CONTACTING DEVICE FOR TRANSMITTING ELECTRIC CURRENTS, AND MACHINES COMPRISING SUCH A CONTACTING DEVICE

Abstract

A contacting device for transmitting electric currents of a rotor part of a machine, said rotor part being formed by a shaft and/or slip ring, to a machine, and to the use of a discharge device, wherein the discharge device comprises a contact element for forming an electrically conductive sliding contact between a sliding contact surface of the contact element, said sliding contact surface being provided in order to form the sliding contact, and a rotor contact surface of the shaft or the slip ring, and a recess is formed in the sliding contact surface. The contact element is at least partly coated with an oily fluid, in particular at least in the region of the sliding contact surface.

Claims

1. Contacting device for transmitting electric currents from a rotor part of a machine configured with a shaft and/or a slip ring, comprising a contact element to form an electrically conductive slip contact between a sliding contact surface of the contact element provided to form the slip contact and a rotor contact surface of the shaft or the slip ring, wherein a recess is formed in the sliding contact surface, wherein the contact element is wetted with an oily fluid at least partially, in particular at least in the area of its sliding contact surface.

2. Contacting device according to claim 1, wherein the oily fluid is engine oil and/or gear oil.

3. Contacting device according to claim 1, wherein the recess within the sliding contact surface is formed by at least one bore or a slit.

4. Contacting device according to claim 1, wherein two or more recesses are formed within the sliding contact surface.

5. Contacting device according to claim 1, wherein the recess is formed as at least one channel that passes through the contact element and forms respectively one opening in the sliding contact surface and in a lateral surface of the contact element facing away from the sliding contact surface.

6. Contacting device according to claim 5, wherein a ratio of a cross-section of the channel in the sliding contact surface to a cross-section of the channel in the lateral surface, in particular side surface or rear surface of the contact element is 1.1.

7. Contacting device according to claim 5, wherein the channel is configured to be conical in a longitudinal section, with reduced diameters and/or with channel sections running longitudinally and/or transversely relative to one another.

8. Contacting device according to claim 1, wherein a ratio of an area within the sliding contact surface to the sliding contact surface is 0.08.

9. Contacting device according to claim 1, wherein the contact element is accommodated and displaceable at least partially in a guide device of the contacting device, wherein the contact element is connected in an electrically conducting manner to the guide device and/or a holding element of the machine and wherein the contact element is pre-tensioned by means of a spring element in the direction of the rotor contact surface, wherein the guide device can be connected in an electrically conducting manner to a stator part of the machine.

10. Contacting device according to claim 9, wherein the contact element is connected in an electrically conducting manner to the guide device or a holding element of the machine by means of a preferably low-resistance strand, wherein the strand is preferably pressed or stamped in the contact element at one end and is preferably welded or soldered or crimped with the guide device at the other end.

11. Contacting device according to claim 1, wherein the contact element is substantially fabricated from a carbon-metal mixture, in particular from a mixture of graphite and metal, wherein the total volume fraction of the metal is preferably at least 30 vol. %, wherein at least in a front region of the contact element having the sliding contact surface, preferably silver is provided as metal and wherein in a rear region of the contact element preferably copper is provided as metal, wherein the contact element is preferably free from copper in the region of the sliding contact surface.

12. Contacting device according to claim 1, characterized in that the contact element is a rod-shaped brush, wherein the sliding contact surface is preferably configured to be rectangular or square.

13. Contacting device according to claim 1, wherein a cross-section of the contact element is configured to be at least partially conical, in particular bow-shaped.

14. Machine, in particular electric drive motor or transmission, comprising a rotor part having a shaft and/or a slip ring as well as a contacting device according to claim 1, wherein the contact element of the contacting device contacts the shaft or the slip ring with its sliding contact surface to form a sliding contact.

15. Machine according to claim 14, wherein the contact element contacts a circumferential surface of the shaft or the slip ring.

16. Machine according to claim 14, wherein a longitudinal axis of the contact element is arranged to run at a distance relative to an axis of rotation of the shaft.

17. Machine according to claim 14, wherein the contact element contacts a front face of the shaft or the slip ring, wherein the contact element is preferably arranged substantially coaxially to the shaft.

18. Machine according to claim 14, wherein oily fluid, in particular engine or gear oil, is provided at least in a space surrounding the slip contact at the shaft or the slip ring and the contact element.

19. Use of a contacting device for transmitting electric currents from a rotor part of a machine formed with a shaft and/or a slip ring, comprising a contact element for forming an electrically conducting slip contact between a sliding contact surface of the contact element provided to form the slip contact and a rotor contact surface of the shaft or the slip ring, wherein a recess is formed in the sliding contact surface, wherein the contact element is wetted with an oily fluid at least partially, in particular at least in the region of its sliding contact surface.

Description

[0035] Further features are obtained from the following descriptions of the figures in connection with the drawings and the dependent claims. Here, the individual features can be implemented alone or in combination with one another.

[0036] In the following drawings:

[0037] FIG. 1 shows a shaft with a contact element according to a first embodiment;

[0038] FIG. 2 shows a shaft with a contact element according to a second embodiment;

[0039] FIG. 3 shows a shaft with a contact element according to a third embodiment;

[0040] FIG. 4 shows a side view of a contact element;

[0041] FIG. 5 shows a plan view of a contact element according to a first embodiment;

[0042] FIG. 6 shows a longitudinal sectional view of the contact element from FIG. 5;

[0043] FIG. 7 shows a longitudinal sectional view of a second embodiment of a contact element;

[0044] FIG. 8 shows a longitudinal sectional view of a third embodiment of a contact element;

[0045] FIG. 9 shows a longitudinal sectional view of a fourth embodiment of a contact element;

[0046] FIG. 10 shows a longitudinal sectional view of a fifth embodiment of a contact element;

[0047] FIG. 11 shows a plan view of a sixth embodiment of a contact element;

[0048] FIG. 12 shows a plan view of a seventh embodiment of a contact element.

[0049] FIG. 1 shows a purely schematic diagram of a contact element 10 of a contacting device, not shown here, on a shaft 11 of a machine, also not shown in detail. The shaft 11 is wetted with an oily fluid, which is also not visible, and rotates in the direction of the arrow 12. The contact element 10 forms a sliding contact surface 13 and abuts against a rotor contact surface 14 formed by a circumferential surface 15 of the shaft 11. The sliding contact surface 13 and the rotor contact surface 14 together form a sliding contact 16 between the shaft 11 and the contact element 10, via which electrical currents can be dissipated from the shaft 11. A recess, which cannot be seen here, is formed within the sliding contact surface 13.

[0050] In principle, in all of the described embodiments, a rotor contact surface can be formed by a slip ring.

[0051] FIG. 2 shows a contact element 17 which abuts against the shaft 11, wherein a longitudinal axis 18 of the contact element 17 is arranged to run at a distance A relative to an axis of rotation 19 of the shaft 11. In particular, a cutting edge 20 is thus formed on the contact element 17 with which oily fluid can be scraped off the circumferential surface 15.

[0052] FIG. 3 shows a contact element 21 on a shaft 22, wherein the contact element 21 contacts the shaft 22 on an axial side 23. Here, too, the contact element 21 has a recess, not shown in more detail, in a sliding contact surface 24.

[0053] FIG. 4 shows a contact element 25 which substantially consists of a carbon-metal mixture, in particular a mixture of graphite and metal. In a front area 27 of the contact element 25 having a sliding contact surface 26, a metal silver is provided, with copper being provided as a metal in a rear area 28 of the contact element 25. A strand 30 is attached to the contact element 25 on a rear surface 29 of the contact element 25. A recess, not shown in detail here, is formed within the sliding contact surface 26.

[0054] A combined view of FIGS. 5 and 6 shows a contact element 31 with a sliding contact surface 32 within which a bore 33 is formed, which forms a channel 34 which penetrates the contact element 31. The bore 33 forms a diameter d1 in the sliding contact surface 32 which corresponds to a diameter d2 on a rear surface 35 of the contact element 31. The bore 33 accordingly runs coaxially through the contact element 31.

[0055] FIG. 7 shows a contact element 36 in which a channel 37 is configured to be conical. A diameter d1 in a sliding contact surface 38 is configured to be larger in relation to a diameter d2 in a rear surface 35 of the contact element 36.

[0056] FIG. 8 shows a contact element 40 with a channel 41 which is formed from a first bore 42 and a second bore 43. The first bore 42 has a comparatively smaller diameter d2 than the second bore 43 having the diameter d1.

[0057] FIG. 9 shows a contact element 44 with a blind hole 45 in a sliding contact surface 46. Another blind hole 48 that crosses the blind hole 45 is formed in a side face 47 of the contact element 44. A discharge of oily fluid to the side surface 47 is possible via a channel 49 configured in this way. This is particularly useful when a rear face 50 of the contact element 44 cannot be provided with an opening for structural reasons.

[0058] FIG. 10 shows a contact element 51 with a through hole 52 which connects two side surfaces 53 of the contact element 51. Two blind holes 55 are formed in a sliding contact surface 54, both of which open into the through hole 52. Two channels 56 are thus formed.

[0059] FIG. 11 shows a contact element 57 with a bore 58 in a sliding contact surface 59, wherein parallel side surfaces 60 here are configured to be partially conical with a slope 61, relative to a cross-section 62 of the contact element 57. When oily fluid flows against the sliding contact surface 59, this can be displaced at least partially in the area of the slopes 61 along the side surfaces 60.

[0060] FIG. 12 shows a contact element 63 in which two bores 65 are formed in a sliding contact surface 64. The two bores 65 lie on a transverse axis 66 of the sliding contact surface 64 relative to a direction of movement of a shaft not shown here.