A steel ring type friction transmission continuously variable transmission

Abstract

The present invention relates to a steel ring type friction transmission continuously variable transmission, comprising an input flange assembly, an output flange assembly, and an intermediate roller assembly. The intermediate roller assembly is located between the input flange assembly and the output flange assembly, and a pressure mechanism is installed at the axial position of the input flange assembly and the output flange assembly. The friction transmission power between the intermediate roller assembly and the input and output flange assemblies is realized by the pressing force of the pressure mechanism. A friction pair mechanism is installed between the intermediate roller assembly and the input and output flange assemblies, and one end of the friction pair mechanism is clamped between one end face of the intermediate roller assembly and the input flange assembly, and the other end of the friction pair mechanism is clamped between the other end face of the intermediate roller assembly and the output flange assembly. The present invention can improve the transmission torque and increase the contact area of ​​the friction pair under the conditions of a certain service life, structure size, speed ratio, material and state.

Description

Technical Field

[0001] The invention belongs to the technical field of continuously variable transmission, and in particular relates to a steel ring type friction transmission continuously variable transmission which is driven and speed-regulated by an intermediate friction wheel. Background Art

[0002] The transmission is a mechanism used to change the speed and torque from the power transmission and control equipment (such as: engine), and can change the transmission ratio of the output shaft and the input shaft in a fixed or step-by-step manner. The continuously variable transmission is a transmission that can achieve continuous change of the transmission ratio and can obtain the best match between the transmission system and the engine working conditions. In order to achieve continuously variable speed, three transmission methods can be used according to the transmission mode: liquid transmission, electric transmission and mechanical transmission. However, most of the continuously variable transmissions on the market currently use mechanical transmission. The main reason why the friction transmission mechanical continuously variable transmission cannot transmit large torque is determined by the life requirements of the product (friction pair), not because the structural design cannot meet the mechanical properties and fails. When the friction pair structure has been finalized, the transmission torque is reduced to ensure or meet the life requirements of the continuously variable transmission. On the contrary, when the life requirements have been specified, the friction pair structure is improved to increase the transmission torque. For example, in a continuously variable transmission with application number 2016102074282, the friction ring is arranged between the input and output flanges and the cylindrical cone (tourmaline) to ensure replacement and maintenance of the wearable parts in actual applications; the upper part of the inner end face of the friction ring abuts against the conical surfaces of the input conical section and the output conical section in a point contact manner. This contact method makes the contact area of ​​the friction ring very small, and the contact stress will increase accordingly, which is not conducive to increasing the torque of the transmission.

[0003] At present, the friction pairs of automobile continuously variable transmissions use special steel belts and chains to meet the mechanical and life requirements, but the production technology and quality requirements are very high, the structure is complex, the cost is high, and the failure rate is high. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide a steel ring friction drive continuously variable transmission for the purpose of improving the transmission torque and increasing the contact area of ​​the friction pair under given life, structural size, speed ratio, material and state conditions.

[0005] The objective of the present invention is achieved through the following technical scheme. The steel ring type friction transmission continuously variable transmission comprises an input flange assembly, an output flange assembly, and an intermediate roller assembly. The intermediate roller assembly is located between the input flange assembly and the output flange assembly, and a pressure mechanism is installed at the axial position of the input flange assembly and the output flange assembly. The friction transmission power between the intermediate roller assembly and the input and output flange assemblies is realized by the clamping force of the pressure mechanism. A friction pair mechanism is installed between the intermediate roller assembly and the input and output flange assemblies, and one end of the friction pair mechanism is clamped between one end face of the intermediate roller assembly and the input flange assembly, and the other end of the friction pair mechanism is clamped between the other end face of the intermediate roller assembly and the output flange assembly.

[0006] Preferably, the input flange assembly includes an input flange and a first pressure rail, wherein the first pressure rail is mounted on the input flange; the output flange assembly includes an output flange and a second pressure rail, wherein the second pressure rail is mounted on the output flange; and the first pressure rail and the second pressure rail are relatively distributed.

[0007] Preferably, the pressurizing mechanism includes a center shaft, an input bearing, an output bearing, a disc spring, and a flange nut. The input bearing is installed at the axial end of the input flange, the output bearing is installed at the axial end of the output flange, and the input and output bearings are respectively installed at both ends of the center shaft, wherein a disc spring is installed on the center shaft at the input bearing end and is tightened by a flange nut.

[0008] Preferably, the intermediate roller assembly includes a bracket, a tourbillon, and a guide shaft. The tourbillon is mounted on the guide shaft and can move axially repeatedly. The guide shaft is circumferentially arranged on the bracket and is inclined, and both ends of the guide shaft are connected to the bracket through bearings.

[0009] Preferably, the friction pair mechanism comprises an input friction ring and an output friction ring, the radial end face of the input friction ring is clamped between the end face of the tourbillon and an annular groove provided on the first pressure rail, the radial end face of the output friction ring is clamped between the end face of the tourbillon and an annular groove provided on the second pressure rail, and the input friction ring and the output friction ring are pressed between the annular grooves of the first and second pressure rails and the tourbillon by a pressurizing mechanism.

[0010] Preferably, the number of the friction pair mechanisms is equal to the number of the tourbillons and they are arranged one-to-one, and the input friction ring and the output friction ring are arranged in a cross shape, and the diameter of the output friction ring is smaller than the diameter of the input friction ring.

[0011] Preferably, the radial inner end faces of the first pressure rail and the second pressure rail are each provided with a circle of racks, and the radial outer end faces of the input flange and the output flange are each provided with a circle of convex teeth and pressure blocks arranged in an alternating manner, and the convex teeth are meshed with the racks, and the pressure blocks are pressed against the inner radial wall of the pressure rail.

[0012] Preferably, the tour wheel is in a rhombus shape, and its two conical surfaces are in contact with the input friction ring and the output friction ring respectively, and the diameters of the input friction ring and the output friction ring are both larger than the cross-sectional diameter of the conical surface of the tour wheel.

[0013] Preferably, the input friction ring and the output friction ring are steel rings, and their inner end faces in contact with the tourbillon conical surface are flat and coincide with the tourbillon conical surface.

[0014] Preferably, the groove surfaces of the annular grooves of the first pressure rail and the second pressure rail are both arc-shaped, and the outer end surfaces of the input friction ring and the output friction ring in contact with the annular groove are both arc-shaped, and the outer end surfaces are located in the annular groove and coincide with each other.

[0015] The beneficial effects of the present invention are as follows: a friction pair mechanism of a steel ring structure is added between the input and output flange assemblies and the intermediate roller assembly, and at the same time, the contact area between the friction pair mechanism and the tourbillon and the pressure rail is increased, so as to solve the problem of the life of the friction pair of the continuously variable transmission and the inability to transmit large torque transmission force. In order to effectively transmit power, the pressing force of the pressure mechanism is used to ensure that there is no slippage between the structures, so that the entire transmission can achieve the effect of increasing the transmission torque. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a three-dimensional structural schematic diagram of the present invention.

[0017] Figure 2 It is a main structural schematic diagram of the present invention.

[0018] Figure 3 yes Figure 2 Schematic diagram of the AA cross-section structure.

[0019] Figure 4 It is a schematic diagram of the connection structure between the tour wheel and each pressure rail of the present invention.

[0020] Figure 5 It is a schematic diagram of the exploded structure of the input flange assembly of the present invention.

[0021] Figure 6 It is a schematic diagram of the three-dimensional structure of the friction ring of the present invention.

[0022] The numbers in the accompanying drawings are: 1. input flange assembly; 2. output flange assembly; 3. intermediate roller assembly; 4. pressurizing mechanism; 5. friction pair mechanism; 6. annular groove; 7. rack; 8. convex tooth; 9. pressure block; 11. input flange; 12. first pressure rail; 21. output flange; 22. second pressure rail; 31. bracket; 32. tourbillon; 33. guide shaft; 34. bearing; 41. center shaft; 42. input bearing; 43. output bearing; 44. disc spring; 45. flange nut; 51. input friction ring; 52. output friction ring. DETAILED DESCRIPTION

[0023] The present invention will be described in detail below with reference to the accompanying drawings: Figure 1 As shown, the present invention includes an input flange assembly 1, an output flange assembly 2, and an intermediate roller assembly 3. The intermediate roller assembly 3 is located between the input flange assembly 1 and the output flange assembly 2, and a pressure mechanism 4 is installed at the axial position of the input flange assembly 1 and the output flange assembly 2. The friction transmission power between the intermediate roller assembly 3 and the input and output flange assemblies is realized by the pressing force of the pressure mechanism 4. A friction pair mechanism 5 is installed between the intermediate roller assembly 3 and the input and output flange assemblies, and one end of the friction pair mechanism 5 is clamped between one end surface of the intermediate roller assembly 3 and the input and output flange assemblies. The input flange assembly 1, the other end of the friction pair mechanism 5 is clamped between the other end surface of the intermediate roller assembly 3 and the output flange assembly 2; a friction pair mechanism of a steel ring structure is added between the input and output flange assemblies and the intermediate roller assembly, and the contact area between the friction pair mechanism and the tourbillon and the pressure rail is increased to solve the problem of the life of the friction pair of the continuously variable transmission that causes the inability to transmit large torque transmission force. In order to effectively transmit power, the pressing force of the pressure mechanism is used to ensure that there is no slippage between the structures, so that the entire transmission can achieve an increase in the transmission torque.

[0024] As attached Figure 2 , 3 As shown, the power transmission sequence of the above-mentioned steel ring type friction transmission continuously variable transmission is: power is input from the central shaft 41, connected to the input flange 11, the input flange 11 is installed with the first pressure rail 12, the input friction ring 51 revolves in the annular groove 6 of the first pressure rail 12, the input friction ring 51 and a conical surface of the tourbillon 32 roll and rub against each other to transmit power, the other conical surface and the output friction ring 52 roll and rub against each other to transmit power to the second pressure rail 22, the second pressure rail 2 is installed on the output flange 21, and the power is output by the output flange 21.

[0025] Speed ​​regulation method: The speed regulation mode of this continuously variable transmission is the speed regulation of the intermediate wheel working diameter; the two conical surfaces of the tourbillon 32 are respectively pressurized and contacted with the input friction ring 51 and the output friction ring 52. When the tourbillon 32 moves toward the axial direction of the guide shaft 33, the contact surface diameters of the tourbillon 32 and the input friction ring 51 and the output friction ring 52 change, thereby achieving the speed regulation purpose.

[0026] Pressurization method: In order to effectively transmit power through rolling friction between the input friction ring 51 and the output friction ring 52 and the tourbillon 32 and the two pressure rails to prevent slipping; the input flange 11 and the output flange 21 are connected together by the central shaft 41 and the flange nut 45, and are isolated from each other by the bearing 34. The disc spring 44 provides axial clamping force to clamp the tourbillon 32 between the input friction ring 51 and the output friction ring 52.

[0027] Movement mode of the friction pair: the two friction rings respectively roll in the annular grooves of the two pressure rails and revolve together, while rotating around the central axis 41. The friction force between the input friction ring 51 and the tourbillon 32 drives the tourbillon 32 to rotate around the guide shaft 33, and the friction force drives the output friction ring 52 and the output flange assembly to revolve.

[0028] The input flange assembly 1 includes an input flange 11 and a first pressure rail 12, wherein the first pressure rail 12 is mounted on the input flange 11; the output flange assembly 2 includes an output flange 21 and a second pressure rail 22, wherein the second pressure rail 22 is mounted on the output flange 21; and the first pressure rail 12 and the second pressure rail 22 are arranged relative to each other, so that the intermediate roller assembly 3 and the friction pair mechanism 5 can be clamped between the first and second pressure rails. Figure 5 As shown, the radial inner end faces of the first pressure rail 12 and the second pressure rail 22 are each provided with a circle of racks 7, and the radial outer end faces of the input flange 11 and the output flange 21 are each provided with a circle of convex teeth 8 and pressure blocks 9 arranged in an alternating manner, and the convex teeth 8 are meshed with the racks 7 so that the flange and the pressure rail can mesh and transmit power, and the pressure block 9 is pressed against the inner radial wall of the pressure rail so that the two oppositely arranged pressure rails provide axial pressure, and the advantage of the separate shape of the flange and the pressure rail is that disassembly and maintenance are more convenient, and the cost will not be too high when replacing parts.

[0029] The pressurizing mechanism 4 includes a central shaft 41, an input bearing 42, an output bearing 43, a disc spring 44, and a flange nut 45. The input bearing 42 is installed at the axial end of the input flange 11, and the output bearing 43 is installed at the axial end of the output flange 21. The input and output bearings are installed at both ends of the central shaft 41, respectively. A disc spring 44 is installed on the central shaft 41 at the input bearing end, and is pressed by a flange nut 45. The power is transmitted by the friction force (i.e., friction pair) between the intermediate rolling element and the input and output structure of the mechanical continuously variable transmission. In order to effectively transmit the power, the pressing force of the pressurizing mechanism is required to ensure that the intermediate rolling element and the input and output structure do not slip. The friction force (F) is related to the pressing force (Q) and the friction coefficient (μ): F = μQ. Therefore, in general, the continuously variable transmission (the structure size, material and state are fixed) increases the friction force by increasing the pressing force to transmit greater power (torque). As the clamping force increases, the contact stress of the contact surface between the friction pairs increases, thereby reducing the life of the friction pairs (this conclusion can be drawn based on the calculation of the allowable contact stress and the number of cyclic stresses). Therefore, in order to ensure that the CVT increases the transmission torque within the specified life, the clamping force must be increased, but in order not to reduce the life, the contact stress cannot be increased, so the contact area of ​​the friction pairs must be increased accordingly.

[0030] The intermediate roller assembly 3 includes a bracket 31, a tourbillon 32, and a guide shaft 33. The tourbillon 32 is installed on the guide shaft 33 and can move axially repeatedly. The guide shaft 33 is evenly arranged on the bracket 31 in the circumferential direction and is axially distributed along the central axis 41 and is inclined. The two ends of the guide shaft 33 are connected to the bracket 31 through bearings 34. The bracket 31 can move relative to the axis of the central axis 41, thereby driving the tourbillon 4 to move relative to the axis of the guide shaft 33 to achieve the purpose of continuously variable transmission speed regulation.

[0031] The friction pair mechanism 5 comprises an input friction ring 51 and an output friction ring 52. The radial end face of the input friction ring 51 is sandwiched between the end face of the tourbillon 32 and the annular groove 6 provided on the first pressure rail 12. The radial end face of the output friction ring 52 is sandwiched between the end face of the tourbillon 32 and the annular groove 6 provided on the second pressure rail 22. The input friction ring 51 and the output friction ring 52 are pressed between the annular groove 6 of the first pressure rail 12 and the second pressure rail 22 and the tourbillon 32 through a pressurizing mechanism 4. The outer end faces of the input friction ring 51 and the output friction ring 52 are in pressure contact with the annular groove 6 and revolve. At the same time, the inner end faces of the input friction ring 51 and the output friction ring 52 are in pressure contact with the two end faces of the tourbillon 32 while rotating relative to the center line of the central shaft 41. As the tourbillon 32 moves along the axis of the guide shaft, the diameter of the contact surface also changes.

[0032] The number of the friction pair mechanisms 5 is equal to the number of the tourbillons 32 and they are arranged one by one, and the input friction ring 51 and the output friction ring 52 are arranged in a cross shape, so that the spatial arrangement is more compact and the stability is better; the diameter of the output friction ring 52 is smaller than the diameter of the input friction ring 51.

[0033] As attached Figure 4 , 6 As shown, the tour wheel 32 is in a diamond cone shape, and its two cone surfaces are in contact with the input friction ring 51 and the output friction ring 52 respectively, and the diameters of the input friction ring 51 and the output friction ring 52 are both larger than the cross-sectional diameter of the cone surface of the tour wheel 32 .

[0034] The input friction ring 51 and the output friction ring 52 are steel ring structures, which are simpler, lower in cost and more reliable than other structures (chains or steel belts, etc.) in terms of mechanics and manufacturing cost. The inner end faces thereof in contact with the conical surface of the tourbillon 32 are flat and coincide with the conical surface of the tourbillon 32. The groove surfaces of the annular grooves 6 of the first pressure rail 12 and the second pressure rail 22 are both arc-shaped, and the outer end faces of the input friction ring 51 and the output friction ring 52 in contact with the annular grooves 6 are both arc-shaped, and the outer end faces are located in the annular grooves 6 and coincide with each other.

[0035] The "allowable contact stress" of the friction pair of a mechanical continuously variable transmission is also fixed when the service life requirement is specified. In order to increase the transmission torque but not exceed the "allowable contact stress", the contact area of ​​the friction pair must be increased.

[0036] The contact form between the diamond cone wheel and the pressure rail without the friction ring is the external contact between the cylinder and the plane. If you want to reduce the contact stress (i.e., increase the transmission torque), according to the "Hertz formula", the comprehensive curvature radius and contact width of the friction pair contact surface must be increased. When the outer ring of the input friction ring 51 and the output friction ring 52 contacts the annular groove 6 of the pressure rail, the outer diameter of the friction ring is much larger than the diameter of the cone section of the diamond cone wheel, so the comprehensive curvature radius is higher than that of the form without the friction ring; at the same time, the semicircular arc contact form increases the contact width of the contact surface and becomes an internal contact form (hole and shaft contact). According to the Hertz formula, it is inferred that the comprehensive curvature radius of the contact surface increases, thereby increasing the contact area and reducing the contact stress; the inner ring surface of the input friction ring 51 and the output friction ring 52 contacts the outer diameter of the diamond cone surface of the diamond cone wheel, and the existing plane and cylinder contact form becomes an internal contact (hole and shaft) form. According to the Hertz formula, it is inferred that the comprehensive curvature radius is greatly increased, thereby increasing the contact area, reducing the contact stress, and increasing the transmission torque.

[0037] The present invention is not limited to the above-mentioned embodiments. No matter any changes are made in the shape or material composition, any structural design provided by the present invention is a variation of the present invention and should be considered to be within the protection scope of the present invention.

Claims

1. A steel ring type friction drive continuously variable transmission, comprising an input flange assembly (1), an output flange assembly (2), and an intermediate roller assembly (3), characterized in that: The intermediate roller assembly (3) is located between the input flange assembly (1) and the output flange assembly (2), and a pressure mechanism (4) is installed at the axial position of the input flange assembly (1) and the output flange assembly (2), and the friction transmission power between the intermediate roller assembly (3) and the input and output flange assemblies is realized by the pressing force of the pressure mechanism (4). A friction pair mechanism (5) is installed between the intermediate roller assembly (3) and the input and output flange assemblies, and one end of the friction pair mechanism (5) is clamped between one end surface of the intermediate roller assembly (3) and the input flange assembly (1), and the other end of the friction pair mechanism (5) is clamped between the other end surface of the intermediate roller assembly (3) and the output flange assembly (2); the input flange assembly The assembly (1) comprises an input flange (11) and a first pressure rail (12), wherein the first pressure rail (12) is mounted on the input flange (11); the output flange assembly (2) comprises an output flange (21) and a second pressure rail (22), wherein the second pressure rail (22) is mounted on the output flange (21); and the first pressure rail (12) and the second pressure rail (22) are arranged relative to each other; the pressurizing mechanism (4) comprises a central shaft (41), an input bearing (42), an output bearing (43), a disc spring (44), and a flange nut (45), wherein the input bearing (42) is mounted at an axial end of the input flange (11), and the output bearing (43) is mounted at an axial end of the output flange (21), and the input and output shafts are arranged relative to each other. The bearings are respectively mounted on both ends of the central shaft (41), wherein a disc spring (44) is mounted on the central shaft (41) at the input bearing end and is compressed by a flange nut (45); the intermediate roller assembly (3) comprises a bracket (31), a tourbillon (32), and a guide shaft (33); the tourbillon (32) is mounted on the guide shaft (33) and can repeatedly move axially, and the guide shaft (33) is evenly arranged on the bracket (31) in a circumferential direction and is inclined, and the two ends of the guide shaft (33) are connected to the bracket (31) through bearings (34); the friction pair mechanism (5) comprises an input friction ring (51) and an output friction ring (52); the radial end surface of the input friction ring (51) is clamped on the tourbillon The first pressure rail (32) and the second pressure rail (22) are provided with an annular groove (6), the radial end surface of the output friction ring (52) is sandwiched between the end surface of the tourbillon (32) and the annular groove (6) provided on the second pressure rail (22), and the input friction ring (51) and the output friction ring (52) are pressed between the annular grooves (6) of the first pressure rail (12), the second pressure rail (22) and the tourbillon (32) by a pressurizing mechanism (4); the number of the friction pair mechanisms (5) is equal to the number of the tourbillons (32) and they are arranged one by one, and the input friction ring (51) and the output friction ring (52) are arranged in a cross shape, and the diameter of the output friction ring (52) is smaller than the diameter of the input friction ring (51);The radial inner end faces of the first pressure rail (12) and the second pressure rail (22) are each provided with a circle of racks (7); the radial outer end faces of the input flange (11) and the output flange (21) are each provided with a circle of convex teeth (8) and a pressure block (9) arranged in an alternating manner, and the convex teeth (8) are meshed with the racks (7); the pressure block (9) is pressed against the inner radial wall of the pressure rail; the tourbillon (32) is in a diamond cone shape, and its two cone surfaces are in contact with the input friction ring (51) and the output friction ring (52) respectively, and the input friction ring (51) and the output friction ring (52) are in contact with each other. The diameter of the friction ring (52) is greater than the cross-sectional diameter of the conical surface of the tourbillon (32); the input friction ring (51) and the output friction ring (52) are steel ring-type structures, and their inner end surfaces in contact with the conical surface of the tourbillon (32) are flat and coincide with the conical surface of the tourbillon (32); the groove surfaces of the annular groove (6) of the first pressure rail (12) and the second pressure rail (22) are both arc-shaped, and the outer end surfaces of the input friction ring (51) and the output friction ring (52) in contact with the annular groove (6) are both arc-shaped, and the outer end surfaces are located in the annular groove (6) and coincide with each other. ;

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