Electric drive assembly, four-wheel drive system and vehicle

Abstract

The application relates to an electric drive assembly, a four-wheel drive system and a vehicle, the electric drive assembly comprising a first motor, a second motor, a first speed reducer, a second speed reducer, a first half shaft and a second half shaft; the first speed reducer is a first planetary gear speed reducer, and the second speed reducer is a second planetary gear speed reducer; the first planetary gear speed reducer and the second planetary gear speed reducer are located on the two sides of the first motor and the second motor, and the first planetary gear speed reducer, the second planetary gear speed reducer, the first motor and the second motor are coaxially arranged. The electric drive assembly can effectively solve the abnormal shaking or humming noise problem of the existing double-motor wheel edge independent drive system arranged in a centralized manner.

Description

Electric drive system, four-wheel drive system and vehicle

[0001] This application is a divisional application of Chinese patent application filed on August 31, 2022, with application number 202211063839.0 and title "Electric Drive Assembly, Four-Wheel Drive System and Vehicle". Technical Field

[0002] This application belongs to the field of vehicle drive technology and relates to an electric drive assembly, a four-wheel drive system and a vehicle. Background Technology

[0003] Dual-motor independent drive allows for precise and independent control of the torque and speed of the left and right wheels, resulting in a range of advantages such as smaller turning radius, ESP assistance, assisted steering, and assisted braking, thereby improving vehicle handling. Simultaneously, the independently driven motors enable higher power and stronger off-road capability.

[0004] However, compared with a single-motor centralized drive system, a centrally arranged dual-motor wheel-side independent drive system may sometimes experience abnormal vibrations or buzzing noises that affect the overall vehicle comfort. Summary of the Invention

[0005] The technical problem to be solved by this application is: for the existing centralized dual-motor wheel-side independent drive system, there is sometimes abnormal vibration or buzzing noise that affects the overall vehicle comfort, so an electric drive assembly, four-wheel drive system and vehicle are provided.

[0006] To solve the above-mentioned technical problems, on the one hand, this application provides an electric drive assembly, including a first motor, a second motor, a first reducer, a second reducer, a first half-shaft, and a second half-shaft. The input end of the first reducer is connected to the first motor, the output end of the first reducer is connected to the first half-shaft, the input end of the second reducer is connected to the second motor, and the output end of the second reducer is connected to the second half-shaft.

[0007] Both the first reducer and the second reducer are multi-stage reducers with the same number of stages. The speed ratio of the first reducer is the same as that of the second reducer. The speed ratio of at least two stages of the reduction gear set of the first reducer is different from that of at least two corresponding reduction gear sets of the second reducer.

[0008] The housings of the first reducer, the second reducer, the first motor, and the second motor are separately disposed but fixedly connected together; or, at least two of the housings of the first reducer, the second reducer, the first motor, and the second motor are integrated into one unit.

[0009] In the electric drive assembly of this application embodiment, both the first and second reducers are multi-stage reduction gears with the same number of stages. In the vehicle width direction, the speed ratios of the first and second reducers located on the left and right sides are the same. The speed ratios of at least two stages of the first reducer's reduction gear sets are different from the speed ratios of at least two corresponding stages of the second reducer's reduction gear sets. Specifically, at least two stages of the first and second reducers have the following characteristics: the speed ratio of one stage of the first reducer's reduction gear set is greater than the speed ratio of one stage of the second reducer's reduction gear set, and the speed ratio of another stage of the first reducer's reduction gear set is less than the speed ratio of another stage of the second reducer's reduction gear set. As a result, the noise frequencies generated by the movement of the driving gear in the last stage of the first reducer's reduction gear set and the driving gear in the last stage of the second reducer's reduction gear set differ significantly. The combined noise waveform has a high frequency, effectively solving the abnormal vibration or buzzing noise problems of existing centrally arranged dual-motor wheel-side independent drive systems, resulting in a better driving experience and improved overall vehicle comfort.

[0010] On the other hand, embodiments of this application also provide a four-wheel drive system, including a front drive axle and a rear drive axle, both of which are equipped with the aforementioned electric drive assembly.

[0011] The four-wheel drive system of this application embodiment has all the advantages of the electric drive assembly described above.

[0012] In another aspect, embodiments of this application also provide a vehicle that includes the aforementioned electric drive assembly or four-wheel drive system.

[0013] The four-wheel drive system of this application embodiment has all the advantages of the electric drive assembly described above. Attached Figure Description

[0014] Figure 1 is a schematic diagram of the electric drive assembly provided in the first embodiment of this application;

[0015] Figure 2 is a schematic diagram of the electric drive assembly provided in the second embodiment of this application;

[0016] Figure 3 is a schematic diagram of the electric drive assembly provided in the third embodiment of this application;

[0017] Figure 4 is a schematic diagram of the electric drive assembly provided in the fourth embodiment of this application;

[0018] Figure 5 is a schematic diagram of the electric drive assembly provided in the fifth embodiment of this application;

[0019] Figure 6 is a schematic diagram of the electric drive assembly provided in the sixth embodiment of this application;

[0020] Figure 7 is a schematic diagram of the electric drive assembly provided in the seventh embodiment of this application;

[0021] Figure 8 is a schematic diagram of the electric drive assembly provided in the eighth embodiment of this application;

[0022] Figure 9 is a schematic diagram of the four-wheel drive system provided in an embodiment of this application;

[0023] Figure 10 is a schematic diagram of the vehicle provided in an embodiment of this application;

[0024] Figure 11 is a gear noise waveform diagram of the left reducer of an existing centralized dual-motor wheel-side independent drive system;

[0025] Figure 12 is a gear noise waveform diagram of the right reducer of an existing centralized dual-motor wheel-side independent drive system;

[0026] Figure 13 shows the gear noise of the left reducer and the gear noise of the right reducer in the same time domain of an existing centralized dual-motor wheel-side independent drive system.

[0027] Figure 14 is a waveform diagram of the gear noise of the left reducer and the gear noise of the right reducer superimposed on the existing centralized dual-motor wheel-side independent drive system.

[0028] Figure 15 is a gear noise waveform diagram of the first reducer of the electric drive assembly according to an embodiment of this application.

[0029] Figure 16 is a gear noise waveform diagram of the second reducer of the electric drive assembly according to an embodiment of this application;

[0030] Figure 17 is a waveform diagram of the gear noise of the first reducer and the gear noise of the second reducer in the same time domain of the electric drive assembly of the present application embodiment;

[0031] Figure 18 is a waveform diagram showing the superposition of gear noise from the first reducer and the second reducer in the electric drive assembly of this application embodiment.

[0032] The reference numerals in the accompanying drawings are as follows:

[0033] 10000, Vehicle; 1000, Four-wheel drive system; 100, Electric drive assembly; 200, First wheel; 300, Second wheel; 400, Reducer assembly; 401, Chamber; 501, Front drive axle; 502, Rear drive axle;

[0034] 1. First motor; 2. Second motor; 3. First reducer; 31. First parallel shaft gear reducer; 311. First input shaft; 312. First intermediate shaft; 313. First output shaft; 314. First stage reduction drive gear; 315. First stage reduction driven gear; 316. First and second stage reduction drive gear; 317. First and second stage reduction driven gear; 32. First planetary gear reducer; 321. First sun gear; 322. First planet gear; 3221. First large planet gear; 3222. First small planet gear; 323. First planet carrier; 324. First gear ring; 4. Second reducer; 41. Second parallel shaft gear reducer; 411. Second input shaft; 412. Second intermediate shaft; 412a, Second-stage intermediate shaft; 412b, Second-stage intermediate shaft; 413, Second output shaft; 414, Second-stage reduction drive gear; 415, Second-stage reduction driven gear; 416, Second-stage reduction drive gear; 417, Second-stage reduction driven gear; 42, Second planetary gear reducer; 421, Second sun gear; 422, Second planetary gear; 4221, Second large planetary gear; 4222, Second small planetary gear; 423, Second planetary carrier; 424, Second gear ring; 5, First half-shaft; 6, Second half-shaft; 7, Differential locking device; 8, Connecting shaft; 8a, First connecting shaft; 8b, Second connecting shaft; 91, First clutch device; 92, Second clutch device. Detailed Implementation

[0035] To make the technical problems, technical solutions, and beneficial effects solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0036] Compared to a single-motor centralized drive system, a centrally arranged dual-motor wheel-side independent drive system may sometimes experience abnormal vibrations or buzzing noises that affect the overall vehicle comfort.

[0037] The inventors of this invention discovered through research and analysis that this phenomenon, known as "beat frequency," arises because the operating states of the centrally arranged left and right motors and reducers cannot remain completely consistent during operation. Specifically, referring to Figures 11 to 13, assuming that the gear noise waveforms of the left and right reducers in an existing centrally arranged dual-motor wheel-side independent drive system are standard sine waves with different frequencies but the same amplitude, and the left and right noise waveforms differ by 2% (see Figure 13), as shown in Figure 14, the gear noise from the left and right reducers is superimposed to form a new low-frequency noise waveform, resulting in a low-pitched "humming" sound from the entire vehicle—this is the "beat frequency" problem.

[0038] The electric drive assembly provided in this application embodiment includes a first motor, a second motor, a first reducer, a second reducer, a first half-shaft, and a second half-shaft. The input end of the first reducer is connected to the first motor, and the output end of the first reducer is connected to the first half-shaft. The input end of the second reducer is connected to the second motor, and the output end of the second reducer is connected to the second half-shaft.

[0039] Both the first reducer and the second reducer are multi-stage reducers with the same number of stages. The speed ratio of the first reducer is the same as that of the second reducer. The first reducer and the second reducer have at least two different speed ratios.

[0040] The housings of the first reducer, the second reducer, the first motor, and the second motor are separately disposed but fixedly connected together; or, at least two of the housings of the first reducer, the second reducer, the first motor, and the second motor are integrated into one unit.

[0041] The speed ratios of at least two stages of reduction gear sets in the first reducer are different from the speed ratios of at least two corresponding stages of reduction gear sets in the second reducer. Specifically, at least two stages of reduction gear sets in both the first and second reducers exhibit the following characteristics: the speed ratio of one stage of the first reducer is greater than the speed ratio of one stage of the second reducer, and the speed ratio of the other stage of the first reducer is less than the speed ratio of the other stage of the second reducer. This can be categorized into the following cases:

[0042] (1) The speed ratio of the last stage reduction gear set of the first reducer is the same as that of the last stage reduction gear set of the second reducer. At this time, the first reducer and the second reducer have more than three stages. Among the multiple stages of reduction gear sets before the last stage reduction gear set of the first reducer and the second reducer, at least two stages have the following characteristics: the speed ratio of one stage of the first reducer is greater than the speed ratio of one stage of the second reducer, and the speed ratio of the other stage of the first reducer is less than the speed ratio of the other stage of the second reducer.

[0043] (2) The speed ratio of the last stage reduction gear set of the first reducer is different from that of the last stage reduction gear set of the second reducer. In this case, the first reducer and the second reducer have more than two stages. The speed ratios of each stage reduction gear set of the first reducer and the second reducer are different. Among the multi-stage reduction gear sets of the first reducer and the second reducer, at least two stages have the following characteristics: the speed ratio of one stage of the first reducer is greater than the speed ratio of one stage of the second reducer, and the speed ratio of another stage of the first reducer is less than the speed ratio of another stage of the second reducer.

[0044] (3) The speed ratio of the last stage reduction gear set of the first reducer is different from that of the last stage reduction gear set of the second reducer. In this case, the first reducer and the second reducer have more than three stages. At least one stage of the reduction gear sets of the first reducer and the second reducer has the same speed ratio. Among the multi-stage reduction gear sets of the first reducer and the second reducer, at least two stages have the following characteristics: the speed ratio of one stage of the first reducer is greater than the speed ratio of one stage of the second reducer, and the speed ratio of another stage of the first reducer is less than the speed ratio of another stage of the second reducer.

[0045] In the electric drive assembly of this application embodiment, both the first and second reducers are multi-stage reduction gears with the same number of stages. In the vehicle width direction, the speed ratios of the first and second reducers located on the left and right sides are the same. The speed ratios of at least two stages of the first reducer's reduction gear sets are different from the speed ratios of at least two corresponding stages of the second reducer's reduction gear sets. Specifically, at least two stages of the first and second reducers have the following characteristics: the speed ratio of one stage of the first reducer's reduction gear set is greater than the speed ratio of one stage of the second reducer's reduction gear set, and the speed ratio of another stage of the first reducer's reduction gear set is less than the speed ratio of another stage of the second reducer's reduction gear set. As a result, the noise frequencies generated by the movement of the driving gear in the last stage of the first reducer's reduction gear set and the driving gear in the last stage of the second reducer's reduction gear set differ significantly. The combined noise waveform has a high frequency, effectively solving the abnormal vibration or buzzing noise problems of existing centrally arranged dual-motor wheel-side independent drive systems, resulting in a better driving experience and improved overall vehicle comfort.

[0046] Referring to Figures 15 to 17, the gear noise waveforms of the left reducer (first reducer) and the right reducer (second reducer) of the electric drive assembly in this embodiment are standard sine waves with different frequencies but the same amplitude. Because the speed ratios of at least two stages of the reduction gear sets in the first reducer are different from those in the corresponding gear sets of at least two stages in the second reducer, the left and right noise waveforms differ significantly (see Figure 17). Referring to Figure 18, the gear noise from the left reducer and the gear noise from the right reducer are superimposed to form a new noise waveform. When the gear noise frequencies of the left and right reducers differ significantly, the synthesized new waveform has a high frequency, avoiding a low-pitched "humming" sound throughout the vehicle, solving the "beat frequency" problem, improving the driving experience, and enhancing overall vehicle comfort.

[0047] In this article, the speed ratio of the first reducer refers to the ratio of its input speed to its output speed, i.e., the reduction ratio of the first reducer. Similarly, the speed ratio of the second reducer refers to the ratio of its input speed to its output speed, i.e., the reduction ratio of the second reducer. The reduction ratio is a value greater than 1.

[0048] Similarly, the speed ratio of each reduction stage is the ratio of the input speed to the output speed of that stage. The speed ratio of the first reducer is the cumulative product of the speed ratios of its each reduction stage, and the speed ratio of the second reducer is the cumulative product of the speed ratios of its each reduction stage.

[0049] In some embodiments, the number of teeth on the driving gear of the last stage of the first reducer gear set is different from that on the driving gear of the last stage of the second reducer gear set.

[0050] In other embodiments, the number of teeth on the driving gear of the last stage of the first reducer is the same as that on the driving gear of the last stage of the second reducer.

[0051] In some embodiments, the speed ratio of the last stage reduction gear set of the first reducer is different from the speed ratio of the last stage reduction gear set of the second reducer.

[0052] In some embodiments, the electric drive assembly further includes a differential locking device connected between the first half-shaft and the second half-shaft for selectively engaging or disengaging the first half-shaft and the second half-shaft.

[0053] In other embodiments, the differential lock device may also be omitted.

[0054] In some embodiments, the first motor and the second motor have the same rated speed and rated torque.

[0055] In other embodiments, the motor corresponding to the one with the larger speed ratio between the first and second reducers has a higher output limit. That is, when the speed ratio of the first reducer is greater than that of the second reducer, the rated torque and rated power of the first motor are higher. Conversely, when the speed ratio of the second reducer is greater than that of the first reducer, the rated torque and rated power of the second motor are higher.

[0056] In some embodiments, the meshing frequency f of the last stage reduction gear set of the first reducer is... z The meshing frequency f with the last stage reduction gear set of the second reducer y The decoupling rate σ between them is greater than 8%, and the meshing frequency f of the last stage reduction gear set of the first reducer is... z The frequency f of the last stage reduction gear set of the first reducer is indicated by the number of times it engages during one revolution of the first motor. y This indicates the number of times the last stage reduction gear set of the second reducer engages during one revolution of the second motor; the decoupling rate σ is expressed by formula (1):

[0057]

[0058] Among them, f z f represents the meshing frequency of the last stage reduction gear set of the first reducer. y This indicates the meshing frequency of the last stage reduction gear set in the second reducer; abs(f z -f y ) indicates taking f z with f y The absolute value of the difference, max(f z f y ) indicates taking f z with f y The maximum value in.

[0059] f z This can be expressed by formula (2):

[0060] f z =Z nzz *(i (n-1)z *......i 1z (2);

[0061] In formula (2), Z nzz This indicates the number of teeth on the driving gear (pinion) of the last stage reduction gear set of the first reducer, (i (n-1)z *......i 1z The expression represents the cumulative product of the speed ratios of each stage of reduction before the last stage of the first reducer.

[0062] f y This can be expressed by formula (3):

[0063] f y =Z myz *(i (m-1)y *......i 1y (3);

[0064] In formula (3), Z myz This indicates the number of teeth on the driving gear (pinion) of the last stage reduction gear set of the second reducer, (i (m-1)y *......i 1y This represents the cumulative product of the speed ratios of all stages of reduction before the final stage of the second reducer. m and n are positive integers greater than or equal to 1, and m and n may be equal or different.

[0065] In some embodiments, the housings of the first reducer, the second reducer, the first motor, and the second motor are each independently and fixedly connected together. The fixed connection described herein can be a bolted connection or a riveted connection, etc.

[0066] In other embodiments, at least two of the housings of the first reducer, the second reducer, the first motor, and the second motor are integrated into one unit. The non-integrated portions (separately set portions) are fixedly connected to the integrated portions. This can be categorized into the following cases;

[0067] (1) The housing of the first reducer, the housing of the second reducer, the housing of the first motor and the housing of the second motor are integrated into one unit.

[0068] (2) The housing of the first reducer and the housing of the second reducer are integrated to form a reducer housing, while the housing of the first motor and the housing of the second motor are separately provided and fixedly connected to the reducer housing.

[0069] (3) The housing of the first reducer and the housing of the second reducer are integrated into one to form a reducer housing, and the housing of the first motor and the housing of the second motor are integrated into one to form a motor housing. The reducer housing and the motor housing are separately arranged and fixedly connected.

[0070] (4) The housing of the first motor and the housing of the second motor are integrated into one to form a motor housing, and the housing of the first reducer and the housing of the second reducer are separately provided and fixedly connected to the motor housing.

[0071] (5) The housing of the first motor, the housing of the second motor and the housing of the first reducer are integrated into one unit to form an integrated housing, and the housing of the second reducer is separately disposed from the integrated housing but fixedly connected.

[0072] (6) The housing of the first motor, the housing of the second motor and the housing of the second reducer are integrated into one unit to form an integrated housing, and the housing of the first reducer and the integrated housing are separately set and fixedly connected.

[0073] (7) The housing of the first motor and the housing of the first reducer are integrated into one unit to form an integrated housing, and the housing of the second motor and the housing of the second reducer are independently set and fixedly connected to the integrated housing.

[0074] (8) The housing of the first motor and the housing of the first reducer are integrated into one to form a first integrated housing, and the housing of the second motor and the housing of the second reducer are integrated into one to form a second integrated housing. The first integrated housing and the second integrated housing are separately arranged and fixedly connected.

[0075] (9) The housing of the second motor and the housing of the second reducer are integrated into one unit to form an integrated housing, and the housing of the first motor and the housing of the first reducer are independently set and fixedly connected to the integrated housing.

[0076] In some embodiments, in the vehicle width direction, the first reducer and the second reducer are arranged between the first motor and the second motor, and the first motor and the second motor are arranged in parallel or coaxially.

[0077] In other embodiments, in the vehicle width direction, the first motor and the second motor are arranged between the first reducer and the second reducer, the first motor, the second motor and the first half-shaft are arranged in parallel, and the axial directions of the first half-shaft and the second half-shaft pass through the first motor or the second motor.

[0078] In other embodiments, in the vehicle width direction, the first motor and the second motor are arranged between the first reducer and the second reducer, the first motor, the second motor and the first half-shaft are arranged in parallel, and the axis of the first motor, the axis of the second motor and the axis of the first half-shaft and the second half-shaft are arranged in a triangle.

[0079] In other embodiments, in the vehicle width direction, the first motor and the second motor are arranged between the first reducer and the second reducer, and the first motor, the second motor, the first half-shaft and the second half-shaft are coaxial.

[0080] In other embodiments, the first reducer and the second reducer are combined to form a reducer assembly. In the vehicle width direction, the first motor and the second motor are arranged on the same side of the reducer assembly, and the first motor and the second motor are arranged in parallel or coaxially.

[0081] In some embodiments, the first reducer is a first planetary gear reducer, and the second reducer is a second planetary gear reducer.

[0082] In other embodiments, the first reducer is a first parallel shaft gear reducer, and the second reducer is a second parallel shaft gear reducer.

[0083] In other embodiments, the multi-stage reduction of the first reducer includes a portion of parallel shaft gear reduction and a portion of planetary gear reduction.

[0084] In other embodiments, the multi-stage reduction of the second reducer includes a portion of parallel shaft gear reduction and a portion of planetary gear reduction.

[0085] The present application will be described in detail below with reference to the accompanying drawings and several embodiments.

[0086] First Embodiment

[0087] Referring to Figure 1, the electric drive assembly 100 provided in the first embodiment of this application includes a first motor 1, a second motor 2, a first reducer 3, a second reducer 4, a first half-shaft 5, and a second half-shaft 6. The input end of the first reducer 3 is connected to the first motor 1, and the output end of the first reducer 1 is connected to the first half-shaft 5. The input end of the second reducer 4 is connected to the second motor 2, and the output end of the second reducer 4 is connected to the second half-shaft 6. The outer end of the first half-shaft 5 is connected to a first wheel 200, and the outer end of the second half-shaft 6 is connected to a second wheel 300. The first wheel 200 is the left wheel, denoted by W1 in the figure. The second wheel 200 is the right wheel, denoted by W2 in the figure. The first motor 1 is denoted by M1 in the figure, and the second motor 2 is denoted by M2 in the figure.

[0088] The electric drive assembly 100 of the first embodiment of this application includes a first reducer 3 and a second reducer 4, both of which are multi-stage reduction gears. In the vehicle width direction, the speed ratios of the first reducer 3 and the second reducer 4 located on the left and right sides are the same. The speed ratios of at least two stages of the reduction gear sets in the first reducer 3 are different from the speed ratios of at least two corresponding stages of the reduction gear sets in the second reducer 4. Specifically, at least two stages of the reduction gear sets in the first reducer 3 and the second reducer 4 have the following characteristics: the speed ratio of one stage of the reduction gear set in the first reducer 3 is greater than the speed ratio of one stage of the reduction gear set in the second reducer 4, and the speed ratio of the other stage of the reduction gear set in the first reducer 3 is less than the speed ratio of the other stage of the reduction gear set in the second reducer 4. Thus, the noise frequencies generated by the movement of the driving gear in the last stage of the reduction gear set in the first reducer 3 and the driving gear in the last stage of the reduction gear set in the second reducer 4 are significantly different. The resulting superimposed noise waveform has a high frequency, effectively solving the abnormal vibration or buzzing noise problems of existing centrally arranged dual-motor wheel-side independent drive systems, improving the driving experience and overall vehicle comfort.

[0089] In this embodiment, the number of teeth on the driving gear of the last stage reduction gear set of the first reducer 3 is different from that on the driving gear of the last stage reduction gear set of the second reducer 4.

[0090] In this embodiment, the electric drive assembly 100 further includes a differential locking device 7, which is connected between the first half-shaft 5 and the second half-shaft 6 and is used to selectively engage or disengage the first half-shaft 5 and the second half-shaft 6.

[0091] The differential locking device 7 can be a clutch, brake, or synchronizer. In this embodiment, a synchronizer is preferred. By engaging and disengaging the differential locking device 5, equal torque and speed output can be achieved between the first half-shaft 5 and the second half-shaft 6 under special working conditions, enabling the vehicle to get out of trouble and improving the off-road capability of the vehicle equipped with the electric drive assembly 100.

[0092] The electric drive assembly 100 of the first embodiment can be used in front-wheel drive vehicles, rear-wheel drive vehicles, and four-wheel drive vehicles.

[0093] The first motor 1 and the second motor 2 have the same rated speed and rated torque. Preferably, the first motor 1 and the second motor 2 are arranged symmetrically from left to right. The first motor 1, the first reducer 3, the second reducer 4, and the second motor 2 are arranged sequentially from left to right.

[0094] In this embodiment, both the first reducer 3 and the second reducer 4 are two-stage reduction gears. In the vehicle width direction, the first reducer 3 and the second reducer 4 are arranged between the first motor 1 and the second motor 2. The area of ​​the end face of the housing of the first reducer 3 near the first motor 1 is larger than the end face area of ​​the first motor 1, and the area of ​​the end face of the housing of the second reducer 4 near the second motor 2 is larger than the end face area of ​​the second motor 2, thereby making the electric drive assembly 100 T-shaped.

[0095] In this embodiment, the housing of the first reducer 3 and the housing of the second reducer 4 are integrated to form a reducer housing, while the housings of the first motor 1 and the second motor 2 are separately disposed and fixedly connected to the left and right sides of the reducer housing.

[0096] In this embodiment, the first reducer 3 is a first parallel shaft gear reducer 31, and the second reducer 4 is a second parallel shaft gear reducer 41.

[0097] The first parallel shaft gear reducer 31 includes a first input shaft 311, a first intermediate shaft 312, and a first output shaft 313. The first input shaft 311, the first intermediate shaft 312, and the first output shaft 313 are parallel and spaced apart from each other. The first input shaft 311 is coaxially connected to the motor shaft of the first motor 1, and the first output shaft 313 is coaxially connected to the first half-shaft 5. A first-stage reduction drive gear 314 is provided on the first input shaft 311. A first-stage reduction driven gear 315 and a first-stage reduction drive gear 316 (the drive gear of the last stage reduction gear set of the first reducer 3) are provided on the first intermediate shaft 312. A first-stage reduction driven gear 317 is provided on the first output shaft 313. The first-stage reduction drive gear 314 and the first-stage reduction driven gear 315 mesh to form the first stage reduction gear set of the first reducer 3, and the first-stage reduction drive gear 316 and the first-stage reduction driven gear 317 mesh to form the second stage reduction gear set of the first reducer 3. The driving gear of the first parallel shaft gear reducer 31 has a smaller diameter and fewer teeth than the driven gear.

[0098] The second parallel shaft gear reducer 41 includes a second input shaft 411, a second intermediate shaft 412, and a second output shaft 413. The second input shaft 411, the second intermediate shaft 412, and the second output shaft 413 are parallel and spaced apart from each other. The second input shaft 411 is coaxially connected to the motor shaft of the second motor 2, and the second output shaft 413 is coaxially connected to the second half-shaft 6. A second first-stage reduction drive gear 414 is provided on the second input shaft 411. A second first-stage reduction driven gear 415 and a second second-stage reduction drive gear 416 (the drive gear of the last stage reduction gear set of the second reducer 4) are provided on the second intermediate shaft 412. A second second-stage reduction driven gear 417 is provided on the second output shaft 413. The second first-stage reduction drive gear 414 and the second first-stage reduction driven gear 415 mesh to form the first stage reduction gear set of the second reducer 4, and the second second-stage reduction drive gear 416 and the second second-stage reduction driven gear 417 mesh to form the second stage reduction gear set of the second reducer 4. The driving gear of the second parallel shaft gear reducer 41 has a smaller diameter and fewer teeth than the driven gear.

[0099] The differential locking device 7 is connected between the inner end of the first output shaft 313 and the inner end of the second output shaft 413. By engaging or disengaging the inner end of the first output shaft 313 and the second output shaft 413, the engagement and disengagement of the first half-shaft 5 and the second half-shaft 6 are achieved.

[0100] The differential locking device 7 is integrated into the housing of the first reducer 3 and the second reducer 4, which has a higher degree of integration and occupies less space.

[0101] In the first embodiment, the meshing frequency f of the last stage reduction gear set (the second stage reduction gear set of the first reducer 3) is... z The meshing frequency f with the last stage reduction gear set of the second reducer 4 (the second stage reduction gear set of the second reducer 4) y The decoupling rate σ between them is greater than 8%, and the meshing frequency f of the last stage reduction gear set of the first reducer 3 is... z The frequency f of the last stage reduction gear set of the first reducer 3 is the number of times it engages during one revolution of the first motor 1, and the frequency f of the last stage reduction gear set of the second reducer 4 is the number of times it engages. y This indicates the number of times the last stage reduction gear set of the second reducer 4 engages during one revolution of the second motor 2; the decoupling rate σ is expressed by formula (1):

[0102]

[0103] Among them, f z f represents the meshing frequency of the last stage reduction gear set of the first reducer. yThis indicates the meshing frequency of the last stage reduction gear set in the second reducer; abs(f z -f y ) indicates taking f z with f y The absolute value of the difference, max(f z f y ) indicates taking f z with f y The maximum value in.

[0104] f z This can be expressed by formula (2):

[0105] f z =Z nzz *(i (n-1)z *......i 1z (2);

[0106] In formula (2), Z nzz This indicates the number of teeth on the driving gear (pinion) of the last stage reduction gear set in the first reducer 3, (i (n-1)z *......i 1z The expression represents the cumulative product of the speed ratios of each stage of the first reducer (before the last stage). Here, n equals 2. Therefore:

[0107]

[0108] In formula (4), Z 2zz Z represents the number of teeth on the first and second stage reduction drive gear 316. 1zz Z represents the number of teeth on the first-stage reduction drive gear 314. 1zc Indicates the number of teeth on the first-stage reduction driven gear 315, i 1z This indicates the speed ratio of the first stage reduction of the first reducer 3.

[0109] f y This can be expressed by formula (3):

[0110] f y =Z myz *(i (m-1)y *......i 1y (3);

[0111] In formula (3), Z myz This indicates the number of teeth on the driving gear (pinion) of the last stage reduction gear set of the second reducer, (i (m-1)y *......i 1y The expression represents the cumulative product of the speed ratios of all stages of reduction before the final stage of the second reducer. Here, m is greater than 2. Therefore:

[0112]

[0113] In formula (5), Z 2yz Z represents the number of teeth on the second and second stage reduction drive gear 416. 1yz Z represents the number of teeth on the second-stage reduction drive gear 414. 1yc i1 indicates the number of teeth on the second-stage reduction driven gear 415, and i1 indicates the speed ratio of the first-stage reduction of the second reducer 4.

[0114] Simulation results show that when the decoupling rate σ is greater than 8%, the "beat frequency" problem of the electric drive assembly 100 can be solved, that is, the problem of abnormal vibration or buzzing noise of the electric drive assembly 100 can be solved.

[0115] In this embodiment, it can be:

[0116] (1) The speed ratio of the first stage reduction gear set of the first reducer 3 is different from that of the first stage reduction gear set of the second reducer 4. The speed ratio of the second stage reduction gear set of the first reducer 3 is different from that of the second stage reduction gear set of the second reducer 4. The speed ratio of the first stage reduction gear set of the first reducer 3 is greater than that of the first stage reduction gear set of the second reducer 4. The speed ratio of the second stage reduction gear set of the first reducer 3 is less than that of the first stage reduction gear set of the second reducer 4. The cumulative product of the speed ratios of each stage reduction gear set of the first reducer 3 and the second reducer 4 is equal. The number of teeth of the first stage reduction drive gear 314 of the first reducer 3 and the second stage reduction drive gear 414 of the second reducer 4 are the same or different. The number of teeth of the first stage reduction drive gear 316 of the first reducer 3 and the second stage reduction drive gear 416 of the second reducer 4 are the same or different.

[0117] (2) The speed ratio of the first stage reduction gear set of the first reducer 3 is different from that of the first stage reduction gear set of the second reducer 4. The speed ratio of the second stage reduction gear set of the first reducer 3 is different from that of the second stage reduction gear set of the second reducer 4. The speed ratio of the first stage reduction gear set of the first reducer 3 is less than that of the first stage reduction gear set of the second reducer 4. The speed ratio of the second stage reduction gear set of the first reducer 3 is greater than that of the first stage reduction gear set of the second reducer 4. The cumulative product of the speed ratios of each stage reduction gear set of the first reducer 3 and the second reducer 4 is equal. The number of teeth of the first stage reduction drive gear 314 of the first reducer 3 and the second stage reduction drive gear 414 of the second reducer 4 are the same or different. The number of teeth of the first stage reduction drive gear 316 of the first reducer 3 and the second stage reduction drive gear 416 of the second reducer 4 are the same or different.

[0118] Second Embodiment

[0119] Figure 2 shows an electric drive assembly 100 provided in the second embodiment of this application. The main difference between this assembly and the first embodiment is that the electric drive assembly 100 is H-shaped. In the vehicle width direction, the first motor 1 and the second motor 2 are arranged between the first reducer 3 and the second reducer 4. The first motor 1, the second motor 2, and the first half-shaft 5 are arranged in parallel. The first half-shaft 5 and the second half-shaft 6 are coaxial, and their axes pass through either the first motor 1 or the second motor 2. Preferably, the first motor 1 is arranged above the second motor 2. The first reducer 3 is arranged to the left of the first motor 1 and the second motor 2, and the second reducer 4 is arranged to the right of the first motor 1 and the second motor 2.

[0120] In this embodiment, the housing of the first motor 1 and the housing of the second motor 2 are integrated into one to form a motor housing, and the housing of the first reducer 3 and the housing of the second reducer 4 are separately disposed and fixedly connected to the left and right sides of the motor housing.

[0121] The motor shaft of the second motor 2 is a hollow shaft, and a connecting shaft 8 is provided inside the motor shaft of the second motor 2. One end of the connecting shaft 8 is connected to the first output shaft 313, and the differential locking device 7 is connected between the other end of the second output shaft 413 and the connecting shaft 8. The motor shaft, connecting shaft 8, first output shaft 313 and first output shaft 413 of the second motor 2 are coaxial.

[0122] The second input shaft 411 is coaxially connected to the motor shaft of the second motor 2 or is formed as a single unit.

[0123] The differential locking device 7 is connected between the connecting shaft 8 and the inner end of the second output shaft 413. By engaging or disengaging the connecting shaft 8 and the second output shaft 413, the engagement and disengagement of the first half-shaft 5 and the second half-shaft 6 can be achieved.

[0124] The differential locking device 7 is integrated into the housing of the second reduction gear 4, which has a higher degree of integration and occupies less space.

[0125] Third Embodiment

[0126] Figure 3 shows the electric drive assembly 100 provided in the third embodiment of this application. The main difference between it and the first embodiment is that, in the vehicle width direction, the first motor 1 and the second motor 2 are arranged between the first reducer 3 and the second reducer 4. The first motor 1, the second motor 2 and the first half-shaft 5 are arranged in parallel. The first half-shaft 5 and the second half-shaft 6 are coaxial. The axis of the first motor 1, the axis of the second motor 2 and the axis of the first half-shaft 5 and the second half-shaft 6 are arranged in a triangle.

[0127] Specifically, the electric drive assembly 100 is V-shaped; the first reducer 3 and the second reducer 4 are combined to form a V-shaped reducer assembly 400, the reducer assembly 400 has an open cavity 401, and the first motor 1 and the second motor 2 are arranged in the cavity 401.

[0128] In this embodiment, the housings of the first reducer 3, the second reducer 4, the first motor 1, and the second motor 2 are integrated into one unit.

[0129] Preferably, the first motor 1 is arranged below the second motor 2. The first reducer 3 is arranged near the first wheel 200, and the second reducer 4 is arranged near the second wheel 300.

[0130] Fourth embodiment

[0131] Figure 4 shows the electric drive assembly provided in the fourth embodiment of this application. The difference between the electric drive assembly 100 and the first embodiment is that the electric drive assembly 100 is in a straight line shape. In the vehicle width direction, the first motor 1 and the second motor 2 are arranged between the first reducer 3 and the second reducer 4, and the first motor 1, the second motor 2, the first half-shaft 5, and the second half-shaft 6 are coaxial. The first reducer 3, the first motor 1, the second motor 2, and the second reducer 4 are arranged sequentially from left to right.

[0132] The first input shaft 311 is coaxial with the first output shaft 313, and the first intermediate shaft 312 is parallel and spaced apart from the first input shaft 311. The second input shaft 411 is coaxial with the second output shaft 413, and the second intermediate shaft 412 is parallel and spaced apart from the second input shaft 411.

[0133] The electric drive assembly 300 further includes a first clutch device 91 and a second clutch device 92. The first clutch device 91 is connected between the first input shaft 311 and the first output shaft 313, and is used to selectively engage or disengage the first input shaft 311 and the first output shaft 313. The second clutch device 92 is connected between the second input shaft 411 and the second output shaft 413, and is used to selectively engage or disengage the second input shaft 411 and the second output shaft 413.

[0134] When the first clutch device 91 is engaged, the power of the first motor 1 is transmitted to the first wheel 200 via the first input shaft 311, the first clutch device 91, the first output shaft 313, and the first half-shaft 5. When the first clutch device 91 is disengaged, the power of the first motor 1 is transmitted to the first wheel 200 via the first input shaft 311, the first primary reduction drive gear 314, the first primary reduction driven gear 315, the first secondary reduction drive gear 316, the first secondary reduction driven gear 317, the first output shaft 313, and the first half-shaft 5. Thus, the first reducer 3 has two selectable speeds.

[0135] Similarly, when the second clutch 92 is engaged, the power of the second motor 2 is transmitted to the second wheel 300 via the second input shaft 411, the second clutch 92, the second output shaft 413, and the second half-shaft 6. When the second clutch 91 is disengaged, the power of the second motor 2 is transmitted to the second wheel 300 via the second input shaft 411, the second first-stage reduction drive gear 414, the second first-stage reduction driven gear 415, the second second-stage reduction drive gear 416, the second second-stage reduction driven gear 417, the second output shaft 413, and the second half-shaft 6. Thus, the second reducer 3 has two selectable gears.

[0136] In this embodiment, the housing of the first motor 1 and the housing of the second motor 2 are integrated into one to form a motor housing, and the housing of the first reducer 3 and the housing of the second reducer 4 are separately disposed and fixedly connected to the left and right sides of the motor housing.

[0137] Fifth embodiment

[0138] Figure 5 shows the electric drive assembly 100 provided in the fifth embodiment of this application. The difference between the electric drive assembly 100 and the first embodiment is that the electric drive assembly 100 is L-shaped. The first reducer 3 and the second reducer 4 are combined to form a reducer assembly 400. In the vehicle width direction, the first motor 3 and the second motor 4 are arranged on the left side of the reducer assembly 400. The end face area of ​​the reducer assembly 400 closest to the first motor 1 and the second motor 2 is larger than the end face area of ​​the first motor 1 and the second motor 2. The reducer assembly 400 is arranged on the right, closer to the second wheel 300.

[0139] In this embodiment, the housings of the first motor 1 and the second motor 2 are integrated to form a motor housing, and the housings of the first reducer 3 and the second reducer 4 are integrated to form a reducer housing. The reducer housing and the motor housing are separately disposed but fixedly connected, that is, the motor housing is fixedly connected to the left side of the reducer housing.

[0140] The first motor 1 and the second motor 2 are coaxially arranged, and the second motor 2, the first motor 1, the first reducer 3, and the second reducer 4 are arranged sequentially from left to right. The motor shaft of the first motor 1 is a hollow shaft, and the motor shaft of the second motor 2 passes through the motor shaft of the first motor 1. The first input shaft 311 is a hollow shaft and is coaxially connected to the motor shaft of the first motor 1. The first intermediate shaft 312 is a hollow shaft and is loosely fitted onto the second intermediate shaft 412.

[0141] Sixth Embodiment

[0142] Figure 6 shows the electric drive assembly 100 provided in the sixth embodiment of this application. The difference between the electric drive assembly 100 and the fifth embodiment is that the electric drive assembly 100 is arranged as a mirror image of the embodiment shown in Figure 5. That is, in the vehicle width direction, the first motor 3 and the second motor 4 are arranged on the right side of the reducer assembly 400. The reducer assembly 400 is arranged on the left, closer to the first wheel 200.

[0143] The motor shaft of the second motor 2 is a hollow shaft, and the motor shaft of the first motor 1 passes through the motor shaft of the second motor 2. The second input shaft 411 is a hollow shaft and is coaxially connected to the motor shaft of the second motor 1. The second intermediate shaft 412 is a hollow shaft and is loosely fitted onto the first intermediate shaft 312.

[0144] The first reducer 3, the second reducer 4, the second motor 2, and the first motor 1 are arranged from left to right.

[0145] Seventh Embodiment

[0146] Figure 7 shows the electric drive assembly 100 provided in the seventh embodiment of this application. The difference between this assembly and the fourth embodiment is that the first reducer 3 is a first planetary gear reducer 32, and the second reducer 4 is a second planetary gear reducer 42. The first planetary gear reducer 32 and the second planetary gear reducer 42 are located on both sides of the first motor 1 and the second motor 2, and are coaxially arranged. The first reducer 3, the first motor 1, the second motor 2, and the second reducer 4 are arranged sequentially from left to right.

[0147] Both the first planetary gear reducer 32 and the second planetary gear reducer 42 are two-stage reduction gears.

[0148] The first planetary gear reducer 32 includes a first input element, a first output element, and a first intermediate element; the second planetary gear reducer 42 includes a second input element, a second output element, and a second intermediate element. The first input element is connected to the motor shaft of the first motor 1, the first output element is connected to the first half-shaft 5, and the first intermediate element is connected to the housing of the first planetary gear reducer 32. The second input element is connected to the motor shaft of the second motor 2, the second output element is connected to the second half-shaft 6, and the second intermediate element is connected to the housing of the second planetary gear reducer 42. The first input element is the input end of the first reducer 3, and the first output element is the output end of the first reducer 3. The second input element is the input end of the second reducer 4, and the second output element is the output end of the second reducer 4.

[0149] Specifically, the first planetary gear reduction mechanism 32 is a planetary gear set consisting of a first sun gear 321, a first planetary gear 322, a first planetary carrier 323, and a first ring gear 324. The first input element is the first sun gear 321, the first output element is the first planetary carrier 323, and the first intermediate element is the first ring gear 324. The first planetary gear 322 is rotatably supported on the first planetary carrier 323 and meshes between the first sun gear 321 and the first ring gear 324. The first planetary carrier 323 is connected to the first half-shaft 5, the first sun gear 321 is connected to the motor shaft of the first motor 1, and the first ring gear 324 is connected to the housing of the first planetary gear reduction mechanism 32.

[0150] The second planetary gear reduction mechanism 42 is a planetary gear set consisting of a second sun gear 421, a second planetary gear 422, a second planetary carrier 423, and a second ring gear 424. The second input element is the second sun gear 421, the second output element is the second planetary carrier 423, and the second intermediate element is the second ring gear 424. The second planetary gear 422 is rotatably supported on the second planetary carrier 423 and meshes between the second sun gear 421 and the second ring gear 424. The second planetary carrier 423 is connected to the second half-shaft 6, the second sun gear 421 is connected to the motor shaft of the second motor 2, and the second ring gear 424 is connected to the housing of the second planetary gear reduction mechanism 42.

[0151] In this embodiment, the housing of the first motor 1 and the housing of the second motor 2 are integrated into one to form a motor housing, and the housing of the first reducer 3 and the housing of the second reducer 4 are separately disposed and fixedly connected to the left and right sides of the motor housing.

[0152] In order to achieve two-stage reduction of the first reducer 3, the first planetary gear 322 includes a first large planetary gear 3221 and a first small planetary gear 3222 with a diameter smaller than the first large planetary gear 3221, which are coaxially connected. The first large planetary gear 3221 meshes with the first sun gear 321, and the first small planetary gear 3222 meshes with the first gear ring 324.

[0153] In order to achieve two-stage reduction of the second reducer 4, the second planetary gear 422 includes a second large planetary gear 4221 coaxially connected and a second small planetary gear 4222 with a diameter smaller than that of the second large planetary gear 4221. The second large planetary gear 4221 meshes with the second sun gear 421, and the second small planetary gear 4222 meshes with the second gear ring 424.

[0154] The two-speed ratio design of the first reducer 3 and the second reducer 4 can achieve a wide range of speed ratios, enabling the two motors to operate in the high-efficiency speed range.

[0155] Eighth embodiment

[0156] Figure 8 shows the electric drive assembly 100 provided in the ninth embodiment of this application. The difference between the ninth and seventh embodiments is that the first motor 1 and the second motor 2 are located on both sides of the first planetary gear reducer 32 and the second planetary gear reducer 42. The first motor 1, the first reducer 3, the second reducer 4, and the second motor 2 are arranged sequentially from left to right.

[0157] The electric drive assembly 100 further includes a first connecting shaft 8a and a second connecting shaft 8b. The motor shaft of the first motor 1 is a hollow shaft, and the motor shaft of the second motor 2 is a hollow shaft. The first connecting shaft 8a passes through the motor shaft of the first motor 1. The outer end of the first connecting shaft 8a is connected to the first half-shaft 5, and the inner end of the first connecting shaft 8a is connected to the first planetary carrier 323. The second connecting shaft 8b passes through the motor shaft of the second motor 2. The outer end of the second connecting shaft 8b is connected to the second half-shaft 6, and the inner end of the second connecting shaft 8b is connected to the second planetary carrier 423. The first connecting shaft 8a, the second connecting shaft 8b, the first half-shaft 5, the second half-shaft 6, the motor shaft of the first motor 1, and the motor shaft of the second motor 2 are coaxial.

[0158] In this embodiment, the housing of the first reducer 3 and the housing of the second reducer 4 are integrated to form a reducer housing, while the housings of the first motor 1 and the second motor 2 are separately disposed and fixedly connected to the left and right sides of the reducer housing.

[0159] Referring to Figure 9, this application embodiment also provides a four-wheel drive system 1000, including a front drive axle 501 and a rear drive axle 502, both of which are provided with the above-mentioned electric drive assembly 100.

[0160] Referring to Figure 10, this application embodiment also provides a vehicle 10000, including the above-described electric drive assembly 100 or four-wheel drive system 1000.

[0161] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An electric drive assembly, characterized in that, It includes a first motor, a second motor, a first reducer, a second reducer, a first half-shaft, and a second half-shaft. The input end of the first reducer is connected to the first motor, and the output end of the first reducer is connected to the first half-shaft. The input end of the second reducer is connected to the second motor, and the output end of the second reducer is connected to the second half-shaft. The first reducer is a first planetary gear reducer, and the second reducer is a second planetary gear reducer; the first planetary gear reducer and the second planetary gear reducer are located on both sides of the first motor and the second motor, and are arranged coaxially with the first planetary gear reducer, the second planetary gear reducer, the first motor, and the second motor; the meshing frequency of the last stage reduction gear set of the first planetary gear reducer... The meshing frequency with the last stage reduction gear set of the second planetary gear reducer Decoupling rate between Greater than 8%, wherein the decoupling rate Based on the meshing frequency of the last stage reduction gear set of the first planetary gear reducer The meshing frequency with the last stage reduction gear set of the second planetary gear reducer Sure.

2. The electric drive assembly according to claim 1, characterized in that, The electric drive assembly is in the shape of an "I", with the first planetary gear reducer, the first motor, the second motor, and the second planetary gear reducer arranged sequentially from left to right.

3. The electric drive assembly according to claim 1, characterized in that, Both the first planetary gear reducer and the second planetary gear reducer are multi-stage reduction gears with the same number of stages, and the speed ratio of the first planetary gear reducer is the same as that of the second planetary gear reducer.

4. The electric drive assembly according to claim 1 or 3, characterized in that, Both the first planetary gear reducer and the second planetary gear reducer are two-stage reduction gears.

5. The electric drive assembly according to claim 1, characterized in that, The housings of the first planetary gear reducer, the second planetary gear reducer, the first motor, and the second motor are separately configured but fixedly connected together.

6. The electric drive assembly according to claim 1, characterized in that, The first motor and the second motor have the same rated speed.

7. The electric drive assembly according to claim 1, characterized in that, The first motor and the second motor have the same rated torque.

8. The electric drive assembly according to claim 1, characterized in that, The meshing frequency of the last stage reduction gear set of the first planetary gear reducer This indicates the number of times the last stage reduction gear of the first planetary gear reducer engages during one revolution of the first motor, and the meshing frequency of the last stage reduction gear of the second planetary gear reducer. The decoupling rate represents the number of times the last stage reduction gear set of the second planetary gear reducer engages during one revolution of the second motor; This can be expressed by formula (1): (1); where, This indicates the meshing frequency of the last stage reduction gear set in the first planetary gear reducer. This indicates the meshing frequency of the last stage reduction gear set in the second planetary gear reducer; Indicates taking and The absolute value of the difference Indicates taking and The maximum value in.

9. The electric drive assembly according to claim 8, characterized in that, This can be expressed by formula (2): (2); in formula (2), This indicates the number of teeth on the driving gear of the last stage reduction gear set of the first planetary gear reducer. This represents the cumulative product of the speed ratios of each stage of reduction before the last stage of the first planetary gear reducer.

10. The electric drive assembly according to claim 9, characterized in that, (4); in formula (4), This indicates the number of teeth on the first and second stage reduction drive gears. This indicates the number of teeth on the first-stage reduction drive gear. This indicates the number of teeth on the first-stage reduction driven gear. This indicates the speed ratio of the first stage reduction of the first planetary gear reducer.

11. The electric drive assembly according to claim 8, characterized in that, This can be expressed by formula (3): (3); in formula (3), This indicates the number of teeth on the driving gear of the last stage reduction gear set in the second planetary gear reducer. This represents the cumulative product of the speed ratios of each stage of reduction before the last stage of the second planetary gear reducer.

12. The electric drive assembly according to claim 11, characterized in that, (5); in formula (5), This indicates the number of teeth on the second and second stage reduction drive gear. This indicates the number of teeth on the second-stage reduction drive gear. This indicates the number of teeth on the driven gear of the second-stage reduction gear. This indicates the speed ratio of the first stage reduction of the second planetary gear reducer.

13. The electric drive assembly according to claim 1, characterized in that, In the vehicle width direction, the first motor and the second motor are arranged between the first planetary gear reducer and the second planetary gear reducer. The first motor, the second motor and the first half-shaft are arranged in parallel, and the axial directions of the first half-shaft and the second half-shaft pass through the first motor or the second motor.

14. The electric drive assembly according to claim 1 or 13, characterized in that, In the vehicle width direction, the first motor and the second motor are arranged between the first planetary gear reducer and the second planetary gear reducer, and the first motor, the second motor, the first half-shaft and the second half-shaft are coaxial.

15. The electric drive assembly according to claim 1, characterized in that, The motor shaft of the first motor is a hollow shaft.

16. The electric drive assembly according to claim 1, characterized in that, The motor shaft of the second motor is a hollow shaft.

17. The electric drive assembly according to claim 1, characterized in that, The first planetary gear reducer includes a first input element, a first output element, and a first intermediate element. The first input element is connected to the motor shaft of the first motor, the first output element is connected to the first half-shaft, and the first intermediate element is connected to the housing of the first planetary gear reducer. The first input element is the input end of the first planetary gear reducer, and the first output element is the output end of the first planetary gear reducer.

18. The electric drive assembly according to claim 17, characterized in that, The first planetary gear reduction mechanism is a planetary gear set consisting of a first sun gear, a first planet gear, a first planet carrier, and a first ring gear. The first input element is the first sun gear, the first output element is the first planet carrier, the first intermediate element is the first ring gear, the first planet gear is rotatably supported on the first planet carrier, and the first planet gear meshes between the first sun gear and the first ring gear. The first planet carrier is connected to the first half-shaft, the first sun gear is connected to the motor shaft of the first motor, and the first ring gear is connected to the housing of the first planetary gear reducer.

19. The electric drive assembly according to claim 18, characterized in that, The first planetary gear includes a first large planetary gear and a first small planetary gear with a diameter smaller than the first large planetary gear, which are coaxially connected. The first large planetary gear meshes with the first sun gear, and the first small planetary gear meshes with the first gear ring.

20. The electric drive assembly according to claim 1, characterized in that, The second planetary gear reducer includes a second input element, a second output element, and a second intermediate element; the second input element is connected to the motor shaft of the second motor, the second output element is connected to the second half-shaft, and the second intermediate element is connected to the housing of the second planetary gear reducer; the second input element is the input end of the second planetary gear reducer, and the second output element is the output end of the second planetary gear reducer.

21. The electric drive assembly according to claim 20, characterized in that, The second planetary gear reduction mechanism is a planetary gear set consisting of a second sun gear, a second planet gear, a second planet carrier, and a second ring gear. The second input element is the second sun gear, the second output element is the second planet carrier, and the second intermediate element is the second ring gear. The second planet gear is rotatably supported on the second planet carrier and meshes between the second sun gear and the second ring gear. The second planet carrier is connected to the second half-shaft, the second sun gear is connected to the motor shaft of the second motor, and the second ring gear is connected to the housing of the second planetary gear reducer.

22. The electric drive assembly according to claim 21, characterized in that, The second planetary gear includes a second large planetary gear and a second small planetary gear with a diameter smaller than that of the second large planetary gear, which are coaxially connected. The second large planetary gear meshes with the second sun gear, and the second small planetary gear meshes with the second gear ring.

23. The electric drive assembly according to claim 1, characterized in that, The gear noise waveform of the first planetary gear reducer and the gear noise waveform of the second planetary gear reducer are both standard sine waves with different frequencies but the same amplitude.

24. The electric drive assembly according to claim 1, characterized in that, It is used in front-wheel drive vehicles, rear-wheel drive vehicles, or four-wheel drive vehicles.

25. A four-wheel drive system, characterized in that, It includes a front drive axle and a rear drive axle, wherein the front drive axle and / or the rear drive axle are provided with an electric drive assembly as described in any one of claims 1-24.

26. A vehicle, characterized in that, Includes the electric drive assembly as described in any one of claims 1-24 or the four-wheel drive system as described in claim 25.

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