Two-stage speed reducer for light truck electric drive axle
By designing a secondary reducer for light truck electric drive axles, the existing three-stage reducer has solved the problem of complex structure and large mass, and a lighter, smaller and more compact reducer is achieved, which improves transmission efficiency and application It reduces manufacturing costs and effectively controls the problems of temperature rise and lubricating oil fluid agitation.
Patent Information
- Application Number
- CN202420952957.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-06
- Publication Date
- 2025-01-14
- Estimated Expiration
- 2034-05-06
AI Technical Summary
The existing three-stage reducer has a complex structure, large mass and volume, and cannot be effectively applied to light truck electric drive axle systems.
A secondary reducer for light truck electric drive axle was designed, adopting a secondary reducer structure with three sets of parallel shafts, including input shaft, output shaft and intermediate shaft, with differential and parking brake, transmission speed ratio It is 16.098, with a maximum output torque of 5795N.m. It adopts an integrated housing design. The intermediate shaft is located above the central horizontal plane of the input shaft and the output shaft. The oil plane is located below the central horizontal plane. The bearing is adjusted by locking nuts and adjusting nuts. to ensure the lubricating oil passage is unobstructed.
It realizes that the speed ratio and output torque are unchanged, the mass and volume of the reducer are reduced, the transmission efficiency is improved, and the manufacturing cost is reduced. It is suitable for light truck electric drive axles, and the reducer temperature rise and lubrication is effectively controlled. The problem of agitation of the oil.
Smart Images
Figure CN222351340U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a reducer, in particular to a two-stage reducer for an electric drive axle of a light truck. Background Art
[0002] In recent years, major OEMs have launched their own new energy light truck models around the national dual carbon goals. In 2023, the cumulative sales of domestic new energy light trucks reached 46,800, a year-on-year increase of 15%, of which pure electric vehicles accounted for 89% of the total sales. The electric drive axle is the most important power transmission component on new energy vehicles. The quality of its assembly structure and transmission performance directly affects the vehicle layout and performance of electric vehicles. Therefore, models equipped with electric drive axles have become the focus of users. The electric drive axle transmission system can improve vehicle driving efficiency, reduce vehicle weight, and to a certain extent increase load capacity and endurance.
[0003] For light commercial vehicles, a single-speed (fixed gear ratio) parallel shaft electric drive axle is generally used. The entire system includes main components such as motor, reducer, bridge pipe, and half shaft. As a torque transmission reducer, it needs to meet the requirements of high speed, high torque, and high efficiency, so as to ensure the high reliability and good NVH performance requirements of the whole vehicle. In order to achieve a certain transmission speed ratio and output torque, the reducer commonly used in the prior art usually requires three-stage reduction, which leads to a more complex structure of the reducer, and a larger mass and volume, which cannot be well applied to the light truck electric drive axle system. Utility Model Content
[0004] The purpose of the utility model is to solve the technical problem that the existing three-stage reducer has a complex structure, large mass and volume, and cannot be well applied to the electric drive axle system of light trucks, and proposes a two-stage reducer for the electric drive axle of light trucks.
[0005] In order to solve the above technical problems, the technical solutions provided by the utility model are as follows:
[0006] A two-stage speed reducer for an electric drive axle of a light truck is special in that it comprises an input shaft, an output shaft and an intermediate shaft which are installed in a housing and are parallel to each other, and a differential; the axis lines of the input shaft and the output shaft are located on the same central horizontal plane, and the axis line of the intermediate shaft is higher than the central horizontal plane;
[0007] One end of the input shaft is used to receive power, and the other end of the input shaft is provided with a primary active reduction gear, and the intermediate shaft is provided with a primary passive reduction gear and a secondary active reduction gear, and the primary active reduction gear is meshed with the primary passive reduction gear; the output shaft passes through the differential and is fixedly connected to the differential, and the power on the output shaft is output to both ends through the differential; the differential is sleeved with a secondary passive reduction gear meshed with the secondary active reduction gear;
[0008] The input shaft is provided with a first bearing at both ends, the intermediate shaft is provided with a second bearing at one end, and a third bearing and a flange at the other end, and the end of the other end of the intermediate shaft is connected to the parking brake through the flange; the output shaft is provided with a fourth bearing at both ends; the oil level of the lubricating oil in the housing is lower than the central horizontal plane.
[0009] Furthermore, the differential is installed inside the bridge pack, the housing and the bridge pack are connected by a flange, and the side of the flange close to the parking brake is processed with a full-circle chamfer to avoid interference between the parking brake and the flange surface.
[0010] Furthermore, the third bearing and the second bearing are both installed in a bearing seat, and the bearing seats of the third bearing and the second bearing are respectively provided with a first oil baffle plate and a second oil baffle plate, and the bearing seat is provided with a lubricating oil channel along the first oil baffle plate to the third bearing, and a lubricating oil channel along the second oil baffle plate to the second bearing.
[0011] Furthermore, a locking nut and an intermediate shaft oil seal are sequentially arranged between the third bearing and the flange, and the locking nut is threadedly connected to the intermediate shaft for locking the first-stage passive reduction gear and the inner ring of the third bearing to prevent the first-stage passive reduction gear from sliding.
[0012] Furthermore, it also includes a first adjusting nut and a second adjusting nut. The first adjusting nut is installed on the housing through a threaded connection, located on the outside of the second bearing, and is used to tighten the outer ring of the second bearing and adjust the clearance between the second bearing and the third bearing; the second adjusting nut is installed on the housing through a threaded connection, located on the outside of the fourth bearing, and is used to tighten the outer ring of the fourth bearing and adjust the clearance of the fourth bearing.
[0013] Furthermore, the first-stage passive reduction gear is located above the oil level.
[0014] Furthermore, one end of the input shaft that receives power is connected to the drive motor, and an input shaft oil seal is provided at the connection.
[0015] Furthermore, the first bearing is a deep groove ball bearing; the second bearing, the third bearing and the fourth bearing are tapered roller bearings.
[0016] Furthermore, the shell is an integrated structure.
[0017] Compared with the prior art, the utility model has the following beneficial effects:
[0018] 1. The utility model is a two-stage reducer for light truck electric drive axle, which adopts a two-stage reduction structure with three sets of parallel shafts and is equipped with a parking brake, with a transmission speed ratio of 16.098 and a maximum output torque of 5795N.m. Compared with the three-stage reducer in the prior art, the reducer is lighter, smaller, more compact and more efficient in transmission, while the speed ratio and output torque remain basically unchanged; the manufacturing cost of the product is reduced to the maximum extent, and it is better suitable for light truck electric drive axle.
[0019] 2. In the utility model, a two-stage reducer for a light truck electric drive axle has a layout structure with an intermediate shaft placed on top, which effectively controls the temperature rise of the reducer and reduces power loss; the housing of the reducer adopts an integrated design, which reduces the number of parts and reduces the manufacturing cost.
[0020] 3. In the utility model, a two-stage reducer for a light truck electric drive axle is provided, in which the intermediate shaft is located above the central horizontal plane of the input shaft and the output shaft inside the housing, and the oil level in the reducer is located below the central horizontal plane. This avoids the problem of rapid temperature rise caused by the large-diameter, high-speed rotating primary passive reduction gear on the intermediate shaft stirring the lubricating oil. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 It is a structural schematic diagram of an embodiment of a two-stage speed reducer for a light truck electric drive axle of the utility model;
[0022] Figure 2 It is a schematic diagram of the arrangement of each shaft and the oil level surface in an embodiment of a two-stage speed reducer for a light truck electric drive axle of the utility model.
[0023] Figure 3 It is a structural schematic diagram of the lubricating oil circuit of the third bearing and the first oil baffle plate in an embodiment of a two-stage speed reducer for a light truck electric drive axle of the utility model;
[0024] Figure 4 It is a structural schematic diagram of the lubricating oil circuit of the second bearing and the second oil baffle plate in an embodiment of a two-stage speed reducer for a light truck electric drive axle of the utility model;
[0025] Figure 5 It is a side view of an embodiment of a two-stage speed reducer for a light truck electric drive axle of the utility model;
[0026] Description of reference numerals:
[0027] A1-input shaft, B1-intermediate shaft, C1-output shaft; Z1-first active reduction gear, Z2-first passive reduction gear, Z3-second active reduction gear, Z4-second passive reduction gear; E1-first bearing, E2-second bearing, E3-third bearing, E4-fourth bearing; D1-input shaft oil seal, D2-intermediate shaft oil seal; F1-first adjusting nut, F2-second adjusting nut, G-locking nut; I-parking brake, H-flange, J-differential, Q-housing; R1-first oil baffle, R2-second oil baffle, R3-lubricating oil channel; 1-oil level surface, 2-center horizontal surface. DETAILED DESCRIPTION
[0028] The utility model is further described below in conjunction with the accompanying drawings and embodiments.
[0029] The utility model provides a two-stage reducer for a light truck electric drive axle, such as Figure 1 , Figure 2 As shown, the two-stage reducer is a three-axis two-stage reduction structure with a single gear and fixed gear ratio, which includes three sets of parallel shafts, namely the input shaft A1, the intermediate shaft B1 and the output shaft C1; the axis lines of the input shaft A1 and the output shaft C1 are located on the same horizontal plane, which is defined as the center horizontal plane 2, and the axis line of the intermediate shaft B1 is higher than the center horizontal plane 2. Figure 2 As shown, the three axes of the input shaft A1, the output shaft C1 and the central shaft B1 are distributed in a triangle, making the entire reducer structure more compact, smaller in size, lighter in weight, and the power transmission route shorter, thereby improving the transmission efficiency.
[0030] The input shaft A1, the intermediate shaft B1 and the output shaft C1 are all installed in the housing Q, and the housing Q is an integrated structure. One end of the input shaft A1 is connected to the external drive motor fixed on the housing Q through a spline. A primary active reduction gear Z1 is provided on the other end of the input shaft A1, and the input shaft A1 and the primary active reduction gear Z1 are an integrated shaft gear structure. A primary passive reduction gear Z2 is connected to the intermediate shaft B1 through a spline, and the primary active reduction gear Z1 is meshed with the primary passive reduction gear Z2. A secondary active reduction gear Z3 is also provided on the intermediate shaft B1, and the intermediate shaft B1 is an integrated shaft gear structure with the secondary active reduction gear Z3. The secondary active reduction gear Z3 is meshed with the secondary passive reduction gear Z4, and the secondary passive reduction gear Z4 is fixedly connected to the differential J by bolts. The output shaft C1 passes through the differential and is fixedly connected to the half-shaft gear on the differential J.
[0031] The input shaft A1 is supported by first bearings E1 at both ends. The inner ring of the first bearing E1 cooperates with the input shaft A1, and the outer ring of the first bearing E1 is fixed in the bearing seat on the housing Q. The first bearing E1 adopts a deep groove ball bearing to meet the high-speed and low-torque support strength requirements of the input shaft A1. An input shaft oil seal D1 is provided at one end of the input shaft A1 connected to the external drive motor.
[0032] The third bearing E3, the locking nut G, and the intermediate shaft oil seal D2 are arranged on one end of the intermediate shaft B1 in sequence, and the end is connected to the flange H, which is fixedly connected to the brake drum of the parking brake I. The back plate of the parking brake I is fixed on the housing Q, and the entire braking torque acts on the intermediate shaft B1. The brake drum is fixedly connected to the intermediate shaft B1 through the flange H, and the inner ring of the third bearing E3 is connected to the first-stage passive reduction gear Z2. The locking nut G is connected to the intermediate shaft B1 through threads, and is used to lock the first-stage passive reduction gear Z2 and the inner ring of the third bearing E3 to prevent the first-stage passive reduction gear B1 from moving on the intermediate shaft. The intermediate shaft oil seal D2 plays a sealing role. The second bearing E2 and the first adjustment nut F1 are arranged on the other end of the intermediate shaft B1. The fourth bearing E4 is respectively arranged at both ends of the output shaft C1 for support, and the second adjustment nut F2 is arranged on the outer ring of the fourth bearing E4 at one end. The first adjusting nut F1 and the second adjusting nut F2 are connected to the housing Q by threads. The first adjusting nut F1 is located on the outside of the second bearing E2, pressing the outer ring of the second bearing E2, and adjusting the clearance of the second bearing E2 and the third bearing E3 at both ends of the intermediate shaft B1 by the tightening force. The second adjusting nut F2 is located on the outside of the fourth bearing E4, pressing the outer ring of the fourth bearing E4, and adjusting the clearance of the fourth bearing E4 by the tightening force.
[0033] The output shaft C1 outputs power through the two ends of the semi-axial direction of the differential J. The second bearing E2, the third bearing E3 and the fourth bearing E4 are all tapered roller bearings, which can meet the support strength requirements of the intermediate shaft B1 and the output shaft C1.
[0034] like Figure 3 As shown, a first oil baffle plate R1 symmetrically distributed about the bearing seat is arranged on the bearing seat of the third bearing E3, and a lubricating oil passage R3 leading to the third bearing E3 along the first oil baffle plate R1 is also arranged on the bearing seat. Figure 4 As shown, a second oil baffle plate R2 is arranged on the bearing seat of the second bearing E2, and a lubricating oil channel R3 leading to the second bearing E2 along the second oil baffle plate is also arranged on the bearing seat.
[0035] like Figure 5 As shown, the differential J is installed inside the bridge pack, and the housing Q is connected to the bridge pack through a flange, and the flange surface at the connection is processed with a full circle chamfer. The problem of interference between the parking brake I and the flange surface is avoided, and the outer diameter of the brake is increased to the maximum, which can ensure the braking torque required by the vehicle under working conditions such as full load 5T, rolling radius 0.372 and slope 20%. At the same time, the length of the intermediate shaft B1 is shortened, eliminating the vibration problem caused by the excessive length of the shaft.
[0036] The working process of the secondary reducer:
[0037] Power transmission process: the external drive motor transmits power to the input shaft A1, the input shaft A1 drives the first-stage active reduction gear Z1, the first-stage active reduction gear Z1 meshes with the first-stage passive reduction gear Z2, and transmits power to the intermediate shaft B1 to achieve first-stage reduction; the intermediate shaft B1 drives the second-stage active reduction gear Z3, the second-stage active reduction gear Z3 meshes with the second-stage passive reduction gear Z4, and transmits power to the output shaft C1 through the differential J to achieve second-stage reduction. In the whole process, the reducer completes the function of reducing speed and increasing torque.
[0038] Parking brake process: After the vehicle stops, the cable is tightened, and the shoe brake friction pad exerts a certain pressure on the brake drum, which is fixed to the intermediate shaft B1 through the flange H. Due to factors such as the road slope, the reverse drag torque generated by the vehicle as a whole under the action of gravity offsets the braking torque formed by the pressure exerted by the shoe brake friction pad on the brake drum, thereby preventing the vehicle from slipping after stopping.
[0039] Lubrication process: The inner cavity of the housing Q is connected to the inner cavity of the bridge pack of the differential J. The oil level 1 in the housing Q is lower than the central horizontal plane 2 of the input shaft A1 and the output shaft C1, so that the first-stage active reduction gear Z1, the second-stage passive reduction gear Z4, the first bearing E1 and the fourth bearing E4 are immersed in the lubricating oil, realizing oil bath lubrication. At the same time, the lubrication of the first-stage passive reduction gear Z2 and the second-stage active reduction gear Z3, which are respectively meshed with the first-stage active reduction gear Z1 and the second-stage passive reduction gear Z4, is ensured. Figure 2 As shown, the intermediate shaft B1 and the first-stage passive reduction gear Z2 are both located above the oil level 1, and the second bearing E2 and the third bearing E3 are also suspended above the oil level 1. When the reducer is working, the oil thrown out flows down the inner wall of the housing Q and is collected in the oil guide groove by the oil baffle plate, and flows into the bearing hole through the lubricating oil channel R3 to achieve lubrication of the second bearing E2 and the third bearing E3. Placing the intermediate shaft B1 upward avoids the problem of rapid temperature rise caused by the large-diameter, high-speed rotating first-stage passive reduction gear Z2 stirring the lubricating oil, and ensures sufficient lubrication of each bearing and reduction gear.
[0040] Bearing clearance adjustment:
[0041] By adjusting the first adjusting nut F1 and the second adjusting nut F2, the second bearing E2 and the third bearing E3 on the intermediate shaft B1 and the fourth bearing E4 on the output shaft C1 can be axially moved to adjust the bearing clearance. After the first adjusting nut F1 and the second adjusting nut F2 are locked in a directional manner, the bearing clearance can be ensured while preventing failure due to vibration generated during the operation of the reducer. This structure makes the installation and maintenance of the bearings more convenient and quick.
Claims
1. A two-stage reducer for a light truck electric drive axle, characterized by: The invention comprises an input shaft (A1), an output shaft (C1) and an intermediate shaft (B1) which are installed in a housing (Q) and are parallel to each other, and a differential (J); the axis centers of the input shaft (A1) and the output shaft (C1) are located on the same central horizontal plane (2), and the axis center line of the intermediate shaft (B1) is higher than the central horizontal plane (2); One end of the input shaft (A1) is used to receive power, and the other end of the input shaft (A1) is provided with a primary active reduction gear (Z1), and the intermediate shaft (B1) is provided with a primary passive reduction gear (Z2) and a secondary active reduction gear (Z3), and the primary active reduction gear (Z1) is meshed with the primary passive reduction gear (Z2); the output shaft (C1) passes through the differential (J) and is fixedly connected to the differential (J), and the power on the output shaft (C1) is output to both ends through the differential (J); the differential (J) is sleeved with a secondary passive reduction gear (Z4) meshed with the secondary active reduction gear (Z3); The input shaft (A1) is provided with a first bearing (E1) at both ends, the intermediate shaft (B1) is provided with a second bearing (E2) at one end, and a third bearing (E3) and a flange (H) at the other end, and the end of the other end of the intermediate shaft (B1) is connected to the parking brake (I) through the flange (H); the output shaft (C1) is provided with a fourth bearing (E4) at both ends, and the oil level (1) of the lubricating oil in the housing (Q) is lower than the central horizontal plane (2).
2. A two-stage reducer for a light truck electric drive axle according to claim 1, characterized in that: The differential (J) is installed inside the bridge pack, and the housing (Q) is connected to the bridge pack through a flange. The side of the flange close to the parking brake (I) is processed with a full-circle chamfer to avoid interference between the parking brake (I) and the flange surface.
3. The two-stage reducer for a light truck electric drive axle according to claim 2, characterized in that: The third bearing (E3) and the second bearing (E2) are both installed in a bearing seat, and the bearing seats of the third bearing (E3) and the second bearing (E2) are respectively provided with a first oil baffle plate (R1) and a second oil baffle plate (R2), and the bearing seat is provided with a lubricating oil passage (R3) leading to the third bearing (E3) along the first oil baffle plate (R1), and a lubricating oil passage (R3) leading to the second bearing (E2) along the second oil baffle plate (R2).
4. The two-stage reducer for a light truck electric drive axle according to claim 3, characterized in that: A locking nut (G) sleeved on the intermediate shaft (B1) and an intermediate shaft oil seal (D2) are also arranged in sequence between the third bearing (E3) and the flange (H); the locking nut (G) is threadedly connected to the intermediate shaft (B1) and is used to lock the first-stage passive reduction gear (Z2) and the inner ring of the third bearing (E3) to prevent the first-stage passive reduction gear (Z2) from sliding.
5. The two-stage reducer for a light truck electric drive axle according to claim 4, characterized in that: It also includes a first adjusting nut (F1) and a second adjusting nut (F2), wherein the first adjusting nut (F1) is installed on the housing (Q) through a threaded connection and is located outside the second bearing (E2) and is used to tighten the outer ring of the second bearing (E2) and adjust the clearance between the second bearing (E2) and the third bearing (E3); The second adjusting nut (F2) is installed on the housing (Q) through a threaded connection and is located on the outside of the fourth bearing (E4) for tightening the outer ring of the fourth bearing (E4) to adjust the clearance of the fourth bearing (E4).
6. The two-stage reducer for a light truck electric drive axle according to claim 5, characterized in that: The first-stage passive reduction gear (Z2) is located above the oil level (1).
7. The two-stage reducer for a light truck electric drive axle according to claim 6, characterized in that: One end of the input shaft (A1) that receives power is connected to a drive motor, and an input shaft oil seal (D1) is provided at the connection.
8. The two-stage reducer for a light truck electric drive axle according to claim 7, characterized in that: The first bearing (E1) is a deep groove ball bearing; the second bearing (E2), the third bearing (E3) and the fourth bearing (E4) are tapered roller bearings.
9. The two-stage reducer for a light truck electric drive axle according to claim 8, characterized in that: The housing (Q) is an integrated structure.