Friction element and clutch

Abstract

The application belongs to the technical field of clutches. A kind of friction element and clutch are disclosed, comprising: annular base body with friction layer;Multiple arc-shaped grooves are arranged circumferentially on the friction layer with the center point of annular base body as the center, the width of arc-shaped groove is configured to be gradually changed, the width of end portion of arc-shaped groove close to the center point of annular base body is less than the width of end portion of arc-shaped groove away from the center point of annular base body;The friction layer includes inner ring area and outer ring area sleeved outside the inner ring area, and the friction coefficient of outer ring area is less than the friction coefficient of inner ring area.The application can realize that the arc-shaped groove on the friction layer is a variable-width groove, reduce the heat dissipation of lubricating oil at the inner diameter and increase the heat dissipation at the outer diameter, to improve the radial temperature distribution uniformity of the friction element, and improve the phenomenon that the radial temperature difference of the friction element is too large.

Description

Technical Field

[0001] This invention belongs to the field of clutch technology, and particularly relates to a friction element and a clutch. Background Technology

[0002] Wet shift clutches are widely used in vehicle transmissions, primarily for transmitting or disconnecting engine power. However, as transmission power density increases, the clutch engagement speed difference widens, generating more and more heat. When the friction elements rotate at high speeds, the linear velocity near the inner diameter is low, while the linear velocity near the outer diameter is high. This results in more heat generation on the outer diameter and less on the inner diameter, meaning the heat is unevenly distributed radially. Without sufficient cooling, localized high temperatures in the clutch can cause thermal warping and deformation of the friction elements, as well as oxidation and decomposition of the lubricating oil, ultimately affecting the clutch's transmission performance and the lifespan of the friction elements.

[0003] To provide more effective cooling, friction plates are designed with various grooves to allow lubricating oil to flow across the friction pair. Currently, common oil groove forms on the surface of wet clutch friction plates include radial grooves, waffle grooves, three-way multi-track parallel grooves, two-way multi-track parallel grooves, double circular arc grooves, and spiral grooves, among others. Different oil groove forms have different friction performance and heat dissipation effects. Multi-plate clutches typically use a method of spraying lubricating oil from the internal oil passages of the shaft into the inner diameter of the friction elements for cooling. While this can reduce the overall temperature of the friction elements, this non-uniform cooling method often worsens the radial temperature distribution of the friction elements. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention proposes a friction element and clutch that can realize the arc-shaped groove on the friction layer as a variable width groove, reduce the heat dissipation of lubricating oil at the inner diameter and increase its heat dissipation at the outer diameter, so as to improve the radial temperature distribution uniformity of the friction element and improve the phenomenon of excessive radial temperature difference of the friction element.

[0005] To achieve the above objectives, the present invention provides a friction element, comprising:

[0006] Ring-shaped matrix with a friction layer;

[0007] Multiple arc-shaped grooves are arranged circumferentially on the friction layer with the center point of the annular substrate as the center. The width of the arc-shaped grooves is configured to be gradually varied, and the width of the end of the arc-shaped groove near the center point of the annular substrate is smaller than the width of the end of the arc-shaped groove away from the center point of the annular substrate.

[0008] Furthermore, the friction layer includes an inner ring region and an outer ring region sleeved outside the inner ring region, wherein the friction coefficient of the outer ring region is less than that of the inner ring region;

[0009] Wherein, the radius of the inner ring region is r, and the radius of the outer ring region is R.

[0010] Furthermore, the area of ​​the inner ring region where the arc-shaped groove is not provided is provided with a plurality of micro-textured holes, so that the friction coefficient of the outer ring region is less than that of the inner ring region.

[0011] Furthermore, the depth of the plurality of microtextured pores is configured to gradually decrease radially inward along the inner ring region.

[0012] Furthermore, multiple through holes are arranged along the extending direction within the arc-shaped groove on the outer ring area.

[0013] Furthermore, the diameter of the plurality of through holes is configured to gradually decrease radially inward along the outer ring region.

[0014] Furthermore, the arc-shaped groove includes a plurality of first grooves arranged along a first orientation and a plurality of second grooves arranged along a second orientation, the first orientation being opposite to the second orientation, such that the first grooves and the second grooves are intersecting.

[0015] Furthermore, the first arc-shaped edge of the first groove and the first arc-shaped edge of the second groove are disposed on a first contour circle having a first center, the radius of the first contour circle being R1, and the first center being disposed on a first circle having the center point of the annular base as the center, the radius of the first circle being r1.

[0016] The second arc-shaped edge of the first groove and the second arc-shaped edge of the second groove are disposed on a third contour circle having a third center. The radius of the third contour circle is R3. The third center is disposed on a third circle with the center point of the annular base as the center. The radius of the third circle is r3.

[0017] Where r3-r1=R3-R1.

[0018] Furthermore, r3 < r - 12 mm;

[0019] 4mm < r3 - r1 < 10mm;

[0020] 4mm < R3 - R1 < 10mm;

[0021] R+40mm<R3<r+R-45mm.

[0022] A clutch comprising the aforementioned friction element.

[0023] Compared with the prior art, the present invention has the following advantages and technical effects:

[0024] The arc-shaped grooves on the friction layer are variable-width grooves, which reduce the heat dissipation of lubricating oil at the inner diameter and increase its heat dissipation at the outer diameter, thereby improving the uniformity of radial temperature distribution of the friction element and improving the phenomenon of excessive radial temperature difference of the friction element. Attached Figure Description

[0025] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0026] Figure 1 This is a schematic diagram of the friction element.

[0027] Figure 2 for Figure 1 Sectional view of AA;

[0028] Figure 3 This is a schematic diagram showing the positional relationship between the first and third contour circles;

[0029] Figure 4 This is a schematic diagram of the through-hole distribution;

[0030] Figure 5 This is a schematic diagram of the friction block distribution;

[0031] Figure 6 A schematic diagram showing the distribution of microtexture pores;

[0032] Figure 7 This is a schematic diagram of the temperature field of an existing friction plate;

[0033] Figure 8 This is a schematic diagram of the temperature field of the friction plate in this technical solution;

[0034] Wherein, 1-ring matrix, 2-friction layer, 201-inner ring area, 202-outer ring area, 3-arc groove, 301-first groove, 302-second groove, 4-microtextured pores, 5-through holes. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Reference Figures 1-8 The present invention provides a friction element, comprising: an annular base 1 with a friction layer 2, and a plurality of arc-shaped grooves 3 arranged circumferentially on the friction layer 2 with the center point of the annular base 1 as the center. The width of the arc-shaped grooves 3 is configured to be gradually varied, and the width of the end of the arc-shaped groove 3 near the center point of the annular base 1 is smaller than the width of the end of the arc-shaped groove 3 away from the center point of the annular base 1.

[0038] Specifically, the structure of the arc-shaped groove 3 is designed so that the arc-shaped groove of equal width is designed as a variable width groove with a small inner diameter opening and a large outer diameter opening. This reduces the heat dissipation of lubricating oil at the inner diameter and increases its heat dissipation at the outer diameter, so as to avoid excessive radial temperature difference of the friction element.

[0039] Among them, the annular substrate 1 has an annular structure, and copper-based friction material is sintered on both sides of it to form a friction layer 2.

[0040] In this embodiment, refer to Figure 1 The friction layer 2 includes an inner ring region 201 and an outer ring region 202 sleeved outside the inner ring region 201. The friction coefficient of the outer ring region 202 is less than that of the inner ring region 201. The radius of the inner ring region 201 is r, and the radius of the outer ring region 202 is R.

[0041] Specifically, with the middle diameter of the friction layer 2 as the boundary, an inner ring region 201 and an outer ring region 202 sleeved outside the inner ring region 201 are provided. At the same time, the friction coefficient of the outer ring region 202 needs to be smaller than that of the inner ring region 201 in order to balance the uneven heat generation between the inner and outer diameters of the original friction plate.

[0042] In one specific embodiment of the present invention, the friction layer 2 is a ring structure with r = 56 mm and R = 125 mm. The thickness of the ring substrate 1 is 2 mm-2.2 mm, and the thickness of the friction layer 2 is 0.6 mm-0.8 mm.

[0043] In this embodiment, refer to Figure 1 , Figure 5 , Figure 6 In the inner ring region 201, where there is no arc-shaped groove 3, multiple micro-textured holes 4 are arranged so that the friction coefficient of the outer ring region 202 is less than that of the inner ring region 201.

[0044] Specifically, multiple first grooves 301 and multiple second grooves 302 are arranged in a cross pattern. To increase heat generation at the inner diameter, the friction element has a microtextured structure in the friction layer 2 in the non-groove region. The microtextured structure consists of multiple microtextured holes 4. Due to the symmetry of the circle and the symmetrical design of the groove, and because the arc-shaped groove 3 is arc-shaped and widens, the friction layer 2 is divided into friction blocks of different sizes. That is, the inner ring region 201 from the inner diameter to the middle diameter has microtextured holes 4 to increase the friction coefficient of the inner ring region 201.

[0045] In this embodiment, Figure 1 , Figure 5 , Figure 6 The depth of the multiple microtextured apertures 4 is configured to gradually decrease radially inward along the inner ring region 201.

[0046] In a specific embodiment of the present invention, the inner ring region 201 has a first friction block 203, a second friction block 204, and a third friction block 205 with successively decreasing areas. The radial position of the first friction block 203 is close to the median diameter, and the microtexture depth reaches the annular substrate 1, that is, it penetrates the friction layer 2. The microtexture depth of the second friction block 204 is 3 / 4 of the thickness of the friction layer 2, and the microtexture depth of the third friction block 205 is 1 / 2 of the thickness of the friction layer 2.

[0047] Meanwhile, since the areas of the first friction block 203, the second friction block 204, and the third friction block 205 decrease sequentially, the number of microtextured holes 4 within each friction block differs. The number of microtextured holes 4 in the first friction block 203, the second friction block 204, and the third friction block 205 are 19, 19, and 11, respectively. Taking the first friction block 203 as an example, the microtexture 9-1 is symmetrically distributed along line r91. The radial and circumferential spacing of the microtextured holes 4 above line r92 is b1, and the radial and circumferential spacing of the microtextured holes 4 below line r92 is b2. The distribution characteristics of the microtexture on the second friction block 204 are consistent with those of the microtexture 11-1 on the third friction block 205 and the microtexture 9-1 on the first friction block 203. Based on the above characteristics and the symmetry of the microtexture on the surface of the friction blocks, the distribution of each friction block can be obtained. Finally, the distribution of the entire microtexture of the friction block is obtained by using symmetry and array methods.

[0048] The diameter of the microtextured pores ranges from 400μm to 600μm.

[0049] In this embodiment, refer to Figure 1 , Figure 2 , Figure 4 Multiple through holes 5 are arranged along the extension direction in the arc-shaped groove 3 on the outer ring area 202.

[0050] In this embodiment, refer to Figure 1 , Figure 2 , Figure 4 The diameter of the multiple through holes 5 is configured to gradually decrease radially inward along the outer ring region 202.

[0051] Specifically, taking the middle diameter of the friction layer 2 ring as the boundary, circular through holes 5 are opened along the direction of the first groove 301 and the second groove 302 from the middle diameter to the outer diameter to enhance the convective heat transfer effect of the lubricating oil.

[0052] In one specific embodiment of the present invention, center lines 14, 16, and 18 can be determined by the endpoints of the friction blocks on the friction layer 2. The average value of the radii of center lines 14 and 16 is the radius of center line 15, the average value of the radii of center lines 16 and 18 is the radius of center line 17, and the average value of the radii of center line 18 and the outer diameter line 20 of friction layer 2 is the radius of center line 19. The intersections of these center lines with arcs R21 and R22 are the circular through holes 501-508.

[0053] Arcs R21 and R22 are set on a second contour circle with a second center, the radius of which is R2. The second center is set on a second circle with the center point of the annular base 1 as its center, the radius of which is r2.

[0054]

[0055]

[0056] Furthermore, the diameters of through holes 501-508 increase by 0.2 mm sequentially, with through hole 501 having a diameter of 1.2 mm and through hole 508 having a diameter of 2.2 mm. The through holes on the remaining first groove 301 and second groove 302 are arranged in the same manner as described above.

[0057] In this embodiment, refer to Figure 1 , Figure 3 The arc-shaped groove 3 includes a plurality of first grooves 301 arranged along a first orientation and a plurality of second grooves 302 arranged along a second orientation. The first orientation is opposite to the second orientation, so that the first grooves 301 and the second grooves 302 are intersected.

[0058] In one specific embodiment of the present invention, the first groove 301 and the second groove 302 are extended by 30 in the circumferential direction to form a double arc friction pad with variable groove width.

[0059] In this embodiment, refer to Figure 1 , Figure 3 The first arc-shaped edge of the first groove 301 and the first arc-shaped edge of the second groove 302 are disposed on the first contour circle with the first center, the radius of the first contour circle is R1, and the first center is disposed on the first circle with the center point of the annular base 1 as the center, the radius of the first circle is r1.

[0060] The second arc-shaped edge of the first groove 301 and the second arc-shaped edge of the second groove 302 are set on the third contour circle with the third center. The radius of the third contour circle is R3. The third center is set on the third circle with the center point of the annular base 1 as the center. The radius of the third circle is r3. Wherein, r3-r1=R3-R1.

[0061] In a specific embodiment of the present invention, the two arc lines of the first groove 301 and the two arc lines of the second groove 302 are determined as follows: the centers of the two arc lines lie on the first circle r1 and the third circle r3, which are concentric with the annulus of the friction layer 2, wherein the radius of the first circle is r1 and the radius of the third circle is r3. The radius line of the extended first circle r1 intersects the arc of the third circle r3, and the intersection point of this extended line with the arcs of the first circle r1 and the third circle r3 is the center of the groove arc line.

[0062] Subsequently, circles are drawn with the two centers to obtain the first contour circle R1 and the third contour circle R3, where the radius of the first contour circle R1 is R1 and the radius of the third contour circle R3 is R3. Both the first contour circle R1 and the third contour circle R3 have two arcs that intersect with the annulus of the friction layer 2. The arcs intersecting the first contour circle R1 with the annulus of the friction layer 2 are R11 and R12, and the arcs intersecting the third contour circle R3 with the annulus of the friction layer 2 are R31 and R32. Therefore, the two groove lines of the first groove 301 are R11 and R31, and the two groove lines of the second groove 302 are R12 and R32.

[0063] In this embodiment, r3 < r-12mm; 4mm < r3-r1 < 10mm; 4mm < R3-R1 < 10mm; R+40mm < R3 < r+R-45mm.

[0064] A clutch includes the aforementioned friction element. The friction element on the clutch has variable-width arc-shaped grooves, micro-textured holes 4 of different depths, and through holes 5 of different diameters. The radial temperature distribution of the friction element is relatively uniform, ensuring the transmission performance and lifespan of the clutch.

[0065] In a specific embodiment of the present invention, reference is made to Figure 7 , Figure 8 Given the clutch operating conditions of 0.1 MPa, speed of 200 r / min, and friction plate slippage of 10 s. Figure 7 and Figure 8 The images show the temperature field of the friction pad before and after the implementation of this friction pad design. It was found that after implementation, the inner diameter temperature of the friction pad increased, the outer diameter temperature decreased, the radial temperature difference of the friction pad decreased, and the beneficial effect of failure was obvious.

[0066] The proposed friction pad for reducing radial temperature gradient optimizes the heat dissipation and heat generation characteristics of the friction element through a variable groove width design and increased microtextured porosity. The groove opening is large at the outer diameter, and there are through holes 5 within the groove to facilitate heat dissipation at the outer diameter. At the inner diameter, the groove opening is small, and the friction material layer has microtextured porosity to increase heat generation at the inner diameter. Therefore, by enhancing heat dissipation at the outer diameter and heat generation at the inner diameter, the radial temperature difference of the friction pad is reduced, thereby protecting the friction pad and preventing its failure and deformation.

[0067] The above structure changes the radially equal-width layout of the double circular arc grooves. The newly designed grooves have a small inner diameter opening and a large outer diameter opening, which can increase the convective heat transfer effect of the oil at the outer diameter and prevent oil carbonization and carbon black adsorption at the outer diameter.

[0068] A lubrication through hole 5 is opened at the groove of the middle and outer diameters. The radius of the lubrication through hole 5 gradually increases from the middle diameter to the outer diameter, which can increase the convective heat transfer effect of the oil at the outer diameter and reduce the temperature rise of the outer diameter.

[0069] In the friction layer 2 region at the inner diameter, microtextured holes 4 are provided. The hole depth is set differently according to the radial position, which can increase the friction coefficient at the inner diameter, thereby increasing the heat generation at the inner diameter.

[0070] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A friction element, characterized in that: include: A ring-shaped matrix (1) with a friction layer (2); Multiple arc-shaped grooves (3) are arranged circumferentially on the friction layer (2) with the center point of the annular substrate (1) as the center. The width of the arc-shaped grooves (3) is configured to be gradually changed. The width of the end of the arc-shaped groove (3) near the center point of the annular substrate (1) is smaller than the width of the end of the arc-shaped groove (3) away from the center point of the annular substrate (1). The friction layer (2) includes an inner ring region (201) and an outer ring region (202) sleeved outside the inner ring region (201), wherein the friction coefficient of the outer ring region (202) is less than the friction coefficient of the inner ring region (201); Wherein, the radius of the inner ring region (201) is r, and the radius of the outer ring region (202) is R; The arc-shaped groove (3) includes a plurality of first grooves (301) arranged along a first orientation and a plurality of second grooves (302) arranged along a second orientation, wherein the first orientation is opposite to the second orientation, so that the first grooves (301) and the second grooves (302) are intersected. The first arc-shaped edge of the first groove (301) and the first arc-shaped edge of the second groove (302) are disposed on a first contour circle with a first center. The radius of the first contour circle is R1. The first center is disposed on a first circle with the center point of the annular base (1) as the center. The radius of the first circle is r1. The second arc-shaped edge of the first groove (301) and the second arc-shaped edge of the second groove (302) are disposed on a third contour circle with a third center. The radius of the third contour circle is R3. The third center is disposed on a third circle with the center point of the annular base (1) as the center. The radius of the third circle is r3. Where r3-r1=R3-R1.

2. The friction element according to claim 1, characterized in that: The inner ring region (201) without the arc-shaped groove (3) is provided with a plurality of micro-textured holes (4) so ​​that the friction coefficient of the outer ring region (202) is less than that of the inner ring region (201).

3. The friction element according to claim 2, characterized in that: The depth of the plurality of microtextured pores (4) is configured to gradually decrease radially inward along the inner ring region (201).

4. The friction element according to claim 1, characterized in that: Multiple through holes (5) are arranged along the extension direction in the arc-shaped groove (3) on the outer ring area (202).

5. The friction element according to claim 4, characterized in that: The diameter of the plurality of through holes (5) is configured to gradually decrease radially inward along the outer ring region (202).

6. The friction element according to claim 1, characterized in that: r3 < r-12mm; 4mm < r3 - r1 < 10mm; 4mm < R3 - R1 < 10mm; R+40mm<R3<r+R-45mm.

7. A clutch, characterized in that: Includes the friction element as described in any one of claims 1-6.

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