A wet multi-plate clutch with reduced radial temperature gradient of friction elements

Abstract

The application discloses a wet multi-plate clutch with reduced radial temperature gradient of friction elements, comprising a cylinder sleeve, a piston, a friction element, a pressing plate and a clasp spring arranged in the groove of the cylinder sleeve in sequence, the friction element comprising a plurality of paired steel sheets and a plurality of friction plates, the paired steel sheets and the friction plates being arranged alternately, the spline of the paired steel sheet being connected with the cylinder sleeve to form a passive end, the inner teeth of the friction plate being engaged with a driving shaft to transmit power, one side of the pressing plate away from the friction element being provided with a ring of bosses, and the bosses and the outer edge of the pressing plate forming a ring of steps for placing the clasp spring. The bosses are additionally arranged on the basis of the original pressing plate, the contact pressure at the inner diameter of the friction pair is improved, the difference in the contact pressure distribution of the friction pair is reduced, and thus the thermal load of the wet multi-plate clutch is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of clutch structure design, and in particular to a wet multi-plate clutch capable of reducing the radial temperature gradient of a friction element. Background Art

[0002] Wet friction pairs are widely used in transmission components such as wet clutches, wet brakes, and hydroviscous speed control clutches. They are one of the most core components of integrated transmission systems, and their performance directly affects the transmission efficiency and operational reliability of the transmission system. The integrated transmission system determines the maneuverability of the entire vehicle, especially in the field of heavy-duty military vehicles, which places high demands on the reliability and durability of the integrated transmission system. Reducing the radial temperature gradient of the clutch friction element is a key method to extend the service life of the clutch. Existing technical solutions include the following:

[0003] 1. Use new materials to manufacture clutch friction plates to improve friction efficiency and heat dissipation efficiency. For example, using nanocomposites, carbon fiber materials, etc. to manufacture friction plates can improve the wear resistance and heat dissipation performance of the clutch.

[0004] 2. Use a transmission cooling system to reduce clutch temperature. By adding a cooler and water pump to the transmission, coolant circulates back and forth to reduce clutch temperature. This method has been widely used in actual production.

[0005] 3. Adopt new clutch design. For example, the dual-clutch design can achieve stepless speed change and fast shifting, thereby reducing the clutch usage time and thermal load.

[0006] 4. Install a radiator on the clutch. By installing a radiator on the clutch, the heat dissipation area can be increased and the heat dissipation efficiency of the clutch can be improved.

[0007] Currently, numerous documents and patents describe related technologies. For example, Chinese utility model patent publication number CN204558397U discloses a cooling system for an automotive clutch. By adding a cooler and a water pump to the transmission, the coolant circulates back and forth to reduce clutch temperature. Chinese utility model patent publication number CN201755180U discloses a clutch with a radiator. By adding a radiator to the clutch, the heat dissipation area is increased, thereby improving the heat dissipation efficiency of the clutch.

[0008] The main advantage of these technical solutions is that they can effectively reduce clutch temperature, thereby increasing clutch life and stability. However, these solutions all have some disadvantages. For example, the manufacturing cost of new materials is high, which needs to be further reduced; the transmission cooling system requires increased equipment and maintenance costs; and the new clutch design requires redesigning and manufacturing the clutch, which is also costly. Summary of the Invention

[0009] In order to overcome the problems in the prior art of reducing the radial temperature gradient of the clutch friction element, such as high manufacturing costs of new materials, increased equipment costs and maintenance costs, and the need to redesign and manufacture the clutch, the present invention provides a wet multi-plate clutch that reduces the radial temperature gradient of the friction element.

[0010] The technical solution of the present invention is as follows:

[0011] A wet multi-plate clutch for reducing the radial temperature gradient of a friction element comprises a cylinder liner, wherein a piston, a friction element, a pressure plate and a retaining spring are sequentially arranged in a groove of the cylinder liner. The invention is characterized in that a circle of bosses is provided on a side of the pressure plate away from the friction element, and the bosses and the outer edge of the pressure plate form a circle of steps for placing the retaining spring.

[0012] According to the wet multi-plate clutch for reducing the radial temperature gradient of the friction element according to the above solution, in one embodiment, the cross section of the boss is rectangular.

[0013] According to the wet multi-plate clutch for reducing the radial temperature gradient of the friction element according to the above solution, in one embodiment, the inner edge of the boss is flush with the inner edge of the pressure plate.

[0014] Furthermore, the outer diameter of the pressure plate is 250 mm, the inner diameter is 170 mm, and the thickness is 10 mm; the outer diameter of the boss is 228 mm, the inner diameter is 170 mm, and the thickness is 10 mm.

[0015] According to the above-mentioned scheme for reducing the radial temperature gradient of the friction element of the wet multi-plate clutch, in another embodiment, the outer diameter of the pressure plate is 250 mm, the inner diameter is 170 mm, and the thickness is 10 mm; the outer diameter of the boss is 224 mm, the inner diameter is 176 mm, and the thickness is 7 mm.

[0016] Furthermore, a circle of grooves with a rectangular cross-section is provided on the inner edge of one side of the boss close to the pressure plate.

[0017] Furthermore, the diameter of the groove is 184.6 mm and the thickness is 4.6 mm.

[0018] According to the wet multi-plate clutch for reducing the radial temperature gradient of the friction element of the above-mentioned scheme, in one embodiment, the side of the piston away from the friction element is flat, the side of the piston close to the friction element is tapered, and the thickness of the piston gradually becomes thinner from the inside to the outside.

[0019] Furthermore, the outer diameter of the piston is 250 mm, the inner diameter is 170 mm, the thickness of the outer edge of the piston is 10 mm, and the thickness of the inner edge of the piston is 14 mm.

[0020] According to the above-mentioned scheme, a wet multi-plate clutch for reducing the radial temperature gradient of the friction element, in one embodiment, the friction element includes a plurality of dual steel plates and a plurality of friction plates, the dual steel plates and the friction plates are arranged alternately with each other, the splines of the dual steel plates are connected to the cylinder liner to form a passive end, and the internal teeth of the friction plates are engaged with the driving shaft to transmit power.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. Within a limited space, the present invention does not require changes to the main structure of the wet multi-plate clutch. Instead, it achieves the goal of reducing radial temperature differences in the friction elements by modifying only a single component, thereby reducing the thermal load of the wet multi-plate clutch at minimal cost.

[0023] 2. By separating the pressure plate from the dual steel plates and removing the splines on the pressure plate, the mass is reduced. A boss is added to the original pressure plate. The boss increases the equivalent stiffness at the inner diameter of the wet multi-plate clutch. Under the same piston pressure, the contact pressure at the inner diameter of the friction pair is increased, reducing the variability in the contact pressure distribution of the friction pair, thereby reducing the thermal load of the wet multi-plate clutch. At the same time, the pressure plate can be designed with different materials.

[0024] 3. The boss structure of the pressure plate was explored through structural optimization methods, achieving a balance between minimizing mass and maximizing heat load reduction;

[0025] 4. The piston is designed with a tapered structure. By changing the piston taper, the contact pressure between the friction pairs can be optimized, thereby reducing the thermal load of the clutch;

[0026] 5. Through the combined action of the pressure plate and the piston, the deformation of the friction element of the wet multi-plate clutch can be reduced, and the clutch temperature field can be further reduced, thereby improving the performance of the wet multi-plate clutch and extending the service life of the wet multi-plate clutch. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 This is an exploded view of the structure of Example 1 of the present invention;

[0029] Figure 2 This is a side view of the pressure plate in Example 1 of the present invention;

[0030] Figure 3 for Figure 2 Cross-sectional view of AA;

[0031] Figure 4 1 is a top view of the piston in Example 1 of the present invention;

[0032] Figure 5 for Figure 4 Cross-sectional view of the middle BB;

[0033] Figure 6 This is a schematic structural diagram of the left side of the pressure plate and the retaining spring obtained by the topology optimization method in Example 2;

[0034] Figure 7 This is a partial schematic diagram of the left side of the pressure plate obtained by the topology optimization method in Example 2;

[0035] Figure 8 A top view of the pressure plate in Example 2 of the present invention;

[0036] Figure 9 for Figure 8 Cross-sectional view of CC.

[0037] In the figure,

[0038] 1. Cylinder liner; 2. Piston; 3. Pressure plate; 301. Boss; 302. Step; 303. Groove; 4. Circlip; 5. Dual steel sheets; 6. Friction plate. DETAILED DESCRIPTION

[0039] To make the technical problems, technical solutions, and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings. It should also be noted that the embodiments described below are intended only to illustrate the present invention and are not intended to limit the present invention.

[0040] It should be noted that the terms "setting", "connection" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. The indicated orientation or position relationship is based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the application product is usually placed when in use, or the orientation or position relationship commonly understood by those skilled in the art, or the orientation or position relationship in which the application product is usually placed when in use. It is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. The meaning of "plurality" is two or more, unless otherwise clearly defined.

[0041] Example 1

[0042] See also Figure 1 This embodiment provides a wet multi-plate clutch for reducing radial temperature gradients in friction elements. The clutch comprises a cylinder liner 1, wherein a piston 2, a friction element, a pressure plate 3, and a retaining spring 4 are sequentially disposed within a groove of the cylinder liner 1. The friction element comprises a plurality of paired steel plates 5 and a plurality of friction plates 6, which are arranged alternately. The splines of the paired steel plates 5 connect to the cylinder liner 1 to form the passive end, while the internal teeth of the friction plates 6 engage with the active shaft to transmit power. During operation of the wet multi-plate clutch, the piston 2 moves axially under the action of hydraulic pressure. The retaining spring 4 within the groove of the cylinder liner 1 restricts the axial movement of the friction element, eliminating the gap between the friction elements and generating sliding friction. Ultimately, the speed difference between the paired steel plates 5 and the friction plates 6 is reduced to zero, completing the clutch engagement.

[0043] See also Figure 2 、 Figure 3 To reduce the thermal load of the wet multi-plate clutch, the pressure plate 3 of the present embodiment eliminates the conventional spline structure, thus reducing clutch mass. Furthermore, a circle of rectangular-section bosses 301 are provided on the side of the pressure plate 3 facing away from the dual steel plates 5. These bosses 301 and the outer edge of the pressure plate 3 form a circle of steps 302 for the retaining spring 4. When the wet multi-plate clutch is operating, the presence of bosses 301 increases the equivalent stiffness at the inner diameter of the wet multi-plate clutch. Under the same piston pressure, this increases the contact pressure at the inner diameter of the friction pair, reducing the variability in contact pressure distribution between the friction pairs and thus reducing the thermal load of the wet multi-plate clutch.

[0044] Preferably, the inner edge of boss 301 is flush with the inner edge of pressure plate 3. Pressure plate 3 has an outer diameter of 250 mm, an inner diameter of 170 mm, and a thickness of 10 mm; boss 301 has an outer diameter of 228 mm, an inner diameter of 170 mm, and a thickness of 10 mm. This arrangement of pressure plate 3 and boss 301 can maximize the reduction of the equivalent stiffness at the inner diameter of the wet multi-plate clutch, increase the contact pressure at the inner diameter of the friction pair, and reduce the variability in the contact pressure distribution of the friction pair, thereby minimizing the thermal load of the wet multi-plate clutch. Furthermore, it is simple to process and easy to manufacture.

[0045] Due to the restraining effect of the retaining spring 4, the contact pressure distribution of the friction pairs in the wet multi-plate clutch is uneven, with low pressure on the inner diameter and high pressure on the outer diameter. To improve this variability in contact stress distribution, the present invention modifies the pressure acting between the friction elements by changing the taper of the piston 2. Specifically, the side of the piston 2 facing away from the friction element is flat, while the side of the piston 2 facing the friction element is tapered. The thickness of the piston 2 gradually decreases from the inside to the outside, adopting a piston structure design with a high inner diameter and a low outer diameter, such as Figure 4 、 Figure 5 As shown, the piston 2 has a tapered side that contacts the friction element. Therefore, when the piston 2 is hydraulically pushed to engage the friction element, the pressure on the inner diameter increases, offsetting the uneven contact pressure distribution caused by the circlip 4. Furthermore, by varying the taper of the piston 2, the pressure distribution on the friction element can be varied to suit various operating conditions. This configuration of the piston 2 offsets the uneven contact pressure distribution caused by the circlip 4, thereby improving the performance and life of the wet multi-plate clutch.

[0046] Preferably, the outer diameter of the piston 2 is 250 mm, the inner diameter is 170 mm, the thickness of the outer edge of the piston 2 is 10 mm, and the thickness of the inner edge of the piston 2 is 14 mm. This configuration of the piston 2 can largely offset the uneven contact pressure distribution caused by the retaining spring 4, thereby improving the performance and life of the wet multi-plate clutch.

[0047] In summary, the wet multi-plate clutch for reducing the radial temperature gradient of the friction element provided by the embodiment of the present invention does not need to change the main structure of the wet multi-plate clutch within a limited space (the inner space of the groove of the cylinder liner 1), and can achieve the goal of reducing the radial temperature difference of the friction element by changing only a single element, thereby reducing the thermal load of the wet multi-plate clutch at a minimum cost; by separating the pressure plate 3 from the dual steel plate 5, removing the spline of the pressure plate 3, reducing the mass, and adding a boss 301 to the original pressure plate 3, the presence of the boss 301 improves the equivalent stiffness at the inner diameter of the wet multi-plate clutch, and at the same Under the same pressure of piston 2, the contact pressure at the inner diameter of the friction pair is increased, the difference in contact pressure distribution of the friction pair is reduced, thereby reducing the thermal load of the wet multi-plate clutch. At the same time, the pressure plate 3 can be designed with different materials; the piston 2 is designed to have a tapered structure, and the contact pressure between the friction pairs can be optimized by changing the taper of the piston 2, thereby reducing the thermal load of the clutch; through the combined action of the pressure plate 3 and the piston 2, the deformation of the friction element of the wet multi-plate clutch can be reduced, and the clutch temperature field can be further reduced, thereby improving the performance of the wet multi-plate clutch and extending the service life of the wet multi-plate clutch.

[0048] Example 2

[0049] The difference between the wet multi-plate clutch for reducing the radial temperature gradient of the friction element provided in this embodiment and the embodiment 1 lies in the structural design of the pressure plate 3. The pressure plate 3 with the boss 301 in the embodiment 1 increases the mass and does not conform to the trend of lightweight design. Therefore, in order to explore the optimal boss structure, a topology optimization method is used to obtain Figure 6 、 Figure 7 The pressure plate 3 with the boss 301 is shown. In the figure, the dotted line is 95 mm from the axis. The pressure plate 3 with the boss 301 also eliminates the traditional spline structure, and its shape is determined by five variables X1, X2, X3, X4 and X5. The values ​​of these variables are detailed in Table 1 below.

[0050] Table 1: Dimensional parameters of the pressure plate boss

[0051]

[0052] The design goal of the embodiments of the present invention is to improve the performance and reduce the thermal load of a wet multi-plate clutch while minimizing mass and maximum thermal stress. To achieve this goal, the present invention employs response surface methodology and multi-objective design optimization techniques. Figure 8 、 Figure 9An optimized pressure plate 3 with a boss 301, designed using the aforementioned techniques, is shown. The pressure plate 3 with the boss 301 has an outer diameter of 250 mm, an inner diameter of 170 mm, and a thickness of 10 mm. The boss 301 has an outer diameter of 224 mm, an inner diameter of 176 mm, and a thickness of 7 mm. A rectangular groove 303 is provided on the inner edge of one side of the boss 301 near the pressure plate 3. The groove 303 has a diameter of 184.6 mm and a thickness of 4.6 mm.

[0053] During the design process of the optimized pressure plate 3 with the boss 301, the five variables X1, X2, X3, X4 and X5 shown in Table 1 were taken into consideration. By optimizing these variables, the embodiment of the present invention achieves dual optimization of the performance and thermal load of the wet multi-plate clutch, providing an effective technical means for improving the performance and extending the life of the wet multi-plate clutch.

[0054] In summary, the embodiment of the present invention obtains the following technical means through response surface method and multi-objective design optimization: Figure 8 、 Figure 9 The optimized pressure plate 3 with the boss 301 achieves the improvement of clutch performance and the reduction of thermal load under the conditions of minimizing mass and maximum thermal stress.

[0055] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the appended claims of the present invention.

[0056] The above is an exemplary description of the patent of the present invention in conjunction with the accompanying drawings. It is obvious that the implementation of the patent of the present invention is not limited to the above-mentioned method. As long as various improvements are made by adopting the method concept and technical solution of the patent of the present invention, or the concept and technical solution of the patent of the present invention are directly applied to other occasions without improvement, they are all within the scope of protection of the present invention.

Claims

1. A wet multi-plate clutch for reducing radial temperature gradient of friction elements, comprising a cylinder liner, wherein a piston, a friction element, a pressure plate and a retaining spring are sequentially arranged in a groove of the cylinder liner, characterized in that: A circle of bosses is provided on one side of the pressure plate away from the friction element, and the bosses and the outer edge of the pressure plate form a circle of steps for placing the clamping spring; Wherein, a circle of grooves with a rectangular cross section is provided on the inner edge of one side of the boss close to the pressing plate; The outer diameter of the pressure plate is 250mm, the inner diameter is 170mm, and the thickness is 10mm; the outer diameter of the boss is 224mm, the inner diameter is 176mm, and the thickness is 7mm; The groove has a diameter of 184.6 mm and a thickness of 4.6 mm; The side of the piston away from the friction element is flat, and the side of the piston close to the friction element is tapered, and the thickness of the piston gradually becomes thinner from the inside to the outside; The outer diameter of the piston is 250 mm, the inner diameter is 170 mm, the thickness of the outer edge of the piston is 10 mm, and the thickness of the inner edge of the piston is 14 mm.

2. The wet multi-plate clutch for reducing radial temperature gradient of friction elements according to claim 1, characterized in that: The cross section of the boss is rectangular.

3. The wet multi-plate clutch for reducing radial temperature gradient of friction elements according to claim 1, characterized in that: The inner edge of the boss is flush with the inner edge of the pressing plate.

4. The wet multi-plate clutch for reducing radial temperature gradient of friction elements according to claim 1, characterized in that: The friction element includes a plurality of dual steel plates and a plurality of friction plates, the dual steel plates and the friction plates are arranged alternately, the splines of the dual steel plates are connected to the cylinder sleeve to form a passive end, and the internal teeth of the friction plates are engaged with the active shaft to transmit power.

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