Novel electric drive axle assembly

Abstract

The utility model provides a novel electric drive axle assembly. The novel electric drive axle assembly comprises an axle housing, a speed reducer assembly and a motor. Wherein the axle housing is integrally cast and formed, and the speed reducer assembly and the motor are in driving connection and are fixedly mounted on the same side of the axle housing. And a brake assembly is arranged on the axle housing. Hub assemblies in driving connection with the speed reducer assembly are arranged at the two ends of the axle housing, and the brake assembly can brake the hub assemblies. The axle housing and the speed reducer assembly are provided with ventilation assemblies used for balancing the air pressure of the cavity. The axle housing of the drive axle assembly adopts an integral casting forming process, so that the axle housing realizes light weight, and meanwhile, the deformation quantity, the vibration frequency and the noise of the axle assembly are reduced. Besides, the ventilation plugs are arranged on the axle housing and the speed reducer housing correspondingly and used for balancing the pressure balance between the space between the motor and the speed reducer housing and the pressure balance outside the motor and keeping the pressure balance between the internal space of the axle housing and the speed reducer housing and the pressure balance outside the axle housing and the speed reducer housing, and the sealing ring failure caused by pressure increase is prevented.

Description

Technical Field

[0001] This utility model relates to the field of drive axle assembly technology, specifically a novel electric drive axle assembly. Background Technology

[0002] Driven by the requirements of new energy and environmental protection, electric and hybrid technologies for commercial vehicles have been widely used, and the design and development of electric drive axles have gradually become mainstream.

[0003] Currently, most electric drive axle housings with a load capacity of less than 10 tons are made by stamping and welding steel plates. While this method achieves weight reduction, the housing has low rigidity and is prone to deformation. Some components connecting the housing are also welded, which hinders maintenance and adjustment. The reducer also uses cast aluminum parts for weight reduction, but this fails to achieve sufficient rigidity for heavy loads, resulting in poor noise and vibration. Furthermore, commercial vehicle reducers are often exposed, making them more susceptible to environmental influences and exhibiting poor wear resistance. The connection between the motor and reducer is simply a bolt connection, with the motor torque transmitted to the reducer via splines. This results in poor sealing, and the simplistic design fails to consider complex operating conditions, impacting the lifespan of both the motor and reducer. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a new type of electric drive axle assembly to solve the problems of low strength and easy deformation of the drive axle housing structure and poor sealing of the connection between the motor and the reducer in the prior art.

[0005] This utility model provides a novel electric drive axle assembly, which includes an axle housing, a reducer assembly, and a motor. The axle housing is integrally cast, and the reducer assembly is driven and connected to the motor, both being fixedly mounted on the same side of the axle housing. A braking assembly is provided on the axle housing. Wheel hub assemblies, which are driven and connected to the reducer assembly, are provided at both ends of the axle housing, and the braking assembly can brake the wheel hub assemblies. Ventilation components for balancing the air pressure in the cavity are provided on the axle housing and the reducer assembly.

[0006] Furthermore, the motor output shaft of the motor is driven to connect with the reducer assembly via an internal spline connection; one end of the motor output shaft connected to the reducer assembly is a hollow shaft with an internal spline in the shaft hole that mates with the input shaft of the reducer assembly; a sealing structure is provided at the drive connection between the motor and the reducer assembly, the sealing structure including a first skeleton seal ring and an O-ring, wherein the first skeleton seal ring is disposed between the input shaft and the reducer housing of the reducer assembly; and the O-ring is disposed between the input shaft and the inner wall of the motor output shaft.

[0007] Furthermore, the sealing structure also includes a second skeleton sealing ring, which is disposed between the motor housing of the motor and the outer wall of the motor output shaft.

[0008] Furthermore, the ventilation assembly includes a first ventilation plug and a second ventilation plug, wherein the first ventilation plug is disposed on the reducer housing of the reducer assembly, connecting the motor and the internal space of the reducer assembly with the external space; the second ventilation plug is disposed on the axle housing, connecting the axle housing and the internal space of the reducer assembly with the external space.

[0009] In the embodiments of this utility model, the wheel hub assembly is respectively connected to the wheel half-shaft.

[0010] In this embodiment of the invention, the braking assembly includes a left brake caliper and a right brake caliper, used to brake the wheel hub assembly.

[0011] In this embodiment of the invention, the axle housing is further provided with a V-shaped thrust rod support and a longitudinal thrust rod support. The V-shaped thrust rod support is located in the middle of the axle housing and is used to install a V-shaped thrust rod that supports the vehicle and maintains vehicle stability. The longitudinal thrust rod supports are symmetrically arranged on both sides of the axle housing in the transverse direction and are used to install a longitudinal thrust rod that supports the vehicle body and maintains vehicle stability.

[0012] In this embodiment of the invention, an airbag support is also provided on the axle housing. The airbag support is symmetrically arranged on both sides of the axle housing in the lateral direction and is used to install an airbag assembly that supports the weight of the vehicle body.

[0013] In an embodiment of this utility model, the reducer assembly further includes a primary reduction output gear, an intermediate shaft, an output gear, and a differential assembly. The primary reduction output gear is integrally formed with the input shaft and is used to transmit power. The intermediate shaft is interference-fitted with the primary reduction output gear. The output gear is fixedly connected to the differential assembly, and the output gear meshes with the intermediate shaft. The differential assembly is provided with an annular lock nut for adjusting the clearance of the bearings on both sides of the differential assembly.

[0014] Furthermore, the first-stage reduction output gear is connected to the intermediate shaft via an interference fit; a flat key is provided at the connection between the first-stage reduction output gear and the intermediate shaft to improve the safety factor.

[0015] As can be seen from the above embodiments, the novel electric drive axle assembly provided by this utility model has at least the following advantages: Compared with the prior art, the axle housing of this drive axle assembly adopts an integral casting process, which enables the axle housing to achieve lightweight while maintaining high structural strength, reducing deformation, reducing vibration frequency and noise of the axle assembly.

[0016] In addition, vent plugs are installed on both the axle housing and the reducer housing. One vent is used to balance the pressure between the space between the motor and reducer housing and the external environment, preventing the internal air pressure from surging due to heat from the motor and reducer assembly, which could cause the first skeleton seal, O-ring, and second skeleton seal to fail. The other vent is used to maintain the pressure balance between the internal space of the axle housing and the reducer housing and the external environment, preventing the sealing structure from failing due to increased pressure.

[0017] The motor and reducer assembly are connected by a double-seal structure. The second skeleton seal isolates the motor from the outside, preventing foreign matter from entering the motor. The O-ring seal prevents lubricating oil from leaking from the reducer to the motor side, thus preventing oil loss and potential failure of the gears and bearings inside the axle due to poor lubrication.

[0018] It should be understood that the above general description and the following specific embodiments are merely exemplary and illustrative, and do not limit the scope of the present invention. Attached Figure Description

[0019] The accompanying drawings are part of the specification of this utility model and illustrate exemplary embodiments of the utility model. The drawings, together with the description in the specification, are used to illustrate the principles of this utility model.

[0020] Figure 1 A schematic diagram of the overall structure of a novel electric drive axle assembly provided by this utility model. Figure 1 .

[0021] Figure 2 A schematic diagram of the overall structure of a novel electric drive axle assembly provided by this utility model. Figure 2 .

[0022] Figure 3 This is a cross-sectional view of the motor and reducer assembly of a novel electric drive axle assembly provided by this utility model.

[0023] Figure 4 for Figure 3 Enlarged view of the structure at point A in the middle.

[0024] Figure 5 A cross-sectional view of the reducer assembly of a novel electric drive axle assembly provided by this utility model.

[0025] Figure 6A schematic diagram of the bridge housing structure of a novel electric drive axle assembly provided by this utility model. Figure 1 .

[0026] Figure 7 A schematic diagram of the bridge housing structure of a novel electric drive axle assembly provided by this utility model. Figure 2 .

[0027] Explanation of reference numerals in the attached figures:

[0028] 1-Axle housing, 2-Reducer assembly, 3-Motor, 4-Brake assembly, 5-Wheel hub assembly, 6-Ventilation assembly, 7-Motor output shaft, 8-Sealing structure, 9-Wheel half-shaft, 10-V-type thrust rod support, 11-Longitudinal thrust rod support, 12-Airbag support;

[0029] 21-Input shaft, 22-First stage reduction output gear, 23-Intermediate shaft, 24-Output gear, 25-Differential assembly, 26-Ring lock nut, 27-Straight key;

[0030] 61-First vent plug, 62-Second vent plug;

[0031] 81-First skeleton sealing ring, 82-O-ring seal, 83-Second skeleton sealing ring. Detailed Implementation

[0032] Various exemplary embodiments of the present invention are now described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, features and implementations of the present invention.

[0033] Various improvements and variations can be made to the specific embodiments described in this utility model without departing from the scope or spirit of this utility model, which will be obvious to those skilled in the art. Other embodiments derived from this utility model description will also be obvious to those skilled in the art. This application specification and embodiments are merely exemplary.

[0034] This utility model provides a novel electric drive axle assembly, such as Figure 1-2 The diagram shown is a structural schematic of the drive axle assembly. In a specific embodiment, the electric drive axle assembly includes an axle housing 1, a reducer assembly 2, and a motor 3. The axle housing 1 is integrally cast. In this embodiment, as... Figure 6 and 7 As shown, the axle housing 1 is integrally cast from ductile iron. The integrally cast ductile iron axle housing 1 significantly improves its rigidity and strength while ensuring lightweight design. Moreover, the axle housing 1 has small deformation and low vibration frequency, which can effectively reduce the noise of the axle assembly, improve the overall vehicle comfort, and has better advantages under heavy loads.

[0035] The reducer assembly 2 is driven and connected to the motor 3, and both are fixedly installed on the same side of the axle housing 1. In this embodiment, the reducer housing of the reducer assembly 2 is integrally cast from ductile iron. The integral casting process of the reducer housing not only provides high mechanical properties and hardness, but also excellent noise and vibration suppression capabilities, good sound insulation, and low vibration and resonance. Furthermore, due to its high mechanical strength, we have significantly improved its lightweight design through optimized structural design.

[0036] Braking assemblies 4 are installed on the axle housing 1, and are respectively installed at both ends of the axle housing 1.

[0037] The axle housing 1 has wheel hub assemblies 5 at both ends that are driven and connected to the reducer assembly 2, and the brake assembly 4 can brake the wheel hub assemblies 5.

[0038] The axle housing 1 and the reducer assembly 2 are equipped with a venting component 6 for balancing the air pressure in the cavity. This component is used to keep the air pressure inside the axle housing 1 and the reducer housing consistent with the external air pressure, thereby reducing the damage to the sealing structure caused by pressure difference and improving the sealing effect.

[0039] Furthermore, such as Figure 3 and 4 As shown, the motor output shaft 7 of motor 3 is connected to the reducer assembly 2 via an internal spline. One end of the motor output shaft 7 that connects to the reducer assembly 2 is a hollow shaft with an internal spline inside the shaft hole that mates with the input shaft 21 of the reducer assembly 2. That is, the input shaft 21 of the reducer assembly 2 extends from the hollow end of the motor output shaft 7 into the shaft hole of the motor output shaft 7, and power is transmitted through the connecting spline.

[0040] In addition, a sealing structure 8 is provided at the drive connection between the motor 3 and the reducer assembly 2. The sealing structure 8 includes a first skeleton seal ring 81 and an O-ring seal 82. The first skeleton seal ring 81 is located between the input shaft 21 and the reducer housing of the reducer assembly 2 to prevent the lubricating oil inside the reducer housing from leaking to the motor 3 side, which would result in lubricating oil loss and poor lubrication of the gears and bearings inside the reducer housing, leading to accelerated wear and failure.

[0041] O-ring 82 is installed between the inner wall of the input shaft 21 and the motor output shaft 7 to prevent grease from leaking from the output shaft of the motor 3 and the spline joint of the input shaft 21 of the reducer assembly 2. During assembly, a certain amount of grease is applied to both the output shaft of the motor 3 and the input shaft 21 of the reducer assembly 2. The grease can effectively seal the parts, reduce wear, cool the parts, and reduce vibration.

[0042] Specifically, the O-ring 82 is installed on the outer wall of the input shaft at the end of the motor output shaft 7. Compared with the prior art, this structure can prevent the loss of lubricating grease, thereby reducing the wear of the output shaft of the motor 3 and the input shaft 21 of the reducer assembly 2, and improving the service life of the motor and reducer assembly 2.

[0043] In addition, an annular groove or shoulder is provided on the outer wall of the input shaft 21, and the O-ring seal 82 is placed in the groove or shoulder to prevent the O-ring seal 82 from moving axially when the input shaft rotates, which would cause the seal to fail.

[0044] Furthermore, the sealing structure 8 also includes a second skeleton sealing ring 83. The second skeleton sealing ring 83 is disposed between the motor housing of the motor 3 and the outer wall of the motor output shaft 7, and is used to isolate the inside of the motor 3 from the outside to prevent foreign objects from entering the motor 3.

[0045] Furthermore, the venting assembly 6 includes a first vent plug 61 and a second vent plug 62. The first vent plug 61 is disposed on the reducer housing of the reducer assembly 2, connecting the internal space of the motor 3 and the reducer assembly 2 with the external space. It is used to maintain the pressure balance between the internal space and the external space of the motor 3 and the reducer assembly 2, and to prevent the internal air pressure from increasing due to heat generation of the motor and the reducer assembly, thereby causing the sealing ring to fail.

[0046] The second vent plug 62 is installed on the axle housing 1, connecting the internal space of the axle housing 1 and the reducer assembly 2 with the external space, and is used to maintain the pressure balance between the internal space and the external space of the axle housing 1 and the reducer assembly 2.

[0047] In a specific embodiment of this utility model, the wheel hub assembly 5 is connected to the wheel half-shaft 9 respectively.

[0048] In a specific embodiment of this utility model, the brake assembly 4 includes a left brake caliper and a right brake caliper, which are used to brake the wheel hub assembly 5, thereby achieving the braking effect on the vehicle.

[0049] In a specific embodiment of this utility model, the axle housing 1 is further provided with a V-shaped thrust rod support 10 and a longitudinal thrust rod support 11. The V-shaped thrust rod support 10 is located in the middle of the axle housing 1 and is used to install a V-shaped thrust rod that supports the vehicle and maintains vehicle stability.

[0050] The longitudinal thrust rod supports 11 are symmetrically arranged on both sides of the axle housing 1 in the lateral direction, and are used to install the longitudinal thrust rods that support the vehicle body and maintain the stability of the vehicle body.

[0051] In a specific embodiment of this utility model, an airbag support 12 is also provided on the axle housing 1. The airbag support 12 is symmetrically arranged on both sides of the axle housing 1 in the lateral direction, and is used to install the airbag assembly that supports the weight of the vehicle body, so as to play a buffering role.

[0052] In specific embodiments of this utility model, such as Figure 5 As shown, the reducer assembly 2 also includes a first-stage reduction output gear 22, an intermediate shaft 23, an output gear 24, and a differential assembly 25. The first-stage reduction output gear 22 is integrally mounted with the input shaft 21 and is used to transmit power.

[0053] The first-stage reduction output gear 22 is connected to the intermediate shaft 23 by an interference fit.

[0054] In addition, a flat key 27 is provided at the connection between the first-stage reduction output gear 22 and the intermediate shaft 23 to improve the safety factor.

[0055] Specifically, the reduction output gear 22 is press-fitted onto the intermediate shaft 23 using a hot-pressing process. A keyway is then cut inside the bore, and a key is installed to transmit torque via an interference fit. This increases the safety factor of the torque transmitted by the first-stage reduction output gear 22, providing a certain degree of protection during operation.

[0056] The output gear 24 is fixedly connected to the differential assembly 25 by bolts, and the output gear 24 meshes with the intermediate shaft 23 to transmit power and control speed through the differential.

[0057] Additionally, the differential assembly 25 is equipped with an annular lock nut 26 for adjusting the clearance of the bearings on both sides of the differential assembly 25. Specifically, the clearance of the bearings on both sides of the differential is adjusted by loosening and tightening the annular lock nut.

[0058] In the technical solution of this utility model, a structure of adding a vent plug and double sealing rings is adopted. The two structural designs can complement each other. The vent plug can balance the space between the motor-gearbox and the external air pressure, avoid the influence of high-pressure gas on the motor and sealing rings, effectively increase the service life of the sealing rings, reduce the risk of lubricating oil leakage due to sealing ring failure, thereby increasing the reliability of the seal and the service life of the motor-gearbox.

[0059] The above description is merely an illustrative embodiment of this utility model. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of this utility model shall fall within the scope of protection of this utility model.

Claims

1. A new electric drive axle assembly characterized in that, The electric drive axle assembly comprises an axle housing (1), a reducer assembly (2) and an electric motor (3), wherein, The axle housing (1) is integrally cast, the reducer assembly (2) and the electric motor (3) are drivingly connected and are fixedly installed on the same side of the axle housing (1); The axle housing (1) is provided with a brake assembly (4); The axle housing (1) is provided with hub assemblies (5) at both ends and drivingly connected with the reducer assembly (2), and the brake assembly (4) can brake the hub assemblies (5); The axle housing (1) and the reducer assembly (2) are provided with a ventilation assembly (6) for balancing the air pressure in the cavity.

2. The new electric drive axle assembly of claim 1, wherein, The motor output shaft (7) of the electric motor (3) is drivingly connected with the reducer assembly (2) through internal spline cooperation; The end of the motor output shaft (7) connected with the reducer assembly (2) is a hollow shaft, and the shaft hole has internal splines matched with the input shaft (21) of the reducer assembly (2); The driving connection between the electric motor (3) and the reducer assembly (2) is provided with a sealing structure (8), and the sealing structure (8) comprises a first skeleton sealing ring (81) and an O-shaped sealing ring (82), wherein, The first skeleton sealing ring (81) is arranged between the input shaft (21) and the reducer housing of the reducer assembly (2); The O-shaped sealing ring (82) is arranged between the input shaft (21) and the inner wall of the motor output shaft (7).

3. The new electric drive axle assembly of claim 2, wherein, The sealing structure (8) further comprises a second skeleton sealing ring (83), which is arranged between the motor housing of the electric motor (3) and the outer wall of the motor output shaft (7).

4. The new electric drive axle assembly of claim 3, wherein, The ventilation assembly (6) comprises a first ventilation plug (61) and a second ventilation plug (62), wherein, The first ventilation plug (61) is arranged on the reducer housing of the reducer assembly (2), and the internal space of the electric motor (3) and the reducer assembly (2) is communicated with the external space; The second ventilation plug (62) is arranged on the axle housing (1), and the internal space of the axle housing (1) and the reducer assembly (2) is communicated with the external space.

5. The new electric drive axle assembly of claim 1, wherein, The hub assemblies (5) are respectively connected with wheel half shafts (9).

6. The new electric drive axle assembly of claim 1, wherein, The brake assembly (4) comprises left and right brake calipers for braking the hub assemblies (5).

7. The new electric drive axle assembly of claim 1, wherein, The axle housing (1) is further provided with a V-shaped thrust rod support (10) and a longitudinal thrust rod support (11), wherein, The V-shaped thrust rod support (10) is arranged in the middle of the axle housing (1) and is used for installing a V-shaped thrust rod for supporting the vehicle and keeping the vehicle body stable; The longitudinal thrust rod support (11) is symmetrically arranged on both sides of the axle housing (1) in the transverse direction and is used for installing a longitudinal thrust rod for supporting the vehicle body and keeping the vehicle body stable.

8. The new electric drive axle assembly of claim 1, wherein, The axle housing (1) is further provided with an air bag support (12), which is symmetrically arranged on both sides of the axle housing (1) in the transverse direction and is used for installing an air bag assembly for supporting the weight of the vehicle body.

9. The new electric drive axle assembly of claim 1, wherein, The reducer assembly (2) further comprises a primary reduction output gear (22), an intermediate shaft (23), an output gear (24) and a differential assembly (25), wherein, The primary reduction output gear (22) is integrally arranged with the input shaft (21) for transmitting power; The intermediate shaft (23) is connected with the primary reduction output gear (22) through interference fit; The output gear (24) is fixedly connected with the differential assembly (25), and the output gear (24) is engaged with the intermediate shaft (23); The differential assembly (25) is provided with an annular lock nut (26) for adjusting the backlash of the bearings on both sides of the differential assembly (25).

10. The new electric drive axle assembly of claim 9, wherein, The primary reduction output gear (22) is connected with the intermediate shaft (23) through interference fit; The connection between the primary reduction output gear (22) and the intermediate shaft (23) is provided with a flat key (27) for improving the safety factor.

Images