Single-motor two-gear efficient electric drive axle transmission system

Abstract

The invention relates to a single-motor two-gear efficient electric drive axle transmission system which is characterized by comprising a motor, a parallel shaft set, a driving gear set, a driven gear set, a gear shifting combination gear, a spline gear hub, a gear shifter, a differential mechanism module and a tire module. Symmetrical arrangement is adopted, gear parameters can be designed more reasonably, the first shaft, the second shaft and the fourth shaft are located on the two sides of the half shaft, the third shaft is a hollow shaft sleeved on the right half shaft, the structure is more stable, and space is saved. According to the gear shifter structure, the two-gear function can be achieved, a low gear is matched with a large transmission speed ratio, four-stage speed reduction is achieved, a large enough torque is provided for a vehicle under the working conditions such as starting, getting out of difficulty and climbing, a high gear is matched with a small transmission speed ratio, and a high enough rotating speed is provided for the vehicle under the high-speed working condition; the first gear is four-stage speed reduction, the transmission ratio is large, and large torque can be provided under the low-speed working condition; and the second gear adopts two-stage speed reduction, so that mechanical loss can be reduced, and the transmission efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicle transmission technology, and in particular to a single-motor two-speed high-efficiency electric drive axle transmission system. Background Art

[0002] With the gradual deepening of the national new energy strategy, the electrification of commercial vehicles is in full swing, and more and more OEMs have begun to transform from traditional fuel vehicle production to electric drive vehicle production. At present, in the field of commercial vehicles, most electric drive vehicles are still centrally driven, but the engine and multi-speed gearbox powertrain are changed to motor and small gearbox powertrain, and the traditional drive shaft and drive axle structure are still used. Although it can reduce the development cost to the greatest extent, the mechanical efficiency of the entire power transmission is low due to the long transmission chain and the retention of the spiral bevel gear main reduction structure.

[0003] Judging from the trend of electrification, the overall trend is towards high integration, high efficiency, small size and lightweight. The electric drive axle can integrate the drive motor, gearbox, drive shaft and axle into one to reduce the system size, improve the mechanical transmission efficiency of the entire drive system, and reduce the weight of the vehicle. Therefore, the electric drive axle has become a solution that domestic and foreign automakers are competing to adopt for the electrification of commercial vehicles.

[0004] The electric drive axle has been used in commercial vehicles for a relatively short time. It is currently in an explosive research and development stage. There are not many truly mature products. Due to the limited space layout of the electric drive axle, most of the electric drive axles that have been used or are being developed on the market are single-speed or two-speed structures. The single-speed electric drive axle can reduce the complexity of the gearbox. It only needs to be equipped with a reduction mechanism, but the demand for the motor is high. The motor needs to be able to provide sufficient torque and high speed to adapt to the vehicle's climbing and high speed requirements. The motor size is often made larger, and the cost of the motor and electronic control is high. Moreover, because there is no gear adjustment, the proportion of the motor running in the high-efficiency range is not large, and the overall efficiency of the motor is not high. The two-speed electric drive axle can greatly improve the problems caused by the one-speed electric drive axle. The low-speed gear is equipped with a large transmission ratio to provide sufficient power for the vehicle, and the high-speed gear is equipped with a small transmission ratio to provide sufficient speed for the vehicle. It can also reduce the demand for the motor, reduce the size of the motor, and reduce the cost of the motor and electronic control. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an electric drive axle transmission system which has a compact structure, high efficiency, and can achieve two-speed shifting by single motor drive.

[0006] In order to solve the above technical problems, the technical solution of the present invention is: a single-motor two-speed high-efficiency electric drive axle transmission system, the innovation of which is: comprising a motor, a parallel shaft group, a driving gear group, a passive gear group, a shifting coupling tooth, a spline gear hub, a shifter, a differential module and a tire module; The parallel axis group includes a first parallel axis, a second parallel axis, a third parallel axis and a fourth parallel axis; The driving gear set includes a primary driving gear, a secondary driving gear, a tertiary driving gear and a quaternary driving gear; The passive gear set includes a primary passive gear, a secondary passive gear, a tertiary passive gear and a quaternary passive gear; The shift-combining teeth include a first shift-combining tooth and a second shift-combining tooth; The differential module includes a differential housing and a differential gear set; The tire module includes a left wheel, a right wheel, a left half-axle and a right half-axle; The motor is arranged on one side of the axle, and the first parallel shaft is connected to the rotor shaft of the motor through a spline; the primary driving gear is fixedly mounted on the first parallel shaft; A primary passive gear and a secondary active gear are fixedly disposed at both ends of the second parallel shaft, and the primary passive gear is meshed and assembled with the primary active gear; A secondary passive gear is fixedly arranged on the third parallel shaft, and the secondary passive gear is meshed and assembled with the secondary driving gear; the third driving gear is installed on the third parallel shaft through a slewing bearing; the first shift combination tooth is fixed on the third driving gear, the second shift combination tooth is fixed on the fourth passive gear, and the fourth passive gear is fixed on the differential housing; the shifter is installed on the third parallel shaft through a spline gear hub, and the shifter can slide on the spline gear hub along the axial direction of the third parallel shaft to mesh with the first shift combination tooth and the second shift combination tooth respectively; The fourth parallel shaft is arranged on the other side of the axle, and two ends of the fourth parallel shaft are respectively provided with a third-stage passive gear and a fourth-stage driving gear; the third-stage passive gear is meshed and assembled with the third-stage driving gear; the fourth-stage driving gear is assembled with the fourth-stage passive gear core on the differential housing; The differential housing is provided with a differential gear set, and the two ends of the differential gear set are respectively connected to the left half shaft and the right half shaft of the tire module; one end of the left half shaft is connected to the left wheel, and the other end of the right half shaft is connected to the right wheel.

[0007] Furthermore, the third parallel shaft is a hollow shaft, which is convenient for lubrication of the slewing bearing; the right half shaft passes through the third parallel shaft and is connected to the differential gear set, saving space; the motor, the first parallel shaft, the second parallel shaft and the fourth parallel shaft are symmetrically arranged, and the structure is more stable.

[0008] Furthermore, the left wheel and the right wheel are an assembly without a reducer structure, or one of the left wheel and the right wheel has a reducer structure, and a planetary gear reduction mechanism is provided on the side wheel with the reducer structure, and the sun gear of the planetary gear reduction mechanism is connected to the left half shaft or the right half shaft, and a plurality of planetary gears are distributed axially on the sun gear, and the planetary gears are mounted on the planetary carrier through bearings, and the planetary gears are meshed with the sun gear and the ring gear fixed on the bridge housing at the same time, and the power of the planetary gear is input by the sun gear and output by the planetary carrier to the left wheel or the right wheel.

[0009] Furthermore, the secondary passive gear is connected to a PTO device, and the PTO device and the secondary passive gear have a connection and disconnection mechanism; when the connection and disconnection mechanism is connected, the PTO device is connected to power and is in a working mode, and when the connection and disconnection mechanism is disengaged, the PTO device is disconnected from power and is in a non-working mode.

[0010] Furthermore, a fifth parallel shaft is arranged between the second parallel shaft and the third parallel shaft; a five-stage passive gear and a five-stage driving gear are arranged at both ends of the fifth parallel shaft respectively; the five-stage passive gear is meshed and assembled with the two-stage driving gear fixed on the second parallel shaft; the five-stage driving gear is meshed and assembled with the two-stage passive gear on the third parallel shaft; by adding a first-stage reduction gear, the design value of the gear transmission ratio of each stage can be reduced while ensuring that the total transmission ratio remains unchanged, thereby reducing the design size of the passive gear, and ultimately achieving the design purpose of reducing the total weight and saving space.

[0011] The advantages of the present invention are: 1) The present invention adopts a symmetrical arrangement, which can design gear parameters more reasonably. The first shaft, the second shaft and the fourth shaft are located on both sides of the half shaft, and the third shaft is a hollow shaft sleeved on the right half shaft. The structure is more stable and saves space; the shifter structure can realize two gear functions, the low gear matches a large transmission speed ratio and four-stage reduction, which provides a sufficiently large torque for the vehicle during starting, getting out of trouble, climbing and other working conditions, and the high gear matches a small transmission speed ratio, which provides a sufficiently high speed for the vehicle when running at high speed; the first gear is a four-stage reduction with a large transmission ratio, which can provide a large torque under low-speed conditions; the second gear is a two-stage reduction, which can reduce mechanical losses and improve transmission efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0013] Figure 1 FIG1 is a structural embodiment of a single-motor two-speed high-efficiency electric drive axle transmission system of the present invention.

[0014] Figure 2 It is a schematic diagram of the A-gear power flow of a single-motor two-gear high-efficiency electric drive axle transmission system of the present invention.

[0015] Figure 3 It is a schematic diagram of the B-gear power flow of a single-motor two-gear high-efficiency electric drive axle transmission system of the present invention.

[0016] Figure 4 FIG2 is a structural embodiment of a single-motor two-speed high-efficiency electric drive axle transmission system of the present invention.

[0017] Figure 5 FIG3 is a structural embodiment of a single-motor two-speed high-efficiency electric drive axle transmission system of the present invention.

[0018] like Figure 6 The present invention discloses a single-motor two-speed high-efficiency electric drive axle transmission system structure without a reducer wheel side structure.

[0019] like Figure 7 This is a schematic diagram of a single-motor two-speed high-efficiency electric drive axle transmission system structure with a reducer wheel side structure of the present invention.

[0020] In the figure: 01: motor, 02: first parallel shaft, 03: first driving gear, 04: first passive gear, 05: second parallel shaft, 06: second driving gear, 07: second passive gear, 08: third parallel shaft, 09: third driving gear, 10: first shift engaging tooth, 11: spline gear hub, 12: shifter, 13: second shift engaging tooth, 14: fourth passive gear, 15: differential case, 16: third passive gear, 17: fourth driving gear, 18: fourth parallel shaft, 19: differential gear set, 20: left half shaft, 21: right half shaft, 22: left wheel side, 23: right wheel side, 24: PTO device, 25: fifth parallel shaft, 26: fifth driving gear, 27: fifth passive gear. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Embodiment 1:

[0023] like Figure 1As shown: a single-motor two-speed high-efficiency electric drive axle transmission system, a second parallel shaft 05, a first-stage passive gear 04, and a second-stage driving gear 06 are arranged on one side of the axle, the first-stage passive gear 04 and the second-stage driving gear 06 are fixedly mounted on the second parallel shaft 05, wherein the first-stage passive gear 04 is meshed and assembled with the first-stage driving gear 03.

[0024] The third parallel shaft 08 is a hollow shaft, on which two gears are installed. The secondary passive gear 07 is fixed on the shaft, and the tertiary driving gear 09 is installed on the shaft through a bearing, wherein the secondary passive gear 07 is meshed and assembled with the above-mentioned secondary driving gear 06; the third parallel shaft 08 is also equipped with a shifter, and the shifter 12 can slide left and right to engage with the first shift coupling tooth 10 and the second shift coupling tooth 13 respectively.

[0025] The first shift engaging tooth 10 is fixed on the third-stage driving gear 09 , the second shift engaging tooth 13 is fixed on the fourth-stage passive gear 14 , and the shifter 12 can slide left and right on the spline gear hub 11 , wherein the spline gear hub 11 is fixed on the third parallel shaft 08 .

[0026] The fourth parallel shaft 18, the third-stage passive gear 16 and the fourth-stage driving gear 17 are arranged on the other side of the axle. The third-stage passive gear 16 and the fourth-stage driving gear 17 are fixedly mounted on the fourth parallel shaft 18, wherein the third-stage passive gear 16 is meshed and assembled with the third-stage driving gear 09.

[0027] The four-stage passive gear 14 is fixed on the differential case 15, and the four-stage passive gear 14 is meshed and assembled with the four-stage driving gear 17.

[0028] A differential gear set 19 is installed in the differential case 15 , and two ends of the differential gear set 19 are connected to a left half shaft 20 and a right half shaft 21 respectively.

[0029] The left half shaft 20 is connected to the left wheel side 22, and the right half shaft 21 is connected to the right wheel side 23. The left wheel side and the right wheel side can be an assembly without a reducer structure, such as Figure 6 Schematic diagram of the wheel structure without a reducer; it can also be an assembly with a reducer structure, such as Figure 7 As shown in the schematic diagram of the wheel-side structure with reducer, the wheel-side reducer is a planetary gear reduction mechanism. The above-mentioned half-shaft is connected to the sun gear of the planetary gear reduction mechanism. Several planetary gears are distributed circumferentially on the sun gear. The planetary gears are mounted on the planetary carrier through bearings. The planetary gears are meshed with the sun gear and the ring gear fixed on the bridge housing at the same time. The power of the planetary gear is input by the sun gear and output by the planetary carrier to the tire.

[0030] The third parallel shaft 08 is a hollow shaft to facilitate bearing lubrication. The right half shaft 21 passes through the third parallel shaft 08 and is connected to the differential gear set 19 to save space. The motor 01, the first parallel shaft 02, the second parallel shaft 05 and the fourth parallel shaft 18 are symmetrically arranged, and the structure is more stable. Embodiment 2:

[0031] The rest is the same as in Example 1, except that: Figure 4 As shown: the secondary passive gear 07 can be connected to a PTO device 24, and the PTO device and the secondary passive gear 07 have a connection and disconnection mechanism. When the mechanism is connected, the PTO device is connected to power and is in a working mode. When the mechanism is disconnected, the PTO device is disconnected from power and is in a non-working mode. Embodiment 3:

[0032] The rest is the same as in Example 1, except that: Figure 5 As shown: a fifth parallel shaft 25 is added between the second parallel shaft 05 and the third parallel shaft 08, and the two ends of the fifth parallel shaft 25 are respectively connected to the fifth-stage passive gear 27 and the fifth-stage driving gear 26, as shown in FIG. Figure 5 The five-stage passive gear 27 is meshed with the two-stage active gear 06 fixed on the second parallel shaft 05, and the five-stage active gear 26 is meshed with the two-stage passive gear 07 on the third parallel shaft 08. By adding a first-stage reduction gear, the design value of the gear ratio of each stage can be reduced while ensuring that the total transmission ratio remains unchanged, thereby reducing the design size of the passive gear, and ultimately achieving the design purpose of reducing the total weight and saving space.

[0033] The working principle of the present invention is: A gear power flow: Figure 2As shown, the torque of the motor 01 is transmitted to the primary driving gear 03 through the first parallel shaft 02, and the primary driving gear 03 and the primary passive gear 04 are in a constant meshing state. The primary passive gear 04 is fixedly mounted on the second parallel shaft 05, so the torque on the primary driving gear 03 is transmitted to the second parallel shaft 05 through the primary passive gear 04 meshing therewith. The secondary driving gear 06 is also fixedly mounted on the second parallel shaft 05, and the secondary driving gear 06 is in a constant meshing state with the secondary passive gear 07 fixed on the third parallel shaft 08, so the torque on the secondary driving gear 06 is transmitted to the third parallel shaft 08 through the secondary passive gear 07 meshing therewith. The third parallel shaft 08 is also annularly sleeved with a third driving gear 09 and a fixedly mounted spline hub 11 and a shifter 12, and the third driving gear 09 is constantly meshing with the third passive gear 16 fixed on the fourth parallel shaft 18. When the shifter 12 slides to the right, the shifter 12 meshes with the first shift coupling tooth 10 fixed on the third-stage driving gear 09. At this time, the power on the third parallel shaft 08 is transmitted to the fourth parallel shaft 18 through the shifter 12 and the third-stage gear pair, and the power on the fourth parallel shaft 18 is then transmitted to the fourth-stage driving gear 17 fixed on the shaft. The fourth-stage driving gear 17 is in a constant meshing state with the fourth-stage passive gear 14 fixed on the differential case 15, so the torque on the fourth-stage driving gear 17 is transmitted to the differential case 15 through the fourth-stage passive gear 14 meshed therewith. The power on the differential case 15 is transmitted to the differential gear set 19 through the cross shaft, and the power on the differential gear set 19 is transmitted to the left half shaft 20 and the right half shaft 21 according to the actual road conditions of the vehicle, and the power of the left half shaft 20 is transmitted to the left wheel side 22, and the power of the right half shaft 21 is transmitted to the right wheel side 23.

[0034] Power flow in gear B: Figure 3As shown, the torque of the motor 01 is transmitted to the primary driving gear 03 through the first parallel shaft 02, and the primary driving gear 03 and the primary passive gear 04 are in a constant meshing state. The primary passive gear 04 is fixedly mounted on the second parallel shaft 05, so the torque on the primary driving gear 03 is transmitted to the second parallel shaft 05 through the primary passive gear 04 meshing therewith. The secondary driving gear 06 is also fixedly mounted on the second parallel shaft 05, and the secondary driving gear 06 is in a constant meshing state with the secondary passive gear 07 fixed on the third parallel shaft 08, so the torque on the secondary driving gear 06 is transmitted to the third parallel shaft 08 through the secondary passive gear 07 meshing therewith. The third parallel shaft 08 is fixedly mounted with a spline gear hub 11 and a shifter 12. When the shifter 12 slides to the left, the shifter 12 meshes with the second shifting engagement tooth 13 fixed on the fourth-stage passive gear 14. At this time, the power on the third parallel shaft 08 is transmitted to the fourth-stage passive gear 14 through the spline gear hub 11 and the shifter 12. The fourth-stage passive gear 14 is fixed on the differential case 15, so the power on the fourth-stage passive gear 14 is transmitted to the differential case 15. The power on the differential case 15 is transmitted to the differential gear set 19 through the cross shaft, and the power on the differential gear set 19 is transmitted to the left half shaft 20 and the right half shaft 21 according to the actual road conditions of the vehicle. The power of the left half shaft 20 is transmitted to the left wheel side 22, and the power of the right half shaft 21 is transmitted to the right wheel side 23.

[0035] Those skilled in the art should understand that the present invention is not limited to the above-mentioned embodiments. The above-mentioned embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may be subject to various changes and improvements, and these changes and improvements shall all fall within the scope of the present invention claimed for protection.

Claims

1. A single-motor two-speed high-efficiency electric drive axle transmission system, characterized by: It includes a motor, a parallel shaft set, a driving gear set, a passive gear set, a shifting gear, a spline gear hub, a shifter, a differential module and a tire module; The parallel axis group includes a first parallel axis, a second parallel axis, a third parallel axis and a fourth parallel axis; The driving gear set includes a primary driving gear, a secondary driving gear, a tertiary driving gear and a quaternary driving gear; The passive gear set includes a primary passive gear, a secondary passive gear, a tertiary passive gear and a quaternary passive gear; The shift-combining teeth include a first shift-combining tooth and a second shift-combining tooth; The differential module includes a differential housing and a differential gear set; The tire module includes a left wheel, a right wheel, a left half-axle and a right half-axle; The motor is arranged on one side of the axle, and the first parallel shaft is connected to the rotor shaft of the motor through a spline; the primary driving gear is fixedly mounted on the first parallel shaft; A primary passive gear and a secondary active gear are fixedly disposed at both ends of the second parallel shaft, and the primary passive gear is meshed and assembled with the primary active gear; A secondary passive gear is fixedly arranged on the third parallel shaft, and the secondary passive gear is meshed and assembled with the secondary driving gear; The three-stage driving gear is installed on the third parallel shaft through a slewing bearing; the first shift-combining tooth is fixed on the three-stage driving gear, the second shift-combining tooth is fixed on the fourth-stage passive gear, and the fourth passive gear is fixed on the differential housing; the shifter is installed on the third parallel shaft through a spline gear hub, and the shifter can slide on the spline gear hub along the axial direction of the third parallel shaft to engage with the first shift-combining tooth and the second shift-combining tooth respectively; The fourth parallel shaft is arranged on the other side of the axle, and two ends of the fourth parallel shaft are respectively provided with a third-stage passive gear and a fourth-stage driving gear; the third-stage passive gear is meshed and assembled with the third-stage driving gear; the fourth-stage driving gear is assembled with the fourth-stage passive gear core on the differential housing; The differential housing is provided with a differential gear set, and the two ends of the differential gear set are respectively connected to the left half shaft and the right half shaft of the tire module; one end of the left half shaft is connected to the left wheel, and the other end of the right half shaft is connected to the right wheel.

2. A single-motor two-speed high-efficiency electric drive axle transmission system according to claim 1, characterized in that: The third parallel shaft is a hollow shaft, which is convenient for lubrication of the slewing bearing; the right half shaft passes through the third parallel shaft and is connected to the differential gear set, saving space; the motor, the first parallel shaft, the second parallel shaft and the fourth parallel shaft are symmetrically arranged, and the structure is more stable.

3. A single-motor two-speed high-efficiency electric drive axle transmission system according to claim 1, characterized in that: The left wheel and the right wheel are an assembly without a reducer structure, or one of the left wheel and the right wheel has a reducer structure, and a planetary gear reduction mechanism is arranged on the side wheel with the reducer structure, and the sun wheel of the planetary gear reduction mechanism is connected to the left half shaft or the right half shaft, and a plurality of planetary gears are distributed axially on the sun wheel, and the planetary gears are mounted on the planetary carrier through bearings, and the planetary gears are meshed with the sun wheel and the gear ring fixed on the bridge housing at the same time, and the power of the planetary gear is input by the sun wheel and output by the planetary carrier to the left wheel or the right wheel.

4. A single-motor two-speed high-efficiency electric drive axle transmission system according to claim 1, characterized in that: The secondary passive gear is connected to a PTO device, and a connection and disconnection mechanism is provided between the PTO device and the secondary passive gear; when the connection and disconnection mechanism is connected, the PTO device is connected to power and is in a working mode, and when the connection and disconnection mechanism is disconnected, the PTO device is disconnected from power and is in a non-working mode.

5. The single-motor two-speed high-efficiency electric drive axle transmission system according to claim 1, characterized in that: A fifth parallel shaft is arranged between the second parallel shaft and the third parallel shaft; a five-stage passive gear and a five-stage driving gear are arranged at both ends of the fifth parallel shaft respectively; the five-stage passive gear is meshed and assembled with the two-stage driving gear fixed on the second parallel shaft; the five-stage driving gear is meshed and assembled with the two-stage passive gear on the third parallel shaft; by adding a first-stage reduction gear, the design value of the gear transmission ratio of each stage can be reduced while ensuring that the total transmission ratio remains unchanged, thereby reducing the design size of the passive gear, and finally achieving the design purpose of reducing the total weight and saving space.

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