A parallel shaft electric drive axle clearance automatic compensation structure

Abstract

The present invention relates to a parallel shaft electric drive axle clearance automatic compensation structure, the reducer assembly includes a first gear shaft, a second gear shaft, a third gear shaft, a first helical gear, a second helical gear, a third helical gear and a fourth helical gear; the first gear shaft passes through the bearing seat, the first helical gear, the first deep groove ball bearing and the second deep groove ball bearing are all arranged in the bearing seat, a first axial floating space is arranged outside the first deep groove ball bearing, and a second axial floating space is arranged outside the second deep groove ball bearing; an elastic retaining ring is arranged in the first axial floating space, and a corrugated gasket is arranged in the second axial floating space. This technical solution solves the problems of axial impact and abnormal noise during working condition conversion; this technology has a clearance automatic compensation function, and after a certain mileage of use, it can reduce the axial clearance, reduce the first-order unbalanced excitation of the shaft system, reduce the gear meshing noise, and effectively improve the product quality of the whole vehicle.

Description

Technical Field

[0001] The invention belongs to the technical field of electric vehicle rear axles, and in particular relates to a parallel-axis electric drive axle gap automatic compensation structure. Background Art

[0002] The parallel shaft electric drive rear axle mainly includes the motor, reducer assembly, bridge housing assembly and half-axle assembly, such as Figure 1 As shown; among them, the transmission diagram of the reducer assembly is as follows Figure 2 As shown, the first gear shaft 21 is also called the reducer input shaft, also called the motor input shaft, the second gear shaft 22 is also called the intermediate shaft, and the third gear shaft 23 is also called the half-shaft assembly. The transmission route is that the motor torque is transmitted through the first gear shaft 21 to the first bevel gear 24, to the second bevel gear 25, to the second gear shaft 22, to the third bevel gear 26, to the fourth bevel gear 27, to the third gear shaft 23, and output to the half-shaft assembly to drive the vehicle to travel.

[0003] When the reducer assembly is working, the first bevel gear 24 and the second bevel gear 25 form a pair of active and passive gears. When the vehicle moves forward and the motor drives the positive torque, the first bevel gear 24 is the active gear, and the axial force direction of the first bevel gear 24 is the Y direction. Figure 2 As shown; if the vehicle is moving forward, the motor is in the generating state with negative torque, then the first bevel gear 24 is a passive gear, and the axial force direction of the first bevel gear 24 is -Y direction; similarly, when the vehicle is moving backward, the axial force direction is opposite to the above.

[0004] The magnitude of the axial force Fd can be calculated by the formula:

[0005] Fd = 2*T / d*tanβ;

[0006] Fd is the axial force;

[0007] T is the gear shaft torque;

[0008] d is the gear pitch circle diameter;

[0009] β is the helix angle.

[0010] Due to the existence of axial force, each gear shaft in the reducer assembly needs to be constrained by a bearing and the reducer housing. The bearing constraint method is crucial to the operation of the gears.

[0011] Technical solutions of existing technology:

[0012] The first gear shaft is restrained by deep groove ball bearings on both sides. According to the recommended bearing formula, the bearing and the bearing seat need to be clearance-fitted, such as Figure 2 As shown, the first clearance fit portion 211 and the second clearance fit portion 212 are specifically as follows Figure 3As shown, a second axial floating space 2122 is reserved on the outside of the second deep groove ball bearing 2121 at the second clearance fit to allow floating along the -Y direction. At the same time, in order to prevent axial Y-direction movement caused by the axial force of the gear during the operation of the first bevel gear 24 when moving forward, a first elastic retaining ring 2112 is provided on the outside of the first deep groove ball bearing 2111 at the first clearance fit.

[0013] Disadvantages of existing technology:

[0014] (1) When the vehicle is in the gliding condition, during the gear operation, the first gear shaft 21 moves along the -Y direction, causing the deep groove ball bearing at the first clearance fit 211 to collide with the base, resulting in a loud "click" impact sound.

[0015] (2) There are risks in reliability. First, the outer ring of the deep groove ball bearing 2111 on the floating side may slip. Second, axial movement may cause abnormal gear meshing, resulting in gear whistling and abnormal noise.

[0016] (3) As the mileage increases, the bearing clearance increases, and the axial runout of the gear shaft increases during operation, resulting in an increase in the first-order unbalanced excitation of the shaft and generating operating noise.

[0017] In order to overcome the defects of the prior art 1, on the basis of the prior art 1, a second elastic retaining ring 2113 is also provided on the inner side of the first clearance fitting 211 to prevent axial movement along the -Y direction. Figure 4 However, the disadvantages of this technique are:

[0018] (1) During assembly, since the second elastic retaining ring 2113 needs to be pre-installed into the housing in advance, the bevel gear 24 and the deep groove ball bearing 2111 on the first gear shaft 21 cannot be pre-installed with the first gear shaft 21, which makes the assembly complicated and difficult, and the efficiency is low.

[0019] (2) As the mileage increases, the bearing clearance increases, and the axial runout of the gear shaft increases during operation, resulting in an increase in the first-order unbalanced excitation of the shaft and generating operating noise.

[0020] (3) Reliability risk: changes in machining tolerances may cause the outer ring of the first deep groove ball bearing 2111 on the floating side to slip, which may lead to bearing burnout. Summary of the invention

[0021] The purpose of the present invention is to provide a parallel shaft electric drive axle clearance automatic compensation structure to solve the problems mentioned in the background technology, optimize the bearing constraint conditions on the basis of the existing structure, and improve the assembly efficiency and reliability of parts.

[0022] To achieve the above objectives, this application is implemented through the following technical solutions:

[0023] A parallel shaft type electric drive axle clearance automatic compensation structure includes a reducer assembly, wherein the reducer assembly includes a first gear shaft, a second gear shaft, a third gear shaft, a first helical gear, a second helical gear, a third helical gear and a fourth helical gear;

[0024] The first gear shaft is provided with a first bevel gear, the second gear shaft is provided with a second bevel gear and a third bevel gear, and the second bevel gear is meshed with the first bevel gear; the third gear shaft is provided with a fourth bevel gear, and the fourth bevel gear is meshed with the third bevel gear;

[0025] A first deep groove ball bearing and a second deep groove ball bearing are arranged on both sides of the first helical gear of the first gear shaft;

[0026] The first gear shaft passes through the bearing seat, the first helical gear, the first deep groove ball bearing and the second deep groove ball bearing are all arranged in the bearing seat, an opening is arranged on the side of the bearing seat, and the first helical gear protrudes out of the bearing seat from the opening;

[0027] A first axial floating space is provided between the first deep groove ball bearing and the bearing seat, and a second axial floating space is provided between the second deep groove ball bearing and the bearing seat;

[0028] An elastic retaining ring is arranged in the first axial floating space, and a corrugated gasket is arranged in the second axial floating space.

[0029] Furthermore, the corrugated gasket is in a compressed state and is installed in the second axial floating space according to the set assembly compression force F0 and related performance parameters.

[0030] Furthermore, the assembly pressing force F0 and related performance parameters of the corrugated gasket are designed as follows:

[0031] S1. Calculate the relevant axial force by using the forward driving torque T0 of the first gear shaft under the forward driving condition, the reverse motor energy recovery torque T1 under the coasting condition, and the reverse driving torque T2 under the reverse condition, then:

[0032] Under forward drive conditions, the axial force Fd0 is: Fd0 = 2*T0 / d*tanβ;

[0033] When the reverse motor energy is recovered under the gliding condition, the axial force Fd1 is: Fd1 = -2*T1 / d*tanβ;

[0034] Under the reversing condition, the axial force Fd2 is: Fd2 = -2*T2 / d*tanβ; where β is the helix angle;

[0035] The allowable axial load of deep groove ball bearing is Fk;

[0036] S2. In order to ensure that there is no axial movement and abnormal noise when the reverse motor recovers energy under forward driving conditions and sliding conditions, the assembly clamping force F0 needs to be greater than Fd1;

[0037] To prevent the deep groove bearing from exceeding the allowable load, the sum of the assembly clamping force F0 and the axial force Fd0 under the forward drive condition should be less than the axial allowable load Fk;

[0038] To avoid failure of the corrugated gasket, the axial force Fd2 under reversing conditions shall not exceed the maximum allowable compression force Fmax in the elastic range of the corrugated gasket, that is, Fmax>Fd2.

[0039] Furthermore, it also includes a motor, a bridge housing assembly and a half-axle assembly;

[0040] The motor is connected to the first gear shaft of the reducer assembly, the third gear shaft of the reducer assembly is connected to the half-shaft assembly, and the half-shaft assembly is arranged in the bridge housing assembly.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] This technical solution solves the problems of axial impact and abnormal noise when the forward drive condition is converted to the coasting condition and the reverse motor recovers energy; it solves the influence of the assembly of the elastic retaining ring on the inner side of the bearing on the assembly of the assembly, and improves the assembly efficiency; this technology has an automatic clearance compensation function, after a certain mileage of use, it can reduce the axial clearance, reduce the first-order unbalanced excitation of the shaft system, reduce the gear meshing noise, and effectively improve the quality of the vehicle product. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a schematic diagram of the parallel shaft electric drive rear axle structure.

[0044] Figure 2 This is a simplified transmission diagram of the reducer assembly.

[0045] Figure 3 It is an axial cross-sectional view of the first gear shaft, deep groove ball bearing and bearing seat.

[0046] Figure 4 for Figure 3 Schematic diagram of part of the structure.

[0047] Figure 5 It is a schematic diagram of the automatic compensation structure assembly structure of the present invention.

[0048] Figure 6 It is a schematic diagram of the structure of the corrugated gasket.

[0049] Figure 7 This is a front view of the corrugated gasket.

[0050] Figure 8 The figure is a side view of a corrugated gasket.

[0051] Fig. 9 This is a schematic diagram of the corrugated gasket installation process.

[0052] Fig.10 This is the performance parameter diagram of the corrugated gasket.

[0053] Description of Reference Numerals

[0054] 1 motor, 2 reducer assembly, 3 bridge housing assembly, 4 half-shaft assembly, 21 first gear shaft, 22 second gear shaft, 23 third gear shaft, 24 first bevel gear, 25 second bevel gear, 26 third bevel gear, 27 fourth bevel gear, 28 bearing seat, 211 first clearance fit, 212 second clearance fit, 2111 first deep groove ball bearing, 2112 first elastic retaining ring, 2113 second elastic retaining ring, 2121 second deep groove ball bearing, 2122 second axial floating space, 2123 wave washer. DETAILED DESCRIPTION

[0055] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings. The following embodiments are merely exemplary and can only be used to explain and illustrate the technical solution of the present invention, but cannot be construed as limiting the technical solution of the present invention.

[0056] The technical solution of the present application has the same structure as the parallel shaft electric drive axle of the prior art solution, and both include a motor 1, a bridge housing assembly 3, a reducer assembly 2 and a half-axle assembly 4. And the connection relationship of these parts is also the same, so, Figures 1 to 3 It can also reflect the connection relationship between the various components of this application.

[0057] The reducer assembly 2 includes a first gear shaft 21 , a second gear shaft 22 , a third gear shaft 23 , a first helical gear 24 , a second helical gear 25 , a third helical gear 26 and a fourth helical gear 27 .

[0058] The first gear shaft 21 is provided with a first bevel gear 24 , the second gear shaft 22 is provided with a second bevel gear 25 and a third bevel gear 26 , and the second bevel gear meshes with the first bevel gear; the third gear shaft 23 is provided with a fourth bevel gear 27 , and the fourth bevel gear meshes with the third bevel gear.

[0059] The transmission route is that the motor torque is transmitted through the first gear shaft 21 to the first bevel gear 24, to the second bevel gear 25, to the second gear shaft 22, to the third bevel gear 26, to the fourth bevel gear 27, to the third gear shaft 23, and output to the half-axle assembly to drive the vehicle.

[0060] When the reducer assembly is working, the first bevel gear 24 and the second bevel gear 25 form a pair of active and passive gears. When the vehicle moves forward and the motor drives the positive torque, the first bevel gear 24 is the active gear, and the axial force direction of the first bevel gear 24 is the Y direction. Figure 2 As shown; if the vehicle is moving forward, the motor is in the generating state with negative torque, then the first bevel gear 24 is a passive gear, and the axial force direction of the first bevel gear 24 is -Y direction; similarly, when the vehicle is moving backward, the axial force direction is opposite to the above.

[0061] The motor is connected to the first gear shaft of the reducer assembly, the third gear shaft of the reducer assembly is connected to the half-shaft assembly, and the half-shaft assembly is arranged in the bridge housing assembly.

[0062] A first deep groove ball bearing 2111 and a second deep groove ball bearing 2121 are provided on both sides of the first bevel gear 24 of the first gear shaft 21. The first gear shaft passes through the bearing seat 28, and the first deep groove ball bearing and the second deep groove ball bearing play a role in supporting the first gear shaft.

[0063] The first helical gear, the first deep groove ball bearing and the second deep groove ball bearing are all arranged in the bearing seat. An opening is arranged on the side of the bearing seat. The first helical gear protrudes from the bearing seat through the opening and meshes with the second helical gear.

[0064] In the technical solution of the present application, the deep groove ball bearing close to the motor side is the second deep groove ball bearing 2121, and the deep groove ball bearing away from the motor side is the first deep groove ball bearing 2111. A first axial floating space is provided between the first deep groove ball bearing and the bearing seat, and a second axial floating space 2122 is provided between the second deep groove ball bearing and the bearing seat. An elastic retaining ring is provided in the first axial floating space, and a corrugated gasket 2123 is provided in the second axial floating space 2122. Figures 5 to 8 As shown, a reasonable corrugated gasket structure can be set according to different performance parameters.

[0065] Reasonable selection of the compression force F0 and performance parameters of the corrugated gasket assembly, and clear selection basis, mainly based on the forward driving torque of the first gear shaft under forward driving conditions, the reverse motor energy recovery torque under coasting conditions, the reverse driving torque under reversing conditions, and the deep groove ball bearing axial allowable load related parameters.

[0066] like Fig. 9As shown, the assembly process of the corrugated gasket is as follows: first, place the corrugated gasket 2123 in the second floating space 2122, place the first gear shaft and the first bevel gear, the first deep groove ball bearing and the second deep groove ball bearing assembly into the bearing seat, apply an assembly clamping force F0 at the end face of the first gear shaft, and when the assembly clamping force F0 reaches the set value, select an elastic retaining ring of reasonable thickness and assemble it into the first floating space, that is, the retaining ring mounting groove of the bearing seat, and then install the bearing seat side cover to complete the assembly of the first gear shaft.

[0067] In this application, the assembly pressing force F0 of the corrugated gasket and related performance parameters are designed as follows:

[0068] S1. Calculate the relevant axial force by using the forward driving torque T0 of the first gear shaft under the forward driving condition, the reverse motor energy recovery torque T1 under the coasting condition, and the reverse driving torque T2 under the reverse condition, then:

[0069] Under forward drive conditions, the axial force Fd0 is: Fd0 = 2*T0 / d*tanβ;

[0070] When the reverse motor energy is recovered under the gliding condition, the axial force Fd1 is: Fd1 = -2*T1 / d*tanβ;

[0071] Under the reversing condition, the axial force Fd2 is: Fd2 = -2*T2 / d*tanβ; where β is the helix angle;

[0072] The allowable axial load of deep groove ball bearing is Fk;

[0073] S2. In order to ensure that there is no axial movement and abnormal noise when the reverse motor recovers energy under forward driving conditions and sliding conditions, the assembly clamping force F0 needs to be greater than Fd1;

[0074] To prevent the deep groove bearing from exceeding the allowable load, the sum of the assembly clamping force F0 and the axial force Fd0 under the forward drive condition should be less than the axial allowable load Fk;

[0075] To avoid failure of the corrugated gasket, the axial force Fd2 under the reversing condition shall not exceed the maximum allowable compression force Fmax of the elastic range of the corrugated gasket, that is, Fmax>Fd2. Fig.10 As shown, △Xmax refers to the maximum allowable compression deformation of the corrugated gasket, and Fmax refers to the maximum allowable compression force of the corrugated gasket.

[0076] The specific working principle of the automatic gap compensation structure is as follows: 1) During forward drive, the axial force is in the Y direction, and an elastic retaining ring is set on the outside of the first deep groove ball bearing to provide axial support. 2) During energy recovery and reverse drive under sliding conditions, the axial support is provided by the corrugated gasket, which acts on the outer ring of the bearing. In order to prevent axial movement, the assembly clamping force should be increased when the corrugated gasket is pre-installed. 3) After a certain mileage of use, the gap between the worn bearing and the gear can be supplemented by the compression of the corrugated gasket, which has the function of automatic gap compensation.

[0077] Although the embodiments of the present application have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A parallel shaft electric drive axle clearance automatic compensation structure, comprising a reducer assembly, wherein the reducer assembly comprises a first gear shaft, a second gear shaft, a third gear shaft, a first helical gear, a second helical gear, a third helical gear and a fourth helical gear; The first gear shaft is provided with a first bevel gear, the second gear shaft is provided with a second bevel gear and a third bevel gear, and the second bevel gear is meshed with the first bevel gear; the third gear shaft is provided with a fourth bevel gear, and the fourth bevel gear is meshed with the third bevel gear; A first deep groove ball bearing and a second deep groove ball bearing are arranged on both sides of the first helical gear of the first gear shaft; The first gear shaft passes through the bearing seat, the first helical gear, the first deep groove ball bearing and the second deep groove ball bearing are all arranged in the bearing seat, an opening is arranged on the side of the bearing seat, and the first helical gear protrudes out of the bearing seat from the opening; A first axial floating space is provided between the first deep groove ball bearing and the bearing seat, and a second axial floating space is provided between the second deep groove ball bearing and the bearing seat; the characteristics are as follows: An elastic retaining ring is arranged in the first axial floating space, and a corrugated gasket is arranged in the second axial floating space; The corrugated gasket is in a compressed state and installed in the second axial floating space according to the set assembly compression force F0 and related performance parameters; Set reasonable corrugated gasket structure according to different performance parameters; The relevant performance parameters are based on the forward driving torque of the first gear shaft under forward driving conditions, the reverse motor energy recovery torque under coasting conditions, the reverse driving torque under reverse conditions, and the parameters related to the axial allowable load of the deep groove ball bearing; The assembly pressing force F0 and related performance parameters of the corrugated gasket are designed as follows: S1. Calculate the relevant axial force by using the forward driving torque T0 of the first gear shaft under the forward driving condition, the reverse motor energy recovery torque T1 under the coasting condition, and the reverse driving torque T2 under the reverse condition, then: Under forward drive conditions, the axial force Fd0 is: Fd0 = 2*T0 / d*tanβ; When the reverse motor energy is recovered under the gliding condition, the axial force Fd1 is: Fd1 = -2*T1 / d*tanβ; Under the reverse working condition, the axial force Fd2 is: Fd2 = -2*T2 / d*tanβ; where β is the helix angle; The allowable axial load of deep groove ball bearing is Fk; S2. In order to ensure that there is no axial movement and abnormal noise when the reverse motor recovers energy under forward driving conditions and sliding conditions, the assembly clamping force F0 needs to be greater than Fd1; To prevent the deep groove bearing from exceeding the allowable load, the sum of the assembly clamping force F0 and the axial force Fd0 under the forward drive condition should be less than the axial allowable load Fk; To avoid failure of the corrugated gasket, the axial force Fd2 under reversing conditions shall not exceed the maximum allowable compression force Fmax in the elastic range of the corrugated gasket, that is, Fmax>Fd2.

2. The parallel axis electric drive axle gap automatic compensation structure according to claim 1 is characterized in that: 1) When driving in the forward direction, the axial force is in the Y direction, and an elastic retaining ring is arranged on the outside of the first deep groove ball bearing to provide axial support; 2) When energy is recovered and driven in reverse under gliding conditions, the corrugated gasket is used to provide axial support. The corrugated gasket acts on the outer ring of the bearing. To prevent axial movement, the assembly clamping force should be increased when the corrugated gasket is pre-installed. 3) After a certain mileage, the gap between the worn bearings and gears is supplemented by the compression of the corrugated gasket, and it has the function of automatically compensating the gap.

3. The parallel axis electric drive axle gap automatic compensation structure according to claim 1 is characterized in that: It also includes the motor, bridge housing assembly and half-axle assembly; The motor is connected to the first gear shaft of the reducer assembly, the third gear shaft of the reducer assembly is connected to the half-shaft assembly, and the half-shaft assembly is arranged in the bridge housing assembly.

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