EARTHING CONTACT AND METHOD FOR DISSIPATING ELECTRICAL CURRENTS

Abstract

A ground contact and a method for conducting electric currents from a rotor part of a machine to a stationary stator part of the machine, the rotor part having an axis or shaft, the ground contact comprising a holder device connected to the stationary stator part of the machine in an electrically conductive manner and a contact realized as a flexible conductor having a free end disposed on a circumference of the rotor part and an end fastened on the holder device, the conductor being inherently stable such that a contact force can be applied to a contact surface for establishing an electrically conductive sliding contact between a sliding contact surface of the conductor and the circumference of the rotor part. The conductor is bendable such that the free end extends in the direction of a rotational axis of the rotor part when disposing the ground contact on the rotor part.

Claims

1. A ground contact for conducting electric currents from a rotor part of a machine to a stationary stator part of the machine, the rotor part having an axis or shaft, the ground contact comprising a holder device and a contact element, the holder device being able to be connected to the stationary stator part of the machine in an electrically conductive manner, the contact element being realized as a flexible conductor, the conductor having a free end disposed on a circumference of the rotor part and an end fastened on the holder device, the conductor being inherently stable in such a manner that a contact force is able to be applied to a contact surface for establishing an electrically conductive sliding contact between a sliding contact surface of the conductor provided for forming the sliding contact and the contact surface on the circumference of the rotor part, wherein the conductor is formed between the free end and the fastened end so as to be bendable in a curved manner such that the free end extends in the direction of a rotational axis of the rotor part when disposing the ground contact on the rotor part.

2. The ground contact according to claim 1, wherein the free end of a section of the conductor is disposed parallel in relation to the rotational axis.

3. The ground contact according to claim 1, wherein the fastened end is disposed on the holder device so as to extend transversally to the rotational axis of the rotor part.

4. The ground contact according to claim 1, wherein at least sections of the conductor are realized having a rectangular cross section.

5. The ground contact according to claim 1, wherein the conductor is realized as a conductor strip.

6. The ground contact according to claim 1, wherein the conductor is made predominantly of carbon.

7. The ground contact according claim 1, wherein the conductor is made of carbon fibers.

8. The ground contact according to claim 1, wherein the conductor is made of a layer of felt or fleece.

9. The ground contact according to claim 8, wherein the conductor is made of a plurality of layers in a stack arrangement.

10. The ground contact according to claim 1, wherein the conductor is infiltrated with pyrolytic carbon.

11. The ground contact according to claim 1, wherein the holder device has a stationary annular body and at least one pressure element, the fastened end of the conductor being connected to the holder device between the annular body and the pressure element in a force-fitting, form-fitting and or substance-to-substance bonded manner.

12. The ground contact according to claim 11, wherein the annular body is circular having an axial abutment surface for the conductor, the pressure element being an annulus and being able to be clamped against the abutment surface.

13. The ground contact according to claim 12, wherein an inner diameter of the abutment surface approximates an outer diameter of the contact surface.

14. The ground contact according to claim 12, wherein the abutment surface and/or the pressing element forms at least one bump for clamping and/or for securing the conductor in a form-fitting manner.

15. The ground contact according to claim 11, wherein an outer diameter of the annular body is formed by a radial shoulder, the outer diameter together with the inner diameter forming a press fit in the stator part.

16. The ground contact according to claim 1, wherein the ground contact is formed to be connectable in a radially divisible manner.

17. The ground contact according to claim 1, wherein the ground contact comprises at least two conductors which are disposed coaxially on the holder device in relation to the rotational axis.

18. A machine having a ground contact according to claim 1, for conducting electric currents from a rotor part to a stationary stator part, the rotor part having an axis or shaft.

19. A method for conducting electric currents from a rotor part of a machine, to a stationary stator part of the machine having a ground contact comprising a holder device and a contact element, the rotor part having an axis or shaft, the holder device being connected to the stationary stator part of the machine in an electrically conductive manner, the contact element being realized as a flexible conductor, the conductor having a free end disposed on a circumference of the rotor part and an end fastened on the holder device, an electrically conductive sliding contact being formed between a sliding contact surface of the conductor and a contact surface on the circumference of the rotor part, the conductor being inherently stable in such a manner that a contact force is applied to the contact surface, wherein the conductor is formed in a curved manner between the free end and the fastened end, the free end extending in the direction of a rotational axis of the rotor part.

20. The method according to claim 19, wherein an annulus or intermediate arc is formed when the ground contact is slid onto or radially assembled on the rotor part in the progression of the conductor between the free end and the fastened end.

Description

[0029] In the following the disclosure is described in more detail with reference to the attached drawings.

[0030] FIG. 1 shows a longitudinal cut of a ground contact in a mounting configuration having a rotor part and a stator part;

[0031] FIG. 2 shows a longitudinal cut of the ground contact.

[0032] FIGS. 1 and 2 show cut views of a ground contact 10, ground contact 10 being shown in conjunction with a rotor part 11 and a stator part 12 on a machine (not illustrated) in FIG. 1 while the ground contact in FIG. 2 is shown alone. Ground contact 10 serves for conducting electric currents from rotor part 11 to stator part 12 and vice versa. Ground contact 10 comprises a holder device 13 and a contact element 14, which is formed by a conductor 15. Holder device 13 is essentially made of a stationary annulus 16 and a pressure element 17. Annulus 16 is circular and forms an axial abutment surface 18. Pressure element 17 is formed as a circular arc 19 and inserted into annulus 16. Annulus 16 further forms a radial shoulder 20 having an outer diameter 21, outer diameter 21 and/or annulus 16 being inserted into an inner diameter 22 of a casing lid 23 of stator part 12. Via a press fit between outer diameter 21 and inner diameter 22, a good electric contacting and a sufficient fastening of ground contact 10 is ensured on casing lid 23.

[0033] Furthermore, annulus 16 is formed having an inner diameter 24, which is approximated to an outer diameter 25 of a pin 26 of a shaft 27 of rotor part 11. Shaft 27 is thus radially surrounded by ground contact 10. A circumference 28 of pin 26 forms a contact surface 29 for forming a sliding contact with conductor 15. Ground contact 10 comprises four conductors 15 in this instance which are disposed coaxially to a rotational axis 30 of rotor part 11 and are spaced apart equidistantly from each other in relation to one another with respect to circumference 28. Conductors 15 are each realized as conductor strips 31 which are clamped between annulus 16 and pressure element 17. Conductor strip 31 is formed via a one-piece fleece made of carbon fibers. For securing conductors 15, a bump 32 is formed on abutment surface 18 in each instance, bump 32 engaging in a recess (not visible) in conductor 15. Pressure element 17 is screwed to annulus 16 via screws (not illustrated) or a thread connection and thus clamped against abutment surface 18 with conductors 15.

[0034] Conductors 15 are essentially made of carbon fibers, which are infiltrated with pyrolytic carbon and are thus elastic. A fastened end 33 of conductors 15 clamped on holder device 13 is disposed essentially orthogonally with respect to rotational axis 30, a free end 34 of conductor 15 being bent so far in relation to fastened end 33 that free end 34 extends parallel to rotational axis 30. Between fastened end 33 and free end 34, a curve 35 is formed via this bending.

[0035] When mounting ground contact 10 on pin 26, free ends 34 also initially extend orthogonally in relation to rotational axis 30, but are deformed to the illustrated shape or curve 35 as a consequence of being slid onto pins 26, meaning a contact force is exerted on circumference 28 via elastic conductors 15. A direction of the deformation of conductors 15 is always ensured by the fact that conductors 15 are strip-shaped. The orientation of conductors 15 is then not even impacted by a rotational direction of rotor part 11. Furthermore, a particularly good electrical contacting of rotor part 11 can be ensured as conductors 15 adapt to different diameters owing to the elastic properties of conductors 15 and can shape themselves to fit around circumference 28 to a certain extent, whereby a particularly large contact surface 29 is formed.