Electric drive assembly, four-wheel drive system and vehicle

Abstract

The invention relates to an electric drive assembly, a four-wheel drive system and a vehicle. The electric drive assembly comprises 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 and the second speed reducer are both multi-stage speed reduction and are the same in stage number, the speed ratio of the first speed reducer and the speed ratio of the second speed reducer are the same, and a shell of the first speed reducer, a shell of the second speed reducer, a shell of the first motor and a shell of the second motor are arranged in a split mode and fixedly connected together. According to the electric drive assembly, the problem of abnormal jittering or buzzing abnormal sound of an existing drive system which is independently driven by double motors in a concentrated mode on the wheel edge can be effectively solved.

Description

[0001] This application is a divisional application of the Chinese patent application submitted to the China Patent Office on August 31, 2022, with application number 202211063839.0 and invention name "Electric drive assembly, four-wheel drive system and vehicle". Technical Field

[0002] The present 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 Art

[0003] The torque and speed of the left and right wheels of the dual-motor independently driven car can be accurately controlled independently, which brings a series of advantages, such as achieving a smaller radius turn, assisting ESP function, assisting steering function and assisting braking function, thereby improving the vehicle's handling performance. At the same time, the independently driven motor can achieve higher power and stronger escape performance.

[0004] However, compared with a drive system driven by a single motor, a centrally arranged dual-motor wheel-side independent drive system sometimes has problems with abnormal shaking or buzzing noise that affects the comfort of the entire vehicle. Summary of the invention

[0005] The technical problem to be solved by the present application is: in view of the existing centralized dual-motor wheel-side independent drive system, which sometimes has abnormal shaking or buzzing noise that affects the comfort of the entire vehicle, an electric drive assembly, a four-wheel drive system and a vehicle are provided.

[0006] To solve the above technical problems, on the one hand, the present 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, wherein 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] The first reducer and the second reducer are both multi-stage reducers with the same number of stages, the speed ratio of the first reducer is the same as the speed ratio of the second reducer, and the speed ratio of at least two stages of the reduction gear set of the first reducer is different from the speed ratio of the reduction gear set corresponding to at least two stages of the second reducer;

[0008] 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 separately arranged and fixedly connected together; or, 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 into one.

[0009] In the electric drive assembly of the embodiment of the present application, the first reducer and the second reducer are both multi-stage reduction gears with the same number of stages. In the vehicle width direction, the speed ratios of the first reducer and the second reducer on the left and right sides are the same, and the speed ratios of at least two stages of the reduction gear sets of the first reducer are different from the speed ratios of at least two stages of the reduction gear sets corresponding to the second reducer, that is, at least two stages of the reduction gear sets of the first reducer and the second reducer have the following characteristics: the speed ratio of one stage of the reduction gear set of the first reducer is greater than the speed ratio of one stage of the reduction gear set of the second reducer, and the speed ratio of the other stage of the reduction gear set of the first reducer is less than the speed ratio of the other stage of the reduction gear set of the second reducer. In this way, there is a large difference in the noise frequency generated by the movement of the driving gear of the last stage of the reduction gear set of the first reducer and the driving gear of the last stage of the reduction gear set of the second reducer. After superposition, the noise waveform frequency is high, which can effectively solve the abnormal shaking or humming problem of the existing centralized dual-motor wheel-side independent drive drive system, provide a good driving experience, and improve the comfort of the whole vehicle.

[0010] On the other hand, an embodiment of the present application further provides a four-wheel drive system, including a front drive axle and a rear drive axle, and the front drive axle and the rear drive axle are both provided with the above-mentioned electric drive assembly.

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

[0012] On the other hand, an embodiment of the present application further provides a vehicle, which includes the above-mentioned electric drive assembly or four-wheel drive system.

[0013] The four-wheel drive system of the embodiment of the present application has all the advantages of the above-mentioned electric drive assembly. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

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

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

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

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

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

[0023] Fig.10 is a schematic diagram of a vehicle provided in an embodiment of the present application;

[0024] Fig.11 It is a gear noise waveform diagram of the left reducer of the existing centrally arranged dual-motor wheel-side independent drive drive system;

[0025] Fig.12 It is a gear noise waveform diagram of the right reducer of the existing centrally arranged dual-motor wheel-side independent drive drive system;

[0026] Fig.13 It is a waveform diagram of the gear noise of the left reducer and the gear noise of the right reducer in the same time domain of the existing centrally arranged dual-motor wheel-side independent drive drive system;

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

[0028] Fig.15 is a gear noise waveform diagram of the first reducer of the electric drive assembly of an embodiment of the present application;

[0029] Fig.16 is a gear noise waveform diagram of the second reducer of the electric drive assembly of an embodiment of the present application;

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

[0031] Fig.18 It is a waveform diagram of the superposition of the gear noise of the first reducer and the gear noise of the second reducer of the electric drive assembly of the embodiment of the present application.

[0032] The reference numerals in the specification 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, cavity; 501, front drive axle; 502, rear drive axle;

[0034] 1. First motor; 2. Second motor; 3. First reducer; 31. First parallel axis 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 planetary gear; 3221. First large planetary gear; 3222. First small planetary gear; 323. First planet carrier; 324. First ring gear; 4. Second reducer; 41. Second parallel axis gear reducer; 411. Second input shaft; 412. Second intermediate shaft 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; 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 planet 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

[0035] In order to make the technical problems, technical solutions and beneficial effects solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0036] Compared with a drive system with a single motor driving the wheel, a centrally arranged dual-motor wheel-side independent drive system sometimes has problems with abnormal shaking or buzzing noise that affects the comfort of the entire vehicle.

[0037] The inventor of the present invention has found through research and analysis that this is because the working conditions of the centrally arranged left and right motors and reducers cannot be kept completely consistent during operation, thus generating the "beat frequency" phenomenon. Figures 11 to 13 , assuming that the gear noise waveform of the left reducer and the gear noise waveform of the right reducer of the existing centralized dual-motor wheel-side independent drive system are standard sine waves with different frequencies and the same amplitude, and the difference between the left and right noise waveforms is 2% (see Fig.13 ). See Fig.14 The gear noise of the left reducer and the gear noise of the right reducer are superimposed to synthesize a new low-frequency noise waveform. The whole vehicle exhibits a low "buzzing" sound, which means a "beat frequency" problem occurs.

[0038] The electric drive assembly provided in the embodiment of the present application includes a first motor, a second motor, a first reducer, a second reducer, a first half-shaft and a second half-shaft, wherein 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;

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

[0040] 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 separately arranged and fixedly connected together; or, 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 into one.

[0041] The speed ratio of at least two stages of reduction gear sets of the first reducer is different from the speed ratio of at least two stages of reduction gear sets corresponding to the second reducer, that is, at least two stages of reduction gear sets of the first reducer and the second reducer have the following characteristics: the speed ratio of one stage of reduction gear set of the first reducer is greater than the speed ratio of one stage of reduction gear set of the second reducer, and the speed ratio of another stage of reduction gear set of the first reducer is less than the speed ratio of another stage of reduction gear set of the second reducer. There are several situations as follows:

[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. In this case, the number of stages of the first reducer and the second reducer is three or more. Among the multi-stage reduction gear sets before the last 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.

[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 number of stages of the first reducer and the second reducer is more than two. The speed ratios of the reduction gear sets of each stage of the first reducer and the second reducer are all 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 number of stages of the first reducer and the second reducer is three or more. The speed ratios of the reduction gear sets of each stage of the first reducer and the second reducer are at least one the same, and at least two stages of the multi-stage reduction gear sets of the first reducer and the second reducer 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 the embodiment of the present application, the first reducer and the second reducer are both multi-stage reduction gears with the same number of stages. In the vehicle width direction, the speed ratios of the first reducer and the second reducer on the left and right sides are the same, and the speed ratios of at least two stages of the reduction gear sets of the first reducer are different from the speed ratios of at least two stages of the reduction gear sets corresponding to the second reducer, that is, at least two stages of the reduction gear sets of the first reducer and the second reducer have the following characteristics: the speed ratio of one stage of the reduction gear set of the first reducer is greater than the speed ratio of one stage of the reduction gear set of the second reducer, and the speed ratio of the other stage of the reduction gear set of the first reducer is less than the speed ratio of the other stage of the reduction gear set of the second reducer. In this way, there is a large difference in the noise frequency generated by the movement of the driving gear of the last stage of the reduction gear set of the first reducer and the driving gear of the last stage of the reduction gear set of the second reducer. After superposition, the noise waveform frequency is high, which can effectively solve the abnormal shaking or humming problem of the existing centralized dual-motor wheel-side independent drive drive system, provide a good driving experience, and improve the comfort of the whole vehicle.

[0046] See also Figures 15 to 17 The gear noise waveform of the left reducer (first reducer) and the gear noise waveform of the right reducer (second reducer) of the electric drive assembly of the embodiment of the present application are standard sine waves with different frequencies and the same amplitude. Since the speed ratio of the at least two-stage reduction gear set of the first reducer is different from the speed ratio of the at least two-stage reduction gear set corresponding to the second reducer, the left and right noise waveforms are quite different (see Fig.17 ). See Fig.18The gear noise of the left reducer and the gear noise of the right reducer are superimposed to synthesize a new noise waveform. When the gear noise frequency of the left reducer and the gear noise frequency of the right reducer are greatly different, the synthesized new waveform has a high frequency, which avoids the low "buzzing" sound of the whole vehicle, solves the "beat frequency" problem, improves the driving experience, and improves the comfort of the whole vehicle.

[0047] Herein, 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.

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

[0049] In some embodiments, the driving gear of the last-stage reduction gear set of the first reducer and the driving gear of the last-stage reduction gear set of the second reducer have different numbers of teeth.

[0050] In some other embodiments, the driving gear of the last-stage reduction gear set of the first reducer and the driving gear of the last-stage reduction gear set of the second reducer have the same number of teeth.

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

[0052] In some embodiments, the electric drive assembly further includes a differential locking device, wherein the differential locking device is connected between the first half-shaft and the second half-shaft and is used to selectively engage or disengage the first half-shaft and the second half-shaft.

[0053] In other embodiments, the differential locking device may also be eliminated.

[0054] In some embodiments, the rated speed and rated torque of the first motor are the same as those of the second motor.

[0055] In other embodiments, the output upper limit of the motor corresponding to the one with the larger speed ratio between the first reducer and the second reducer is higher. That is, when the speed ratio of the first reducer is greater than the speed ratio 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 the speed ratio 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 represents the number of times the last stage reduction gear set of the first reducer is engaged when the first motor rotates one circle, and the meshing frequency f of the last stage reduction gear set of the second reducer is y represents the number of times the last stage reduction gear set of the second reducer is engaged when the second motor rotates one circle; the decoupling rate σ is expressed by formula (1):

[0057]

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

[0059] f z It is expressed by formula (2):

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

[0061] In formula (2), Z nzz Indicates the number of teeth of the driving gear (pinion) of the last stage reduction gear set of the first reducer, (i (n-1)z *......i 1z ) represents the cumulative speed ratio of each stage of deceleration before the last stage of deceleration of the first reducer.

[0062] f y It is expressed by formula (3):

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

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

[0065] 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 independent and fixedly connected together. The fixed connection herein may be bolt connection or riveting.

[0066] In some 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 (the independently arranged part) is fixedly connected to the integrated part. There are 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.

[0068] (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.

[0069] (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. 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 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.

[0071] (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 is separately provided and fixedly connected to the integrated housing.

[0072] (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 is separately provided and fixedly connected to the integrated housing.

[0073] (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.

[0074] (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. 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 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.

[0076] In some embodiments, in the vehicle width direction, the first speed reducer and the second speed 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 width direction of the vehicle, 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 direction of the first half-shaft and the second half-shaft passes 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 some 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 width direction of the vehicle, 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, among the multi-stage reduction of the first reducer, part is parallel shaft gear reduction and part is planetary gear reduction.

[0084] In other embodiments, among the multi-stage reduction of the second reducer, part is parallel shaft gear reduction and part is planetary gear reduction.

[0085] The present application is described in detail below with reference to the accompanying drawings and multiple embodiments.

[0086] First embodiment

[0087] See also Figure 1 The electric drive assembly 100 provided in the first embodiment of the present 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, 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 the first wheel 200, and the outer end of the second half-shaft 6 is connected to the second wheel 300. The first wheel 200 is a left wheel, denoted by W1 in the figure. The second wheel 200 is a 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] In the electric drive assembly 100 of the first embodiment of the present application, both the first reducer 3 and the second reducer 4 are multi-stage reduction gears. 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 speed ratios of at least two stages of the reduction gear sets of the first reducer 3 are different from the speed ratios of at least two stages of the reduction gear sets corresponding to the second reducer 4, that is, at least two stages of the reduction gear sets of the first reducer 3 and the second reducer 4 have the following characteristics: the speed ratio of one stage of the reduction gear set of the first reducer 3 is greater than the speed ratio of one stage of the reduction gear set of the second reducer 4, and the speed ratio of the other stage of the reduction gear set of the first reducer 3 is less than the speed ratio of the other stage of the reduction gear set of the second reducer 4. In this way, there is a large difference in the noise frequency generated by the movement of the driving gear of the last stage of the reduction gear set of the first reducer 3 and the driving gear of the last stage of the reduction gear set of the second reducer 4. After superposition, the noise waveform frequency is high, which can effectively solve the abnormal shaking or humming problem of the existing centralized dual-motor wheel-side independent drive drive system, and the driving experience is good, which improves the comfort of the whole vehicle.

[0089] In this embodiment, the driving gear of the last stage reduction gear set of the first reducer 3 and the driving gear of the last stage reduction gear set of the second reducer 4 have different numbers of teeth.

[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 disconnect the first half-shaft 5 and the second half-shaft 6 .

[0091] The differential locking device 7 can be a clutch, a brake or a synchronizer. In this embodiment, a synchronizer is preferred. Through the engagement and disengagement of the differential locking device 5, equal torque and equal speed output of the first half shaft 5 and the second half shaft 6 under special working conditions can be achieved, so that the vehicle can get out of 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 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. 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.

[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 close to 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 close to the second motor 2 is larger than the end face area of ​​the second motor 2, so that the electric drive assembly 100 is 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, 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.

[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 axis gear reducer 31 comprises 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 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 primary reduction driving gear 314 is arranged on the first input shaft 311, a first primary reduction driven gear 315 and a first secondary reduction driving gear 316 (driving gear of the last stage reduction gear set of the first reducer 3) are arranged on the first intermediate shaft 312, and a first secondary reduction driven gear 317 is arranged on the first output shaft 313. The first primary reduction driving gear 314 meshes with the first primary reduction driven gear 315 to form the first stage reduction gear set of the first reducer 3, and the first secondary reduction driving gear 316 meshes with the first secondary reduction driven gear 317 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 a smaller number of 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 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 primary reduction driving gear 414 is provided on the second input shaft 411, a second primary reduction driven gear 415 and a second secondary reduction driving gear 416 (driving gear of the last stage reduction gear set of the second reducer 4) are provided on the second intermediate shaft 412, and a second secondary reduction driven gear 417 is provided on the second output shaft 413. The second primary reduction driving gear 414 meshes with the second primary reduction driven gear 415 to form the first stage reduction gear set of the second reducer 4, and the second secondary reduction driving gear 416 meshes with the second secondary reduction driven gear 417 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 a smaller number of 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 , and achieves engagement and disconnection of the first half shaft 5 and the second half shaft 6 by engaging or disconnecting the inner end of the first output shaft 313 and the second output shaft 413 .

[0100] The differential locking device 7 is integrated in the housings of the first reducer 3 and the second reducer 4, with a higher degree of integration and less space occupied.

[0101] In the first embodiment, the meshing frequency f of the last stage reduction gear set of the first reducer 3 (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 represents the number of times the last stage reduction gear set of the first reducer 3 is engaged when the first motor 1 rotates one circle, and the meshing frequency f of the last stage reduction gear set of the second reducer 4 is y represents the number of times the last stage reduction gear set of the second reducer 4 is engaged when the second motor 2 rotates one circle; the decoupling rate σ is expressed by formula (1):

[0102]

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

[0104] f z It is expressed by formula (2):

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

[0106] In formula (2), Z nzz Indicates the number of teeth of the driving gear (pinion) of the last stage reduction gear set of the first reducer 3, (i (n-1)z *......i 1z ) represents the cumulative multiplication of the speed ratios of the various stages of deceleration before the last stage of deceleration of the first reducer 3. Here, n is equal to 2. Then:

[0107]

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

[0109] f y It is expressed by formula (3):

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

[0111] In formula (3), Z myz Indicates the number of teeth of the driving gear (pinion) of the last stage reduction gear set of the second reducer, (i (m-1)y *......i 1y ) represents the cumulative multiplication of the speed ratios of the various stages of deceleration before the last stage of deceleration of the second reducer. Here, m is greater than 2. Then:

[0112]

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

[0114] Through simulation, it is found 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 shaking or buzzing 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 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 speed ratio of the first stage reduction gear set of the first reducer 3 is greater than 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 less than the speed ratio of the first stage reduction gear set of the second reducer 4. The cumulative product of the speed ratios of the various stages of the reduction gear sets of the first reducer 3 and the second reducer 4 is equal. The number of teeth of the first primary reduction driving gear 314 of the first reducer 3 and the second primary reduction driving gear 414 of the second reducer 4 are the same or different, and the number of teeth of the first secondary reduction driving gear 316 of the first reducer 3 and the second secondary reduction driving 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 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 speed ratio of the first stage reduction gear set of the first reducer 3 is smaller than 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 larger than the speed ratio of the first stage reduction gear set of the second reducer 4. The cumulative product of the speed ratios of the various stages of the reduction gear sets of the first reducer 3 and the second reducer 4 is equal. The number of teeth of the first primary reduction driving gear 314 of the first reducer 3 and the second primary reduction driving gear 414 of the second reducer 4 are the same or different, and the number of teeth of the first secondary reduction driving gear 316 of the first reducer 3 and the second secondary reduction driving gear 416 of the second reducer 4 are the same or different.

[0118] Second embodiment

[0119] Figure 2 The electric drive assembly 100 provided in the second embodiment of the present application is shown. The main difference between the electric drive assembly 100 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 semi-shaft 5 are arranged in parallel, the first semi-shaft 5 is coaxial with the second semi-shaft 6, and the axis direction of the first semi-shaft 5 and the second semi-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.

[0120] 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.

[0121] The motor shaft of the second motor 2 is a hollow shaft, a connecting shaft 8 is arranged 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 second output shaft 413 and the other end of the connecting shaft 8. 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.

[0122] The second input shaft 411 is coaxially connected to the motor shaft of the second motor 2 or is formed integrally therewith.

[0123] The differential locking device 7 is connected between the connecting shaft 8 and the inner end of the second output shaft 413 , and the first half shaft 5 and the second half shaft 6 are engaged or disconnected by engaging or disconnecting the connecting shaft 8 and the second output shaft 413 .

[0124] The differential locking device 7 is integrated in the housing of the second reduction gear 4, with a higher degree of integration and less space occupied.

[0125] Third embodiment

[0126] Figure 3 The third embodiment of the present application is shown as an electric drive assembly 100, which 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 is coaxial with the second half-shaft 6, and 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, and 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 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 into one.

[0129] 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.

[0130] Fourth embodiment

[0131] Figure 4 The electric drive assembly provided in the fourth embodiment of the present application is different from the first embodiment in that the electric drive assembly 100 is in the shape of a "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 semi-shaft 5 and the second semi-shaft 6 are coaxial. 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.

[0132] The first input shaft 311 is coaxial with the first output shaft 313 , and the first intermediate shaft 312 is parallel to and spaced 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 to and spaced 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 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.

[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 disconnected, the power of the first motor 1 is transmitted to the first wheel 200 via 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 choose from.

[0135] Similarly, when the second clutch device 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 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 via 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 choose from.

[0136] 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.

[0137] Fifth embodiment

[0138] Figure 5 The electric drive assembly 100 provided in 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 reducer assembly 400 close to the first motor 1 and the second motor 2 is larger than the end surface 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 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 integrated to form a reducer housing. 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.

[0140] The first motor 1 is coaxially arranged with the second motor 2, and the second motor 2, the first motor 1, the first reducer 3 and the second reducer 4 are arranged 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 with the motor shaft of the first motor 1. The first intermediate shaft 312 is a hollow shaft and is loosely sleeved on the second intermediate shaft 412.

[0141] Sixth embodiment

[0142] Figure 6 The electric drive assembly 100 provided in the sixth embodiment of the present application is different from the fifth embodiment in that the electric drive assembly 100 is Figure 5 The embodiment shown is arranged in a mirror image. 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 sleeved on 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 in sequence from left to right.

[0145] Seventh embodiment

[0146] Figure 7 The electric drive assembly 100 provided in the seventh 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 both 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.

[0147] The first planetary gear reducer 32 and the second planetary gear reducer 42 are both 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, and the second planetary gear reduction mechanism 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 row composed of a first sun gear 321, a first planetary gear 322, a first planet 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 planet carrier 323, the first intermediate element is the first ring gear 324, the first planetary gear 322 is rotatably supported on the first planet carrier 323, and the first planetary gear 322 is meshed between the first sun gear 321 and the first ring gear 324. The first planet 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 row composed of a second sun gear 421, a second planetary gear 422, a second planet 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 planet carrier 423, the second intermediate element is the second ring gear 424, the second planetary gear 422 is rotatably supported on the second planet carrier 423, and the second planetary gear 422 is meshed between the second sun gear 421 and the second ring gear 424. The second planet 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 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.

[0152] In order to achieve two-stage reduction in speed of the first reducer 3 , the first planetary gear 322 includes a coaxially connected first large planetary gear 3221 and a first small planetary gear 3222 having a diameter smaller than that of the first large planetary gear 3221 , the first large planetary gear 3221 is meshed with the first sun gear 321 , and the first small planetary gear 3222 is meshed with the first ring gear 324 .

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

[0154] The two-speed ratio design of the first reducer 3 and the second reducer 4 can realize a relatively large range of speed ratio design, so that the two motors can operate in a high-efficiency speed range.

[0155] Eighth embodiment

[0156] Figure 8 The electric drive assembly 100 provided in the ninth embodiment of the present application is different from the seventh embodiment in 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 in sequence 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, and the outer end of the first connecting shaft 8a is connected to the first semi-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, and the outer end of the second connecting shaft 8b is connected to the second semi-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 semi-shaft 5, the second semi-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, 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.

[0159] See also Fig. 9 The embodiment of the present application further provides a four-wheel drive system 1000, including 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 above-mentioned electric drive assembly 100.

[0160] See also Fig.10 , an embodiment of the present application also provides a vehicle 10000 , including the above-mentioned electric drive assembly 100 or four-wheel drive system 1000 .

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

Claims

1. An electric drive assembly, characterized in that: The invention comprises a first motor, a second motor, a first reducer, a second reducer, a first half-shaft and a second half-shaft, wherein 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; The first reducer and the second reducer are both multi-stage reducers with the same number of stages. The speed ratio of the first reducer is the same as the speed ratio of the second reducer. 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 separately arranged and fixedly connected together.

2. The electric drive assembly according to claim 1, characterized in that: The rated speeds of the first motor and the second motor are the same.

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

4. The electric drive assembly according to claim 1, characterized in that: The meshing frequency f of the last stage reduction gear set of the first reducer z The meshing frequency f with the last stage reduction gear set of the second reducer y The decoupling rate σ between the first reducer and the last stage reduction gear set is greater than 8%, wherein the decoupling rate σ is based on the meshing frequency f of the last stage reduction gear set of the first reducer. z The meshing frequency f with the last stage reduction gear set of the second reducer y Sure.

5. The electric drive assembly according to claim 4, characterized in that: The meshing frequency f of the last stage reduction gear set of the first reducer z represents the number of times the last stage reduction gear set of the first reducer is engaged when the first motor rotates one circle, and the meshing frequency f of the last stage reduction gear set of the second reducer is y represents the number of times the last stage reduction gear set of the second reducer is engaged when the second motor rotates one circle; the decoupling rate σ is expressed by formula (1): Among them, f z represents the meshing frequency of the last stage reduction gear set of the first reducer, f y represents the meshing frequency of the last stage reduction gear set of the second reducer; abs(f z -f y ) means taking f z With f y The absolute value of the difference, max(f z , f y ) means taking f z With f y The maximum value in .

6. The electric drive assembly according to claim 5, characterized in that: f z It is expressed by formula (2): f z =Z nzz *(i (n-1)z *......i 1z ) (2); In formula (2), Z nzz represents the number of teeth of the driving gear of the last stage reduction gear set of the first reducer, (i (n-1)z *......i 1z ) represents the cumulative product of the speed ratios of each stage of deceleration before the last stage of deceleration of the first reducer.

7. The electric drive assembly according to claim 6, characterized in that: In formula (4), Z 2zz Indicates the number of teeth of the first and second reduction driving gears, Z 1zz Indicates the number of teeth of the first stage reduction driving gear, Z 1zc Indicates the number of teeth of the first stage reduction driven gear, i 1z Indicates the speed ratio of the first stage reduction of the first reducer.

8. The electric drive assembly according to claim 5, characterized in that: f y It is expressed by formula (3): f y =Z myz *(i (m-1)y *......i 1y ) (3); In formula (3), Z myz represents the number of teeth of the driving gear of the last stage reduction gear set of the second reducer, (i (m-1)y *......i 1y ) represents the cumulative speed ratio of each stage of deceleration before the last stage of deceleration of the second reducer.

9. The electric drive assembly according to claim 8, characterized in that: In formula (5), Z 2yz Indicates the number of teeth of the second secondary reduction driving gear, Z 1yz Indicates the number of teeth of the second first-stage reduction driving gear, Z 1yc represents the number of teeth of the second first-stage reduction driven gear, and i1 represents the speed ratio of the first-stage reduction of the second reducer.

10. 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 reducer and the second reducer, the first motor, the second motor and the first half shaft are arranged in parallel, and the axial direction of the first half shaft and the second half shaft passes through the second motor.

11. The electric drive assembly according to claim 1 or 10, characterized in that: The first motor and the second motor are arranged between the first speed reducer and the second speed reducer in the vehicle width direction, and the first motor, the second motor, the first half shaft, and the second half shaft are coaxial.

12. 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; 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 the first planetary gear reducer, the second planetary gear reducer, the first motor and the second motor are coaxially arranged.

13. The electric drive assembly according to claim 12, characterized in that: The first planetary gear reducer comprises 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 an input end of the first planetary gear reducer, and the first output element is an output end of the first planetary gear reducer.

14. The electric drive assembly according to claim 13, characterized in that: The first planetary gear reduction mechanism is a planetary row composed 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 is meshed 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.

15. The electric drive assembly according to claim 14, characterized in that: The first planetary gear includes a first large planetary gear and a first small planetary gear with a smaller diameter than the first large planetary gear, the first large planetary gear is meshed with the first sun gear, and the first small planetary gear is meshed with the first ring gear.

16. The electric drive assembly according to claim 12, characterized in that: The second planetary gear reducer comprises 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 an input end of the second planetary gear reducer, and the second output element is an output end of the second planetary gear reducer.

17. The electric drive assembly according to claim 16, characterized in that: The second planetary gear reduction mechanism is a planetary row composed of a second sun gear, a second planetary 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, the second intermediate element is the second ring gear, the second planetary gear is rotatably supported on the second planet carrier, and the second planetary gear is meshed 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.

18. The electric drive assembly according to claim 17, characterized in that: The second planetary gear includes a coaxially connected second large planetary gear and a second small planetary gear with a diameter smaller than that of the second large planetary gear. The second large planetary gear is meshed with the second sun gear, and the second small planetary gear is meshed with the second ring gear.

19. The electric drive assembly according to claim 1, characterized in that: The first reducer and the second reducer are both two-stage reduction gears.

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

21. The electric drive assembly according to claim 1, characterized in that: The electric drive assembly is in the shape of a line, and the first reducer, the first motor, the second motor, and the second reducer are arranged in sequence from left to right.

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

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

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

25. A four-wheel drive system, characterized in that: It comprises a front drive axle and a rear drive axle, and 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: It includes the electric drive assembly according to any one of claims 1 to 24 or the four-wheel drive system according to claim 25.

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