Hub electric drive axle

Abstract

The invention discloses a hub electrically-driven axle which comprises two groups of parking brake assemblies, a knuckle assembly, a motor assembly, a service brake assembly and a hub reduction gear assembly which are symmetrically arranged on two sides of the electrically-driven axle. The parking brake assembly, the knuckle assembly, the motor assembly, the service brake assembly and the hub reduction gear assembly are axially connected in sequence; the parking brake assembly is installed on the steering knuckle assembly and connected with a motor shaft of the motor assembly, and the steering knuckle assembly is connected to a motor shell of the motor assembly. A shaft head is arranged on the periphery of the motor shaft, the service brake assembly is fixed to the outer ring of the shaft head, the hub reduction gear assembly comprises a first-stage planet row assembly and a second-stage planet row assembly which are connected, and a wheel shaft of a first-stage sun wheel of the first-stage planet row assembly is fixedly connected with the motor shaft; the speed reducer shell is connected to the shaft head in a rolling mode and fixedly connected with a service brake disc of the service brake. The axle is compact in structural layout, small in axial space and convenient for arrangement of the whole vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of electric drive axles, and in particular to a wheel hub electric drive axle. Background Art

[0002] With the continuous development of electric drive technology, the trend of automobile electrification is accelerating. Common electric drive structures include: central electric drive assembly, integrated electric drive axle and hub electric drive axle. The central electric drive assembly replaces the engine and gearbox with a motor + reducer structure based on the traditional fuel vehicle, which can be matched and applied to light, medium and heavy-duty vehicles, but its transmission line is long and the driving efficiency is low, which affects the overall structural layout of the electric vehicle chassis. At the same time, the vehicle energy consumption is relatively high; the integrated electric drive axle has the advantages of short transmission line, high integration and light weight, which solves the problems of difficult chassis layout and high energy consumption of the central electric drive assembly, but it mostly adopts a rigid structure and it is difficult to meet the working conditions of all-wheel drive or high-passability vehicles; the hub electric drive axle integrates the motor and reducer in the vehicle's wheel side assembly. Although it can meet the needs of all-wheel drive or high passability, it is limited by its size and structure and cannot use conventional large-ratio gear transmission systems (parallel shaft structures are large in size and cannot be installed; conventional single planetary gears cannot meet the needs of high-speed use and are prone to high wheel side temperatures). The load-bearing and driving capabilities are weak and cannot meet the use needs of characteristic vehicles.

[0003] A commercial off-road vehicle is a vehicle designed specifically to meet the needs of commercial transportation and specific working environments. It is usually used for business reception, traction, and commercial transportation. Therefore, it needs to have the characteristics of high passability, high speed, and relatively large load capacity, especially for new energy off-road vehicles. However, the above three conventional electric drive axles cannot meet the matching requirements. Therefore, it is urgent to develop a high-reliability hub electric drive axle with a large speed ratio. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a wheel hub electric drive axle, and the technical problem to be solved by the present invention is achieved by the following technical solutions:

[0005] A wheel hub electric drive axle, comprising two sets of parking brake assemblies, steering knuckle assemblies, motor assemblies, service brake assemblies and wheel-side reducer assemblies, wherein the two sets of the parking brake assemblies, steering knuckle assemblies, motor assemblies, service brake assemblies and wheel-side reducer assemblies are symmetrically arranged on the left and right sides of the electric drive axle; and the parking brake assembly, steering knuckle assembly, motor assembly, service brake assembly and wheel-side reducer assembly are axially connected in sequence; wherein,

[0006] The parking brake assembly is installed on the steering knuckle assembly and connected to the motor shaft of the motor assembly, and the steering knuckle assembly is connected to the motor housing of the motor assembly; a shaft head is provided on the periphery of the motor shaft of the motor assembly, and the service brake assembly is fixed on the periphery of the shaft head; the wheel-side reducer assembly includes a primary planetary gear assembly and a secondary planetary gear assembly, and the primary planetary gear assembly is connected to the secondary planetary gear assembly and is located in the reducer housing of the wheel-side reducer assembly, and the wheel axle of the primary sun gear of the primary planetary gear assembly is fixedly connected to the motor shaft; the reducer housing is rollingly connected to the shaft head and is fixedly connected to the service brake disc of the service brake.

[0007] Furthermore, the motor assembly also includes a stator, a rotor and a motor inner shell; the motor outer shell is located on the outside of the motor inner shell; a plurality of annular grooves are radially arranged on the outside of the motor inner shell, and the stator, rotor and motor shaft are all arranged in the motor inner shell; external splines are arranged at both ends of the motor shaft, and the end away from the steering knuckle assembly is a hollow shaft; the motor shaft is fixed to the rotor, and the stator is located on the outside of the rotor.

[0008] Furthermore, the service brake assembly also includes a brake housing, a pair of brake caliper bodies and friction plates located on both sides of the service brake disc, the brake housing and the pair of brake caliper bodies are arranged opposite to each other, supported by a caliper body support bracket and connected by fasteners; brake pistons are arranged opposite to each other between the brake housing and the pair of brake caliper bodies, the service brake disc is located between the relative brake pistons, and the brake pistons are in contact with the friction plates, and the relative movement of the brake pistons makes the friction plates and the service brake disc abut against each other to achieve service braking.

[0009] Furthermore, a guide pin and a return spring are arranged between the friction plates on both sides of the service brake disc, and the guide pin passes through the brake caliper body, the upper end of the friction plate on one side of the brake caliper body, the return spring, the upper end of the friction plate on one side of the service brake disc and the brake housing in sequence; and the outer sides of both ends of the return spring respectively abut against the inner sides of the upper ends of the friction plates, and when the brake piston pushes the friction plates to move relative to each other, the return spring contracts; when the return spring is reset, it pushes the friction plates to separate from the service brake disc, so that the brake pistons move away from each other and the brakes are released.

[0010] Furthermore, the brake housing is provided with two oil passages, each of the pair of brake caliper bodies is provided with an oil passage, and the two oil passages on the brake housing are respectively connected with the oil passages on the corresponding brake caliper bodies; the two oil passages on the brake housing each include a first oil passage, a second oil passage, a third oil passage and a fourth oil passage; the oil passages on the pair of brake caliper bodies each include a fifth oil passage and a sixth oil passage, and the fourth oil passage is connected with the fifth oil passage through an oil pipe; the brake pistons are in three groups, which are respectively installed in the third oil passage and the fourth oil passage and in the fifth oil passage and the sixth oil passage, and the brake pistons in the third oil passage and the sixth oil passage, the fourth oil passage and the fifth oil passage are arranged relatively, and two brake oil passage oil inlets are arranged on the brake housing, which correspond to the two oil passages respectively. The brake oil enters the first oil passage, the second oil passage, the third oil passage, the fourth oil passage in sequence through the brake oil passage oil inlets, and enters the fifth oil passage and the sixth oil passage through the oil pipe. At the same time, the brake piston moves relatively under the action of the brake oil and compresses the return spring, so that the friction plate presses against the service brake disc to achieve braking.

[0011] Furthermore, the motor housing and the brake housing are integrally formed.

[0012] Furthermore, the brake housing, the shaft head and the reducer housing are provided with a first air channel, a second air channel, a third air channel, a fourth air channel, a fifth air channel, a sixth air channel, a seventh air channel, an eighth air channel and a ninth air channel which are connected in sequence; the brake housing is provided with a central air charging and discharging air inlet, and the gas enters the tire in sequence through the first air channel, the second air channel, the third air channel, the fourth air channel, the fifth air channel, the sixth air channel, the seventh air channel, the eighth air channel and the ninth air channel through the central air charging and discharging air inlet.

[0013] Furthermore, a sleeve is mounted on the shaft head at the position where the sixth air channel is opened, a first oil seal and a second oil seal are installed on both sides of the sleeve, an air hole is opened in the middle of the sleeve along the circumferential direction, and the gas in the sixth air channel enters the seventh air channel through the air hole on the sleeve.

[0014] Furthermore, the first-stage planetary gear assembly also includes an inner ring gear, a ring gear bracket, a first-stage planetary gear and a first-stage planetary carrier, and the second-stage planetary gear assembly includes a second-stage sun gear, a second-stage planetary gear and a second-stage planetary carrier; one end of the ring gear bracket is connected to the inner ring gear, and the other end is connected to the shaft head; the first-stage planetary gear and the first-stage planetary gear shaft are assembled in the first-stage planetary carrier, and the first-stage planetary gear is meshed with the first-stage sun gear outside and meshed with the inner ring gear inside; the first-stage planetary carrier extends outward from the middle of one end close to the secondary sun gear, so that the secondary sun gear is connected to the extended end of the first-stage planetary carrier, and the secondary planetary gear and the second-stage planetary gear shaft are assembled in the secondary planetary carrier, and the secondary planetary gear is meshed with the secondary sun gear outside and meshed with the inner ring gear inside.

[0015] Furthermore, a bearing is provided between the axle of the primary sun gear and the primary planet carrier and / or between the primary planet carrier and the secondary planet carrier.

[0016] Beneficial effects of the present invention:

[0017] 1. The structural parts of the present invention have a compact structure and small axial space, which is convenient for vehicle layout;

[0018] 2. The multiple gas and oil circuits integrated inside the electric drive axle eliminate the need for laying external pipelines and reduce the risk of product failure;

[0019] 3. By setting the guide pin and caliper support bracket in the service brake assembly, the replacement and installation of the friction plate are facilitated, and the installation efficiency of the brake is finally improved;

[0020] 4. By designing a wheel-side reducer with a two-stage planetary gear structure, the range of the transmission speed ratio is increased, thereby increasing the upper speed limit of the vehicle, increasing the output torque, and improving the vehicle's carrying capacity to meet the use requirements of commercial new energy off-road vehicles. At the same time, bearings are arranged in the two-stage planetary gear of the wheel-side reducer assembly, which greatly improves the transmission efficiency and reduces NVH noise.

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1~Figure 2 It is a structural schematic diagram of the present invention;

[0023] Figure 3 It is a cross-sectional structural schematic diagram of the present invention;

[0024] Figure 4 for Figure 3 A schematic diagram of the partially enlarged structure of part A;

[0025] Figure 5 It is a schematic diagram of the external structure of the service brake assembly;

[0026] Figure 6 It is a schematic cross-sectional view of the guide pin of the service brake assembly;

[0027] Figure 7~Figure 8 It is a structural schematic diagram of the brake oil circuit of the service brake assembly;

[0028] Fig. 9 This is a schematic diagram of the central gas charging and discharging gas circuit structure;

[0029] Fig.10 for Fig. 9 A schematic diagram of the partially enlarged structure of part B;

[0030] Fig.11 It is a schematic diagram of the structure of the sleeve.

[0031] Description of reference numerals:

[0032] 1-parking brake assembly; 2-steering knuckle assembly; 3-motor assembly; 4-driving brake assembly; 5-wheel reducer assembly; 6-axle head; 1-1-parking brake; 1-2-EPB controller; 3-1-motor shaft; 3-2-motor housing; 3-3-stator; 3-4-rotor; 3-5-motor inner housing; 3-6-annular groove; 3-7-water inlet; 3-8-water outlet; 4-1-driving Brake disc; 4-2-brake housing; 4-3-brake caliper body; 4-4-friction plate; 4-5-caliper body support bracket; 4-6-brake piston; 4-7-guide pin; 4-8-reset spring; 4-9-oil pipe; 4-10-first oil channel; 4-11-second oil channel; 4-12-third oil channel; 4-13-fourth oil channel; 4-14-brake oil channel oil inlet; 4-15-central charging and discharging air inlet; 4-16-central charging and discharging joint; 4-17-first airway; 4-18-second airway; 4-19-third airway; 4-20-fourth airway; 4-21-fifth airway; 4-22-sixth airway; 4-23-seventh airway; 4-24-eighth airway; 4-25-ninth airway; 4-26-sleeve; 4-27-sealing ring; 4-28-exhaust hole; 5-1-first-stage planetary gear assembly; 5 -2-secondary planetary gear assembly; 5-3-reducer housing; 5-4-bearing; 1-1-1-parking brake disc; 5-1-1-primary sun gear; 5-1-2-inner ring gear; 5-1-3-ring gear bracket; 5-1-4-primary planetary gear; 5-1-5-primary planetary carrier; 5-2-1-secondary sun gear; 5-2-2-secondary planetary gear; 5-2-3-secondary planetary carrier; 4-26-1-air hole. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0034] See also Figure 1 to Figure 11 The embodiment of the present invention provides a wheel hub electric drive axle, specifically comprising two sets of parking brake assemblies 1, steering knuckle assemblies 2, motor assemblies 3, service brake assemblies 4 and wheel side reducer assemblies 5, wherein the two sets of the parking brake assemblies 1, steering knuckle assemblies 2, motor assemblies 3, service brake assemblies 4 and wheel side reducer assemblies 5 are symmetrically arranged on the left and right sides of the electric drive axle; and the parking brake assembly 1, steering knuckle assembly 2, motor assembly 3, service brake assembly 4 and wheel side reducer assembly 5 are axially connected in sequence; wherein,

[0035] The parking brake assembly 1 is installed on the steering knuckle assembly 2 and connected to the motor shaft 3-1 of the motor assembly 3, and the steering knuckle assembly 2 is connected to the motor housing 3-2 of the motor assembly 3; a shaft head 6 is arranged on the periphery of the motor shaft 3-1 of the motor assembly 3, and the service brake assembly 4 is fixed on the periphery of the shaft head 6, and the wheel-side reducer assembly 5 includes a primary planetary gear assembly 5-1 and a secondary planetary gear assembly 5-2, and the primary planetary gear assembly 5-1 is connected to the secondary planetary gear assembly 5-2 and is located in the reducer housing 5-3 of the wheel-side reducer assembly 5, and the wheel axle of the primary sun gear 5-1-1 of the primary planetary gear assembly 5-1 is fixedly connected to the motor shaft 3-1; the reducer housing 5-3 is connected to the shaft head 6 through a tapered roller bearing, and is fixedly connected to the service brake disc 4-1 of the service brake assembly 4.

[0036] The components of the electric drive axle are compactly arranged and have a small axial space, which facilitates the layout of the vehicle. At the same time, the wheel-side reducer structure of the two-stage planetary gear assembly increases the range of the transmission speed ratio, thereby increasing the upper speed limit of the vehicle, increasing the output torque, and improving the vehicle's carrying capacity.

[0037] Furthermore, the parking brake assembly 1 includes a parking brake 1-1 and an EPB controller 1-2 for controlling the parking brake 1-1. The parking brake 1-1 includes a parking brake disc 1-1-1, and the parking brake disc 1-1-1 is fastened to the motor shaft 3-1 through a spline connection.

[0038] Furthermore, the motor assembly 3 also includes a stator 3-3, a rotor 3-4, and a motor inner shell 3-5; the motor shell 3-2 is located outside the motor inner shell 3-5; the motor inner shell 3-5 is provided with a plurality of annular grooves 3-6 along the radial direction on the outside, and the motor shell 3-2 is provided with a water inlet 3-7 and a water outlet 3-8, and cooling water enters the annular groove 3-6 through the water inlet 3-7 to cool the motor assembly 3, and flows out through the water outlet 3-8; the stator 3-3, the rotor 3-4, and the motor shaft 3-1 are all arranged in the motor inner shell 3-5; both ends of the motor shaft 3-1 are provided with external splines, and the end away from the steering knuckle assembly 2 is a hollow shaft, so as to reduce the overall weight of the motor. A connecting disk is provided on the motor shaft 3-1, and the connecting disk is integrally formed with the motor shaft 3-1, and the connecting disk is connected to the rotor 3-4 by bolts; two bearings are provided on both sides of the connecting disk and are press-fitted on the inner side of the motor shell 3-2. Two oil seals are arranged on the side of the motor shaft 3-1 away from the steering knuckle assembly 2 and are located outside the bearing. The stator 3-3 is located outside the rotor 3-4.

[0039] Furthermore, the service brake assembly 4 adopts a double hydraulic fixed brake caliper structure, specifically including a brake housing 4-2, a pair of brake caliper bodies 4-3 and friction plates 4-4 located on both sides of the service brake disc 4-1; the brake housing 4-2 and the pair of brake caliper bodies 4-3 are arranged opposite to each other and supported by a caliper body support bracket 4-5, and the pair of brake caliper bodies 4-3 are arranged opposite to each other on the brake housing 4-2; the caliper body support bracket 4-5 is provided with a threaded hole, and the brake housing 4-2 and the brake caliper body 4-3 are fixed together by bolts that connect the brake caliper body 4-3, the caliper body support bracket 4-5 and the brake housing 4-2 in sequence. Brake pistons 4-6 are arranged opposite to each other between the brake housing 4-2 and the pair of brake caliper bodies 4-3, and the brake pistons 4-6 abut against the friction plates 4-4. The relative movement of the brake pistons 4-6 makes the friction plates 4-4 abut against the service brake disc 4-1 to achieve service braking.

[0040] Furthermore, a guide pin 4-7 and a return spring 4-8 are provided between the friction plates 4-4 on both sides of the service brake disc 4-1. The guide pin 4-7 passes through the brake caliper body 4-3, the upper end of the friction plate 4-4 on one side of the brake caliper body 4-3, the return spring 4-8, the upper end of the friction plate 4-4 on one side of the service brake disc 4-1 and the brake housing 4-2, and the outer sides of both ends of the return spring 4-8 respectively abut against the inner sides of the upper ends of the friction plates 4-4. When the brake piston 4-6 pushes the friction plates 4-4 to move relative to each other, the return spring 4-8 contracts; when the return spring 4-8 is reset, it pushes the friction plates 4-4 to disengage from the service brake disc 4-1, so that the brake pistons 4-6 move away from each other and the brakes are released.

[0041] Preferably, the motor housing 3 - 2 and the brake housing 4 - 2 are integrally formed, making the component structure more compact.

[0042] Furthermore, the hydraulic oil circuit of the service brake assembly 4 adopts an internal oil circuit design, that is, two oil channels are provided on the brake housing 4-2, and one oil channel is provided on each of a pair of brake caliper bodies 4-3, and the two oil channels on the brake housing 4-2 are respectively connected with the oil channels on the corresponding brake caliper bodies 4-3 through oil pipes 4-9; the two oil channels on the brake housing 4-2 include a first oil channel 4-10, a second oil channel 4-11, a third oil channel 4-12 and a fourth oil channel 4-13, and two brake oil channel oil inlets 4-14 are provided on the brake housing 4-2, corresponding to the two oil channels respectively; the oil channels on the pair of brake caliper bodies 4-3 include a fifth oil channel and a sixth oil channel, and the fourth oil channel 4-13 is connected to the fifth oil channel through an oil pipe 4-9. ; The first oil channel 4-10 is axially arranged inside the brake housing 4-2, and is connected with the brake oil channel oil inlet 4-14 and the second oil channel 4-11 respectively; the second oil channel 4-11 is radially arranged along the brake housing 4-2, and is connected with the third oil channel 4-12; the third oil channel 4-12 is arranged on both sides of the second oil channel 4-11, one end of the third oil channel 4-12 passes through the brake housing 4-2, and an air exhaust screw is provided at the oil channel port, and the other end of the third oil channel 4-12 is connected with the fourth oil channel 4-13; the fourth oil channel 4-13 is connected with the fifth oil channel on the brake caliper body 4-3 through the oil pipe 4-9; one end of the sixth oil channel is connected with the fifth oil channel, and the other end passes through the brake housing 4-2, and an air exhaust screw is provided at the oil channel port. Three groups of brake pistons 4-6 are arranged between the brake housing 4-2 and a brake caliper body 4-3, and are respectively installed in the third oil channel 4-12 and the fourth oil channel 4-13, the fifth oil channel and the sixth oil channel, and the brake pistons 4-6 in the third oil channel 4-12 and the sixth oil channel, the fourth oil channel 4-13 and the fifth oil channel are arranged relatively, and the brake oil respectively enters the first oil channel 4-10, the second oil channel 4-11, the third oil channel 4-12, and the fourth oil channel 4-13 in sequence through two brake oil channel oil inlets 4-14, and enters the fifth oil channel and the sixth oil channel through the corresponding oil pipe 4-9. At the same time, the brake pistons 4-6 move relatively under the action of the brake oil and compress the return spring 4-8, so that the friction plate 4-4 presses against the service brake disc 4-1 to achieve braking; when the brake oil flows back, the return spring 4-8 is reset, pushing the friction plate 4-4 to disengage from the service brake disc 4-1, so that the brake pistons 4-6 move away from each other and the brake is released.

[0043] Furthermore, the brake housing 4-2 is provided with a central air inlet 4-15 and a central air inlet joint 4-16, and the central air inlet and outlet air path passes through the brake housing 4-2, the shaft head 6 and the reducer housing 5-3. Specifically, the brake housing 4-2, the shaft head 6 and the reducer housing 5-3 are provided with a first air channel 4-17, a second air channel 4-18, a third air channel 4-19, a fourth air channel 4-20, a fifth air channel 4-21, a sixth air channel 4-22, a seventh air channel 4-23, an eighth air channel 4-24, and a second air channel 4-25. The first air channel 4-17 is arranged axially inside the brake housing 4-2, and is communicated with the central air inlet 4-15 and the second air channel 4-18 respectively; the second air channel 4-18 is arranged radially along the brake housing 4-2, and is communicated with the third air channel 4-19; the third air channel 4-19 is arranged axially along the brake housing 4-2, and is communicated with the fourth air channel 4-20; the fourth air channel 4-20 is arranged in the middle section of the third air channel 4-19, and runs through the brake housing 4 -2 is inside, and is communicated with the fifth air channel 4-21, the fifth air channel 4-21 is arranged in the connecting plate of the shaft head 6 and is arranged radially along the shaft head 6, and is communicated with the sixth air channel 4-22; the sixth air channel 4-22 is L-shaped, which is located in the shaft head 6, and its vertical part passes through the shaft head 6, and a sleeve 4-26 is set at the position where the sixth air channel 4-22 is opened on the shaft head 6, and the first oil seal and the second oil seal are installed on both sides of the sleeve 4-26, and the middle part of the sleeve 4-26 is opened along the circumferential direction. The sixth air channel 4-22 is L-shaped, and its vertical part passes through the shaft head 6, and the sleeve 4-26 is set at the position where the sixth air channel 4-22 is opened. The first oil seal and the second oil seal are installed on both sides of the sleeve 4-26, and the air hole 4-26-1 is opened in the circumferential direction. The gas in 22 enters the seventh air channel 4-23 through the air hole 4-26-1 on the sleeve 4-26; the seventh air channel 4-23 is arranged inside the reducer housing 5-3, one end of the seventh air channel 4-23 is arranged opposite to the opening of the sixth air channel 4-22, and the other end is connected with the eighth air channel 4-24; the eighth air channel 4-24 is arranged on the reducer housing 5-3, and is connected with the ninth air channel 4-25; the ninth air channel 4-25 is vertically arranged inside the reducer housing 5-3, and is connected with the central charging and discharging joint 4-16.

[0044] Furthermore, a sealing ring 4-27 is provided at the connection between the fourth air channel 4-20 and the fifth air channel 4-21, and a mounting groove is provided on the shaft head 6. The sealing ring 4-27 is horizontally arranged in the mounting groove, thereby sealing the shaft head 6 and the brake housing 4-2 to prevent the gas from overflowing.

[0045] In addition, an exhaust hole 4-28 is also provided on the brake housing 4-2 to facilitate the exhaust gas in the entire service brake assembly 4.

[0046] By integrating multiple air and oil channels inside the electric drive axle, the laying of external pipelines is eliminated, reducing the risk of product failure.

[0047] Furthermore, the first-stage planetary gear assembly 5-1 also includes an inner gear ring 5-1-2, a gear ring bracket 5-1-3, a first-stage planetary gear 5-1-4 and a first-stage planetary carrier 5-1-5, and the second-stage planetary gear assembly 5-2 includes a second-stage sun gear 5-2-1, a second-stage planetary gear 5-2-2 and a second-stage planetary carrier 5-2-3; one end of the gear ring bracket 5-1-3 is connected to the inner gear ring 5-1-2, and the other end is connected to the shaft head 6 through a spline; the first-stage planetary gear 5-1-4 and the first-stage planetary gear 5-1-4 shaft are assembled in the first-stage planetary carrier 5-1-5, and the first-stage planetary gear 5-1-4 is externally meshed with the first-stage sun gear 5-1-1 and internally meshed with the inner gear ring 5-1-2, and the first-stage sun gear 5-1 -1 is integrally formed with its axle, and one end of the axle of the first-stage sun gear 5-1-1 is designed as a hollow shaft, and the inner ring of the hollow shaft is provided with an internal spline, and the axle of the first-stage sun gear 5-1-1 is fixedly connected to the external spline of the motor shaft 3-1 through the internal spline; the middle part of one end of the first-stage planetary carrier 5-1-5 close to the secondary sun gear 5-2-1 extends outward, so that the secondary sun gear 5-2-1 is connected to the extended end of the first-stage planetary carrier 5-1-5. Specifically, the secondary sun gear 5-2-1 is integrally formed with its axle, and the axle of the secondary sun gear 5-2-1 is a stepped hollow type, and an internal spline is designed at the hollow part, and the axle of the secondary sun gear 5-2-1 is fixed to the first-stage planetary carrier 5-1-5 through the internal spline. The secondary planetary gear 5-2-2 and the secondary planetary gear 5-2-2 shaft are assembled in the secondary planetary carrier 5-2-3, and the secondary planetary gear 5-2-2 is externally meshed with the secondary sun gear 5-2-1 and internally meshed with the inner gear ring 5-1-2.

[0048] Preferably, a bearing 5-4 can be arranged between the axle of the first-stage sun gear 5-1-1 and the first-stage planetary carrier 5-1-5; a bearing 5-4 can also be arranged between the first-stage planetary carrier 5-1-5 and the second-stage planetary carrier 5-2-3; or a bearing 5-4 can also be arranged between the axle of the first-stage sun gear 5-1-1 and the first-stage planetary carrier 5-1-5, and between the first-stage planetary carrier 5-1-5 and the second-stage planetary carrier 5-2-3 at the same time, which greatly improves the transmission efficiency and reduces NVH noise.

[0049] Preferably, thrust washers are provided on both sides of the first-stage sun gear 5-1-1 and the first-stage planetary gear 5-1-4, and the second-stage sun gear 5-2-1 and the second-stage planetary gear 5-2-2, and the corresponding sun gear washers and planetary gear washers have an interlocking function.

[0050] The working process of the present invention is:

[0051] The power transmission route is as follows: the two sets of motor assemblies 3 respectively transmit power from the motor shaft 3-1 to the axle of the primary sun gear 5-1-1, the axle of the primary sun gear 5-1-1 drives the primary sun gear 5-1-1 to rotate, the primary sun gear 5-1-1 drives the primary planetary gear 5-1-4 to revolve, and at the same time, the shaft of the primary planetary gear 5-1-4 connected to the primary planetary gear 5-1-4 drives the primary planetary carrier 5-1-5 to rotate, and transmits the power in turn to the secondary sun gear 5-2-1 and the secondary planetary gear 5-2-2, and finally outputs it through the secondary planetary carrier 5-2-3 to drive the tire to rotate.

[0052] When service braking is required, the brake oil enters the first oil channel 4-10, the second oil channel 4-11, the third oil channel 4-12, and the fourth oil channel 4-13 respectively through the two brake oil channel oil inlets 4-14, and then enters the fifth oil channel and the sixth oil channel through the corresponding oil pipe 4-9. The brake piston 4-6 moves relative to each other under the action of the brake oil, thereby driving the friction plate 4-4 to press against the service brake disc 4-1 to achieve service braking.

[0053] When parking brake is required, the parking brake 1 - 1 is controlled by the EPB controller 1 - 2 so that the brake pad and the parking brake disc 1 - 1 - 1 abut against each other to achieve parking brake.

[0054] When the tire needs to be inflated, the gas passes through the central inflation and deflation air inlet 4-15, the first air channel 4-17, the second air channel 4-18, the third air channel 4-19, the fourth air channel 4-20, the fifth air channel 4-21, the sixth air channel 4-22, the seventh air channel 4-23, the eighth air channel 4-24 and the ninth air channel 4-25 in sequence, and finally enters the tire through the central inflation and deflation joint 4-16.

[0055] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A wheel hub electric drive axle, characterized in that: It comprises two groups of parking brake assemblies, steering knuckle assemblies, motor assemblies, service brake assemblies and wheel-side reducer assemblies, and the two groups of the parking brake assemblies, steering knuckle assemblies, motor assemblies, service brake assemblies and wheel-side reducer assemblies are symmetrically arranged on the left and right sides of the electric drive axle; and the parking brake assembly, steering knuckle assembly, motor assembly, service brake assembly and wheel-side reducer assembly are axially connected in sequence; wherein, The parking brake assembly is installed on the steering knuckle assembly and connected to the motor shaft of the motor assembly, and the steering knuckle assembly is connected to the motor housing of the motor assembly; a shaft head is provided on the periphery of the motor shaft of the motor assembly, and the service brake assembly is fixed to the outer ring of the shaft head; the wheel-side reducer assembly includes a primary planetary gear assembly and a secondary planetary gear assembly, and the primary planetary gear assembly is connected to the secondary planetary gear assembly and is located in the reducer housing of the wheel-side reducer assembly, and the wheel axle of the primary sun gear of the primary planetary gear assembly is fixedly connected to the motor shaft; the reducer housing is rollingly connected to the shaft head and is fixedly connected to the service brake disc of the service brake.

2. The wheel hub electric drive axle according to claim 1, characterized in that: The motor assembly also includes a stator, a rotor and a motor inner housing; the motor outer housing is located outside the motor inner housing; a plurality of annular grooves are radially arranged on the outside of the motor inner housing, and the stator, rotor and motor shaft are all arranged in the motor inner housing; external splines are arranged at both ends of the motor shaft, and the end away from the steering knuckle assembly is a hollow shaft; the motor shaft is fixed to the rotor, and the stator is located outside the rotor.

3. The wheel hub electric drive axle according to claim 2, characterized in that: The service brake assembly also includes a brake housing, a pair of brake caliper bodies and friction plates located on both sides of the service brake disc. The brake housing and the pair of brake caliper bodies are arranged opposite to each other, supported by a caliper body support bracket and connected by fasteners. Brake pistons are arranged opposite to each other between the brake housing and the pair of brake caliper bodies, the service brake disc is located between the opposite brake pistons, and the brake piston abuts against the friction plate, and the relative movement of the brake piston makes the friction plate and the service brake disc abut against each other to achieve service braking.

4. The wheel hub electric drive axle according to claim 3, characterized in that: A guide pin and a return spring are arranged between the friction plates on both sides of the service brake disc, and the guide pin passes through the brake caliper body, the upper end of the friction plate on one side of the brake caliper body, the return spring, the upper end of the friction plate on one side of the service brake disc and the brake housing in sequence; and the outer sides of the two ends of the return spring respectively abut against the inner sides of the upper ends of the friction plates, and when the brake piston pushes the friction plates to move relative to each other, the return spring contracts; when the return spring is reset, it pushes the friction plates to separate from the service brake disc, so that the brake pistons move away from each other and the brakes are released.

5. The wheel hub electric drive axle according to claim 4, characterized in that: The brake housing is provided with two oil passages, each of the pair of brake caliper bodies is provided with an oil passage, and the two oil passages on the brake housing are respectively connected with the oil passages on the corresponding brake caliper bodies; the two oil passages on the brake housing include a first oil passage, a second oil passage, a third oil passage and a fourth oil passage; the oil passages on the pair of brake caliper bodies include a fifth oil passage and a sixth oil passage, and the fourth oil passage is connected with the fifth oil passage through an oil pipe; the brake pistons are divided into three groups, which are respectively installed in the third oil passage, the fourth oil passage and the first oil passage. The brake pistons in the fifth oil channel and the sixth oil channel, and in the third oil channel and the sixth oil channel, and in the fourth oil channel and the fifth oil channel are arranged relatively, and two brake oil channel oil inlets are arranged on the brake housing, which correspond to the two oil channels respectively. The brake oil enters the first oil channel, the second oil channel, the third oil channel, and the fourth oil channel in sequence through the brake oil channel oil inlets, and enters the fifth oil channel and the sixth oil channel through the oil pipe. At the same time, the brake piston moves relatively under the action of the brake oil and compresses the return spring, so that the friction plate presses against the service brake disc to achieve braking.

6. The wheel hub electric drive axle according to claim 3, characterized in that: The motor housing and the brake housing are integrally formed.

7. The wheel hub electric drive axle according to claim 3, characterized in that: The brake housing, the shaft head and the reducer housing are provided with a first air channel, a second air channel, a third air channel, a fourth air channel, a fifth air channel, a sixth air channel, a seventh air channel, an eighth air channel and a ninth air channel which are connected in sequence; the brake housing is provided with a central air charging and discharging air inlet, and the gas enters the tire in sequence through the first air channel, the second air channel, the third air channel, the fourth air channel, the fifth air channel, the sixth air channel, the seventh air channel, the eighth air channel and the ninth air channel through the central air charging and discharging air inlet.

8. The wheel hub electric drive axle according to claim 7, characterized in that: A sleeve is mounted on the shaft head at the position where the sixth air channel is opened, a first oil seal and a second oil seal are installed on both sides of the sleeve, an air hole is opened in the middle of the sleeve along the circumferential direction, and the gas in the sixth air channel enters the seventh air channel through the air hole on the sleeve.

9. The wheel hub electric drive axle according to claim 1, characterized in that: The first-stage planetary gear assembly also includes an inner ring gear, a ring gear bracket, a first-stage planetary gear and a first-stage planetary carrier, and the second-stage planetary gear assembly includes a second-stage sun gear, a second-stage planetary gear and a second-stage planetary carrier; one end of the ring gear bracket is connected to the inner ring gear, and the other end is connected to the shaft head; the first-stage planetary gear and the first-stage planetary gear shaft are assembled in the first-stage planetary carrier, and the first-stage planetary gear is meshed with the first-stage sun gear outside and meshed with the inner ring gear inside; the first-stage planetary carrier extends outward from the middle of one end close to the second-stage sun gear, so that the second-stage sun gear is connected to the extended end of the first-stage planetary carrier, and the second-stage planetary gear and the second-stage planetary gear shaft are assembled in the second-stage planetary carrier, and the second-stage planetary gear is meshed with the second-stage sun gear outside and meshed with the inner ring gear inside.

10. The wheel hub electric drive axle according to claim 9, characterized in that: A bearing is arranged between the axle of the primary sun gear and the primary planet carrier and / or between the primary planet carrier and the secondary planet carrier.

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