Noise reduction shaft system of new energy automobile electric drive assembly

Abstract

The noise reduction shaft system of the new energy automobile electric drive assembly comprises a motor shaft, an input shaft, an intermediate shaft and a differential mechanism, the motor shaft and the input shaft are connected in a matched mode through a spline, the input shaft and the intermediate shaft as well as the intermediate shaft and the differential mechanism are in transmission through gear pairs, and a lightening hole is formed in the motor shaft. And a motor shaft viscoelastic damping layer is arranged on the surface of the lightening hole. Compared with the prior art, the motor shaft has the advantages that the lightening holes are formed in the motor shaft, so that the motor shaft can be lightened; a motor shaft viscoelastic damping layer is arranged on the surface of the lightening hole, when motor exciting force is coupled with a motor shaft mode, a resonance effect is generated, a molecular chain of the motor shaft viscoelastic damping layer extends to consume energy, and the vibration resistance is good; the input shaft viscoelastic damping layer is arranged in the input shaft, and the intermediate shaft viscoelastic damping layer is arranged in the intermediate shaft, so that the high-order harmonic content vibration amplitude generated by dynamic meshing force coupling shaft shearing and torsional deformation generated by gear meshing can be attenuated.

Description

Technical Field

[0001] The utility model relates to an electric drive assembly, in particular to a noise-reducing shafting for an electric drive assembly of a new energy vehicle. Background Technique

[0002] In recent years, new energy electric vehicles have developed rapidly, and users and vehicle manufacturers have higher and higher requirements for various performances of new energy electric vehicles. As the power "heart" of new energy electric vehicles, in addition to high requirements for power density and efficiency, the NVH performance of the electric drive assembly system is also an important concern of users. The electric drive assembly generally uses a motor control unit to control a permanent magnet synchronous motor or an asynchronous motor to output power with a wide speed and wide torque range. The reducer uses a two-stage transmission with helical gears and a fixed speed ratio to reduce speed and increase torque. The required rotational speed at the wheel end of the vehicle is about 1200 - 1600 rpm. Therefore, the maximum designed rotational speed of the motor is generally about 16000 rpm. According to the order theory of rotating machinery, medium and high-frequency whistling will inevitably occur at medium and high speeds of rotating machinery, and medium and high-frequency whistling affects the smoothness of the vehicle and is easily perceived by users.

[0003] The published application number CN114165575A discloses a new type of reducer for a new energy vehicle and an input shaft of the reducer, specifically discloses that: the input shaft is a hollow-structured gear shaft, a stepped hole is opened in the middle of the input shaft, an internal spline is arranged on the stepped hole, and a shaft sleeve is also arranged inside the internal spline; the reducer includes an input shaft, and also includes a left housing, a right housing, an intermediate gear shaft assembly, and a differential assembly; the input shaft has a first transmission tooth, the intermediate gear shaft assembly includes an intermediate gear shaft and a middle driven gear, a second transmission tooth is arranged on the intermediate gear shaft, and the differential assembly is provided with a main reduction gear and a half-shaft spline. However, this existing technology is mainly used to improve the 1st order and harmonic orders caused by the fluctuation of the motor shaft, and no effective measures are proposed for the problem of vibration and noise caused by the high-order harmonics generated by the motor tooth-slot effect.

[0004] In summary, how to design a motor shafting that can improve vibration and noise is a technical problem to be solved. Content of the Utility Model

[0005] The purpose of the utility model is to provide a noise-reducing shafting for an electric drive assembly of a new energy vehicle to overcome the defect of large vibration and noise in the above-mentioned existing technology.

[0006] The purpose of the utility model can be realized by the following technical solutions:

[0007] According to one aspect of the present utility model, a noise-reducing shafting for an electric drive assembly of a new energy vehicle is provided, which includes a motor shaft, an input shaft, an intermediate shaft, and a differential. The motor shaft and the input shaft are connected by spline fit. The input shaft and the intermediate shaft, as well as the intermediate shaft and the differential, are both driven by gear pairs. A weight-reducing hole is provided inside the motor shaft, and a viscoelastic damping layer of the motor shaft is provided on the surface of the weight-reducing hole.

[0008] As a preferred technical solution, a first stepped hole is provided inside the input shaft. An internal spline is provided at one end of the first stepped hole connected to the motor shaft, and a viscoelastic damping layer of the input shaft is provided on the surface at the other end.

[0009] As a preferred technical solution, the inner diameter of the viscoelastic damping layer of the input shaft is larger than the major diameter of the internal spline.

[0010] As a preferred technical solution, the internal spline is an internal spline processed by broaching.

[0011] As a preferred technical solution, an external spline is provided at one section of the motor shaft, and the internal spline and the external spline are in clearance fit.

[0012] As a preferred technical solution, a second stepped hole is provided inside the intermediate shaft, and a viscoelastic damping layer of the intermediate shaft is provided on the surface of the second stepped hole.

[0013] As a preferred technical solution, the inner diameters of the viscoelastic damping layer of the intermediate shaft at different sections of the second stepped hole are not equal.

[0014] As a preferred technical solution, the second stepped hole includes two sections of holes.

[0015] As a preferred technical solution, the motor shaft includes a resolver side shaft section and a spline side shaft section connected by interference fit, and the viscoelastic damping layer of the motor shaft is located inside the spline side shaft section.

[0016] As a preferred technical solution, an input shaft pinion is provided on the input shaft; an intermediate shaft pinion is provided on the intermediate shaft, and an intermediate shaft gear is also sleeved; the differential includes a differential housing and a differential assembly installed inside the differential housing, and an output gear is provided on the differential housing; the input shaft pinion is engaged with the intermediate shaft gear, and the intermediate shaft pinion is engaged with the output gear.

[0017] Compared with the prior art, the present utility model has the following beneficial effects:

[0018] 1) The interior of the motor shaft of the present utility model is provided with weight-reducing holes, which can lighten the motor shaft and reduce the use of metal materials. The surface of the weight-reducing holes is provided with a viscoelastic damping layer of the motor shaft. When the excitation force of the motor is coupled with the mode of the motor shaft, a resonance effect occurs, and the molecular chains of the viscoelastic damping layer of the motor shaft extend to consume energy, having good anti-vibration performance.

[0019] 2) The interior of the input shaft of the present utility model is provided with a viscoelastic damping layer of the input shaft, which can attenuate the vibration amplitude of the high-order harmonic content generated by the dynamic meshing force coupling the shear and torsional deformation of the shaft during gear meshing. The inner diameter of the viscoelastic damping layer of the input shaft is greater than the major diameter of the internal spline to ensure that the axial movement of the motor does not damage the damping layer. The internal spline is an internal spline processed by broaching to ensure that the spline accuracy remains unchanged after heat treatment and avoid the generation of low-order harmonic noise of the spline.

[0020] 3) The interior of the intermediate shaft of the present utility model is provided with a viscoelastic damping layer of the intermediate shaft, which can further attenuate the noise generated by gear meshing. The stepped hole inside the intermediate shaft and the inner diameter of the viscoelastic damping layer of the intermediate shaft are not equal, which can lighten the intermediate shaft and improve the transmission efficiency.

[0021] 4) Part of the mechanical vibration kinetic energy generated by the torque pulsation and shaft torsional bending of the motor of the present utility model is converted into heat energy of the viscoelastic damping layer of the motor shaft, and this heat energy is taken away by the motor shaft. The rotation of the motor shaft generates air flow, and the heat is taken away by the air. Part of the shear, bending, and torsional vibration kinetic energy generated by the input shaft and the intermediate shaft is converted into heat energy of the viscoelastic damping layer of the input shaft and the viscoelastic damping layer of the intermediate shaft, and this heat energy is taken away by the lubricating oil. The shafting does not need to add additional heat dissipation components and can still ensure the optimal energy consumption of the molecular extension of the damping material. Due to the existence of the viscoelastic damping layer, the inner hole roughness requirements of each shafting with a viscoelastic damping layer are low, the manufacturing process is simple, and the cost is low. Description of the Drawings

[0022] Figure 1 is an exploded view of a noise-reducing shafting of a new energy vehicle electric drive assembly of the present utility model;

[0023] Figure 2 is a sectional view of the motor shaft of the present utility model;

[0024] Figure 3 is a sectional view of the input shaft of the present utility model;

[0025] Figure 4 is a sectional view of the intermediate shaft of the present utility model;

[0026] As shown by the reference numerals in the figures:

[0027] 1. Front bearing position of the motor, 2. Weight reduction hole, 3. Matching position between the motor shaft and the rotor core, 4. Front bearing position of the input shaft, 5. Matching position between the motor shaft and the input shaft, 6. Surface of the first stepped hole, 7. Rear bearing position of the input shaft, 8. Matching position between the large gear on the intermediate shaft and the intermediate shaft, 9. Front bearing position of the intermediate shaft, 10. Rear bearing position of the intermediate shaft, 11. Inner hole surface of the intermediate shaft, 12. Front bearing position of the differential housing, 13. Rear bearing position of the differential housing, 14. Differential assembly, 15. Internal spline of the differential side gear, 16. Differential housing, 17. Connecting bolt, 31. Spline side shaft section, 32. Resolver side shaft section, 33. Interference fit position between the spline side shaft section and the resolver side shaft section, 55. External spline, 56. Internal spline, 65. Input shaft pinion, 66. First gear pair, 67. Large gear on the intermediate shaft, 76. Small gear on the intermediate shaft, 77. Second gear pair, 111. Viscoelastic damping layer of the motor shaft, 112. Viscoelastic damping layer of the input shaft, 113. Viscoelastic damping layer of the intermediate shaft. Detailed implementation manners

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0029] With the rapid development of the electric drive system, the electric drive assembly system of pure electric vehicles adopts a multi-in-one system, which includes a motor, an electronic control unit, a reducer, an on-board charger, an AC / DC converter, a distribution box, etc. Among them, the motor main drive system mostly uses a permanent magnet synchronous motor considering power density and efficiency. The stator core of the permanent magnet synchronous motor is embedded with a copper wire winding, and the rotor is embedded with a permanent magnet. Power is input through the battery and the motor controller controls the input of current to the embedded winding in the stator. A magnetic field is induced by the electric field in the copper wire winding in the motor stator, and interacts with the magnetic field generated by the permanent magnet of the rotor assembly to generate electromagnetic force.

[0030] Viscoelastic materials are a kind of materials specifically used as damping layers, and their main characteristics are related to temperature and frequency.

[0031] Such as Figure 1As shown in the figure, the present utility model provides a noise reduction shafting for a new energy vehicle electric drive assembly, which includes a motor shaft, an input shaft, an intermediate shaft and a differential. The tangential component of the electromagnetic force drives the rotating shaft to move and output torque. The 6th torque pulsation caused by the 5th and 7th harmonics generated by the stator surface slotting effect and the dead time of the motor controller switch, the 12th torque pulsation caused by the 11th and 13th harmonics, and the high-order harmonic force generated by coupling the rotor torsional mode pass through the motor shaft and the front bearing position 1 of the motor. The front bearing position 1 of the motor is press-fitted with a ball bearing to support the motor shafting. The outer ring of the ball bearing is fitted with the bearing hole of the motor housing and transmits part of the vibration response force to the motor housing, radiating noise outward.

[0032] The external spline 55 of the motor shaft is in clearance fit with the internal spline 56 of the input shaft at the mating position 5 between the motor shaft and the input shaft, and inputs the power generated by the motor to the input shaft. The front bearing position 4 and the rear bearing position 7 of the input shaft are press-fitted with bearings to support the input shaft. The pinion 65 of the input shaft and the large gear 67 of the intermediate shaft form a first gear pair 66, which meshes to transmit the power of the input shaft to the intermediate shaft. The front bearing position 9 and the rear bearing position 10 of the intermediate shaft are press-fitted with ball bearings to support the intermediate shaft. The outer ring of the ball bearing is fitted with the bearing hole at the intermediate shaft position and transmits part of the vibration response force to the external housing.

[0033] The pinion 76 of the intermediate shaft and the output large gear form a second gear pair 77, which meshes and drives. The output large gear is connected to the differential housing 16 through the connecting bolt 17. There are a front bearing position 12 of the differential housing and a rear bearing position 13 of the differential housing on both sides of the differential housing 16 to support the differential housing 16. The front bearing position 12 of the differential housing and the rear bearing position 13 of the differential housing are press-fitted with tapered bearings to support the differential housing 16. The outer ring of the tapered bearing is fitted with the tapered bearing position hole of the reducer housing and transmits part of the vibration response force to the reducer housing. The power of the output large gear is transmitted to the differential housing 16. There is a differential component assembly connected inside the differential housing 16. The power of the differential housing 16 is transmitted to the differential component assembly. The differential assembly 14 includes an internal spline 15 of the differential half shaft gear. The internal spline 15 of the differential half shaft gear is connected to the external spline of the wheel half shaft. The wheel half shaft is connected to the wheel, and then the driving force is generated through the wheel to drive the vehicle to travel.

[0034] Most reduction gears for new energy vehicles adopt involute helical gears. In theory, when there is no elastic deformation of the gears and the manufacturing and assembly errors of the system are zero, there will be no transmission error during the transmission process, that is, the mating gears mesh along the ideal meshing line without vibration and noise problems. However, in actual reduction gears, the tooth shafts mostly use materials such as 20MnCr5 and 20CrMnTi, and the housings mostly use materials such as 6061 and ADC12. According to the SN curves of the materials, obvious plastic deformation will occur. Therefore, elastic deformation will occur in the shafting and housing of the reduction gear system, and the meshing points of the gears along the meshing line will also shift, resulting in transmission errors. During the gear meshing process, the teeth engage alternately, resulting in changes in the meshing stiffness. The transmission error and the meshing stiffness interact to generate meshing dynamic forces. According to the order theory of rotating machinery, this meshing dynamic force will cause a large order of high-frequency harmonic force. This high-frequency harmonic force order passes through the gear web - gear shaft - bearing - reduction gear housing, causing vibration on the housing surface and radiating noise outward. After installing the electric drive system on the vehicle, the vibration and noise generated by the motor shaft and the shafting of the reduction gear in the electric drive system are transmitted to the cab through the transmission paths such as the vehicle frame mounts on the one hand, and the radiated noise of the electric drive system is transmitted to the cab through the air transmission path on the other hand. The two vibrations and noises are superimposed, affecting the driving and riding experience. Therefore, when considering that the performance of each shafting in the electric drive system meets the requirements, a viscoelastic damping layer is attached to the inner diameter surface of each shafting, and the single high-frequency response amplitude is attenuated through the damping effect at multiple positions to improve the vibration and noise.

[0035] As Figure 2 shown, the motor shaft includes a spline side shaft section 31, a resolver side shaft section 32, and an external spline 55. A weight-reducing hole 2 is opened on the inner surfaces of the spline side shaft section 31 and the resolver side shaft section 32, and the size of the weight-reducing hole 2 is checked through the strength and stiffness of the motor shaft; the transition between the outer circle surface and the inner circle surface shoulder of the motor shaft adopts an arc transition to avoid stress concentration; due to the viscoelastic damping layer 111 provided inside, the surface roughness requirement of the weight-reducing inner hole is low, and a rough turning process can be used; a motor shaft and rotor core mating position 3 is also provided on the spline side shaft section 31 to achieve the mating with the rotor core; the spline side shaft section 31 is placed vertically along the axis. The outer circle surface of the motor shaft is clamped by a process clamping device, and a process equipment is placed inside the motor weight-reducing hole 2 to pour and attach the viscoelastic damping layer 111 to the inner hole surface at 360°. After standing and forming, the process equipment placed inside the motor weight-reducing hole 2 is taken out, and the resolver side shaft section 32 is pressed into the spline side shaft section 31 of the motor shaft by a press, and has an interference fit with the spline side shaft section 31. The interference amount of the interference fit position 33 between the spline side shaft section and the resolver side shaft section meets the requirements of torque transmission and strength pre-tightening amount check. The external spline 55 of the motor shaft is used to cooperate with the internal spline 56 of the input shaft to transmit the motor torque to the input shaft.

[0036] As Figure 3As shown, the input shaft includes the front bearing position 4 of the input shaft, the rear bearing position 7 of the input shaft, the inner hole surface 6 of the input shaft, and the internal spline 56. There is a first stepped hole inside the input shaft. The internal spline 56 is provided at one end of the first stepped hole connected to the motor shaft, and the input shaft viscoelastic damping layer 112 is provided on the surface at the other end. The internal spline 56 is machined on the stepped hole by the broaching process to ensure high spline accuracy after heat treatment. The input shaft is placed vertically along the axial direction, and the front bearing position 4 of the input shaft is clamped by the process clamping device. The process equipment is placed on the surface 6 of the first stepped hole to pour and attach the input shaft viscoelastic damping layer 112. The inner diameter of the input shaft viscoelastic damping layer 112 is 1 mm larger than the major diameter of the internal spline 56 to ensure that the axial movement of the motor shaft does not damage the input shaft viscoelastic damping layer 112.

[0037] As Figure 4 As shown, the intermediate shaft includes the front bearing position 9 of the intermediate shaft, the rear bearing position 10 of the intermediate shaft, the inner hole surface 11 of the intermediate shaft, the large gear 67 of the intermediate shaft, and the small gear 76 of the intermediate shaft. The small gear 76 of the intermediate shaft is used as the driving gear for the second-stage transmission. A boss is made on the outer cylindrical surface of the intermediate shaft. The length of the boss is equal to the tooth width of the small gear 76 of the intermediate shaft, and the involute helical gear is machined by the hobbing and gear grinding processes, that is, the small gear 76 of the intermediate shaft is integrally designed with the intermediate shaft; the large gear 67 of the intermediate shaft is used as the driven gear for the first-stage transmission. After the blank part and the spoke of the large gear 67 of the intermediate shaft are integrally forged, the involute helical gear is machined by the hobbing and gear grinding processes. The internal spline 56 is machined on the inner hole surface of the spoke by a broaching tool. The shaft section of the intermediate shaft that cooperates with the internal spline 56 is designed with a boss, and the external spline 55 is hobbed on the boss. The mating position 8 between the large gear of the intermediate shaft and the intermediate shaft is a spline fit. The internal spline 56 of the spoke of the large gear 67 of the intermediate shaft and the external spline 55 of the intermediate shaft section are assembled by the major diameter centering method. After the spline assembly, it meets certain requirements for the press-off force. Considering the lightweight of the intermediate shaft, a second stepped hole is provided inside the intermediate shaft. The second stepped hole is designed through the sensitivity analysis of the misalignment amount of the shafting and gear meshing, and the life check analysis of the two support bearings. The intermediate shaft is designed with a hollow structure with "unequal outer diameters" and "unequal inner diameters" in two sections. The "unequal inner diameters" of the two shaft sections are machined by the drilling and turning processes. The bearing that cooperates with the front bearing position 9 of the intermediate shaft is selected to be a smaller model bearing than the bearing that cooperates with the rear bearing position 10 of the intermediate shaft according to the bearing life check and the spline strength check of the inner hole of the large gear 67 of the intermediate shaft and the mating spline of the intermediate shaft to reduce the bearing use cost. After the intermediate shaft is assembled, the outer cylindrical surface of the bearing position is clamped by the process clamping device, and the intermediate shaft viscoelastic damping layer 113 is poured into the second stepped shaft through the process equipment. After the damping layers of each shafting are statically formed, other components are assembled to form the electric drive assembly system.

[0038] In the inner surface of the motor shaft of the present utility model, a weight-reducing hole 2 is opened, which can make the motor shaft lightweight, reduce the use of metal materials, and a viscoelastic damping layer 111 with a certain thickness is attached to the inner diameter, which can improve the noise and increase the efficiency of the motor shaft at the same time; the inner spline 56 processing technology still adopts the broaching process to ensure that the spline accuracy remains unchanged after heat treatment and avoid the generation of low-order noise of the spline; the surface roughness requirement of the shaft system with the attached viscoelastic damping layer is relatively low, and it can be formed in one step by processing technologies such as rough turning, with low cost and simple manufacturing process; each shaft system is vertically placed along the axial direction, and the clamping process equipment and the damping layer pouring process equipment are simple in design and easy to implement; considering the lightweight and cost of the intermediate shaft, the intermediate shaft bore diameter is designed through the sensitivity analysis of the misalignment amount of the shaft system and gear meshing and the bearing life check analysis of the two end support bearings. The intermediate shaft is designed with a hollow structure of "unequal outer diameter" and "unequal inner diameter" in two sections. According to the bearing life check, the front bearing position 9 of the intermediate shaft can select a smaller model bearing than the rear bearing position 10 of the intermediate shaft to reduce the bearing use cost; the transition surfaces of the inner and outer diameters of the shaft system all adopt arc transitions to avoid stress concentration and damage to components; part of the mechanical vibration kinetic energy generated by the motor torque pulsation and shaft torsional bending is converted into the thermal energy of the viscoelastic damping layer 111 of the motor shaft, and this thermal energy is taken away by the motor shaft. The rotation of the motor shaft generates air flow, and the heat is taken away by the air; part of the shear, bending and torsional vibration kinetic energy generated by the input shaft and the intermediate shaft is converted into the thermal energy of the viscoelastic damping layer 112 of the input shaft and the viscoelastic damping layer 113 of the intermediate shaft, and this thermal energy is taken away by the lubricating oil. The shaft system does not need to add additional heat dissipation components, and still can ensure the optimal energy consumption of the damping material molecular extension; the filled viscoelastic damping layer has good elastic hysteresis. After the molecular chain is stressed, it stretches from the curled state, thereby consuming energy. And the viscoelastic damping material has the advantages of good anti-vibration effect, high strength, high temperature resistance, good dimensional stability and high adhesion.

[0039] The above is only the specific implementation manner of the present utility model, but the protection scope of the present utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present utility model can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be subject to the protection scope of the claims.

Claims

1. A noise reduction shaft system for an electric drive assembly of a new energy vehicle, comprising a motor shaft, an input shaft, an intermediate shaft and a differential, wherein the motor shaft and the input shaft are connected by spline matching, and the input shaft and the intermediate shaft, as well as the intermediate shaft and the differential are all driven by gear pairs, characterized in that: A weight-reducing hole (2) is provided inside the motor shaft, and a motor shaft viscoelastic damping layer (111) is provided on the surface of the weight-reducing hole (2).

2. The noise reduction shaft system of the electric drive assembly of a new energy vehicle according to claim 1 is characterized in that: A first stepped hole is provided inside the input shaft, an end of the first stepped hole connected to the motor shaft is provided with an internal spline (56), and an input shaft viscoelastic damping layer (112) is provided on the surface of the other end.

3. The noise reduction shaft system of the electric drive assembly of a new energy vehicle according to claim 2 is characterized in that: The inner diameter of the input shaft viscoelastic damping layer (112) is greater than the major diameter of the internal spline (56).

4. The noise reduction shaft system of the electric drive assembly of a new energy vehicle according to claim 2 is characterized in that: The internal spline (56) is an internal spline (56) processed by broaching.

5. The noise reduction shaft system of the electric drive assembly of a new energy vehicle according to claim 2, characterized in that: One section of the motor shaft is provided with an external spline (55), and the internal spline (56) and the external spline (55) are clearance-matched.

6. The noise reduction shaft system of the electric drive assembly of a new energy vehicle according to claim 1, characterized in that: A second stepped hole is provided inside the intermediate shaft, and a viscoelastic damping layer (113) of the intermediate shaft is provided on the surface of the second stepped hole.

7. The noise reduction shaft system of the electric drive assembly of a new energy vehicle according to claim 6, characterized in that: The inner diameters of the intermediate shaft viscoelastic damping layer (113) are unequal in different sections of the second stepped hole.

8. A noise reduction shaft system for a new energy vehicle electric drive assembly according to claim 6 or 7, characterized in that: The second stepped hole includes two sections of holes.

9. The noise reduction shaft system of the electric drive assembly of a new energy vehicle according to claim 1, characterized in that: The motor shaft comprises a resolver-side shaft section (32) and a spline-side shaft section (31) which are interference-connected, and the motor shaft viscoelastic damping layer (111) is located inside the spline-side shaft section (31).

10. The noise reduction shaft system of the electric drive assembly of a new energy vehicle according to claim 1, characterized in that: The input shaft is provided with an input shaft pinion (65); the intermediate shaft is provided with an intermediate shaft pinion (76), and is also sleeved with an intermediate shaft gear (67); the differential comprises a differential housing (16) and a differential assembly (14) installed inside the differential housing (16); the differential housing (16) is provided with an output gear; The input shaft pinion (65) cooperates with the intermediate shaft gear (67), and the intermediate shaft pinion (76) cooperates with the output gear.

Images