JP2024503064A - Friction disc with groove pattern formed by friction lining pad - Google Patents

Abstract

The present invention relates to rectangular friction lining pads (11-13) for friction discs (19) having a substantially rhomboid-like or parallelogram-shaped design, the friction lining pads (11-13) having an inner diameter ( 83) and a friction surface having an outer diameter (84), which, when fixed to the carrier disc (18), have two pad grooves (8) defined by the friction lining pads (11-13); It has a stamped groove (9) that meets at an intersection point (81, 82) located inside the. The friction disc (19) has a carrier disc (18) and a plurality of friction lining pads (11-13) of this type, preferably of the same design and size. A groove pattern with pad grooves (8) and embossed grooves (9) is formed by the carrier disc (18) and the friction lining pads (11-13).

Description

The present invention relates to a groove pattern for a friction disc having the features according to the preamble of claim 1.

Grooves or groove patterns, also referred to herein as pad shapes, are used to cool the disk by oil flow even when the switching element is in the closed state. The groove or groove pattern breaks up the oil film, thereby stabilizing the friction values. The desired frictional behavior is thereby achieved during switching. Improved idling behavior and reduced drag torque.

Scope of application of the present invention:
Wet multi-disc clutches and brakes have a wide range of applications in conventional powershift transmissions, new hybrid modules of high-load drivetrains or switchable e-axles, where high-performance components meet high demands. Form. In automotive applications, the need to reduce CO2 emissions and improve drivetrain efficiency is extremely important. In addition to reducing load-dependent losses in the switching elements, attention must be paid to thermal loads and sufficient cooling. When friction properties, heat balance and efficiency interact, the groove pattern of the friction disc plays a central role (see Figure 1).

WO 2016 180 540 (A1) discloses an annular groove with a first set of linearly extending grooves that join the inner and outer peripheries but do not extend radially or intersect. discloses a wet friction lining. U.S. Pat. No. 6,293,382 (B1) has an additional second set of grooves, each groove of the second set of grooves connecting each two adjacent grooves of the first set of grooves. Join.

The problem of the invention is to minimize drag losses (see FIG. 2) and optimize the cooling capacity (see FIG. 4) by means of a suitable groove pattern in the case of friction discs.

This problem is solved by a groove pattern having the features of claim 1 .

Accordingly, the groove pattern according to the invention for a friction disc is such that the groove pattern is formed using friction lining pads, the friction lining pads having a diamond-like shape, and each friction lining pad being embossed. It is intended to have a groove.

In this way the drag torque is further reduced.

A diamond-shaped friction lining pad is attached to a carrier disc, e.g. a carrier plate. The carrier disk has a substantially annular disk shape. On the radially inner or radially outer side of the carrier disc there are provided toothings which serve to provide a non-rotatable connection with the disc carrier. On the radially inner and radially outer sides, the edge of the carrier disc advantageously remains independent of the friction lining pad. Thus, tolerances in the size and/or shape of the friction lining pad can be compensated for when installing the carrier disc. Furthermore, the friction lining pads are advantageously evenly spaced apart from each other in the circumferential direction. The circumferential spacing of the friction lining pads creates grooves between the friction lining pads. Such grooves are referred to below as pad grooves. The pad grooves extend obliquely to the radial direction due to the diamond-like shape of the friction lining pad. Depending on the direction of rotation in which the friction disc is twisted, in this case the steel disc rotates faster than the friction disc, resulting in either a locking action or a pumping action. Both operations are explained in detail in the description of the figures below. By means of the embossed grooves in the friction lining pad, the oil flow can be optimized between the steel disc and the friction disc from radially inside to radially outside, especially with regard to the cooling capacity. Particularly advantageously, the locking effect generated from the locking effect can be varied to the greatest extent possible by the interaction between the pad groove and the embossed groove in combination with the diamond-shaped friction lining pad.

A friction lining pad is a friction surface that has an inner diameter and an outer diameter. The spacing between the friction lining pads forms pad grooves. The friction surface has the shape of an annular surface having an inner diameter and an outer diameter. In that case, the friction surface is defined by the friction lining pad, so that not only the inner diameter but also the outer diameter may have size deviations in relation to tolerances. According to one main aspect of the invention, the two intersection points of the embossed grooves of each friction lining pad having pad grooves defined by the friction lining pad are both necessarily inside the friction surface, thus: Disposed radially between the inner and outer diameters of the friction surface.

According to a preferred embodiment of this groove pattern, the inner pad angle of the pad corner portion is characterized in that it has an angle of 40 to 145 degrees. Each pad corner includes a pad interior corner. Based on the diamond-like shape of the friction lining pads, each friction lining pad includes two opposing interior angles that are greater than 90 degrees and two opposing interior angles that are less than 90 degrees. The specified size range is relevant to this. Two of the internal angles are preferably between 40 and 50 degrees. The other two internal angles are preferably between 125 and 145 degrees.

A further preferred embodiment of the present groove pattern is characterized in that all pad corners are rounded along the circumferential contour. This has been found to be advantageous in view of the flow around the friction lining pad.

A further preferred embodiment of the present groove pattern is characterized in that the pad corner has a radius of curvature of 1 mm or more. This has been found to be sufficient, taking into account the flow around the friction lining pad.

A further preferred embodiment of the present groove pattern is characterized in that the friction lining pads have a width and a height for each friction lining pad, the ratio of width to height being less than 2. The width to height ratio of the friction lining pad is preferably between 1.5 and 1.7. This width to height ratio advantageously applies in both directions in which the friction disc can be twisted.

In a preferred further embodiment of the present groove pattern, one pad groove in each case is arranged between two adjacent friction lining pads and has a groove width, the groove width being equal to that of the embossed grooves of the friction lining pads. It is characterized by being smaller than the groove width. The width of the pad grooves is relatively mutually defined by the spacing of the diamond-shaped friction lining pads. The smaller groove width of the pad grooves is particularly advantageous since the pad grooves preferably have a greater groove depth than the stamped grooves.

A further preferred embodiment of the present groove pattern is characterized in that the divergence angle between the pad groove and the embossed groove is between 90 and 100 degrees. A particularly preferred divergence angle between the pad groove and the embossed groove is 90.4 degrees. The presented angular range provides that the embossed grooves extend substantially across the pad grooves. This has proven to be very effective, taking into account the desired influence on oil flow in the required groove pattern.

A further preferred embodiment of the present groove pattern is characterized in that the embossing depth of the embossed grooves corresponds to at most 50 percent of the thickness of the friction lining pad. This has proven to be advantageous in view of the manufacture and installation of friction lining pads.

A further preferred embodiment of the present groove pattern is characterized in that all friction lining pads have the same shape and size. This has also proven to be advantageous in view of the manufacture and installation of friction lining pads. The term identical shape and size includes manufacturing tolerances.

The invention further relates to a friction lining pad for the groove pattern described above. The friction lining pad can be handled individually.

Further advantages and advantageous embodiments of the invention are the subject of the following drawings and their description.

FIG. 3 is a diagram showing the relationship between air introduction and drag torque. FIG. 3 is a diagram showing issues and improvements. It is a figure which shows a conveyance action and a locking action. It is a figure showing cooling capacity. FIG. 3 shows a groove design according to the invention. FIG. 3 shows the dimensions of a groove design according to the invention. FIG. 3 shows the dimensions of a groove design according to the invention. FIG. 3 shows the dimensions of a groove design according to the invention. FIG. 3 shows a pad with groove design according to the present invention. FIG. 3A is a view similar to FIG. 3A, specifically showing that the intersection between the embossed groove and the pad groove is always located inside the friction surface;

- Angle (1) in Figure 6 is 40 to 145 degrees (see Figure 9 for details).
- The outer edge of the pad is rounded along the periphery, preferably 1 mm or more (see Figure 7 (2)).
- Double-row design with central embossing in mind, resulting in nearly identical pad surfaces in triangular shapes for inner and outer rows, base shape without embossing in mind. The pad is shaped as a diamond; the ratio of the width (3) to the height (4) of the pad is less than 2 (preferably between 1.5 and 1.7) (see Figure 7);
・The width of the embossing (5) is wider than the width of the groove (6) (see Figure 8)
- The ratio of the groove angle to the embossing angle (7) is between 90 and 100 degrees, preferably 90.4 degrees (see Figure 8)

- Optimized manufacturing quality with optimized pad geometry.
- Improved stringability and end quality and thus reduced drag torque, for example by groove embossing, with the friction device open.
- Robust wear characteristics of pad edges and pad corners over lifetime. Maintaining the end shape (slight rounding (1)) provides strong, constant hydrodynamic properties (wedge action) and thus stable friction properties. Control application costs are reduced.
- Rapid removal of oil films according to a further preferred embodiment of the invention, in which the branching angle (7) is between 90 and 100°, preferably 90.4°.
- Depending on the angular position of the grooves, it is possible to realize an oil conveying effect (FIG. 3A) or a locking effect (FIG. 3B) depending on the relative direction of rotation of the steel disk opposite the friction disk (directional). Depending on the relative direction of rotation between the friction disk and the steel disk, the cooling capacity (see FIG. 4) can be varied to suit the application. By means of pad embossing ("embossed grooves" in Figure 5), this inlet can be formed arbitrarily (see Figure 8: embossing depth, width (5), angle (7)) and for each application. can be optimized for

In FIG. 1, three Cartesian coordinate graphs are illustrated one above the other. On the x-axis 20, one rotational speed is plotted in a suitable unit when the wet multi-disc clutch 1 with the friction part 15 is in operation. On the y-axis 21, the volumetric flow rate is plotted in appropriate units. On the y-axis 22, the gap volumetric efficiency is plotted in appropriate units. On the y-axis 23, drag torque is plotted in appropriate units.

FIG. 1 shows specifically how the air introduction 26 is effected by the delivered volumetric flow rate 24 if the delivered volumetric flow rate 24 exceeds the supplied volumetric flow rate 25 . Beyond this limit, the gap volumetric efficiency 26 decreases and the lubricating gap contains air. Beyond this limit, the supplied volume flow 25 contains air. In the lower part of FIG. 2, it is shown that air introduction 26 occurs in the case of maximum drag torque 27.

In FIG. 2, it is shown how a displacement of the air intake 28 to a low rotational speed is achieved in the drag torque curve 30 by means of the stressed friction part 15. The groove pattern illustrated in FIG. 3 makes it possible to improve the conveying effect of the cooling medium and/or the lubricating medium.

FIG. 3 includes FIGS. 3A and 3B. In FIGS. 3A and 3B, a groove pattern 10 according to the invention, also referred to as a groove design, is illustrated. The groove pattern 10 includes friction lining pads 11-13; 14-16 arranged on the carrier disc 18. The carrier disc 18 with the friction lining pads 11-13; 14-16 is referred to as friction disc 19.

The friction lining pads 11-13; 14-16 all have a diamond-like shape with rounded corners. The friction lining pads 11-13; 14-16 are spaced apart from each other in the circumferential direction in such a way that one pad groove 8 in each case occurs between two adjacent friction lining pads 12, 13; 14, 15. The pad groove 8 is limited to the depth of the carrier disk 18. Pad groove 8 extends diagonally with respect to the radial direction.

Furthermore, the friction lining pads 11-13; 14-16 each have one embossed groove 9. The stamped grooves 9 extend across the pad grooves 8. Furthermore, the pad grooves 8 have a greater groove depth than the stamped grooves 9. The groove depth of the embossed grooves 9 is at most 50 percent of the thickness of the friction lining pads 11-13; 14-16. The groove depth of the pad groove 8 corresponds to the thickness of the friction lining pads 11-13; 14-16.

In a multi-disc clutch, a plurality of friction discs 19 with steel discs are arranged in a disc package. In FIGS. 3A and 3B, the direction of rotation of the friction disc 19 during operation is indicated by arrows 60; 70. In that case, the condition applies that the assigned steel disc rotates faster than the respective assigned friction disc 19. Arrows 61-64; 71-74 indicate the forces acting during operation, which result from the oil flow from radially inside to radially outside between the friction disc 19 and the steel disc. .

Arrows 61; 71 specifically indicate centrifugal force. The arrows 62; 72 specifically indicate the flow through the pad groove 8, which is caused by the diamond-like shape of the friction lining pads 11-13; 14-16 depending on the pad internal angle and the direction of rotation 60; , resulting in a force indicated by arrows 62; 72.

In FIGS. 3A and 3B, the forces caused by the relative movement between the steel disc and the friction disc 19 are indicated by arrows 63; 73. Arrows 64; 74 indicate the forces resulting from forces 61-63; 71-73.

In FIG. 3A, the locking effect provided by the friction lining pads 11 to 13 is specifically shown when the friction disk 19 rotates at a slower speed in the direction of rotation 60 than the assigned steel disk. In FIG. 3B, the pumping effect produced by the friction lining pads 14 to 16 is specifically shown when the friction disk 19 rotates at a slower speed in the direction of rotation 70 than the assigned steel disk.

In FIG. 4, a bar graph consisting of a y-axis 40 and bars 41-44 is shown. On the y-axis 40, cooling capacity is plotted in kilowatts. Bars 41-44 are cooling capacities for different magnitudes of volume flow that can be achieved with the groove pattern 10 of FIGS. 3A and 3B.

Bars 41 and 42 illustrate relatively low volumetric flow rates of oil. Bars 43, 44 illustrate a rather high volumetric flow rate. In that case, rods 41, 43 in FIG. 3A are assigned to a pumping action. The rods 42, 44 are assigned a locking action in FIG. 3B.

The pumping action provides an increased cooling capacity not only at low but also at high volumetric flow rates. However, as shown in FIG. 4, when the volume flow rate is high, the cooling capacity does not change as much as when the volume flow rate is low. Depending on the application, the locking action can be relaxed or varied by the specification of the embossed grooves or by the cross-sectional area, ie width and depth, of the embossed grooves. The larger the cross-sectional area, the greater the amount of oil flowing through the embossed grooves.

In FIG. 5, the friction lining pads 11-13 are shown to be rounded at their pad corners 31-34. In FIG. 7, the radius of curvature is shown as 2 and is equal at substantially all pad corners 31-34. The radius of curvature 2 is advantageously greater than or equal to 1 mm.

In FIG. 6, the inner pad corner 1 of the friction lining 12 is indicated by a double arrow. Pad interior angle 1 is 40 to 145 degrees. The central location of the stamped grooves 9 in the friction lining pad 12 provides a double row groove design with identical pad surfaces on the radially inner and radially outer sides. The same pad surfaces each have a triangular shape, based on the diamond-like shape of the friction lining pad 12.

In FIG. 7, the width of the friction lining pad 12 is indicated by the double arrow 3. The height of the friction lining pad 12 is indicated by the double arrow 4. The ratio of width 3 to height 4 is preferably less than 2 for all friction lining pads. The ratio of width 3 to height 4 is advantageously between 1.5 and 1.7 for all friction lining pads 11-13; 14-16 of groove pattern 10.

6 and 7, auxiliary lines have been drawn on the friction lining pad 12 for dimensioning purposes. There is a gap partially between the auxiliary line and the friction lining pad 12. This gap exemplifies the tolerances that may exist due to the manufacturing conditions of the friction lining pad 12.

In FIG. 8, the groove width of the embossed groove 9 is indicated by the double-headed arrow 5. The groove width of the pad groove 8 between the friction lining pads 12 and 13 is indicated by the double arrow 6. The bifurcation angle between the pad groove 8 and the embossed groove 9 is indicated by the double arrow 7.

The divergence angle 7 between the pad grooves 8 and the embossed grooves 9 in the complete groove pattern 10 is advantageously between 90 and 100 degrees, preferably 90.4 degrees.

In FIG. 9, internal pad angles of the friction lining pad 12 are indicated by double-headed arrows 51-54. The angles of the pad interior angles 51 to 54 are 132; 44.5; 142; 41.6 in the order of description.

In FIG. 10, the friction disc 19 according to FIG. 3A is shown with auxiliary lines, specifically illustrating that the friction lining pads 11-13 form a friction surface 80. In FIG. Friction surface 80 is defined radially inwards by an inner diameter 83 and radially outwardly by an outer diameter 84 . Here, tolerances may occur depending on manufacturing conditions.

However, substantially the intersection points 81 , 82 of the embossed grooves 9 of the friction lining pad 12 and the two pad grooves 8 and 78 defined by the friction lining pad 12 are located within the friction surface 80 . has been done.

1 Pad internal angle 2 Radius of curvature 3 Width 4 Height 5 Groove width 6 Groove width 7 Branch angle 8 Pad groove 9 Embossed groove 10 Groove pattern 11 Friction lining pad 12 Friction lining pad 13 Friction lining pad 14 Friction lining pad 15 Friction Lining pad 16 Friction lining pad 18 Carrier disc 19 Friction disc 20 Pad corner 32 Pad corner 33 Pad corner 34 Pad corner 40 Y axis 41 Bar 42 Bar 43 Bar 44 Bar 51 Pad inner angle 52 Pad inner angle 53 Pad inner angle 54 Pad inner angle 60 Rotation direction 61 Arrow 62 Arrow 63 Arrow 64 Arrow 70 Rotation direction 71 Arrow 72 Arrow 73 Arrow 74 Arrow 78 Pad groove 80 Friction surface 81 First intersection 82 Second intersection 83 Inner diameter 84 Outer diameter

Claims (10)

A groove pattern (10) for a friction disc, said groove pattern (10) being formed using friction lining pads (11-13; 14-16), said groove pattern (10) being formed using friction lining pads (11-13; ;14-16) have a diamond-like shape, said friction lining pads (11-13; 14-16) forming a friction surface (80) having an inner diameter (83) and an outer diameter (84); In a groove pattern (10), each said friction lining pad (11-13; 14-16) has an embossed groove (9), said embossed groove (9) The two pad grooves (8; 78) defined by the lining pad intersect at a first intersection (81) and a second intersection (82), which are both located inside said friction surface (80). Features a groove pattern (10). Groove pattern according to claim 1, characterized in that the pad internal angle (1) of the pad corner has an angle of 40 to 145 degrees. Groove pattern according to claim 1 or 2, characterized in that all pad corners are rounded along their peripheral contour. The groove pattern according to any one of claims 1 to 3, characterized in that the radius of curvature (2) of the pad corner is 1 mm or more. Said friction lining pads (11-16) have a width (3) and a height (4) such that, for each said friction lining pad (11-16), the ratio of width (3) to height (4) is less than 2. The groove pattern according to any one of claims 1 to 4, characterized in that it has a groove pattern. Between two adjacent friction lining pads (11 to 16) one pad groove (8; 78) is arranged in each case with a groove width (5), said groove width (5) Groove pattern according to any one of claims 1 to 5, characterized in that it is smaller than the groove width (6) of the embossed grooves (9) of the pad (11-16). Groove pattern according to claim 6, characterized in that the divergence angle (7) between the pad groove (8; 78) and the embossed groove (9) is between 90 and 100 degrees. 8. The embossed groove according to claim 1, wherein the embossed depth of the embossed groove (9) corresponds to at most 50 percent of the thickness of the friction lining pad (11-16). Groove pattern as described in section. Groove pattern according to any one of claims 1 to 8, characterized in that all said friction lining pads (11-16) have the same shape and the same size. Friction lining pads (11-16) for a groove pattern (10) according to any one of claims 1 to 9.

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