FRICTION PART

Abstract

A friction part for a frictionally operating device includes an annular-disc-like friction surface rotatable about a rotational axis in a wet-running manner relative to a mating surface. The annular-disc-like friction surface is formed from a paper material and includes a meso-geometric or a micro-geometric uneven portion in order to create an axially deep friction region and an axially high friction region in the annular-disc-like friction surface. The axially high friction region is more strongly preloaded than the axially deep friction region when the annular-disc-like friction surface and the mating surface are axially pressed together.

Claims

1. A friction part for a frictionally operating device, comprising at least one annular-disc-like friction surface which is rotated about a rotational axis in a wet-running manner relative to a mating surface and is formed from a paper material, wherein the friction surface has at least one meso-geometric or micro-geometric uneven portion in order to create, in the friction surface, at least one axially deep friction region and at least one axially high friction region which is more strongly preloaded than the axially deep friction region when the friction surface and the mating surface are axially pressed together.

2. The friction part according to claim 1, wherein the friction surface is conical.

3. The friction part according to claim 1, wherein the friction surface is double-conical.

4. The friction part according to claim 1, wherein the friction surface is formed from pieces of friction paper, of which at least one piece of friction paper has the meso-geometric or micro-geometric unevenness to create with the piece of friction paper the at least one axially deep friction region and the at least one axially high friction region which is more strongly preloaded than the axially deep friction region when the friction surface and the mating surface are axially pressed together.

5. The friction part according to claim 4, wherein the piece of friction paper is conical in relation to a radial.

6. The friction part according to claim 4, wherein the piece of friction paper is conical in relation to a tangential.

7. The friction part according to claim 4, wherein the piece of friction paper is double-conical.

8. The friction part according to claim 4, wherein the piece of friction paper is spherical.

9. The friction part according to claim 1, wherein an axial distance between the axially deep friction region and the axially high friction region is between five and one hundred microns.

10. A wet-running multi-plate clutch or multiple-disc brake having at least one friction part according to claim 1.

11. A friction part for a frictionally operating device, comprising an annular-disc-like friction surface rotatable about a rotational axis in a wet-running manner relative to a mating surface, the annular-disc-like friction surface being formed from a paper material and comprising a meso-geometric or a micro-geometric uneven portion in order to create an axially deep friction region and an axially high friction region in the annular-disc-like friction surface, wherein the axially high friction region is more strongly preloaded than the axially deep friction region when the annular-disc-like friction surface and the mating surface are axially pressed together.

12. The friction part of claim 11, wherein the annular-disc-like friction surface is conical.

13. The friction part of claim 11, wherein the annular-disc-like friction surface is double-conical.

14. The friction part of claim 11, wherein: the annular-disc-like friction surface is formed from individual pieces of friction paper; and one of the individual pieces of friction paper includes the meso-geometric or the micro-geometric uneven portion that creates the axially deep friction region and the axially high friction region.

15. The friction part of claim 14, wherein the one of the individual pieces of friction paper is conical in a radial direction relative to the rotational axis.

16. The friction part of claim 14, wherein the one of the individual pieces of friction paper is conical in a tangential direction relative to the rotational axis.

17. The friction part of claim 14, wherein the one of the individual pieces of friction paper is a double-conical.

18. The friction part of claim 14, wherein the one of the individual pieces of friction paper is spherical.

19. The friction part of claim 11, wherein an axial distance measured between the axially deep friction region and the axially high friction region is between five microns (0.005 mm) and one hundred microns (0.100 mm).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Further advantages, features and details of the disclosure will be apparent from the following description, in which various exemplary embodiments are described in detail with reference to the drawing. In the figures:

[0018] FIG. 1 shows a friction part with a friction surface in plan view;

[0019] FIG. 2 shows a cross-section through the friction part from FIG. 1 according to a first exemplary embodiment with a conical friction surface;

[0020] FIG. 3 shows a tangential section through the friction part from FIG. 1 according to a second exemplary embodiment with conical pieces of friction paper; and

[0021] FIG. 4 shows an exemplary embodiment similar to that in FIG. 3 with double-conical pieces of friction paper.

DETAILED DESCRIPTION

[0022] In FIG. 1, a friction part 1 with a friction surface 2 is shown in plan view. The friction part 1 is a friction plate for a frictionally operating device 20. The frictionally operating device 20 is, for example, a multi-plate clutch or a multiple-disc brake.

[0023] During operation of the frictionally operating device 20, the friction part 1 can be rotated about a rotational axis 3. The friction surface 2 essentially has the shape of a circular ring disc with an inner diameter 4 and an outer diameter 5. The friction surface 2 is shown with a friction lining, which may be designed as friction paper.

[0024] The friction paper can represent the entire friction surface 2. FIG. 1 shows that the friction surface 2 that is continuous in the circumferential direction can also be represented with pieces of friction paper 10. The pieces of friction paper 10 are spaced apart from one another in the circumferential direction, such that there are radial grooves between the pieces of friction paper 10.

[0025] The friction paper or the pieces of friction paper 10 are glued onto a carrier element 8. Contrary to what is shown, the carrier element 8 is equipped with toothing radially on the inside or radially on the outside. The toothing is used to create a non-rotatable connection with a plate carrier (also not shown) of the frictionally operating device 20.

[0026] The frictionally operating device 20 with the friction part 1 is operated wet. This means that a cooling and/or lubricating medium, such as oil, is conducted past the friction surface 2. Normally, the friction surface 2 is flat. The friction surface 2 of the disclosed friction part 1 is designed to be uneven or not even.

[0027] FIGS. 2 to 4 show different sectional views according to three embodiments of the claimed friction part 1 with uneven friction surfaces 23, 24; 33, 34; 43, 44. The uneven friction surfaces 23, 24; 33, 34; 43, 44 are covered with pieces of friction paper 21, 22; 31, 32; 41, 42, which are glued to the carrier element 8 on both sides.

[0028] An arrow 28; 38; 49 indicates a contact pressure which is applied, for example, to the friction part 1 with the friction surface 23, 24; 33, 34; 43, 44 via a steel plate indicated only by a rectangle 29; 39; 50. When applying the contact pressure 28; 38; 49 the steel plate is pressed against the friction surface 23; 33; 43 with a mating surface 40.

[0029] By means of symbolically indicated springs in the rectangle 29; 39; 50, FIGS. 2 to 4 indicate how the purposefully uneven shape of the friction surface 23, 24; 33, 34; 43, 44 affects the operation of the frictionally operating device 20.

[0030] In FIG. 2, the pieces of friction paper 21, 22 are conical. The result of this is that the friction surface 23 has an axially high friction region 25 radially on the outside and an axially deep friction region 26 radially on the inside. An axial distance between the two friction regions 25 and 26 is indicated by a double arrow 27.

[0031] It should be noted that FIGS. 2 to 4 are not to scale. The spacing 27 between the friction regions 25 and 26 is five to one hundred microns. In contrast to what is shown in FIG. 2, the axially high friction region 25 can also be arranged radially on the inside. Then the axially deep friction region 26 is arranged radially on the outside.

[0032] The conically designed friction paper or piece of friction paper 21 is easy to produce; for example, by a conical design of a pressing tool or gluing tool.

[0033] In FIG. 2, the conical design of the piece of friction paper 21 results in a higher preloading of the friction part 1 on the outer diameter. When the contact pressure 28 is removed, the conical design of the piece of friction paper 21 leads to the formation of a gap between the friction surface 23 and the mating surface 40 through which air can easily penetrate. This supports the separation of the friction surface 23 from the mating surface 40 during operation of the wet-running frictionally operating device 20.

[0034] FIGS. 3 and 4 show tangential sections. The tangential direction is indicated by an arrow 30. In FIG. 3, the pieces of friction paper 31, 32 are conical. In FIG. 4, the pieces of friction paper 41, 42 are double-conical.

[0035] In FIG. 3, the friction surface 33 has an axially high friction region 35 and an axially deep friction region 36. The spacing 37 between the two friction regions 35 and 36 is five to one hundred microns, as in the previous exemplary embodiment. The axial dimension of the friction surface 33 increases steadily from the axially deep friction region 36 until the axially high friction region 35 is reached.

[0036] The embodiment of the piece of friction paper 31 with the friction surface 33 shown in FIG. 3 results in a higher preload in the tangential direction. The cone in the direction of rotation reduces the risk of undesired floating.

[0037] In FIG. 4, the pieces of friction paper 41, 42 are double-conical. The friction surface 43 comprises two axially high friction regions 45 and 47. An axially deep friction region 46 is arranged therebetween. The axial dimension of the piece of friction paper 41 changes steadily between the friction regions 46 and 45, 47. The distance 48 between the axially high friction regions 45, 47 and the axially low friction region 46 is five to one hundred microns.

[0038] The double-conical design results in a higher preload on the piece of friction paper 41 in the tangential direction on both edges, i.e. radially on the outside, when the contact pressure 49 is applied. The edges of the piece of friction paper 41 may be spherical.

REFERENCE NUMERALS

[0039] 1 Friction part [0040] 2 Friction surface [0041] 3 Rotational axis [0042] 4 Inside diameter [0043] 5 Outside diameter [0044] 8 Carrier element [0045] 10 Piece of friction paper [0046] 20 Wet-running multi-plate clutch [0047] 21 Piece of friction paper [0048] 22 Piece of friction paper [0049] 23 Friction surface [0050] 24 Friction surface [0051] 25 Axially high friction region [0052] 26 Axially deep friction region [0053] 27 Double arrow [0054] 28 Arrow [0055] 29 Rectangle [0056] 30 Arrow [0057] 31 Piece of friction paper [0058] 32 Piece of friction paper [0059] 33 Friction surface [0060] 34 Friction surface [0061] 35 Axially high friction region [0062] 36 Axially deep friction region [0063] 37 Double arrow [0064] 38 Arrow [0065] 39 Rectangle [0066] 40 Mating surface [0067] 41 Piece of friction paper [0068] 42 Piece of friction paper [0069] 43 Friction surface [0070] 44 Friction surface [0071] 45 Axially high friction region [0072] 46 Axially deep friction region [0073] 47 Axially high friction region [0074] 48 Double arrow [0075] 49 Arrow [0076] 50 Rectangle