CN114701302A

CN114701302A - Electrically-driven axle and vehicle

Info

Publication number: CN114701302A
Application number: CN202210637946.3A
Authority: CN
Inventors: 王林; 邱照强; 软飞翔
Original assignee: Lingong Group Jinan Heavy Machinery Co Ltd
Current assignee: Lingong Group Jinan Heavy Machinery Co Ltd
Priority date: 2022-06-08
Filing date: 2022-06-08
Publication date: 2022-07-05

Abstract

The invention relates to the technical field of vehicles, in particular to an electrically driven axle and a vehicle. The electrically driven axle comprises an axle housing, two motors, two primary speed reducers, two parking brakes, two half shafts and two wheel side speed reducers, wherein the two motors are arranged in the central axle housing; the primary speed reducer comprises a first shell and a first planet row assembly arranged in the first shell, and the input end of the first planet row assembly is connected with a motor shaft; the two parking brakes are respectively arranged in the two first shells and can brake the output end of the first planet row assembly; one end of the half shaft is connected with the output end of the first planet row component; the input end of the hub reduction gear is in transmission connection with the other end of the half shaft, and the output end of the hub reduction gear is connected with the wheel hub. The invention has higher reliability, can be suitable for the size of the existing tire, and provides a scheme for simultaneously installing a service brake and a parking brake.

Description

Electrically-driven axle and vehicle

Technical Field

The invention relates to the technical field of vehicles, in particular to an electrically driven axle and a vehicle.

Background

At present, the arrangement modes of motors of a mining vehicle drive axle powered by new energy sources are various. The most conventional structure is that a driving motor drives a gearbox, and the gearbox is connected with a drive axle through a transmission shaft so as to drive a vehicle. The scheme is simple to replace a traditional internal combustion engine by an electric motor, and basically has no great change to a gearbox and a drive axle. The structure is theoretically, the gearbox is a redundant structure, the efficiency of the whole vehicle transmission system is low, and the cost is high. And because the gearbox has many gears, no matter be mechanical structure gearbox or automatic transmission gearbox, always can have the smoothness problem of shifting.

The structure is more applied to the traditional small-tonnage road dump truck and the commercial vehicle, the motors are more arranged on the front side and the rear side of the drive axle, and then power is transmitted to a main speed reducer of the drive axle through the motors and then transmitted to a wheel-side speed reducer so as to drive the vehicle to move. The scheme is not suitable for being applied to mine vehicles, and has great challenges to the reliability of the whole system due to the fact that the number of motor suspension vehicle bridges is large, the weight is large, the roads in a mining area are poor, and the vibration is large.

In other large foreign electric drive rigid mine cars, the driving motor is usually directly arranged at the wheel edge end, namely, the driving motor is directly arranged on a wheel edge reducer, and tires are arranged on the wheel edge reducer. The structure has high transmission efficiency, but is suitable for matching with a larger tire.

Aiming at the current domestic electric transmission scheme of 90-120 ton-grade mining vehicles, if the scheme that a motor is externally hung on a drive axle is adopted, the reliability is insufficient, and the arrangement of a whole vehicle suspension system is difficult; a large-scale foreign electric transmission scheme is adopted, and the motor and the speed reducer cannot be arranged due to insufficient size of the tire. Therefore, an electrically driven axle is urgently needed to solve the above technical problems.

Disclosure of Invention

The invention aims to provide an electrically driven axle and a vehicle, which have high reliability, can be suitable for the existing tire size, and provide a scheme capable of simultaneously installing a service brake and a parking brake.

In order to achieve the purpose, the invention adopts the following technical scheme:

an electrically driven axle, comprising:

the axle housing comprises a central axle housing, a left axle housing and a right axle housing;

the two motors are arranged in the central axle housing, and motor shafts of the two motors are arranged in a back-to-back manner;

the two first-stage speed reducers comprise first shells and first planet row assemblies arranged in the first shells, the two first shells are respectively connected between one side of the central axle housing and the left axle housing and between the other side of the central axle housing and the right axle housing, the two first planet row assemblies correspond to the two motors one by one, and the input ends of the first planet row assemblies are in transmission connection with the motor shafts;

the two parking brakes are respectively arranged in the two first shells and can brake the output end of the first planet row assembly;

the two half shafts correspond to the two primary speed reducers one by one, and one ends of the half shafts are connected with the output end of the first planet row assembly;

two hub reduction gears, connect respectively in left side axle housing with right side axle housing, and with two the semi-axis one-to-one, hub reduction gear's input with the other end transmission of semi-axis is connected, hub reduction gear's output and wheel hub are connected.

As a preferred technical scheme of an electrically driven axle, the first planet row assembly comprises a first gear ring, a first sun gear, a first planet gear and a first planet carrier, the first gear ring is fixedly connected with the first shell, the first sun gear is fixedly sleeved on the motor shaft, the first sun gear is meshed with the first planet gear, the first planet gear is meshed with the first gear ring, the first planet gear is rotatably connected with the first planet carrier, the first planet carrier is connected with the half shaft, and the parking brake can brake the first planet carrier.

As a preferred technical solution of the electrically driven axle, the first housing includes a first cavity and a second cavity that are communicated with each other, the first cavity is close to the motor, just the diameter of the first cavity is greater than the diameter of the second cavity, the first ring gear, the first sun gear and the first planet gear are all disposed in the first cavity, the first planet carrier is simultaneously disposed in the first cavity and the second cavity, and the parking brake is disposed in the second cavity.

As a preferable technical scheme of the electrically driven axle, two first bearings are arranged between the first planet carrier and the first housing, one of the first bearings is arranged in an installation groove formed in the motor, and the other first bearing is connected to a step surface between the first cavity and the second cavity.

As a preferred technical solution of the electrically driven axle, the parking brake includes a fixing plate, friction plates, a butterfly spring and a piston, a closed oil cavity is formed between the piston and the first housing, the fixing plate and the friction plates are arranged in a staggered manner and located on one side of the piston, the fixing plate is fixedly connected with the first housing, the friction plates are connected with the first planet carrier through splines and can rotate along with the first planet carrier, the butterfly spring is arranged on the other side of the piston in a compressed state, and the acting direction of hydraulic oil in the oil cavity on the piston is opposite to the acting direction of the butterfly spring on the piston.

As a preferable technical scheme of the electric drive axle, the hub reduction gear comprises a second shell and a second planet row assembly arranged in the second shell, the second planet row assembly comprises a second gear ring, a second sun gear, a second planet gear and a second planet carrier, the electrically driven axle further comprises two axle sleeves which are respectively connected with the left axle housing and the right axle housing, the half shaft penetrates through the half shaft sleeve, the second sun gear is fixedly sleeved on the half shaft, the second sun gear is meshed with the second planet gear, the second planet gear is meshed with the second gear ring, the second gear ring is fixedly connected with a semi-shaft sleeve, the second planet gear is connected with the second planet carrier, the second planet carrier is connected with the second shell, and the second shell is fixedly connected with the hub.

As a preferred technical scheme of the electrically driven axle, a gear ring bracket is fixedly arranged on the semi-axle sleeve, and the second gear ring is fixed on the gear ring bracket.

As a preferred technical solution of the electrically driven axle, two second bearings are provided between the second housing and the axle sleeve.

As the preferred technical scheme of electric drive axle, electric drive axle still includes two service brake, two service brake set up respectively in between left axle housing and one of them wheel reduction gear and right axle housing and another between the wheel reduction gear, be provided with the speed measuring subassembly in the service brake, the speed measuring subassembly is used for monitoring the rotational speed of wheel.

A vehicle comprises a front driving axle and a rear driving axle, wherein the front driving axle and the rear driving axle adopt the electric driving axle of any one scheme.

The invention has the beneficial effects that:

the electrically driven axle provided by the invention has the advantages that firstly, a main reducer structure of the traditional drive axle is cancelled, a motor is arranged in a central axle housing, the motor is prevented from being suspended, the running reliability of a vehicle is improved, the electrically driven axle is suitable for the size of the conventional tire, in addition, the motor is limited by the installation space in the central axle housing, the motor generally adopts a small-torque high-rotation-speed motor, in order to ensure the driving torque required by the whole vehicle, a two-stage speed reducer is adopted as a speed reducing mechanism, a first-stage speed reducer is installed at the end of the motor, a wheel-side speed reducer is used as a second-stage speed reducer, a half shaft is adopted between the first-stage speed reducer and the second-stage speed reducer for connection, the rotation speed is reduced after the motor with high rotation speed is reduced by the first-stage speed reducer, and then the wheel-side speed reducer is connected by the half shaft, so that the dynamic balance requirement and the processing requirement on the half shaft and the wheel-side speed reducer are reduced, and the reliability is guaranteed; secondly, through the modular design of the first-stage speed reducer, the first-stage speed reducer matched with different speed ratios can be replaced conveniently, and the first shell of the other first-stage speed reducer, the central axle housing, the left axle housing and the right axle housing jointly form an axle housing whole body, namely the first shell can be used as a part of the axle housing whole body to play a supporting role; finally, the parking brake is arranged in the first shell of the primary speed reducer and integrated with the primary speed reducer, a novel installation scheme of the parking brake is provided, and the problem of installation and arrangement when the service brake and the parking brake are required to be installed at the same time is solved.

Drawings

FIG. 1 is a schematic structural diagram of an electrically driven axle provided by an embodiment of the present invention;

FIG. 2 is a front view of an electrically driven axle provided by an embodiment of the present invention;

FIG. 3 is a cross-sectional view taken along A-A of FIG. 2;

FIG. 4 is an enlarged view of a portion of FIG. 3 at B;

FIG. 5 is an enlarged view of a portion of FIG. 3 at C;

fig. 6 is a partially enlarged view at D in fig. 3.

In the figure:

11. a central axle housing; 111. a first center axle housing; 112. a second center axle housing; 12. a left axle housing; 13. a right axle housing;

20. a motor; 21. a motor shaft;

31. a first housing; 32. a first ring gear; 33. a first sun gear; 34. a first planet gear; 35. a first carrier; 36. a first bearing;

40. a parking brake; 41. a fixing sheet; 42. a friction plate; 43. a butterfly spring; 44. a piston;

50. a half shaft; 51. a half-shaft sleeve; 511. a ring gear support;

60. a service brake; 61. a brake disc; 62. a brake caliper; 63. braking the bottom plate; 64. a speed measuring fluted disc; 65. a speed measuring sensor;

70. a hub reduction gear; 71. a second housing; 72. a second ring gear; 73. a second sun gear; 74. a second planet wheel; 75. a second planet carrier; 76. a second bearing.

Detailed Description

The technical scheme of the invention is further explained by combining the attached drawings and the embodiment. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention. It should be further noted that, for the convenience of description, only some but not all of the elements associated with the present invention are shown in the drawings.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. "beneath," "under" and "beneath" a first feature includes the first feature being directly beneath and obliquely beneath the second feature, or simply indicating that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like are used based on the orientations and positional relationships shown in the drawings only for convenience of description and simplification of operation, and do not indicate or imply that the referred device or element must have a specific orientation, be configured and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

As shown in fig. 1 to 6, the embodiment of the present invention provides an electrically driven axle, which includes axle housings, two electric motors 20, two primary speed reducers, two parking brakes 40, two half shafts 50, and two wheel reducers 70, wherein the axle housings include a center axle housing 11, a left axle housing 12, and a right axle housing 13; the two motors 20 are both arranged in the central axle housing 11, and motor shafts 21 of the two motors 20 are arranged in a back-to-back manner; the primary speed reducer comprises first shells 31 and first planet row assemblies arranged in the first shells 31, the two first shells 31 are respectively connected between one side of a central axle housing 11 and a left axle housing 12 and between the other side of the central axle housing 11 and a right axle housing 13, the two first planet row assemblies correspond to the two motors 20 one by one, and the input ends of the first planet row assemblies are connected with a motor shaft 21; two parking brakes 40 are respectively arranged in the two first shells 31, and the parking brakes 40 can brake the output end of the first planet row assembly; the two half shafts 50 correspond to the two primary speed reducers one by one, and one end of each half shaft 50 is connected with the output end of the first planet row component; the two hub reduction gears 70 are respectively connected to one ends, far away from the first shell 31, of the left axle housing 12 and the right axle housing 13 and are in one-to-one correspondence with the two half shafts 50, the input end of the hub reduction gear 70 is in transmission connection with the other ends of the half shafts 50, and the output end of the hub reduction gear 70 is connected with a wheel hub.

Firstly, a main speed reducer structure of a traditional driving axle is cancelled, the motor 20 is arranged in the central axle housing 11, the motor 20 is prevented from being suspended, the running reliability of the vehicle is improved, the size of the vehicle is suitable for the size of the existing tire, in addition, the motor 20 is limited by the installation space in the central axle housing 11, the motor 20 generally adopts a small-torque high-rotation-speed motor 20, in order to ensure the driving torque required by the whole vehicle, a double-stage speed reducer is adopted as a speed reducing mechanism, a first-stage speed reducer is arranged at the end of the motor 20, a wheel-side speed reducer 70 is used as a second-stage speed reducer, a half shaft 50 is connected between the first-stage speed reducer and the second-stage speed reducer, after the speed of the high-rotation-speed motor 20 is reduced through the first-stage speed reducer, the rotation speed is reduced, and then the wheel-side speed reducer 70 is connected through the half shaft 50, thus the dynamic balance requirement and the processing requirement on the half shaft 50 and the wheel-side speed reducer 70 are reduced, and the reliability is ensured; secondly, through the modular design of the first-stage speed reducer, the first-stage speed reducer matched with different speed ratios can be replaced conveniently, the first shell 31 of the other first-stage speed reducer, the central axle housing 11, the left axle housing 12 and the right axle housing 13 jointly form an axle housing whole, namely the first shell 31 can be used as a part of the axle housing whole to play a supporting role; finally, the parking brake 40 is arranged in the first shell 31 of the primary speed reducer and is integrated with the primary speed reducer, a new installation scheme of the parking brake 40 is provided, and the installation and arrangement problems when the service brake 60 and the parking brake 40 need to be installed at the same time are solved. It should be noted that the service brake 60 is generally installed at the wheel rim end, and when the service brake 60 adopts a hydraulic disc brake, the parking brake 40 needs to be installed at the same time; when the service brake 60 is an air disc brake, the air disc brake structure can be used as both the service brake 60 and the parking brake 40, and therefore, the parking brake problem does not need to be considered additionally. The embodiment of the invention aims at the condition that the service brake 60 is a hydraulic disc brake, and solves the installation and arrangement problem that the service brake 60 and the parking brake 40 need to be installed at the same time.

In this embodiment, referring to fig. 4, the first planetary row assembly includes a first ring gear 32, a first sun gear 33, a first planet gear 34, and a first carrier 35, the first ring gear 32 is fixedly connected to the first housing 31, the first sun gear 33 is fixedly sleeved on the motor shaft 21, the first sun gear 33 is engaged with the first planet gear 34, the first planet gear 34 is engaged with the first ring gear 32, the first planet gear 34 is rotatably connected to the first carrier 35, the first carrier 35 is connected to the axle shaft 50, and the parking brake 40 can brake the first carrier 35. The first sun gear 33 is the input of the first planetary gearset and the first carrier 35 is the output of the first planetary gearset. The primary speed reducer can perform primary speed reduction on the high rotation speed of the motor 20.

Preferably, the first housing 31 includes a first cavity and a second cavity which are communicated with each other, the first cavity is disposed close to the motor 20, the diameter of the first cavity is larger than that of the second cavity, the first ring gear 32, the first sun gear 33 and the first planet gear 34 are disposed in the first cavity, the first planet carrier 35 is disposed in the first cavity and the second cavity at the same time, and the parking brake 40 is disposed in the second cavity. Further preferably, two first bearings 36 are disposed between the first carrier 35 and the first housing 31, one of the first bearings 36 is disposed in a mounting groove formed on the motor 20, and the other first bearing 36 is connected to a step surface between the first cavity and the second cavity through a bearing seat. The structure is arranged reasonably.

With continued reference to fig. 4, the parking brake 40 includes a fixed plate 41, a plurality of fixed plates 41, a butterfly spring 43, and a piston 44, a closed oil chamber is formed between the piston 44 and the first housing 31, the plurality of fixed plates 41 and the plurality of friction plates 42 are alternately disposed and located on one side of the piston 44, the fixed plate 41 is fixedly connected with the first housing 31, the friction plates 42 are splined to the first carrier 35 and can rotate with the first carrier 35, the butterfly spring 43 is disposed on the other side of the piston 44 in a compressed state, and a direction of action of hydraulic oil in the oil chamber on the piston 44 is opposite to a direction of action of the butterfly spring 43 on the piston 44. When the vehicle is at rest, the piston 44 moves towards the direction close to the friction plate 42 under the elastic force of the butterfly spring 43, so as to push the friction plate 42 to be combined with the fixed plate 41, and the parking of the vehicle is realized; when the vehicle runs, the hydraulic oil in the oil cavity pushes the piston 44 to move in a direction away from the friction plate 42, so that the friction plate 42 is separated from the fixed plate 41, and the brake is released.

Referring to fig. 5, the wheel reduction gear 70 includes a second housing 71 and a second planetary row assembly disposed in the second housing 71, the second planetary row assembly includes a second ring gear 72, a second sun gear 73, a second planetary gear 74 and a second planet carrier 75, the electric drive axle further includes two axle sleeves 51, the two axle sleeves 51 are respectively connected with the left axle housing 12 and the right axle housing 13, the axle shaft 50 penetrates through the axle sleeves 51, the second sun gear 73 is fixedly sleeved on the axle shaft 50, the second sun gear 73 is engaged with the second planetary gear 74, the second planetary gear 74 is engaged with the second ring gear 72, the second ring gear 72 is fixedly connected with the axle sleeves 51, the second planetary gear 74 is connected with the second planet carrier 75, the second planet carrier 75 is connected with the second housing 71, and the second housing 71 is fixedly connected with the wheel hub. The second sun gear 73 is an input end of the wheel reduction gear 70, and the second carrier 75 is an output end of the wheel reduction gear 70. The wheel reduction gear 70 is arranged to perform two-stage speed reduction, so that the effects of increasing the reduction ratio of the electrically driven axle, improving the rotating speed of the motor shaft 21, reducing the size and weight of the motor 20 and improving the operating efficiency of the motor 20 can be achieved.

Preferably, the axle sleeve 51 is fixedly provided with a ring gear bracket 511, and the second ring gear 72 is fixed to the ring gear bracket 511. By providing the ring gear bracket 511, the second ring gear 72 is more easily fixed. Preferably, two second bearings 76 are disposed between the second housing 71 and the half shaft sleeve 51, and the second bearings 76 are used for supporting the second housing 71 to rotate.

In this embodiment, the electrically driven axle further includes two service brakes 60, the two service brakes 60 are respectively disposed between the left axle housing 12 and one of the wheel reducers 70 and between the right axle housing 13 and the other wheel reducer 70, referring to fig. 6, the service brakes 60 include a brake disc 61 and a brake caliper 62, the brake disc 61 is connected to the wheel hub, the brake disc 61 can rotate along with the wheel, the brake caliper 62 is fixed on the axle housing through a brake base plate 63, and the brake caliper 62 can brake the brake disc 61. A speed measuring component is arranged in the service brake 60 and used for monitoring the rotating speed of the wheels so as to calculate the whole vehicle. Preferably, the speed measuring assembly comprises a speed measuring fluted disc 64 and a speed measuring sensor 65, wherein the speed measuring fluted disc 64 is connected with the brake disc 61, the speed measuring sensor 65 is arranged on the brake bottom plate 63, and the speed measuring sensor 65 is arranged opposite to the speed measuring fluted disc 64. The speed measuring fluted disc 64 can rotate together with the brake disc 61, and the speed measuring sensor 65 can monitor the rotating speed of the speed measuring fluted disc 64, so that the rotating speed of the wheel is obtained.

Further, in the present embodiment, the center axle case 11 includes the first center axle case 111 and the second center axle case 112 that are connected to each other, and the two electric motors 20 are respectively disposed in the first center axle case 111 and the second center axle case 112. By providing the center axle housing 11 in a split form, assembly of the motor 20 is facilitated. Alternatively, in other embodiments, the first and

second axle housings

111 and 112 may also be integrally formed, and are not limited to this embodiment.

The embodiment of the invention also provides a vehicle which comprises a front driving axle and a rear driving axle, wherein the front driving axle and the rear driving axle both adopt the electric driving axle.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An electrically driven axle, comprising:

the axle housing comprises a central axle housing (11), a left axle housing (12) and a right axle housing (13);

the two motors (20) are arranged in the central axle housing (11), and motor shafts (21) of the two motors (20) are arranged in a back-to-back manner;

the two first-stage speed reducers comprise first shells (31) and first planet row assemblies arranged in the first shells (31), the two first shells (31) are respectively connected between one side of the central axle housing (11) and the left axle housing (12) and between the other side of the central axle housing (11) and the right axle housing (13), the two first planet row assemblies correspond to the two motors (20) one by one, and the input ends of the first planet row assemblies are in transmission connection with the motor shaft (21);

two parking brakes (40) respectively arranged in the two first shells (31), wherein the parking brakes (40) can brake the output end of the first planet row assembly;

the two half shafts (50) correspond to the two primary speed reducers one by one, and one ends of the half shafts (50) are connected with the output end of the first planet row assembly;

two hub reduction gears (70), connect respectively in left side axle housing (12) with right side axle housing (13), and with two semi-axis (50) one-to-one, the input of hub reduction gear (70) with the other end transmission of semi-axis (50) is connected, the output and the wheel hub of hub reduction gear (70) are connected.

2. The electrically driven axle according to claim 1, characterized in that the first planetary row assembly comprises a first ring gear (32), a first sun gear (33), a first planet gear (34) and a first planet carrier (35), the first ring gear (32) is fixedly connected with the first housing (31), the first sun gear (33) is fixedly sleeved on the motor shaft (21), the first sun gear (33) is meshed with the first planet gear (34), the first planet gear (34) is meshed with the first ring gear (32), the first planet gear (34) is rotatably connected with the first planet carrier (35), the first planet carrier (35) is connected with the half shaft (50), and the parking brake (40) can brake the first planet carrier (35).

3. The electrically driven axle according to claim 2, characterized in that the first housing (31) comprises a first cavity and a second cavity communicating with each other, the first cavity being arranged close to the electric machine (20) and having a diameter greater than a diameter of the second cavity, the first ring gear (32), the first sun gear (33) and the first planet gear (34) being arranged in the first cavity, the first carrier (35) being arranged in both the first and the second cavity, and the parking brake (40) being arranged in the second cavity.

4. Electrically driven axle according to claim 3, characterized in that two first bearings (36) are arranged between the first planet carrier (35) and the first housing (31), one of the first bearings (36) being arranged in a mounting groove provided in the electric machine (20), the other first bearing (36) being connected to a step surface between the first cavity and the second cavity.

5. Electrically driven axle according to any of claims 2 to 4, the parking brake (40) comprises a fixed plate (41), a friction plate (42), a butterfly spring (43) and a piston (44), a closed oil chamber is formed between the piston (44) and the first shell (31), a plurality of fixed plates (41) and a plurality of friction plates (42) are arranged in a staggered manner, and is positioned at one side of the piston (44), the fixed plate (41) is fixedly connected with the first shell (31), the friction plate (42) is connected with the first planet carrier (35) through a spline, and is rotatable with the first carrier (35), the butterfly spring (43) being disposed in a compressed state on the other side of the piston (44), the action direction of the hydraulic oil in the oil cavity on the piston (44) is opposite to the action direction of the butterfly spring (43) on the piston (44).

6. The electrically driven axle according to claim 1, characterized in that the wheel reduction gear (70) comprises a second housing (71) and a second planet row assembly arranged in the second housing (71), the second planet row assembly comprising a second ring gear (72), a second sun gear (73), second planet gears (74) and a second planet carrier (75), the electrically driven axle further comprises two axle sleeves (51), the two axle sleeves (51) are respectively connected with the left axle housing (12) and the right axle housing (13), the axle shaft (50) is arranged through the axle sleeves (51), the second sun gear (73) is fixedly sleeved on the axle shaft (50), the second sun gear (73) is engaged with the second planet gears (74), the second planet gears (74) are engaged with the second ring gear (72), and the second ring gear (72) is fixedly connected with the axle sleeves (51), the second planet wheel (74) is connected with the second planet carrier (75), the second planet carrier (75) is connected with the second shell (71), and the second shell (71) is fixedly connected with the hub.

7. Electrically driven axle according to claim 6, characterized in that a ring gear carrier (511) is fixedly arranged on the axle sleeve (51), the second ring gear (72) being fixed to the ring gear carrier (511).

8. Electrically driven axle according to claim 6, characterized in that two second bearings (76) are provided between the second housing (71) and the axle sleeve (51).

9. The electrically driven axle according to claim 1, characterized in that it further comprises two service brakes (60), two service brakes (60) being respectively arranged between the left axle housing (12) and one of the wheel reducers (70) and between the right axle housing (13) and the other wheel reducer (70), a speed measuring assembly being arranged in the service brakes (60) for monitoring the rotational speed of the wheels.

10. A vehicle comprising a front drive axle and a rear drive axle, both of which employ an electrically driven axle as claimed in any one of claims 1 to 9.