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; at least one of the first speed reducer and the second speed reducer is a multi-stage speed reducer, the speed ratio of the first speed reducer is the same as that of the second speed reducer, the number of teeth of a driving gear of a last-stage speed reduction gear set of the first speed reducer is different from that of a driving gear of a last-stage speed reduction gear set of the second speed reducer; the housings of the first speed reducer and the second speed reducer, the housings of the first motor and the second motor are separately arranged and fixedly connected together; or at least two of the housings of the first speed reducer, the housings of the second speed reducer, the housings of the first motor and the housings of the second motor are integrated. The electric drive assembly can solve the abnormal shaking or humming noise problem of the existing double-motor wheel edge independent drive system arranged in a centralized manner.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of vehicle driving, and relates to an electric driving assembly, a four-wheel drive system and a vehicle. BACKGROUND

[0002] The torque and speed of the left and right wheels of the dual-motor independently driven automobile can be accurately controlled independently of each other, thereby bringing a series of advantages, such as realizing smaller-radius turning, assisting ESP function, assisting steering function and assisting braking function, so as to improve the handling performance of the vehicle. Meanwhile, the independently driven motor can realize higher power performance and stronger escape performance.

[0003] However, the centrally arranged dual-motor wheel edge independent driving system sometimes has the problem of abnormal vibration or humming abnormal noise affecting the comfort of the whole vehicle compared with the single-motor centralized driving system. SUMMARY

[0004] The application aims to solve the problem that the existing centrally arranged dual-motor wheel edge independent driving system sometimes has the problem of abnormal vibration or humming abnormal noise affecting the comfort of the whole vehicle, and provides an electric driving assembly, a four-wheel drive system and a vehicle.

[0005] To solve the above technical problem, on the one hand, the application provides an electric driving 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 input end of the first speed reducer is connected to the first motor, the output end of the first speed reducer is connected to the first half shaft, the input end of the second speed reducer is connected to the second motor, and the output end of the second speed reducer is connected to the second half shaft.

[0006] At least one of the first speed reducer and the second speed reducer is a multi-stage speed reducer, the speed ratio of the first speed reducer is the same as that of the second speed reducer, and the number of teeth of the driving gear of the last-stage speed reduction gear set of the first speed reducer is different from that of the driving gear of the last-stage speed reduction gear set of the second speed reducer.

[0007] The housings of the first speed reducer and the second speed reducer, the housings of the first motor and the second motor are separately arranged and fixedly connected together, or at least two of the housings of the first speed reducer, the second speed reducer, the first motor and the second motor are integrated.

[0008] The electric drive assembly provided by the embodiment of the application is characterized in that at least one of the first reducer and the second reducer is a multi-stage reducer, the speed ratios of the first reducers and the second reducers located on the left and right sides in the vehicle width direction are the same, and the number of teeth of the driving gear of the last-stage reduction gear set of the first reducer is different from that of the driving gear of the last-stage reduction gear set of the second reducer. In this way, the noise frequencies generated by the driving gears of the last-stage reduction gear sets of the first reducer and the second reducer are greatly different, the noise waveform frequency is high after superposition, and the abnormal jitter or humming abnormal sound problem of the existing double-motor wheel-side independent drive system arranged in a centralized manner can be effectively solved, the driving experience is good, and the vehicle comfort is improved.

[0009] In another aspect, the embodiment of the application further provides a four-wheel drive system, comprising a front drive axle and a rear drive axle, and the front drive axle and the rear drive axle are both provided with the electric drive assembly.

[0010] The four-wheel drive system provided by the embodiment of the application has all the advantages of the electric drive assembly.

[0011] In another aspect, the embodiment of the application further provides a vehicle comprising the electric drive assembly or the four-wheel drive system.

[0012] The four-wheel drive system provided by the embodiment of the application has all the advantages of the electric drive assembly. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a schematic view of the electric drive assembly provided by the first embodiment of the application;

[0014] Figure 2 is a schematic view of the electric drive assembly provided by the second embodiment of the application;

[0015] Figure 3 is a schematic view of the electric drive assembly provided by the third embodiment of the application;

[0016] Figure 4 is a schematic view of the electric drive assembly provided by the fourth embodiment of the application;

[0017] Figure 5 is a schematic view of the electric drive assembly provided by the fifth embodiment of the application;

[0018] Figure 6 is a schematic view of the electric drive assembly provided by the sixth embodiment of the application;

[0019] Figure 7 is a schematic view of the electric drive assembly provided by the seventh embodiment of the application;

[0020] Figure 8 is a schematic view of the electric drive assembly provided by the eighth embodiment of the application;

[0021] Figure 9 is a schematic diagram of an electric drive assembly provided by a ninth embodiment of the present application;

[0022] Figure 10 is a schematic diagram of a four-wheel drive system provided by an embodiment of the present application;

[0023] Figure 11 is a schematic diagram of a vehicle provided by an embodiment of the present application;

[0024] Figure 12 is a gear noise waveform diagram of a left side reducer of an existing centrally arranged dual-motor wheel-side independent drive drive system;

[0025] Figure 13 is a gear noise waveform diagram of a right side reducer of an existing centrally arranged dual-motor wheel-side independent drive drive system;

[0026] Figure 14 is a waveform diagram of gear noise of a left side reducer and gear noise of a right side reducer of an existing centrally arranged dual-motor wheel-side independent drive drive system in the same time domain;

[0027] Figure 15 is a waveform diagram of gear noise of a left side reducer and gear noise of a right side reducer of an existing centrally arranged dual-motor wheel-side independent drive drive system after superposition;

[0028] Figure 16 is a gear noise waveform diagram of a first reducer of an electric drive assembly of an embodiment of the present application;

[0029] Figure 17 is a gear noise waveform diagram of a second reducer of an electric drive assembly of an embodiment of the present application;

[0030] Figure 18 is a waveform diagram of gear noise of a first reducer and gear noise of a second reducer of an electric drive assembly of an embodiment of the present application in the same time domain;

[0031] Figure 19 is a waveform diagram of gear noise of a first reducer and gear noise of a second reducer of an electric drive assembly of an embodiment of the present application after superposition;

[0032] Figure 20 is a schematic diagram of an axis parallel to and offset from a driving gear of a stage reduction gear set of a first reducer and a second reducer of an electric drive assembly provided by an embodiment of the present application.

[0033] The reference signs in the specification are as follows:

[0034] 10000, vehicle; 1000, four-wheel drive system; 100, electric drive assembly; 200, first wheel; 300, second wheel; 400, reducer assembly; 401, cavity; 501, front drive axle; 502, rear drive axle;

[0035] 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 primary reduction driving gear; 315, first primary reduction driven gear; 316, first secondary reduction driving gear; 317, first secondary 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 carrier; 324, first ring gear; 4, second reducer; 41, second parallel shaft gear reducer; 411, second input shaft; 412, second intermediate shaft; 412a, second primary intermediate shaft; 412b, second secondary intermediate shaft; 413, second output shaft; 414, second primary reduction driving gear; 415, second primary reduction driven gear; 416, second secondary reduction driving gear; 417, second secondary reduction driven gear; 418, second tertiary reduction driving gear; 419, second tertiary reduction driven gear; 42, second planetary gear reducer; 421, second sun gear; 422, second planet gear; 4221, second large planet gear; 4222, second small planet gear; 423, second carrier; 424, second ring gear; 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 DESCRIPTION

[0036] In order to make the technical problems, technical solutions and beneficial effects solved in the present application clearer, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0037] The centrally arranged double-motor wheel edge independent drive system may sometimes have abnormal jitter or humming noise problems that affect the comfort of the whole vehicle compared with the single-motor centralized drive system.

[0038] The inventor of the present application found through research and analysis that this is because the working state of the centrally arranged left and right motors and reducers cannot be kept completely consistent during operation, thereby generating a "beat frequency" phenomenon. Specifically, see Figures 12 to 14, assuming that the gear noise waveforms of the left side reducer and the right side reducer of the existing centrally arranged double-motor wheel-side independent drive system are standard sinusoidal waves with different frequencies and the same amplitudes, the left and right noise waveforms differ by 2% (see Figure 14 ). Figure 15 After the gear noise of the left side reducer and the right side reducer are superimposed, a new low-frequency noise waveform is synthesized, and the vehicle exhibits a low-pitched "hum" sound, i.e., the "beat frequency" problem is generated.

[0039] The electric drive assembly provided by the embodiment of the present application comprises 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. At least one of the first reducer and the second reducer is a multi-stage reducer. The speed ratio of the first reducer is the same as that of the second reducer. The number of teeth of the driving gear of the last-stage reducer gear set of the first reducer is different from that of the driving gear of the last-stage reducer gear set of the second reducer. The housings of the first reducer and the second reducer, the housing of the first motor and the housing of the second motor are separately arranged and fixedly connected together. Alternatively, at least two of the housings of the first reducer, the second reducer, the first motor and the second motor are integrated.

[0040] The electric drive assembly of the embodiment of the present application is characterized in that at least one of the first reducer and the second reducer is a multi-stage reducer. In the vehicle width direction, the speed ratio of the first reducer and the second reducer located on the left and right sides is the same, and the number of teeth of the driving gear of the last-stage reducer gear set of the first reducer is different from that of the driving gear of the last-stage reducer gear set of the second reducer. In this way, the noise frequencies generated by the movement of the driving gears of the last-stage reducer gear sets of the first reducer and the second reducer are greatly different, and the frequency of the noise waveform after superposition is high, which can effectively solve the abnormal jitter or humming abnormal sound problem of the existing centrally arranged double-motor wheel-side independent drive system, improve the driving experience and improve the vehicle comfort.

[0041] Figures 16 to 18 The gear noise waveforms of the left side reducer (the first reducer) and the right side reducer (the second reducer) of the electric drive assembly of the embodiment of the present application are standard sinusoidal waves with different frequencies and the same amplitudes. Since the number of teeth of the driving gear of the last-stage reducer gear set of the first reducer is different from that of the driving gear of the last-stage reducer gear set of the second reducer, the left and right noise waveforms differ greatly (see Figure 18 Figure 19 ​​The gear noise of the left side reducer and the gear noise of the right side reducer are superimposed to form a new noise waveform. When the gear noise frequency of the left side reducer and the gear noise frequency of the right side reducer are quite different, the frequency of the new waveform is high, the low-pitched "hum" sound of the whole vehicle is avoided, the "beat frequency" problem is solved, the driving experience is good, and the comfort of the whole vehicle is improved.

[0042] In the present document, the speed ratio of the first reducer refers to the ratio of the input speed to the output speed of the first reducer, i.e., the reduction ratio of the first reducer. Similarly, the speed ratio of the second reducer refers to the ratio of the input speed to the output speed of the second reducer, i.e., the reduction ratio of the second reducer. The reduction ratio is a value greater than 1.

[0043] Similarly, the speed ratio of each stage of reduction is the ratio of the input speed to the output speed of the stage of reduction. The speed ratio of the first reducer is the multiplication of the speed ratios of each stage of reduction thereof, and the speed ratio of the second reducer is the multiplication of the speed ratios of each stage of reduction thereof.

[0044] In some embodiments, the electric drive assembly further comprises a differential lock device connected between the first half shaft and the second half shaft for selectively engaging or disconnecting the first half shaft and the second half shaft.

[0045] In other embodiments, the differential lock device can also be cancelled.

[0046] In some embodiments, the first reducer is a multi-stage reduction, and the second reducer is a multi-stage reduction; the number of reduction stages of the first reducer and the second reducer is the same, and the number of teeth of the driving gear of the stage of reduction with the same speed ratio of the first reducer and the second reducer is different. There are several cases:

[0047] (1) The number of teeth of the driving gear of the last stage of reduction of the first reducer and the number of teeth of the driving gear of the last stage of reduction of the second reducer are different, and the speed ratios are the same. The number of teeth of the driving gears of the stages of reduction before the last stage of reduction of the first reducer and the second reducer is the same, and the multiplication of the speed ratios of the stages of reduction before the last stage of reduction of the first reducer and the second reducer is equal.

[0048] (2) The number of teeth of the driving gear of the last stage of reduction of the first reducer and the number of teeth of the driving gear of the last stage of reduction of the second reducer are different, and the speed ratios are the same. The number of teeth of the driving gears of at least one stage of reduction before the last stage of reduction of the first reducer and the second reducer is different, but the speed ratios are the same. And the multiplication of the speed ratios of the stages of reduction before the last stage of reduction of the first reducer and the second reducer is equal.

[0049] (3) the number of teeth of the driving gear of the last stage of the first reducer is different from the number of teeth of the driving gear of the last stage of the second reducer, and the speed ratio is different. The number of teeth of the driving gear of at least one stage of the first reducer and the second reducer is different, but the speed ratio is the same. The product of the speed ratios of each stage of the first reducer and the second reducer is equal.

[0050] In some embodiments, the modulus of the driving gear of the stage of the first reducer and the second reducer with the same speed ratio is the same, and the axes of the driving gears of the stage of the first reducer and the second reducer with the same speed ratio are parallel and offset.

[0051] In some other embodiments, the modulus of the driving gear of the stage of the first reducer and the second reducer with the same speed ratio is different, and the axes of the driving gears of the stage of the first reducer and the second reducer with the same speed ratio are parallel and offset or coaxial.

[0052] In some other embodiments, the number of stages of the first reducer and the second reducer is different. The following cases are included:

[0053] (1) both the first reducer and the second reducer are multi-stage reducers.

[0054] (2) the first reducer is a multi-stage reducer, and the second reducer is a single-stage reducer.

[0055] (3) the first reducer is a single-stage reducer, and the second reducer is a multi-stage reducer.

[0056] In some embodiments, the rated speed and the rated torque of the first motor and the second motor are the same.

[0057] In some embodiments, the decoupling rate between the meshing frequency of the last stage of the first reducer and the meshing frequency of the last stage of the second reducer is greater than 8%, the meshing frequency of the last stage of the first reducer represents the number of times of engagement of the last stage of the first reducer when the first motor rotates one circle, and the meshing frequency of the last stage of the second reducer represents the number of times of engagement of the last stage of the second reducer when the second motor rotates one circle; the decoupling rate is represented by formula (1):

[0058] (1); ​

[0059] wherein, represents the meshing frequency of the last stage of the first reducer, represents the meshing frequency of the last stage of the second reducer; represents the maximum value of and the absolute value of the difference, represents the maximum value of and the absolute value of the difference.

[0060] is represented by formula (2):

[0061] (2);

[0062] In formula (2), represents the number of teeth of the driving gear (pinion) of the last stage of the first reducer, represents the cumulative multiplication of the speed ratios of each stage of reduction before the last stage of reduction of the first reducer.

[0063] is represented by formula (3):

[0064] (3);

[0065] In formula (3), represents the number of teeth of the driving gear (pinion) of the last stage of the second reducer, represents the cumulative multiplication of the speed ratios of each stage of reduction before the last stage of reduction of the second reducer. m and n are positive integers greater than or equal to 1, and m and n are equal or not equal.

[0066] In some embodiments, 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 each independently and fixedly connected together. The fixed connection herein can be bolted or riveted, etc.

[0067] In other embodiments, at least two of 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. The non-integrated part (independently arranged part) is fixedly connected with the integrated part. There are several cases:

[0068] (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.

[0069] (2) The housing of the first reducer and the housing of the second reducer are integrated to form a reducer housing, and the housing of the first motor and the housing of the second motor are separately arranged and fixedly connected to the reducer housing.

[0070] (3) The housing of the first reducer and the housing of the second reducer are integrated to form a reducer housing, and the housing of the first motor and the housing of the second motor are integrated to form a motor housing, and the reducer housing and the motor housing are separately arranged and fixedly connected.

[0071] (4) The housing of the first motor and the housing of the second motor are integrated to form a motor housing, and the housing of the first reducer and the housing of the second reducer are separately arranged and fixedly connected to the motor housing.

[0072] (5) The housing of the first motor, the housing of the second motor, and the housing of the first reducer are integrated to form an integrated housing, and the housing of the second reducer and the integrated housing are separately arranged and fixedly connected.

[0073] (6) The housing of the first motor, the housing of the second motor, and the housing of the second reducer are integrated to form an integrated housing, and the housing of the first reducer and the integrated housing are separately arranged and fixedly connected.

[0074] (7) The housing of the first motor and the housing of the first reducer are integrated to form an integrated housing, and the housing of the second motor and the housing of the second reducer are independently arranged and fixedly connected to the integrated housing.

[0075] (8) The housing of the first motor and the housing of the first reducer are integrated to form a first integrated housing, and the housing of the second motor and the housing of the second reducer are integrated to form a second integrated housing, and the first integrated housing and the second integrated housing are separately arranged and fixedly connected.

[0076] (9) The housing of the second motor and the housing of the second reducer are integrated to form an integrated housing, and the housing of the first motor and the housing of the first reducer are independently arranged and fixedly connected to the integrated housing.

[0077] 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.

[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, and the first motor, the second motor, and the first half shaft are arranged in parallel, and the axis directions of the first half shaft and the second half shaft pass through the first motor or the second motor.

[0079] In some embodiments, the first motor and the second motor are arranged between the first speed reducer and the second speed reducer in the vehicle width direction, the first motor, the second motor, the first half axle and the second half axle are coaxial.

[0080] In some embodiments, the first motor and the second motor are arranged between the first speed reducer and the second speed reducer in the vehicle width direction, the first motor, the second motor, the first half axle and the second half axle are coaxial.

[0081] In some embodiments, the first speed reducer and the second speed reducer are combined to form a speed reducer assembly, the first motor and the second motor are arranged on the same side of the speed reducer assembly in the vehicle width direction, and the first motor and the second motor are arranged in parallel or coaxially.

[0082] In some embodiments, the first speed reducer is a first planetary gear speed reducer, and the second speed reducer is a second planetary gear speed reducer.

[0083] In some embodiments, the first speed reducer is a first parallel shaft gear speed reducer, and the second speed reducer is a second parallel shaft gear speed reducer.

[0084] In some embodiments, the first speed reducer has a multi-stage reduction, part of which is parallel shaft gear reduction and part of which is planetary gear reduction.

[0085] In some embodiments, the second speed reducer has a multi-stage reduction, part of which is parallel shaft gear reduction and part of which is planetary gear reduction.

[0086] The present application is described in detail below in conjunction with the drawings and embodiments.

[0087] First embodiment

[0088] Referring to Figure 1 The electric drive assembly 100 provided by the first embodiment of the present application includes a first motor 1, a second motor 2, a first speed reducer 3, a second speed reducer 4, a first half axle 5 and a second half axle 6. The input end of the first speed reducer 3 is connected to the first motor 1, the output end of the first speed reducer 1 is connected to the first half axle 5, the input end of the second speed reducer 4 is connected to the second motor 2, and the output end of the second speed reducer 4 is connected to the second half axle 6. The outer end of the first half axle 5 is connected to the first wheel 200, and the outer end of the second half axle 6 is connected to the 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.

[0089] The electric drive assembly 100 of the first embodiment of the present application, the first reducer 3 and the second reducer 4 are both multi-stage reducers, in the vehicle width direction, the speed ratios of the first reducer 3 and the second reducer 4 on the left and right sides are the same, and the number of teeth of the driving gear of the last stage of the first reducer 3 is different from that of the driving gear of the last stage of the second reducer 4. In this way, the noise frequencies generated by the driving gears of the last stages of the first reducer 3 and the second reducer 4 are greatly different, and the frequency of the superimposed noise waveform is high, which can effectively solve the problem of abnormal jitter or humming noise of the existing double-motor wheel-edge independent drive system arranged in a centralized manner, improve the driving experience, and improve the vehicle comfort.

[0090] In the embodiment, the electric drive assembly 100 further comprises a differential lock device 7 connected between the first half shaft 5 and the second half shaft 6 for selectively engaging or disconnecting the first half shaft 5 and the second half shaft 6.

[0091] The differential lock device 7 can be a clutch, a brake, or a synchronizer. In the embodiment, the synchronizer is preferred. Through the engagement and disconnection of the differential lock device 5, the torque and the same speed output of the first half shaft 5 and the second half shaft 6 in special working conditions can be realized, the vehicle can be escaped from the trouble, and the off-road capability of the vehicle equipped with the electric drive assembly 100 can be improved.

[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 rated speed and the rated torque of the first motor 1 and the second motor 2 are the same. Preferably, the first motor 1 and the second motor 2 are arranged symmetrically left and right. The first motor 1, the first reducer 3, the second reducer 4, and the second motor 2 are arranged from left to right in sequence.

[0094] In the embodiment, the first reducer 3 and the second reducer 4 are both two-stage reducers. 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 first motor 1 and the second motor 2 are coaxially arranged, the area of the side end face of the housing of the first reducer 3 close to the first motor 1 is greater than the area of the end face of the first motor 1, and the area of the side end face of the housing of the second reducer 4 close to the second motor 2 is greater than the area of the end face of the second motor 2, so that the electric drive assembly 100 is T-shaped.

[0095] In the embodiment, the modulus of the driving gear of the gear set of the first reducer 3 and the second reducer 4 with the same speed ratio is different, and the shafts on which the driving gears of the gear set of the first reducer 3 and the second reducer 4 with the same speed ratio are coaxial. That is, the first intermediate shaft 312 and the second intermediate shaft 412 are coaxial.

[0096] In the embodiment, the housing of the first reducer 3 and the housing of the second reducer 4 are integrated to form a reducer housing, and the housing of the first motor 1 and the housing of the second motor 2 are separately arranged and fixedly connected to the left and right sides of the reducer housing.

[0097] In the 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.

[0098] The first parallel shaft gear reducer 31 includes a first input shaft 311, a first intermediate shaft 312, and a first output shaft 313, which 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. The first input shaft 311 is provided with a first primary reduction driving gear 314, the first intermediate shaft 312 is provided with a first primary reduction driven gear 315 and a first secondary reduction driving gear 316 (the driving gear of the last gear set of the first reducer 3), and the first output shaft 313 is provided with a first secondary reduction driven gear 317. The first primary reduction driving gear 314 and the first primary reduction driven gear 315 are engaged to form a first gear set of the first reducer 3, and the first secondary reduction driving gear 316 and the first secondary reduction driven gear 317 are engaged to form a second gear set of the first reducer 3. The driving gears of the first parallel shaft gear reducer 31 are smaller in diameter and fewer in teeth than the driven gears.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] In the first embodiment, the meshing frequency of the last stage reduction gear set (the second stage reduction gear set of the first reducer 3) is... The meshing frequency with the last stage reduction gear set of the second reducer 4 (the second stage reduction gear set of the second reducer 4) Decoupling rate between Greater than 8%, the meshing frequency of the last stage reduction gear set of the first reducer 3 This indicates the number of times the last stage reduction gear of the first reducer 3 engages during one revolution of the first motor 1, and the meshing frequency of the last stage reduction gear of the second reducer 4. The decoupling rate indicates the number of times the last stage reduction gear of the second reducer 4 engages during one revolution of the second motor 2; This can be expressed by formula (1):

[0103] (1);

[0104] in, This indicates the meshing frequency of the last stage reduction gear set of the first reducer. represents the meshing frequency of the last stage reduction gear set of the second reduction gear 4. represents the maximum value of the absolute values of the difference between the represents the maximum value of the absolute values of the difference between the absolute values of the difference between the represents the maximum value of the absolute values of the difference between the represents the maximum value of the absolute values of the difference between the represents the maximum value of the absolute values of the difference between the

[0105] is represented by formula (2):

[0106] (2);

[0107] In formula (2), represents the number of teeth of the driving gear (pinion) of the last stage reduction gear set of the first reduction gear 3, represents the cumulative multiplication of the speed ratios of the stages of reduction before the last stage reduction of the first reduction gear 3. Here, n is equal to 2. Then, we have:

[0108] (4);

[0109] In formula (4), represents the number of teeth of the driving gear of the second stage reduction of the first reduction gear 3, represents the number of teeth of the driving gear of the first stage reduction of the first reduction gear 3, represents the number of teeth of the driven gear of the first stage reduction of the first reduction gear 3, represents the speed ratio of the first stage reduction of the first reduction gear 3.

[0110] is represented by formula (3):

[0111] (3);

[0112] In formula (3), represents the number of teeth of the driving gear (pinion) of the last stage reduction gear set of the second reduction gear 4, represents the cumulative multiplication of the speed ratios of the stages of reduction before the last stage reduction of the second reduction gear 4. Here, m is equal to 2. Then, we have:

[0113] (5);

[0114] In formula (5), represents the number of teeth of the driving gear of the second stage reduction of the second reduction gear 4, represents the number of teeth of the driving gear of the first stage reduction of the second reduction gear 4, represents the number of teeth of the driven gear of the first stage reduction of the second reduction gear 4, represents the speed ratio of the first stage reduction of the second reduction gear 4.

[0115] When the decoupling rate is greater than 8%, the beat frequency problem of the electric drive assembly 100 can be solved, i.e., the abnormal vibration or humming noise problem of the electric drive assembly 100 can be solved.

[0116] In this embodiment, the following can be implemented:

[0117] (1) The speed ratio of the first-stage reduction gear set of the first reducer 3 is different from the speed ratio of the first-stage reduction gear set of the second reducer 4, and the speed ratio of the second-stage reduction gear set of the first reducer 3 is different from the speed ratio of the second-stage reduction gear set of the second reducer 4. The product of the speed ratios of the respective-stage reduction gear sets of the first reducer 3 and the second reducer 4 is equal. The number of teeth of the first primary-stage reduction driving gear 314 of the first reducer 3 is the same as or different from the number of teeth of the second primary-stage reduction driving gear 414 of the second reducer 4, and the number of teeth of the first secondary-stage reduction driving gear 316 of the first reducer 3 is different from the number of teeth of the second secondary-stage reduction driving gear 416 of the second reducer 4.

[0118] (2) The speed ratio of the first-stage reduction gear set of the first reducer 3 is the same as the speed ratio of the first-stage reduction gear set of the second reducer 4, and the speed ratio of the second-stage reduction gear set of the first reducer 3 is the same as the speed ratio of the second-stage reduction gear set of the second reducer 4. The number of teeth of the first primary-stage reduction driving gear 314 of the first reducer 3 is the same as or different from the number of teeth of the second primary-stage reduction driving gear 414 of the second reducer 4, and the number of teeth of the first secondary-stage reduction driving gear 316 of the first reducer 3 is different from the number of teeth of the second secondary-stage reduction driving gear 416 of the second reducer 4.

[0119] Second embodiment

[0120] Figure 2 The electric drive assembly 100 provided by the second embodiment of the present application is mainly different from the first embodiment in that the electric drive assembly 100 is in the shape of H. 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 is coaxial with the second half shaft 6, and the axis direction of the first half shaft 5 and the second half shaft 6 passes through 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 on the left side of the first motor 1 and the second motor 2, and the second reducer 4 is arranged on the right side of the first motor 1 and the second motor 2.

[0121] In this embodiment, the housing of the first motor 1 and the housing of the second motor 2 are integrated to form a motor housing, and the housing of the first reducer 3 and the housing of the second reducer 4 are separately arranged and fixedly connected to the left and right sides of the motor housing.

[0122] ​The motor shaft of the second motor 2 is a hollow shaft, and a connecting shaft 8 is arranged in the motor shaft of the second motor 2. One end of the connecting shaft 8 is connected with the first output shaft 313, and the differential lock device 7 is connected between the other end of the connecting shaft 8 and the second output shaft 413. The motor shaft of the second motor 2, the connecting shaft 8, the first output shaft 313 and the first output shaft 413 are coaxial.

[0123] The second input shaft 411 is coaxially connected with the motor shaft of the second motor 2 or is integrally formed.

[0124] The differential lock device 7 is connected between the connecting shaft 8 and the inner end of the second output shaft 413, and the engagement and disengagement of the first half shaft 5 and the second half shaft 6 are realized by engaging or disengaging the connecting shaft 8 and the second output shaft 413.

[0125] The differential lock device 7 is integrated in the housing of the second reduction 4, and has higher integration and less space occupation.

[0126] Third embodiment

[0127] Figure 3 The electric drive assembly 100 provided by the third embodiment of the application is mainly different from the first embodiment in 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, and the axis of the first motor 1, the axis of the second motor 2 and the axes of the first half shaft 5 and the second half shaft 6 are arranged in a triangular manner.

[0128] 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.

[0129] In this embodiment, the housing of the first reducer 3, the housing of the second reducer 4, the housing of the first motor 1 and the housing of the second motor 2 are integrated.

[0130] Preferably, the first motor 1 is arranged below the second motor 2. The first reducer 3 is arranged close to the first wheel 200, and the second reducer 4 is arranged close to the second wheel 300.

[0131] Fourth embodiment

[0132] Figure 4The fourth embodiment of the application provides the electric drive assembly. The electric drive assembly 100 is different from the first embodiment in that the electric drive assembly 100 is in the shape of "one". 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 from left to right in sequence.

[0133] 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.

[0134] The electric drive assembly 300 further comprises 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 disconnect 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 disconnect the second input shaft 411 and the second output shaft 413.

[0135] When the first clutch device 91 is engaged, the power of the first motor 1 is transmitted to the first wheel 200 through 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 disconnected, the power of the first motor 1 is transmitted to the first wheel 200 through the first input shaft 311, the first primary reduction driving gear 314, the first primary reduction driven gear 315, the first secondary reduction driving gear 316, the first secondary reduction driven gear 317, the first output shaft 313 and the first half shaft 5. In this way, the first reducer 3 has two gears to select.

[0136] Similarly, when the second clutch device 92 is engaged, the power of the second motor 2 is transmitted to the second wheel 300 through the second input shaft 411, the second clutch device 92, the second output shaft 413 and the second half shaft 6. When the second clutch device 91 is disconnected, the power of the second motor 2 is transmitted to the second wheel 300 through the second input shaft 411, the second primary reduction driving gear 414, the second primary reduction driven gear 415, the second secondary reduction driving gear 416, the second secondary reduction driven gear 417, the second output shaft 413 and the second half shaft 6. In this way, the second reducer 3 has two gears to select.

[0137] In the embodiment, the housing of the first motor 1 and the housing of the second motor 2 are integrated to form a motor housing, the housing of the first reducer 3 and the housing of the second reducer 4 are separately arranged and fixedly connected to the left and right sides of the motor housing.

[0138] Fifth embodiment

[0139] Figure 5 The electric drive assembly 100 provided by the fifth embodiment of the present application is different from the first embodiment in 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, and the end surface area of the side of the reducer assembly 400 close to the first motor 1 and the second motor 2 is greater than the end surface area of the first motor 1 and the second motor 2. The reducer assembly 400 is arranged on the right side and is closer to the second wheel 300.

[0140] In the embodiment, the housing of the first motor 1 and the housing of the second motor 2 are integrated to form a motor housing, the housing of the first reducer 3 and the housing of the second reducer 4 are integrated to form a reducer housing, and the reducer housing and the motor housing are separately arranged and fixedly connected, that is, the motor housing is fixedly connected to the left side of the reducer housing.

[0141] 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 in sequence 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 sleeved on the second intermediate shaft 412.

[0142] Sixth embodiment

[0143] Figure 6 The electric drive assembly 100 provided by the sixth embodiment of the present application is different from the fifth embodiment in that the electric drive assembly 100 is arranged relative to Figure 5 The embodiment is mirror image arrangement. 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 side and is closer to the first wheel 200.

[0144] 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 sleeved on the first intermediate shaft 312.

[0145] The first speed reducer 3, the second speed reducer 4, the second motor 2 and the first motor 1 are arranged from left to right in sequence.

[0146] Seventh embodiment

[0147] Figure 7 The electric drive assembly 100 provided by the seventh embodiment of the present application is different from the first embodiment in that the first speed reducer 3 and the second speed reducer 4 have different numbers of stages, specifically, the first speed reducer 3 is a two-stage speed reducer, and the second speed reducer 3 is a three-stage speed reducer.

[0148] The first speed reducer 3 of the present embodiment is the same as that of the first embodiment. The second speed reducer 4 is different from that of the first embodiment.

[0149] The second speed reducer 4 is a second parallel-shaft gear speed reducer 41. The second parallel-shaft gear speed reducer 41 includes a second input shaft 411, a second first-stage intermediate shaft 412a, a second first-stage intermediate shaft 412b and a second output shaft 413, which are parallel and spaced apart from each other. The second input shaft 411 is coaxially connected with the motor shaft of the second motor 2, and the second output shaft 413 is coaxially connected with the second half shaft 6. The second input shaft 411 is provided with a second first-stage speed reducer driving gear 414, the second first-stage intermediate shaft 412a is provided with a second first-stage speed reducer driven gear 415 and a second second-stage speed reducer driving gear 416, the second first-stage intermediate shaft 412b is provided with a second second-stage speed reducer driven gear 417 and a second third-stage speed reducer driving gear 418, and the second output shaft 413 is provided with a second third-stage speed reducer driven gear 419. The second first-stage speed reducer driving gear 414 and the second first-stage speed reducer driven gear 415 are in meshing engagement to form a first-stage speed reducer gear set of the second speed reducer 4, the second second-stage speed reducer driving gear 416 and the second second-stage speed reducer driven gear 417 are in meshing engagement to form a second-stage speed reducer gear set of the second speed reducer 4, and the second third-stage speed reducer driving gear 418 and the second third-stage speed reducer driven gear 419 are in meshing engagement to form a third-stage speed reducer gear set of the second speed reducer 4.

[0150] In the present embodiment, the following can be true:

[0151] (1) The speed ratio of the first-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, and the speed ratio of the second-stage reduction gear set of the first reducer 3 is different from that of the third-stage reduction gear set of the second reducer 4. The product of the speed ratios of the respective-stage reduction gear sets of the first reducer 3 and the second reducer 4 is equal. The number of teeth of the first second-stage reduction driving gear 316 of the first reducer 3 is different from that of the second third-stage reduction driving gear 419 of the second reducer 4, and the number of teeth of the first first-stage reduction driving gear 314 of the first reducer 3 is the same as or different from that of the second second-stage reduction driving gear 416 of the second reducer 4.

[0152] (2) The speed ratio of the first-stage reduction gear set of the first reducer 3 is the same as that of the second-stage reduction gear set of the second reducer 4, and the speed ratio of the second-stage reduction gear set of the first reducer 3 is different from that of the third-stage reduction gear set of the second reducer 4. The product of the speed ratios of the respective-stage reduction gear sets of the first reducer 3 and the second reducer 4 is equal. The number of teeth of the first second-stage reduction driving gear 316 of the first reducer 3 is different from that of the second third-stage reduction driving gear 419 of the second reducer 4, and the number of teeth of the first first-stage reduction driving gear 314 of the first reducer 3 is the same as or different from that of the second second-stage reduction driving gear 416 of the second reducer 4.

[0153] (3) The speed ratio of the first-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, and the speed ratio of the second-stage reduction gear set of the first reducer 3 is the same as that of the third-stage reduction gear set of the second reducer 4. The product of the speed ratios of the respective-stage reduction gear sets of the first reducer 3 and the second reducer 4 is equal. The number of teeth of the first second-stage reduction driving gear 316 of the first reducer 3 is different from that of the second third-stage reduction driving gear 419 of the second reducer 4, and the number of teeth of the first first-stage reduction driving gear 314 of the first reducer 3 is the same as or different from that of the second second-stage reduction driving gear 416 of the second reducer 4.

[0154] Eighth Embodiment

[0155] Figure 8 The electric drive assembly 100 provided by the eighth embodiment of the present application is different from the fourth embodiment in 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 the two sides of the first motor 1 and the second motor 2, and the first planetary gear reducer 32, the second planetary gear reducer 42, the first motor 1 and the second motor 2 are coaxially arranged. The first reducer 3, the first motor 1, the second motor 2 and the second reducer 4 are arranged in sequence from left to right.

[0156] The first planetary gear reducer 32 and the second planetary gear reducer 42 are both two-stage reducers.

[0157] The first planetary gear reducer 32 comprises a first input element, a first output element and a first intermediate element, and the second planetary gear reducer 42 comprises 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.

[0158] Specifically, the first planetary gear reducer 32 is a planetary gear train composed 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 rotationally supported on the first planetary carrier 323 and is engaged 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 reducer 32.

[0159] The second planetary gear reducer 42 is a planetary gear train composed 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 rotationally supported on the second planetary carrier 423 and is engaged 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 reducer 42.

[0160] In this embodiment, the housing of the first motor 1 and the housing of the second motor 2 are integrated to form a motor housing, and the housing of the first reducer 3 and the housing of the second reducer 4 are separately arranged and fixedly connected to the left and right sides of the motor housing.

[0161] In order to realize two-stage reduction of the first reducer 3, the first planetary gear 322 comprises a first large planetary gear 3221 coaxially connected with a first small planetary gear 3222 with a smaller diameter than the first large planetary gear 3221, the first large planetary gear 3221 is engaged with the first sun gear 321, and the first small planetary gear 3222 is engaged with the first ring gear 324.

[0162] In order to realize two-stage reduction of the second reducer 4, the second planetary gear 422 comprises a second large planetary gear 4221 coaxially connected with a second small planetary gear 4222 with a smaller diameter than the second large planetary gear 4221, the second large planetary gear 4221 is engaged with the second sun gear 421, and the second small planetary gear 4222 is engaged with the second ring gear 424.

[0163] The two-stage speed ratio design of the first reducer 3 and the second reducer 4 can realize a larger range of speed ratio design, so that the two motors can work in the high-efficiency speed range.

[0164] Ninth embodiment

[0165] Figure 9 The electric drive assembly 100 provided by the ninth embodiment of the present application is different from the eighth embodiment in that the first motor 1 and the second motor 2 are located on the two 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 in sequence from left to right.

[0166] The electric drive assembly 100 further comprises a first connecting shaft 8a and a second connecting shaft 8b, the motor shaft of the first motor 1 is a hollow shaft, 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 with the first half shaft 5, the inner end of the first connecting shaft 8a is connected with 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 with the second half shaft 6, and the inner end of the second connecting shaft 8b is connected with 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.

[0167] 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, and the housing of the first motor 1 and the housing of the second motor 2 are separately arranged and fixedly connected on the left and right sides of the reducer housing.

[0168] Reference is made to Figure 20In some embodiments, the modulus of the driving gear of the stage of the reduction gear set with the same speed ratio of the first and second reducers is the same, and the shafts on which the driving gears of the stage of the reduction gear set with the same speed ratio of the first and second reducers are arranged are staggered in parallel. That is, Figure 20 In some embodiments, the first intermediate shaft 312 of the first reducer and the second intermediate shaft 412 of the second reducer are staggered in parallel, the first motor and the second motor are coaxial on Z1, the first axle and the second axle are coaxial on Z2, and Z1, Z2, the first intermediate shaft 312 and the second intermediate shaft 412 are arranged in a quadrilateral.

[0169] Referring to Figure 10 The embodiments of the present application also provide a four-wheel drive system 1000, which comprises a front drive axle 501 and a rear drive axle 502, and the front drive axle 501 and the rear drive axle 502 are both provided with the electric drive assembly 100.

[0170] Referring to Figure 11 The embodiments of the present application also provide a vehicle 10000, which comprises the electric drive assembly 100 or the four-wheel drive system 1000.

[0171] The above only describes the preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present 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. At least one of the first reducer and the second reducer is a multi-stage reduction gear. The speed ratio of the first reducer is the same as that of the second reducer. The number of teeth of the driving gear of the last stage reduction gear set of the first reducer is different from that of the driving gear of the last stage reduction gear set of the second reducer. 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. The meshing frequency of the last stage reduction gear set of the first reducer The meshing frequency with the last stage reduction gear set of the second reducer Decoupling rate between Greater than 8%, the meshing frequency of the last stage reduction gear set of the first reducer This indicates the number of times the last stage reduction gear of the first reducer engages during one revolution of the first motor, and the meshing frequency of the last stage reduction gear of the second reducer. The decoupling rate represents the number of times the last stage reduction gear set of the second reducer engages during one revolution of the second motor; This can be expressed by formula (1): （1）； in, This indicates the meshing frequency of the last stage reduction gear set of the first reducer. This indicates the meshing frequency of the last stage reduction gear set in the second reducer; Indicates taking and The absolute value of the difference Indicates taking and The maximum value in.

2. The electric drive assembly according to claim 1, characterized in that, The electric drive assembly also 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.

3. The electric drive assembly according to claim 1, characterized in that, The first reducer is a multi-stage reducer, and the second reducer is also a multi-stage reducer; The first reducer and the second reducer have the same number of reduction stages, and the first reducer and the second reducer have at least one stage with the same speed ratio. Furthermore, the number of teeth on the driving gear of the reduction gear set with the same speed ratio in the first reducer and the second reducer are different.

4. The electric drive assembly according to claim 3, characterized in that, The driving gears of the same speed reduction gear set with the same speed ratio as the first reducer and the second reducer have the same module, and the shafts where the driving gears of the same speed reduction gear set with the same speed ratio as the first reducer and the second reducer are located are parallel and offset. or, The first reducer and the second reducer have the same speed ratio but different driving gears with different modules, and the driving gears of the first reducer and the second reducer have parallel but offset or coaxial axes.

5. The electric drive assembly according to claim 1, characterized in that, The first reducer and the second reducer have different numbers of reduction stages.

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

7. The electric drive assembly according to claim 1, characterized in that, 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. or, 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. The axial directions of the first half-shaft and the second half-shaft pass through the first motor or the second motor. or, 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. 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. or, 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; or, The first reducer and the second reducer together constitute 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. The first motor and the second motor are arranged in parallel or coaxially.

8. The electric drive assembly according to claim 1, characterized in that, The first reducer is a first planetary gear reducer, and the second reducer is a second planetary gear reducer; or, The first reducer is a first parallel shaft gear reducer, and the second reducer is a second parallel shaft gear reducer.

9. A four-wheel drive system, characterized in that, It includes a front drive axle and a rear drive axle, and both the front drive axle and the rear drive axle are provided with the electric drive assembly as described in any one of claims 1-8.

10. A vehicle, characterized in that, Includes the electric drive assembly as described in any one of claims 1-8 or the four-wheel drive system as described in claim 9.

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