individually adjustable phase shift means, each of which is respectively coupled to one of said stator coils and one of said rotor coils, there being one stator coil and one rotor coil to which no phase shift means is coupled, to effect phase displacement of the signals applied to each coil with respect to the signal applied to the adjacent coils; and

a plurality of operational amplifiers, each of which is coupled in series with one of said phase shift means, and two additional operational amplifiers, coupled respectively to the stator coil and the rotor coil which are not coupled to any phase shift means.

12. The combination of claim 11, in which said phase shift means and operational amplifiers are mounted within the motor.

13. The combination of claim 11, in which said means for providing electrical signals to the stator coils and the rotor coils includes first and second cables, and further comprising a recorder coupled to both cables, said recorder being effective to record both the electrical signals provided to the stator coils and the electrical signals provided to the rotor coils, and a switch arrangement associated with the stator windings, operative when actuated both to interrupt the normal energization of said stator coils and to complete a signal path between one of said stator coils and the recorder, to facilitate recording of signals provided by the motor when the motor shaft is driven.

14. The combination of claim 11, and further comprising an overspeed protection circuit coupled to the means for providing electrical signals to the stator coils and to the rotor coils, including a comparator stage which switches when a preset phase difference is sensed, and switching means connected for actuation by the comparator stage to interrupt the signal transfer when the phase difference between the stator coil signals and the rotor coil signals signifies the motor has reached a preset speed limit.

15. The combination of claim 11, and further comprising a data processor connected to supply said electrical signals to the stator coils and to the rotor coils, which data processor includes a counter circuit having an input for receiving "jam" data to set the start-up condition of said counter circuit, thus setting the phase differences between adjacent coils of the rotor and stator, a conditioning logic stage connected to receive digital signals from said counter circuit, and a digital-to-analog converter coupled between said conditioning logic stage and one of said coils, to drive said coil with an analog signal related to the output of said counter circuit.