DISCHARGE DEVICE FOR DISCHARGING ELECTRIC CURRENTS

Abstract

The invention relates to a discharge device (10) for discharging electric currents from a rotor part of a machine, in particular a rotor part realized with a shaft, into a stator part of the machine, the discharge device comprising a contact element (12), a support (13) and a spring mechanism (14), the support being connectable to a stator part in an electrically conductive manner, the contact element being predominantly made of carbon, the contact element being accommodated on the support in an axially movable manner and being connected to it in an electrically conductive manner, a contact force being applicable to the contact element by means of the spring mechanism so as to establish an electrically conductive sliding contact (17) between a sliding contact surface (15) of the contact element, said sliding contact surface serving to establish the sliding contact, and an axial shaft contact surface (16) of the shaft, wherein the contact element is disk-shaped, the sliding contact surface being at least annular and disposable coaxially relative to the shaft contact surface.

Claims

1. A discharge device (10, 66, 78, 83, 93, 98) for discharging electric currents from a rotor part of a machine, in particular a rotor part realized with a shaft (11, 67, 81, 84), into a stator part of the machine, the discharge device comprising a contact element (12, 24, 31, 43, 46, 49, 51, 53, 57, 61, 63, 74, 79, 87, 94, 99), a support (13, 27, 34, 70, 88) and a spring mechanism (14), the support being connectable to a stator part in an electrically conductive manner, the contact element being predominantly made of carbon, the contact element being accommodated on the support in an axially movable manner and being connected to it in an electrically conductive manner, a contact force being applicable to the contact element by means of the spring mechanism so as to establish an electrically conductive sliding contact (17) between a sliding contact surface (15, 26, 45, 58, 80) of the contact element, said sliding contact surface serving to establish the sliding contact, and an axial shaft contact surface (16, 82) of the shaft, characterized in that the contact element is disk-shaped, the sliding contact surface being at least annular and disposable coaxially relative to the shaft contact surface, the support having a base plate (21, 28, 35, 71, 89), the spring element being disposed between the base plate and a contact pressure side (19) of the contact element, said contact pressure side facing away from a contact surface side, which has the sliding contact surface.

2. The discharge device according to claim 1, characterized in that the contact element (12, 24, 31, 43, 46, 49, 51, 53, 57, 61, 63, 74, 79, 87, 94, 99) is realized in one piece and consists predominantly of carbon.

3. The discharge device according to claim 1, characterized in that the support (13, 27, 34, 70, 88) is made of a metal selected from the group comprising steel, aluminum, copper or an alloy of these materials.

4. The discharge device according to claim 1, characterized in that the support (13, 27, 34, 70, 88) and the contact element (12, 24, 31, 43, 46, 49, 51, 53, 57, 61, 63, 74, 79, 87, 94, 99) together form a lock against rotation (42) for the contact element.

5. The discharge device according to claim 1, characterized in that the spring mechanism (14) has a spring element, preferably selected from the group comprising a spiral spring, a compression spring, a disk spring (18, 77, 90), a leaf spring, a conical spring, an annular spring or a diaphragm spring, the spring element being disposed coaxially relative to the sliding contact surface (15, 26, 45, 58, 80).

6. The discharge device according to claim 1, characterized in that the contact element (12, 24, 31, 43, 46, 49, 51, 53, 57, 61, 63, 74, 79, 87, 94, 99) is composed of at least two layers (95, 96, 100, 101, 102) having different material mixtures.

7. The discharge device according to claim 6, characterized in that the layers (95, 96, 100, 101, 102) are formed back to back in the axial direction, the sliding contact surface (15, 26, 45, 58, 80) being formed by a sliding layer (95, 100) having a copper content of <60 wt % and the contact pressure side (19) being formed by a bonding layer (96, 101) having a copper content of >80 wt %, an expansion layer (102) formed between the sliding layer and the bonding layer.

8. The discharge device according to claim 6, characterized in that the contact element (12, 24, 31, 43, 46, 49, 51, 53, 57, 61, 63, 74, 79, 87, 94, 99) is realized with a contoured transition zone (97) between the layers (95, 96, 100, 101, 102) by sintering.

9. The discharge device according to claim 1, characterized in that the support (13, 27, 34, 70, 88) has at least one guiding element assembly (39) which extends in the axial direction and on which the contact element (12, 24, 31, 43, 46, 49, 51, 53, 57, 61, 63, 74, 79, 87, 94, 99) can axially slide.

10. The discharge device according to claim 9, characterized in that at its circumference (41, 54, 92), the contact element (12, 24, 31, 43, 46, 49, 51, 53, 57, 61, 63, 74, 79, 87, 94, 99) has a guiding contour which is inserted into the guiding element assembly (39).

11. The discharge device according to claim 9, characterized in that the contact element (12, 24, 31, 43, 46, 49, 51, 53, 57, 61, 63, 74, 79, 87, 94, 99) has a guiding recess (23, 33, 47, 50, 52, 56, 62) into which the guiding element assembly (39) or a guiding pin (85) of the shaft (11, 67, 81, 84) engages.

12. The discharge device according to claim 11, characterized in that the guiding recess (23, 33, 47, 50, 52, 56, 62) and the guiding element assembly (39) have corresponding cross-sections.

13. The discharge device according to claim 9, characterized in that the guiding element assembly (39) is disposed coaxially with the sliding contact surface (15, 26, 45, 58, 80).

14. The discharge device according to claim 9, characterized in that the guiding element assembly (39) hast at least one guiding element (22, 29, 36, 73).

15. The discharge device according to claim 14, characterized in that the guiding element (22, 29, 36, 73) is integral to a base plate (21, 28, 35, 71, 89) of the support (13, 27, 34, 70, 88) or plugged into the base plate.

16. The discharge device according to claim 14 or 15, characterized in that the support (13, 27, 34, 70, 88) is realized in one piece.

17. The discharge device according to claim 14, characterized in that an inner surface of the guiding recess (23, 33, 47, 50, 52, 56, 62) is in electrically conductive contact with an outer surface (30) of the guiding element (22, 29, 36, 73).

18. The discharge device according to claim 14, characterized in that the guiding element (22, 29, 36, 73) is disposed on the support (13, 27, 34, 70, 88) concentrically relative to the shaft contact surface (16, 82).

19. The discharge device according to claim 14, characterized in that the guiding element is disposed on the support eccentrically relative to the shaft contact surface.

20. The discharge device according to claim 1, characterized in that at least one groove (60, 64) running in the radial direction is formed in the sliding contact surface (58).

21. The discharge device according to claim 1, characterized in that the contact element (53, 87) is connected to the support (88) via at least one electrically conductive stranded wire (55, 91) or a flexible flat metal tape.

22. The discharge device according to claim 1, characterized in that the sliding contact surface (80) is conical in order to come into contact with a correspondingly shaped shaft contact surface (82).

23. A machine comprising a discharge device (10, 66, 78, 83, 93, 98) claim 1.

Description

[0032] Hereinafter, advantageous embodiments of the invention are explained in more detail with reference to the accompanying drawings.

[0033] FIG. 1: is a section view of a first embodiment of a discharge device on a shaft;

[0034] FIG. 2: is a top view of a contact element according to the first embodiment of the discharge device;

[0035] FIG. 3: is a side view of the contact element of FIG. 2;

[0036] FIG. 4: is a top view of a base plate according to the first embodiment of the discharge device;

[0037] FIG. 5: is a side view of the base plate of FIG. 4;

[0038] FIG. 6: is a top view of a second embodiment of a contact element;

[0039] FIG. 7: is a side view of the contact element of FIG. 6;

[0040] FIG. 8: is a top view of a second embodiment of a base plate;

[0041] FIG. 9: is a side view of the base plate of FIG. 8;

[0042] FIG. 10: is a top view of a third embodiment of a contact element;

[0043] FIG. 11: is a side view of the contact element of FIG. 10;

[0044] FIG. 12: is a top view of a fourth embodiment of a contact element;

[0045] FIG. 13: is a side view of the contact element of FIG. 12;

[0046] FIG. 14: is a top view of a fifth embodiment of a contact element;

[0047] FIG. 15: is a side view of the contact element of FIG. 14;

[0048] FIG. 16: is a top view of a sixth embodiment of a contact element;

[0049] FIG. 17: is a side view of the contact element of FIG. 16;

[0050] FIG. 18: is a top view of a seventh embodiment of a contact element;

[0051] FIG. 19: is a side view of the contact element of FIG. 18;

[0052] FIG. 20: is a top view of an eighth embodiment of a contact element;

[0053] FIG. 21: is a side view of the contact element of FIG. 20;

[0054] FIG. 22: is a top view of a ninth embodiment of a contact element;

[0055] FIG. 23: is a side view of the contact element of FIG. 22;

[0056] FIG. 24: is a top view of a tenth embodiment of a contact element;

[0057] FIG. 25: is a side view of the contact element of FIG. 24;

[0058] FIG. 26: is a section view of a second embodiment of a discharge device on a shaft;

[0059] FIG. 27: is a section view of a third embodiment of a discharge device on a shaft;

[0060] FIG. 28: is a section view of a fourth embodiment of a discharge device on a shaft;

[0061] FIG. 29: is a section view of a fifth embodiment of a discharge device on a shaft;

[0062] FIG. 30: is a section view of a sixth embodiment of a discharge device on a shaft.

[0063] FIG. 1 shows a section view of a discharge device 10 on a shaft 11. Discharge device 10 is composed of a contact element 12, a support 13 and a spring mechanism 14. Contact element 12 consists predominantly of carbon, is circular and has a sliding contact surface 15 which is in contact with an end-side or axial shaft contact surface 16 of shaft 11, whereby an electrically conductive sliding contact 17 is established. Spring mechanism 14 is formed by a disk spring 18 which is in contact with a contact pressure side 19 of contact element 12 and exerts a contact force on contact element 12 in an axial direction relative to an axis of rotation 20 of shaft 11. Support 13 is composed of a base plate 21 having a guiding element 22 formed thereon, which is circular in the case at hand. Because of its annular shape, contact element 12 has a guiding recess 23 to which guiding element 22 is configured correspondingly in such a manner that contact element 12 is axially displaceable on support 13 relative to axis of rotation 20. Disk spring 18 is plugged onto guiding element 22 and bears against base plate 21. Base plate 21 and guiding element 22 are realized in one piece from metal and are attached to a fixed component of an electric machine (not shown). On the whole, a good electrically conductive connection with low transition resistance from shaft 11 to support 13 can be established via contact element 12 in this way. Also, discharge device 10 can be installed on an electric machine particularly quickly and simply.

[0064] FIGS. 2 and 3 show a contact element 24 which is annular and rotationally symmetrical. Contact element 24 forms a sliding contact surface at an end face 25.

[0065] FIGS. 4 and 5 show a support 27 which is realized in one piece and which has a rectangular base plate 28 with an integral guiding element 29 which is pin-shaped or bolt-shaped. The contact element of FIG. 2 can be plugged onto an outer surface 30 of guiding element 29.

[0066] A combined view of FIGS. 6 to 9 shows a contact element 31 which is disk-shaped and which has a centric bore 32 which forms a guiding recess 33. A support 34 gas a guiding pin 37 as a guiding element 36 on a base plate 35, said guiding pin 37 corresponding to bore 32. Furthermore, quadratic guiding pins 38 which form a guiding element assembly 39 together with guiding pin 37 are formed in base plate 35. Guiding pins 38 can engage into grooves 40 in a circumference 41 of contact element 31, thus forming a lock against rotation 42 for contact element 32 on support 34.

[0067] FIGS. 10 and 11 show a contact element 43 which differs from the contact element of FIG. 6 in that it has a depression 44. Depression 44 is formed in a sliding contact surface 45 and serves to receive a screw head of a screw (not shown) which can serve to attach contact element 43 to a support or base plate and guide it thereon.

[0068] FIGS. 12 and 13 show a contact element 46 having three guiding recesses 47 which are formed in contact element 46 and which are eccentric relative to an axis of rotation 48 of a shaft (not shown) and spaced equidistantly.

[0069] FIGS. 14 and 15 show a contact element 49 having a slot-shaped guiding recess 50.

[0070] FIGS. 16 and 17 show a contact element 51 having a polygonal guiding recess.

[0071] FIGS. 18 and 19 show a contact element 53 having stranded wires 55 (shown in part) which emerge from contact element 53 at its circumference 54 and which can be connected to a support (not shown). A centric guiding recess 56 and equidistantly disposed stranded wires 55 center contact element 53 on the support.

[0072] FIGS. 20 and 21 show a contact element 57 which differs from the contact element of FIG. 2 in that, in a sliding contact surface 58, it has grooves 60 running in the radial direction relative to an axis of rotation 59 of a shaft (not shown). A radial depth T of the grooves corresponds to a wear length of contact element 57.

[0073] FIGS. 22 and 23 show a contact element 61 which differs from the contact element of FIG. 20 in that it has a relatively small guiding recess 62.

[0074] FIGS. 24 and 25 show a contact element 63 which differs from the contact element of FIG. 22 in that it has grooves 64 which run in the manner of a passant relative to an axis of rotation 65 of a shaft (not shown), which means that they do not intersect axis of rotation 65 but are still disposed in the radial direction.

[0075] FIG. 26 shows a discharge device 66 on a shaft 67 which has a centric recess 69 in an end face 68. Discharge device 66 is composed of a support 70 having a base plate 71 and a screw 72 attached thereto as guiding element 73, a contact element 74 of discharge device 66 having a depression 75 which serves to receive a screw head 76 of screw 72. Depression 69 is also large enough for screw head 76 to not come into contact with end face 68 when contact element 74 wears. A disk spring 77 for exerting a contact force is disposed between contact element 74 and base plate 71.

[0076] FIG. 27 shows a discharge device 78 having a contact element 79 which forms a conical sliding contact surface 80. A shaft 81 also forms a conical shaft contact surface 82 which matches sliding contact surface 80. In this way, contact element 79 can be easily centered on shaft 81.

[0077] FIG. 28 shows a discharge device 83 on a shaft 84 which has a journal 85 on an end face 86. Discharge device 83 comprises an annular contact element 87 which is plugged onto journal 85, a support 88 having a base plate 89, a disk spring 90, and stranded wires 91 which emerge from contact element 87 at its circumference 92 and are attached to base plate 89. Thus, a particularly good electrically conductive connection can be established between contact element 87 and base plate 89.

[0078] FIG. 29 shows a discharge device 93 which differs from the discharge device of FIG. 1 in that it has a contact element 94 which has a sliding layer 95 and a bonding layer 96. Sliding layer 95 has a copper content of <60 wt %, and bonding layer 96 has a copper content of >80 wt %. A transition zone 97 between sliding layer 95 and bonding layer 96 is contoured. Contact element 94 is produced by sintering different powder mixtures.

[0079] FIG. 30 shows a discharge device 98 which differs from the discharge device of FIG. 29 in that it has a contact element 99 having a sliding layer 100 and a bonding layer 101, an expansion layer 102 being formed between them. Expansion layer 102 evens out differing thermal expansion coefficients of sliding layer 100 and bonding layer 101.