Double-motor electric drive assembly

Abstract

The invention discloses a double-motor electric drive assembly which comprises a main drive motor, an auxiliary drive motor, an inverter assembly, an integrated speed reducer, a power disengaging mechanism, a left side transition half shaft assembly, a right side transition half shaft assembly and a lubricating assembly. The integrated speed reducer forms power transmission with the main driving motor and the auxiliary driving motor at the same time, the power disengaging mechanism is installed between the auxiliary driving motor and the integrated speed reducer, and the inverter assembly is electrically connected to the main driving motor and the auxiliary driving motor and erected above the integrated speed reducer. According to the device, the problem that an existing electric vehicle cannot give consideration to dynamic property, economical efficiency and gear shifting smoothness at the same time is solved, and meanwhile by adopting the planet wheel type differential mechanism and adding the transition half shaft assembly, the whole electric drive can be more compact and has better adaptability.

Description

Technical Field

[0001] The present invention relates to the technical field of dual-motor electric drive, and particularly to a dual-motor electric drive assembly. Background Art

[0002] At present, most electric vehicle power systems adopt the structure of a drive motor + a single-stage reducer. This structure is simple, but the speed ratio of the main reducer has a great influence on the performance of the electric vehicle, and it is impossible to simultaneously meet the performance requirements of the maximum vehicle speed and the starting acceleration. Therefore, in order to meet the design requirements, it is necessary to increase the peak torque and the maximum speed of the drive motor, which increases the power of the drive motor. However, when selecting a motor with a larger power, during daily driving, the drive motor often operates in a low-efficiency region, reducing the fuel economy of the whole vehicle and increasing the cost of the drive motor.

[0003] The existing dual-motor electric drive has the following defects; With the development of the new energy vehicle industry, the lightweight of electric vehicles has become more and more important. Correspondingly, the requirements for the lightweight of the electric drive assembly have gradually increased. However, the traditional bevel gear differential has a large axial dimension, resulting in a large overall volume and mass of the corresponding electric drive assembly, which is not conducive to the layout of the vehicle power system and cannot meet the increasingly demanding lightweight requirements. Therefore, a solution needs to be given. Summary of the Invention

[0004] The purpose of the present invention is to provide a dual-motor electric drive assembly to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solutions: A dual-motor electric drive assembly includes a main drive motor, an auxiliary drive motor, an inverter assembly, an integrated reducer, a power disengagement mechanism, a left transition half-shaft assembly, a right transition half-shaft assembly, and a lubrication component. The integrated reducer is arranged between the main drive motor and the auxiliary drive motor. The integrated reducer forms power transmission with the main drive motor and the auxiliary drive motor at the same time. The power disengagement mechanism is installed between the auxiliary drive motor and the integrated reducer. The inverter assembly is electrically connected to the main drive motor and the auxiliary drive motor respectively and is mounted above the integrated reducer. The relative direction between the inverter assembly and the integrated reducer is perpendicular to the relative direction between the main drive motor and the auxiliary drive motor. An auxiliary housing is provided on the outside of the auxiliary drive motor. A small output bearing is provided on the lower side of the auxiliary housing, a main housing is provided on the outer side of the main drive motor, a first lubricating oil hole and a second lubricating oil hole are provided in the main housing, the left transition half-shaft assembly is embedded in the auxiliary housing and is connected to the integrated reducer through a spline, the right transition half-shaft assembly is embedded in the main housing and is connected to the integrated reducer through a spline, a second output bearing is provided at the bottom end of the main housing, an auxiliary drive motor driving end is provided with an auxiliary drive motor shaft, a first bearing is provided at one end of the auxiliary drive motor shaft, and a second bearing is provided at the other end, a third lubricating oil hole and a fourth lubricating oil hole are provided on the right side of the auxiliary drive motor shaft, and a first auxiliary lubricating oil hole and a second auxiliary lubricating oil hole are provided in the auxiliary housing.

[0006] As a preferred embodiment of the present invention, the integrated reducer includes a main drive motor shaft, an auxiliary drive input gear shaft and a planetary gear differential assembly, a middle bearing is provided in the middle of the main drive motor shaft, and a right bearing is provided at the right end, a first input bearing is provided on the outer side of the right end of the auxiliary drive input gear shaft, a first oil nozzle is provided on the right end of the auxiliary drive input gear shaft, a first small bearing is provided in the middle of the auxiliary drive input gear shaft, a second input bearing is provided on the outer side of the left end of the main drive motor shaft, a second oil nozzle is provided on the left end of the main drive motor shaft, a first main lubricating oil hole and a second main lubricating oil hole are provided on the left side of the main drive motor shaft, and a main radial lubricating oil hole is opened on the right side, and an auxiliary radial lubricating oil hole is opened on the side of the auxiliary drive input gear shaft.

[0007] As a preferred embodiment of the present invention, the planetary gear differential assembly includes an output ring gear, a planetary gear set, a differential right housing assembly, a differential left housing assembly and a differential tightening bolt. The output ring gear is fixed together with the differential right housing assembly and the differential left housing assembly through the differential tightening bolts to form a whole.

[0008] As a preferred embodiment of the present invention, the planetary gear set includes planetary pins, short planetary gears, large sun gears, small sun gears, and long planetary gears. A number of groups of first limiting holes are provided on the surface of the differential right housing assembly in an equidistant annular distribution manner. A number of groups of second limiting holes are provided on the surface of the differential left housing assembly in an equidistant annular distribution manner. A first inner hole is provided on the surface of the differential right housing assembly. A second inner hole is provided on the surface of the differential left housing assembly. The short planetary gear and the long planetary gear are respectively sleeved on the corresponding planetary pins, and are axially and circumferentially limited through the second limiting holes on the differential left housing assembly and the first limiting holes on the differential right housing assembly. The large sun gear and the small sun gear are also supported and axially limited respectively through the first inner hole on the differential right housing assembly and the second inner hole on the differential left housing assembly.

[0009] As a preferred embodiment of the present invention, the long planetary gear meshes with both the large sun gear and the small sun gear simultaneously, and the short planetary gear meshes with the small sun gear.

[0010] As a preferred embodiment of the present invention, the lubrication assembly includes an oil sump, a first lubricating oil pipe, a second lubricating oil pipe, and an oil baffle. A lubrication port is provided at the outer end of the first lubricating oil pipe.

[0011] As a preferred embodiment of the present invention, the main drive motor shaft is integrated with first double helical gears with opposite helix angles. The auxiliary drive input gear shaft is also integrated with second double helical gears with opposite helix angles. One side of the auxiliary drive input gear shaft is fixedly connected to the spline hub of the power disengaging mechanism through a nut, and is supported on the auxiliary drive motor shaft through a first bearing.

[0012] Compared with the prior art, the beneficial effects of the present invention are: In a dual-motor electric drive assembly of the present invention, by switching the operating mode of the motors, the problems of existing electric vehicles being unable to simultaneously balance power performance, economy, and shift smoothness are solved. At the same time, by adopting a planetary differential and adding a transition half-shaft assembly, the entire electric drive can be made more compact and have better adaptability. A dual-motor electric drive assembly includes: a main drive motor; an auxiliary drive motor; an integrated reducer placed between the main drive motor and the auxiliary drive motor; the reducer assembly forms a power transmission with both the main drive motor and the auxiliary drive motor; and an inverter assembly; the inverter assembly is electrically connected to the main drive motor and the auxiliary drive motor respectively; the relative direction between the inverter assembly and the integrated reducer is perpendicular to the relative direction between the main drive motor and the auxiliary drive motor; and a power disconnect mechanism connected in series between the integrated reducer and the auxiliary drive motor; and a transition half-shaft assembly respectively embedded in the housing of the main drive motor and the housing of the auxiliary drive motor. In the above dual-motor electric drive assembly, the inverter assembly can provide control signals and drive current to the main drive motor and the auxiliary drive motor. In the dual-drive mode of the dual-motor electric drive assembly, at this time, the power disconnect mechanism is in a combined working state, and the main drive motor and the auxiliary drive motor operate simultaneously under the control of the inverter assembly. Deceleration and torque increase are performed through the integrated reducer, and the power is transmitted to the transition half-shaft assemblies on both sides (the transition half-shaft assemblies are built into the housings of the main drive motor and the auxiliary drive motor and provide vehicle half-shaft interfaces) and finally conducted to the vehicle half-shaft. In the main drive mode of the dual-motor electric drive assembly, at this time, the power disconnect mechanism is in a disengaged working state, the auxiliary drive motor has no power output and is in a stopped state, and the main drive motor works alone under the control of the inverter assembly. Deceleration and torque increase are performed through the integrated reducer, and the power is transmitted to the transition half-shaft assemblies on both sides and finally conducted to the vehicle half-shaft. Since the relative direction between the inverter assembly and the integrated reducer is perpendicular to the relative direction between the main drive motor and the auxiliary drive motor, the integrated inverter is not directly arranged in the relative direction of the main drive motor and the auxiliary drive motor. At the same time, compared with the traditional open differential, the planetary differential adopted in the present invention can further shorten the size of the vehicle in the Y direction, thereby reducing the relative distance between the main drive motor and the auxiliary drive motor and the size of the dual-motor electric drive assembly in the relative direction of the main drive motor and the auxiliary drive motor. At the same time, transition half-shaft assemblies with different lengths are added at both ends of the differential, which helps the dual-motor electric drive assembly to be centered and installed in the vehicle at an angle where the relative direction of the main drive motor and the auxiliary drive motor is parallel to the relative direction of the two wheels. Furthermore, the vehicle can use the same specification of constant velocity half-shafts, which is convenient for subsequent vehicle management and improves the vehicle's acceleration control performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 FIG. is an exploded view of a dual-motor electric drive assembly according to an embodiment of the present application.

[0014] Figure 2 is Figure 1 a partial schematic view of the dual-motor electric drive assembly shown.

[0015] Figure 3 is Figure 1 a partial schematic view of the dual-motor electric drive assembly shown.

[0016] Figure 4 is Figure 1 a partial schematic view of the dual-motor electric drive assembly shown.

[0017] Figure 5 is Figure 4 a partial schematic view of the integrated reducer of the dual-motor electric drive assembly shown.

[0018] Figure 6 is Figure 5 a partial schematic view of the planetary gear pair shown.

[0019] Figure 7 is Figure 1 a partial schematic view of the lubrication assembly of the dual-motor electric drive assembly shown.

[0020] Figure 8 is Figure 2 and Figure 3 a partial schematic view of the auxiliary drive motor housing shown.

[0021] Figure 9 is Figure 2 and Figure 3 a partial schematic view of the main drive motor housing shown.

[0022] Figure 10 is Figure 3 a partial schematic view of the main drive motor shaft shown.

[0023] Figure 11 is Figure 2 a partial schematic view of the auxiliary drive motor shaft shown.

[0024] Figure 12 is Figure 2 a partial schematic view of the auxiliary input gear shaft shown.

[0025] In the figure: 10, main drive motor; 110, main drive motor shaft; 111, first double helical gear; 1101, main radial lubricating oil hole; 1102, first main lubricating oil hole; 1103, second main lubricating oil hole; 120, main housing; 1201, first lubricating oil hole; 1202, second lubricating oil hole; 121, middle bearing; 122, second output bearing; 123, right bearing; 124, first input bearing; 125, first oil nozzle; 20, auxiliary drive motor; 210, auxiliary drive motor shaft; 2101, third lubricating oil hole; 2102, fourth lubricating oil hole; 211, first bearing; 220, auxiliary housing; 2201, first auxiliary lubricating oil hole; 2202, second auxiliary lubricating oil hole; 2203, lubrication port; 221, second input bearing; 222, second oil nozzle; 223, small output bearing; 224, first small bearing; 225, second bearing; 230, auxiliary drive input gear shaft; 2301, auxiliary radial lubricating oil hole; 231, second double helical gear; 30, inverter assembly; 40, integrated reducer; 410, planetary differential assembly; 411, output gear ring; 412, planetary gear set; 4121, planetary pin; 4122, short planetary gear; 4123, large sun gear; 4124, small sun gear; 4125, long planetary gear; 413, differential right housing assembly; 4131, first limiting hole; 4132, first inner hole; 414, differential left housing assembly; 4141, second limiting hole; 4142, second inner hole; 415, differential tightening bolt; 50, power disengagement mechanism; 60, left transition half shaft assembly; 70, right transition half shaft assembly; 80, lubrication assembly; 801, oil collecting tank; 802, first lubricating oil pipe; 803, second lubricating oil pipe; 804, oil baffle plate. Detailed implementation manners

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0027] Please refer to Figure 1-12 , the present invention provides a technical solution: A dual-motor electric drive assembly includes a main drive motor 10, an auxiliary drive motor 20, an inverter assembly 30, an integrated reducer 40, a power disconnect mechanism 50, a left transition half shaft assembly 60, a right transition half shaft assembly 70, and a lubrication assembly 80. The integrated reducer 40 is disposed between the main drive motor 10 and the auxiliary drive motor 20. The integrated reducer 40 simultaneously forms power transmission with the main drive motor 10 and the auxiliary drive motor 20. The power disconnect mechanism 50 is installed between the auxiliary drive motor 20 and the integrated reducer 40. The inverter assembly 30 is electrically connected to the main drive motor 10 and the auxiliary drive motor 20 respectively and is mounted above the integrated reducer 40. The relative direction between the inverter assembly 30 and the integrated reducer 40 is perpendicular to the relative direction between the main drive motor 10 and the auxiliary drive motor 20. An auxiliary housing 220 is provided outside the auxiliary drive motor 20. A small output bearing 223 is provided on the lower side inside the auxiliary housing 220. A main housing 120 is provided outside the main drive motor 10. A first lubricating oil hole 1201 and a second lubricating oil hole 1202 are opened in the main housing 120. The left transition half shaft assembly 60 is embedded on the auxiliary housing 220 and is connected to the integrated reducer 40 through a spline. The right transition half shaft assembly 70 is embedded on the main housing 120 and is connected to the integrated reducer 40 through a spline. A second output bearing 122 is provided at the bottom end inside the main housing 120. A drive end of the auxiliary drive motor 20 is provided with an auxiliary drive motor shaft 210. A first bearing 211 is provided at one end of the auxiliary drive motor shaft 210, and a second bearing 225 is provided at the other end. A third lubricating oil hole 2101 and a fourth lubricating oil hole 2102 are opened on the right side of the auxiliary drive motor shaft 210. A first auxiliary lubricating oil hole 2201 and a second auxiliary lubricating oil hole 2202 are opened in the auxiliary housing 220. The inverter assembly 30 can provide control signals and drive currents to the main drive motor 10, the auxiliary drive motor 20, and the power disconnect mechanism 50. In the enhanced mode of the dual-motor electric drive assembly, under the control of the inverter assembly 30, the power disconnect mechanism 50 is in the engaged state, and the main drive motor 10 and the auxiliary drive motor 20 operate simultaneously under the drive of the inverter assembly 30. In the main drive mode of the dual-motor electric drive assembly, the power disconnect mechanism 50 is in the disengaged state, and the main drive motor 10 operates alone under the control of the inverter assembly 30.

[0028] As a preferred embodiment of the present invention, the integrated reducer 40 includes a main drive motor shaft 110, an auxiliary drive input gear shaft 230 and a planetary gear differential assembly 410, the main drive motor shaft 110 is provided with a middle bearing 121 in the middle, and a right bearing 123 at the right end, a first input bearing 124 is provided on the outer side of the right end of the auxiliary drive input gear shaft 230, a first oil nozzle 125 is provided on the right end of the auxiliary drive input gear shaft 230, a first small bearing 224 is provided in the middle of the auxiliary drive input gear shaft 230, a second input bearing 221 is provided on the outer side of the left end of the main drive motor shaft 110, a second oil nozzle 222 is provided on the left end of the main drive motor shaft 110, a first main lubricating oil hole 1102 and a second main lubricating oil hole 1103 are provided on the left side of the main drive motor shaft 110, and a main radial lubricating oil hole 1101 is opened on the right side.

[0029] As a preferred embodiment of the present invention, the planetary gear differential assembly 410 includes an output ring gear 411, a planetary gear set 412, a differential right housing assembly 413, a differential left housing assembly 414 and a differential tightening bolt 415. The output ring gear 411 is fixed together with the differential right housing assembly 413 and the differential left housing assembly 414 through the differential tightening bolt 415 to form a whole.

[0030] As a preferred embodiment of the present invention, the planetary gear set 412 includes a planet pin 4121, a short planet gear 4122, a large sun gear 4123, a small sun gear 4124, and a long planet gear 4125. The surface of the right differential housing assembly 413 is provided with a plurality of groups of first limiting holes 4131 distributed in an annular equidistant manner, and the surface of the left differential housing assembly 414 is provided with a plurality of groups of second limiting holes 4141 distributed in an annular equidistant manner. The surface of the right differential housing assembly 413 is provided with a first inner hole 4132, and the surface of the left differential housing assembly A second inner hole 4142 is opened on the surface of the component 414, and the short planetary gear 4122 and the long planetary gear 4125 are respectively mounted on the corresponding planetary pins 4121, and are circumferentially and axially limited by the second limiting hole 4141 on the left differential housing assembly 414 and the first limiting hole 4131 on the right differential housing assembly 413. The large sun gear 4123 and the small sun gear 4124 are also supported and axially limited by the first inner hole 4132 on the right differential housing assembly 413 and the second inner hole 4142 on the left differential housing assembly 414.

[0031] As a preferred embodiment of the present invention, the long planetary gear 4125 meshes with the large sun gear 4123 and the small sun gear 4124 simultaneously, and the short planetary gear 4122 meshes with the small sun gear 4124. When there is no rotational speed difference between the left and right half shafts of the vehicle, the left half shaft and the right half shaft of the vehicle rotate synchronously; at this time, there is no rotational speed difference between the large sun gear 4123 and the small sun gear 4124. When there is a rotational speed difference between the left and right half shafts of the vehicle, there is a resistance difference between the left half shaft and the right half shaft of the vehicle. The resistance balance is achieved through the relative rotation of the internal short planetary gear 4122 and the long planetary gear 4125 around their respective planetary pins 4121. At this time, there is a rotational speed difference between the large sun gear 4123 and the small sun gear 4124, and finally the differential rotation between the left half shaft and the right half shaft is achieved.

[0032] As a preferred embodiment of the present invention, the planetary gear type differential assembly 410 used in the present invention is relative to the open straight bevel gear differential for transmission. In normal driving conditions (without differential), the efficiency can be increased by 1% - 2%. In differential conditions (turning or skidding), since large tooth surface sliding friction will be generated by the straight bevel gear at this time, resulting in energy loss, compared with the traditional open straight bevel gear differential, the efficiency of the planetary gear type differential assembly 410 of the present invention will be increased by 3% - 5%.

[0033] As a preferred embodiment of the present invention, the lubrication assembly 80 includes an oil sump 801, a first lubricating oil pipe 802, a second lubricating oil pipe 803, and an oil baffle 804. Among them, the first path of oil directly lubricates the first double helical gear 111 on the main drive motor shaft and the second double helical gear 231 on the auxiliary drive input gear shaft 230 through the oil holes on the oil sump 801. Among them, the second path of oil transports the lubricating oil to the second lubricating oil hole 1202 on the main housing 120 through the second lubricating oil pipe 803 and lubricates the second output bearing 122. Among them, the third path of oil transports the lubricating oil to the first lubricating oil hole 1201 on the main housing 120 through the lubricating holes on the oil sump 801. A part of it directly lubricates the first input bearing 124, and another branch enters the auxiliary drive input gear shaft 230 through the first oil nozzle 125. A part of the oil passing through the first oil nozzle 125 lubricates the first small bearing 224 through the auxiliary radial lubricating holes 2301 on the auxiliary drive input gear shaft 230, and another part continues to move along the inner hole of the auxiliary drive motor shaft 210. A part of it lubricates the second bearing 225 through the third lubricating oil hole 2101 and the fourth lubricating oil hole 2102 on the auxiliary drive motor shaft 210, and the other part of the lubricating oil remaining in the inner hole of the auxiliary drive motor shaft 210 lubricates the first bearing 211. Among them, the fourth path of oil enters the second auxiliary lubricating oil hole 2202 on the auxiliary housing 220 through the lubricating oil holes of the oil sump 801, and then continues to flow into the first auxiliary lubricating oil hole 2201 on the auxiliary housing 220 along the second lubricating oil pipe 803 and lubricates the small output bearing 223. Among them, the fifth path of oil enters the first auxiliary lubricating oil hole 2201 on the auxiliary housing 220 through the lubricating oil holes of the oil sump 801. A part of it directly lubricates the second input bearing 221, and another branch enters the main drive motor shaft 110 through the second oil nozzle 222. A part of the oil passing through the second oil nozzle 222 lubricates the middle bearing 121 through the main radial lubricating holes 1101 on the main drive motor shaft 110, and another part continues to move along the inner hole of the main drive motor shaft 110 and lubricates the right bearing 123 through the first main lubricating oil hole 1102 and the second main lubricating oil hole 1103 on the main drive motor shaft 110.

[0034] As a preferred embodiment of the present invention, the oil baffle 804 described in the present invention can significantly reduce the oil churning loss generated during the operation of the output gear ring 411. At the same time, lubrication through the oil holes on the oil sump 801 can reduce the efficiency loss caused by the extrusion of lubricating oil under high-speed conditions of the gear pair.

[0035] As a preferred embodiment of the present invention, a first double helical gear 111 with opposite helix angles is integrated on the main drive motor shaft 110, and a second double helical gear 231 with opposite helix angles is also integrated on the auxiliary drive input gear shaft 230. One side of the auxiliary drive input gear shaft 230 is fixedly connected to the spline hub of the power disengaging mechanism 50 by a nut and is supported on the auxiliary drive motor shaft 210 through a first bearing 211. In this embodiment, the first double helical gear 111 with opposite helix angles is integrated on the main drive motor shaft 110, and the second double helical gear 231 with opposite helix angles is also integrated on the auxiliary drive input gear shaft 230, which is in a constant meshing state with the output gear ring 411. One side of the auxiliary drive input gear shaft 230 is fixedly connected to the spline hub of the power disengaging mechanism 50 by a nut and is supported on the auxiliary drive motor shaft 210 through a first bearing 211.

[0036] Working principle: The main drive motor 10, the auxiliary drive motor 20, and the integrated speed reducer 40. The integrated speed reducer 40 is placed between the main drive motor 10 and the auxiliary drive motor 20; the integrated speed reducer 40 forms a power transmission with both the main drive motor 10 and the auxiliary drive motor 20 at the same time; the inverter assembly 30; the inverter assembly 30 is electrically connected to the main drive motor 10 and the auxiliary drive motor 20 respectively; the relative direction between the inverter assembly 30 and the integrated speed reducer 40 is perpendicular to the relative direction between the main drive motor 10 and the auxiliary drive motor 20; and the power disconnect mechanism 50, which is connected in series between the integrated speed reducer 40 and the auxiliary drive motor 20; and the transition half shaft assembly, which is respectively embedded in the housing of the main drive motor 10 and the housing of the auxiliary drive motor 20. For the above dual-motor electric drive assembly, the inverter assembly 30 can provide control signals and drive current to the main drive motor 10 and the auxiliary drive motor 20. In the dual-drive mode of the dual-motor electric drive assembly, at this time, the power disconnect mechanism is in the combined working state, and the main drive motor 10 and the auxiliary drive motor 20 operate simultaneously under the control of the inverter assembly 30. The integrated speed reducer 40 is used for speed reduction and torque increase, and transmits the power to the transition half shaft assemblies on both sides and finally conducts it to the vehicle half shaft. In the main drive mode of the dual-motor electric drive assembly, at this time, the power disconnect mechanism 50 is in the disconnected working state, the auxiliary drive motor 20 has no power output at this time and is in a stopped state, and the main drive motor 10 works independently under the control of the inverter assembly 30, uses the integrated speed reducer 40 for speed reduction and torque increase, and transmits the power to the transition half shaft assemblies on both sides and finally conducts it to the vehicle half shaft. Since the relative direction between the inverter assembly 30 and the integrated speed reducer 40 is perpendicular to the relative direction between the main drive motor 10 and the auxiliary drive motor 20, the integrated inverter is not directly arranged in the relative direction of the main drive motor 10 and the auxiliary drive motor 20. At the same time, compared with the traditional open differential, the planetary differential used in the present invention can further shorten the size of the vehicle in the Y direction, thereby reducing the relative distance between the main drive motor 10 and the auxiliary drive motor 20, and reducing the size of the dual-motor electric drive assembly in the relative direction of the main drive motor 10 and the auxiliary drive motor 20. At the same time, transition half shaft assemblies with different lengths are added at both ends of the differential, which helps the dual-motor electric drive assembly to be installed in the vehicle centered at an angle where the relative direction of the main drive motor 10 and the auxiliary drive motor 20 is parallel to the relative direction of the two wheels. Furthermore, the vehicle can use the same specification of constant velocity half shafts, which is convenient for subsequent vehicle management and improves the vehicle's acceleration control performance.

[0037] As a preferred embodiment of the present invention, the first double helical teeth 111 with opposite helix angles integrated on the main drive motor shaft 110 and the second double helical teeth 231 with opposite helix angles also integrated on the auxiliary drive input gear shaft 230 both adopt the short tooth system structure. Under the condition of meeting strength and NVH, the face contact ratio is optimized, the tooth surface sliding rate is reduced, and the meshing loss of the gear is further reduced. At the same time, compared with the conventional single helical tooth meshing gear pair design, the double helical tooth meshing scheme can reduce the meshing loss of the gear. And when the double helical tooth meshing scheme is adopted, due to the cancellation of the axial force of the gear, compared with the single helical tooth meshing scheme, the present invention optimizes the support bearing and changes the tapered roller bearing to a deep groove ball bearing or a cylindrical roller bearing. The following is the efficiency comparison of three different schemes under two different driving conditions but with the same input torque and input speed: Table 1: Efficiency Comparison under the Main Drive Mode

[0038] Table 2: Efficiency Comparison under the Dual-Motor Drive Mode

[0039] From the above comparison, it can be seen that under the main drive mode, the electric drive assembly corresponding to the present invention can increase the average efficiency by 0.188% compared with the traditional single helical tooth scheme, and under the dual-motor drive mode, the electric drive assembly corresponding to the present invention can increase the average efficiency by 0.152% compared with the traditional single helical tooth scheme.

[0040] Table 3: Test Data of the Electric Drive Assembly. The following table lists the bench test data of the traditional electric drive assembly and the electric drive assembly of the present invention.

[0041] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A dual-motor electric drive assembly, characterized in that: It includes a main drive motor (10), an auxiliary drive motor (20), an inverter assembly (30), an integrated reducer (40), a power disconnect mechanism (50), a left transition half shaft assembly (60), a right transition half shaft assembly (70), and a lubrication assembly (80). The integrated reducer (40) is disposed between the main drive motor (10) and the auxiliary drive motor (20), and the integrated reducer (40) forms a power transmission with both the main drive motor (10) and the auxiliary drive motor (20) simultaneously. The power disconnect mechanism (50) is installed between the auxiliary drive motor (20) and the integrated reducer (40). The inverter assembly (30) is electrically connected to the main drive motor (10) and the auxiliary drive motor (20) respectively, and is mounted above the integrated reducer (40). The relative direction between the inverter assembly (30) and the integrated reducer (40) is perpendicular to the relative direction between the main drive motor (10) and the auxiliary drive motor (20). An auxiliary housing (220) is provided outside the auxiliary drive motor (20), and a small output bearing (223) is provided on the lower side inside the auxiliary housing (220). A main housing (120) is provided outside the main drive motor (10), and a first lubricating oil hole (1201) and a second lubricating oil hole (1202) are formed inside the main housing (120). The left transition half shaft assembly (60) is embedded on the auxiliary housing (220) and is connected to the integrated reducer (40) through a spline. The right transition half shaft assembly (70) is embedded on the main housing (120) and is connected to the integrated reducer (40) through a spline. A second output bearing (122) is provided at the bottom end inside the main housing (120). A shaft of the auxiliary drive motor (210) is provided at the drive end of the auxiliary drive motor (20). A first bearing (211) is provided at one end of the shaft of the auxiliary drive motor (210), and a second bearing (225) is provided at the other end. A third lubricating oil hole (2101) and a fourth lubricating oil hole (2102) are formed on the right side of the shaft of the auxiliary drive motor (210). A first auxiliary lubricating oil hole (2201) and a second auxiliary lubricating oil hole (2202) are formed inside the auxiliary housing (220).

2. The dual-motor electric drive assembly according to claim 1, wherein: The integrated speed reducer (40) comprises a main drive motor shaft (110), an auxiliary drive input gear shaft (230) and a planetary gear differential assembly (410); a middle bearing (121) is provided in the middle of the main drive motor shaft (110), and a right bearing (123) is provided at the right end; a first input bearing (124) is provided on the outer side of the right end of the auxiliary drive input gear shaft (230); a first oil nozzle (125) is provided at the right end of the auxiliary drive input gear shaft (230); A first small bearing (224) is provided in the middle, a second input bearing (221) is provided on the outer side of the left end of the main drive motor shaft (110), a second oil nozzle (222) is provided on the left end of the main drive motor shaft (110), a first main lubricating oil hole (1102) and a second main lubricating oil hole (1103) are provided on the left side of the main drive motor shaft (110), and a main radial lubricating oil hole (1101) is provided on the right side, and an auxiliary radial lubricating oil hole (2301) is provided on the side of the auxiliary drive input gear shaft (230).

3. The dual-motor electric drive assembly according to claim 2, wherein: The planetary gear differential assembly (410) comprises an output ring gear (411), a planetary gear set (412), a right differential housing component (413), a left differential housing component (414) and a differential tightening bolt (415); the output ring gear (411) is fixed together with the right differential housing component (413) and the left differential housing component (414) via the differential tightening bolt (415) to form a whole.

4. A dual-motor electric drive assembly according to claim 3, characterized in that: The planetary gear set (412) comprises a planet pin (4121), a short planet gear (4122), a large sun gear (4123), a small sun gear (4124), and a long planet gear (4125); the surface of the right differential housing component (413) is provided with a plurality of groups of first limiting holes (4131) distributed in an annular manner with equal spacing; the surface of the left differential housing component (414) is provided with a plurality of groups of second limiting holes (4141) distributed in an annular manner with equal spacing; the surface of the right differential housing component (413) is provided with a first inner hole (4132); the surface of the left differential housing component (414) is provided with a The second inner hole (4142), the short planetary gear (4122) and the long planetary gear (4125) are respectively mounted on the corresponding planetary pins (4121), and are circumferentially and axially limited through the second limiting hole (4141) on the left differential housing assembly (414) and the first limiting hole (4131) on the right differential housing assembly (413), and the large sun gear (4123) and the small sun gear (4124) are also supported and axially limited through the first inner hole (4132) on the right differential housing assembly (413) and the second inner hole (4142) on the left differential housing assembly (414).

5. The dual-motor electric drive assembly according to claim 4, wherein: The long planetary gear (4125) meshes with the large sun gear (4123) and the small sun gear (4124) at the same time, and the short planetary gear (4122) meshes with the small sun gear (4124).

6. A dual-motor electric drive assembly according to claim 1, characterized in that: The lubrication assembly (80) includes an oil sump (801), a first lubricating oil pipe (802), a second lubricating oil pipe (803), and an oil baffle (804). A lubricating port (2203) is provided at the outer end of the first lubricating oil pipe (802).

7. A dual-motor electric drive assembly according to claim 2, wherein: A first double helical gear (111) with opposite helix angles is integrated on the main drive motor shaft (110). A second double helical gear (231) with opposite helix angles is integrated on the auxiliary drive input gear shaft (230). One side of the auxiliary drive input gear shaft (230) is fixedly connected to the spline hub of the power disengaging mechanism (50) by a nut and is supported on the auxiliary drive motor shaft (210) through a first bearing (211).

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