Drive device with an electric motor and a relay switching the motor current

• US 5,877,569 A
• Filed: 12/11/1997
• Issued: 03/02/1999
• Est. Priority Date: 04/20/1995
• Status: Expired due to Fees

• Current Assignee: Brose Fahrzeugteile GmbH & Company KG Coburg
• Original Assignee: Brose Fahrzeugteile GmbH & Company KG Hallstadt (Brose)
• Inventors: Heinrich, Peter, Sesselmann, Helmut
• Primary Examiner(s): Dougherty, Thomas M.
• Assistant Examiner(s): Nguyen, Tran N.
• Application Number:
  US08/945,288
• Time in Patent Office: 446 Days
• Field of Search: 335/228-229, 335/236, 335/250, 335/278, 335/294, 310/68 R, 310/67 R, 310/154, 310/152
• US Class Current: 310/68.00R
• CPC Class Codes: H02K 23/66 Structural association with auxiliary electric devices influencing the characteristic of, or controlling, the machine, e.g. with impedances or switches

Abstract

A drive device with an electric motor with permanent magnets and a pole top more particularly for use with servo drives in motor vehicles. A relay is provided for switching the motor current with at least one electromagnet, which contains a relay coil and a relay armature, and with at least one relay contact. The relay is mounted in the pole top of the electric motor and the magnetic field lines of the electromagnets are closed through the permanent magnets and the pole top of the electric motor.

Claims

1. A drive device for use in combination with an electric motor with a permanent magnet and a pole top, the drive device comprising:

a relay for switching a motor current through the electric motor, comprising at least one electromagnet comprising a relay coil and a relay armature, and at least one relay contact, wherein the relay is mounted in the pole top of the electric motor, and wherein the magnetic field lines generated by the electromagnet are closed through the permanent magnet and the pole top of the electric motor.

2. The drive device according to claim 1, wherein the relay armature and the relay coil are rotatably mounted about an axis in the pole top of the electric motor.

3. The drive device according to claim 1, wherein the relay armature comprises a soft iron armature with a plurality of grooves for a plurality of exciter windings of the relay coil and is connected to a plurality of movable, isolated relay contacts, each of which can move in dependence on an energized state of the relay coil between two adjacent stationary relay contacts.

4. The drive device according to claim 3 further comprising a second relay coil, wherein the relay armature is mounted concentrically with a motor shaft of the electric motor and has the two relay coils embedded in the relay armature.

5. The drive device according to claim 3, wherein an axis of the relay armature is set spaced from a motor shaft of the electric motor and is connected to at least one resetting element which biases the relay armature towards a center position in a stationary magnetic field of the permanent magnet of the electric motor in which the relay coil is in an unenergized state.

6. The drive device according to claim 5 further comprising a second relay coil, wherein the relay armature is forked and has two sections, one of the two sections opposite a north pole of the permanent magnet and the other second opposite a south pole of the permanent magnet, wherein each of the two sections is connected on a first side to a base section supporting the two relay coils and connected to the axis and on a second side is connected to an isolator part which supports the movable, isolated relay contacts and is connected to the at least one resetting element.

7. The drive device according to claim 1, wherein the relay armature has a plurality of flux conducting elements arranged symmetrically relative to the axis wherein the distance of the plurality of flux conducting elements from the counter poles of the permanent magnet of the electric motor is smaller than the distance of the counter poles of the permanent magnet from the radial outer face of the relay armature.

8. The drive device according to claim 1, wherein the relay armature is mounted on a rotary point and is connected to the relay coil, and wherein the relay armature is connected on each of two end sides to a movable relay contact which can move with the relay armature, in dependence on the energized state of the relay coil, between two stationary relay contacts adapted for connection to a voltage source.

9. The drive device according to claim 1, wherein the relay is mounted eccentrically relative to the motor shaft, wherein the relay armature comprises two armature parts connected together through a connecting part comprising a non-magnetic material, each supporting a relay coil fixedly connected thereto, and wherein each of said armature parts is connected at the end opposite their common connection to a rotary element which is coupled with a the movable relay contact.

10. The drive device according to claim 3, wherein the relay armature is movable linearly relative to the relay coil, and wherein the relay coil is fixed and the relay armature is movable and is connected with one of the movable, isolated relay contacts.

11. The drive device according to claim 10, wherein the relay (2d, 2e) is a double relay which has two relay coils and two relay armatures which are mounted linearly movable relative to each other, wherein each relay armature is movable and is connected to one of the movable relay contacts and a common resetting device.

12. The drive device according to claim 11, wherein the relay armatures are mounted flush and in alignment with each other and the resetting device comprises a spring mounted between adjacent end sides of the two relay armatures.

13. The drive device according to claim 12 wherein the two relay armatures are mounted so that each is repelled by an adjacent pole of the permanent magnet in an unenergized state of the associated relay coil, wherein each relay armature is slidably mounted in an associated one of the relay coils, and wherein when the relay coils are in an energized state, the relay armatures are movable out from the relay coils.

14. The drive device according to claim 11, wherein the relay armatures are mounted so that each is attracted by an adjacent pole of the permanent magnet, wherein each relay armature is slidably mounted in an associated one of the relay coils, and wherein when the relay coils are in an energized state, the relay armatures are drawn into the relay coils.

15. The drive device according to claim 11, wherein the relay armatures are connected to a rotary disc on which are mounted two slip contacts connected to the motor winding and two contact paths adapted for connection to a voltage source, the rotary disc being connected to a resetting device which biases the rotary disc towards a neutral central position in an unenergized state of the relay coil.

16. The drive device according to claim 1, wherein the relay is a sliding relay mounted across a motor shaft of the electric motor.

17. The drive device according to claim 16 further comprising at least one additional relay coil, wherein at least two relay coils are integrated in the relay armature of the sliding relay and form an electromagnet which is mounted in the magnetic field of the permanent magnet of the electric motor having a north pole and a south pole.

18. The drive device according to claim 16, wherein the at least one relay contact comprises a plurality of movable relay contacts and a plurality of stationary relay contacts, wherein the relay armature is connected through an isolator designed as a slide element to two of the movable relay contacts opposite each of which are two of the stationary relay contacts, and wherein two isolator bodies are provided, each as an end stop restriction for the sliding relay.

19. The drive device according to claim 1, wherein the relay coil is mounted in a bridging diagonal of a transistor bridge comprising two sets of two transistors of different conductivity type connected in series and is connected to the collectors of each of two series-connected transistors of different conductivity type, wherein the emitters of each set of the series-connected transistors of different conductivity type are connected to at least one of a positive, a negative, and a mass electrical potential.

20. The drive device according to claim 1 further comprising a second relay coil, wherein the relay coils are connected together through an electrical connection and each is connected at another connection to the load path of a transistor having a base adapted for connection to an output of an electronics control unit.

21. The drive device according to claim 17 further comprising an echo sensor for detecting a motor speed of the electric motor, wherein a signal output of the echo sensor and a signal output of the relay coils are each connected to a common driver and signal detection phase through which both the control signals for controlling the relay and the echo sensor output signals are transferred and selectively amplified and filtered.

22. The drive device according to claim 3, wherein the relay coil, and wherein the relay armature is fixed and the relay coil is movable linearly relative to the relay armature is movable and is connected to at least one of the movable, isolated relay contacts.

23. The drive device according to claim 12, wherein the resetting device comprises a tensile spring.

24. The drive device according to claim 12, wherein the resetting device comprises a compression spring.

25. The drive device according to claim 21, further comprising a plurality of non-used control leads, wherein the echo sensor output signals are transferred through the plurality of non-used control leads.

26. The drive device according to claim 22, wherein the relay armature is mounted such that it is fixed between a north pole and a south pole of the permanent magnet and the relay coil is mounted such that it is linearly movable on the relay armature and is connected to two of the movable isolated relay contacts.

27. The drive device according to claim 22, further comprising another armature, wherein the two relay armatures are mounted aligned and flush with each other and fixed between a north pole and a south pole of the permanent magnet, wherein an end side of each relay armature is opposite one of the poles of the permanent magnet and each relay coil is mounted such that it is linearly movable on the relay armatures and is connected to a movable relay contact.

28. The drive device according to claim 27, wherein the two relay armatures are connected together with a non-magnetic connector part.