CN117325591A - Wet-type driving axle - Google Patents

Abstract

The invention discloses a wet drive axle, which comprises a motor, an axle housing, a differential mechanism and a hub assembly, wherein the motor is arranged on the axle housing; the two axle housings are respectively fixed at two sides of the motor, the two hub assemblies are respectively arranged in the two axle housings, the differential mechanism is arranged in the axle housings, and the differential mechanism is connected with the motor and respectively transmits the power of the motor to the two hub assemblies; two ends of a motor shaft extend into the two axle housings respectively, one end of the motor shaft is connected with the differential mechanism, and a parking brake assembly is arranged between the other end of the motor shaft and the axle housings; the axle housing is internally provided with a driving gear shaft, a sun gear shaft and a planet carrier in a rotating way, wherein the differential mechanism is connected with the sun gear shaft through the driving gear shaft, the sun gear shaft can drive the planet carrier to rotate, and one end of the planet carrier extends out of the axle housing to be used as a hub; a service braking mechanism is arranged between the sun gear shaft and the axle housing; the driving axle has two functions of service braking and parking braking, the motor is arranged in the middle, the power source is braked, and the inner structure of the driving axle is plump and has stronger functionality.

Description

Wet-type driving axle

Technical Field

The invention relates to the field of forklift drive axles, in particular to a wet drive axle.

Background

With the development of the domestic forklift industry, the design and manufacture of the wet drive axle are also gradually mature. The drive axle is used as one of main drive systems of the forklift and is applied to various types of forklifts, and the brake systems thereof are generally classified into service brake and parking brake. The service braking function is to apply braking force to the wheels so as to slow down or stop the vehicle; the parking brake is used to ensure that the vehicle can park on a level ground or on a slope, and can also be used for braking in emergency situations.

The patent technical literature with the publication number of CN214028067U discloses a wet axle box integrated drive axle for fork truck, which comprises an axle housing, an input assembly, two service brake assemblies, two half shafts and two hub components, wherein the half shafts are coaxially distributed, the axle housing comprises a first housing and two second housings which are fixedly connected, the two second housings are respectively positioned at the left side and the right side of the first housing, the service brake assemblies are positioned in the second housings and sleeved on the half shafts, the hub components are arranged at the outer ends of the second housings and fixedly connected with the outer ends of the half shafts, the input assembly is arranged on the first housing, and the input assembly comprises an input shaft and an output shaft which are transversely arranged.

The prior art sets up the input assembly outside the axle housing, has not only increased the volume of axle housing like this, also makes the structure of transaxle comparatively loose simultaneously, and such connecing is unfavorable for whole car to arrange, also increases the transmission path and the noise of traveling of transaxle.

Disclosure of Invention

In order to solve the problem of large size of a drive axle in the prior art, the invention aims to provide a wet drive axle which has smaller size and more compact structure and meets the requirement of low noise in running on the premise of having service brake and parking brake.

In order to achieve the above purpose, the present invention adopts the following technical scheme: a wet drive axle comprises a motor, an axle housing, a differential mechanism and a hub assembly; the two axle housings are respectively fixed at two sides of the motor, the two hub assemblies are respectively arranged in the two axle housings, the differential mechanism is arranged in the axle housings, and the differential mechanism is connected with the motor and respectively transmits the power of the motor to the two hub assemblies; two ends of a motor shaft extend into the two axle housings respectively, one end of the motor shaft is connected with the differential mechanism, and a parking brake assembly is arranged between the other end of the motor shaft and the axle housings; the axle housing is internally provided with a driving gear shaft, a sun gear shaft and a planet carrier in a rotating way, wherein the differential mechanism is connected with the sun gear shaft through the driving gear shaft, the sun gear shaft can drive the planet carrier to rotate, and one end of the planet carrier extends out of the axle housing to be used as a hub; a service braking mechanism is arranged between the sun gear shaft and the axle housing; the parking brake assembly comprises a parking outer friction plate, a parking inner friction plate, a parking piston and a parking return bolt, wherein the parking outer friction plate and the parking inner friction plate are sleeved on a motor shaft, the parking outer friction plate is circumferentially fixed with an axle housing, the parking inner friction plate is in sliding connection with the motor shaft and circumferentially fixed, the parking outer friction plate and the parking inner friction plate are alternately arranged, the parking piston is slidably arranged on the axle housing, a parking oil cavity is arranged between the parking piston and the axle housing, and the parking return bolt is arranged between the parking piston and the axle housing; the driving brake assembly comprises a driving inner friction plate, a driving brake piston and a driving return bolt, wherein the driving outer friction plate is circumferentially fixed with the axle housing, the driving inner friction plate is in sliding connection with the hub assembly and circumferentially fixed, the driving brake piston is slidably arranged on the axle housing, a driving oil cavity is arranged between the driving brake piston and the axle housing, and the driving return bolt is arranged on the driving brake piston and the axle housing; when the driving axle is braked by running, the driving axle is braked by running: the parking oil cavity is filled with oil, pressure oil in the parking oil cavity pushes the parking piston to move, the parking return bolt is compressed, and the parking inner friction plate and the parking outer friction plate are separated; the driving oil cavity is filled with oil, pressure oil in the driving oil cavity pushes the driving brake piston to move, the driving return bolt is compressed, and the driving brake piston drives the driving inner friction plate and the driving outer friction plate to be combined, so that the sun gear shaft is braked; when the driving axle is parked: the parking oil cavity discharges oil, the parking return bolt pushes the parking piston to move, and drives the inner friction plate of the parking to be combined with the outer friction plate of the parking, so as to brake the motor shaft; the oil cavity of the travelling crane is not filled with oil, the travelling crane return bolt pushes the travelling crane brake piston to move, and the inner friction plate of the travelling crane is separated from the outer friction plate of the travelling crane.

Preferably, the motor shaft is sleeved on the rotating shaft in an empty mode, one driving gear shaft is directly connected with the differential mechanism, and the other driving gear shaft is connected with the differential mechanism through the rotating shaft.

Preferably, the parking brake assembly further comprises a parking brake end plate fixedly connected with the axle housing, and the parking inner friction plate and the parking outer friction plate are located between the parking brake end plate and the parking brake piston.

Preferably, the parking brake assembly further comprises a return bolt seat, the return bolt seat is fixedly connected with the axle housing, and two ends of the parking return bolt respectively prop against the parking piston and the return bolt seat.

Preferably, an oil cylinder part is arranged in an axle housing of the parking brake assembly in a protruding mode, a parking abutting part is arranged on the parking brake piston in a protruding mode, the parking abutting part stretches into the oil cylinder part, and the axle housing, the oil cylinder part, the parking abutting part and the parking brake piston are enclosed to form a parking oil cavity.

Preferably, a first brake groove is formed in the inner side wall of the oil cylinder part, and the inner parking friction plate and the outer parking friction plate are arranged in the first brake groove.

Preferably, an oil groove is formed in the inner wall of the axle housing, one end of the service brake piston is inserted into the oil groove and is in sliding fit with the oil groove, and the inner wall of the oil groove and the service brake piston enclose a service oil cavity.

Preferably, the driving brake piston is provided with a mounting part in a protruding mode, a plurality of guide pins penetrate through the mounting part in a sliding fit mode, one end of each guide pin penetrates through the mounting part to be in threaded connection with the axle housing, the other end of each guide pin is provided with a head in a protruding mode, the guide pins are sleeved with return bolts, one ends of the return bolts are abutted to the heads of the guide pins, and the other ends of the return bolts are abutted to the mounting part.

Preferably, the mounting portion of the service brake piston is provided with a protrusion for abutting against a service abutment portion of the friction plate.

Preferably, a slidable service brake end plate is also mounted in the axle housing, the service brake end plate being located between the service abutment and the friction plate.

The technical scheme of the invention has the beneficial effects that: the transaxle in this scheme has service braking and two kinds of functions of parking braking to put in the motor and between two axle housing, parking brake subassembly and differential mechanism divide to establish in the motor both sides, and the structure in the axle housing is more plump, and the functional stronger, above-mentioned rational in infrastructure arrangement braking position has improved the compactibility that inner structure arranged, makes the volume of transaxle littleer, and the cost is lower.

Drawings

FIG. 1 is a schematic diagram of a drive axle;

FIG. 2 is an enlarged view of FIG. 1 at A;

FIG. 3 is an enlarged view at B in FIG. 1;

FIG. 4 is a schematic illustration of the connection structure of the axle housing, parking brake assembly and hub assembly.

Reference numerals: 1. a motor; 11. a motor shaft;

2. a bridge housing; 21. a first housing; 22. a second housing; 23. a third housing;

3. a differential; 31. a differential case; 32. a star gear; 33. a left side axle gear; 34. a right side axle gear; 35. a first bearing; 36. a second bearing;

4. a park brake assembly; 41. a parking piston; 42. a parking oil chamber; 43. parking inner friction plate; 44. a parking outer friction plate; 45. a parking brake end plate; 46. parking return bolt; 47. a return bolt seat;

5. a service brake assembly; 51. a service brake piston; 511. a traveling crane abutting part; 52. a driving oil cavity; 53. a guide pin; 54. a return bolt is returned; 55. inner friction plate of travelling crane; 56. outer friction plate of travelling crane; 57. a service brake end plate; 58. a mounting part;

6. a hub assembly; 61. a sun gear shaft; 62. a planet wheel; 63. a planet carrier; 64. a driven gear; 65. a fifth bearing; 66. a sixth bearing; 67. tapered roller bearings; 68. a box seal; 69. an inner gear ring;

71. a drive gear shaft; 72. a rotating shaft; 73. and a spline housing.

Description of the embodiments

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to 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," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more, unless otherwise clearly defined.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present invention, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

Examples

A wet drive axle as illustrated in fig. 1-4, comprising an electric motor 1, an axle housing 2, a differential 3, a hub assembly 6; the two axle housings 2 are respectively fixed on two sides of the motor 1, the two hub assemblies 6 are respectively arranged in the two axle housings 2, the differential mechanism 3 is arranged in the axle housings 2, and the differential mechanism 3 is connected with the motor 1 and respectively transmits the power of the motor 1 to the two hub assemblies 6; a motor shaft 11 of the motor 1 extends into the axle housing 2, a parking brake assembly 4 for braking the motor shaft 11 is arranged in the axle housing 2, and a service brake assembly 5 for braking the hub assembly 6 is also arranged in the axle housing 2;

the parking brake assembly 4 comprises a parking outer friction plate 44, a parking inner friction plate 43, a parking piston 41 and a parking return bolt 46, wherein the parking outer friction plate 44 and the parking inner friction plate 43 are sleeved on a motor shaft 11, the parking outer friction plate 44 is circumferentially fixed with the axle housing 2, the parking inner friction plate 43 is in sliding connection with the motor shaft 11 and circumferentially fixed, the parking outer friction plate 44 and the parking inner friction plate 43 are alternately arranged, the parking piston 41 is slidably arranged on the axle housing 2, a parking oil cavity 42 is arranged between the parking piston 41 and the axle housing 2, and the parking return bolt 46 is arranged between the parking piston 41 and the axle housing 2;

the service brake assembly 5 comprises a service outer friction plate 56, a service inner friction plate 55, a service brake piston 51 and a service return bolt 54, wherein the service outer friction plate 56 is circumferentially fixed with the axle housing 2, the service inner friction plate 55 is slidably connected with the hub assembly 6 and circumferentially fixed, the service outer friction plate 56 and the service inner friction plate 55 are alternately arranged, the service brake piston 51 is slidably mounted on the axle housing 2, a service oil cavity 52 is arranged between the service brake piston 51 and the axle housing 5, and the service return bolt 54 is arranged between the service brake piston 51 and the axle housing 5.

So set up, in this scheme, parking braking and service braking separately set up, and parking braking brakes the motor shaft, and service braking brakes hub assembly, and the effectual complexity that reduces transaxle braking structure, during the parking, parking braking assembly is cut off power from the power supply department, and then can effectually organize the rotation of shafting in the transaxle transmission route, and service braking is braking transaxle power take off position for braking effect is more direct, makes the braking force more outstanding.

In this embodiment, the driving gear shafts 71 are rotatably mounted in the axle housing 5, the driving gear shafts 71 in the two axle housings 2 are connected with the differential 3, the hub assembly 6 comprises a sun gear shaft 61, a planet carrier 63 and planet gears 62, the planet carrier 63 is rotatably mounted in the axle housing 2, one end of the planet carrier 63 extends out of the axle housing 2 to serve as a hub, the plurality of planet gears 62 are rotatably mounted on the planet carrier 63, the planet gears 62 are positioned in the annular gear 69 and meshed with each other, the annular gear 69 is fixed in the axle housing 2, the sun gear shaft 61 is rotatably mounted in the axle housing 2, one end of the sun gear shaft 61 extends into between the plurality of planet gears 62 and meshed with each other, the driving inner friction plates 55 and the driving outer friction plates 56 of the driving brake assembly 5 are sleeved on the other end of the sun gear shaft 16, and the planet inner friction plates 55 are in spline connection with the sun gear shaft 16; a driven gear 62 is fixed to the sun gear shaft 61, the driven gear 62 is meshed with a driving gear shaft 71 rotatably installed in the axle housing 2, and the driving gear shaft 71 is connected to the differential 3. So arranged, the service brake assembly 5 brakes the end part of the sun gear shaft 61, namely brakes the power input part of the hub assembly, so that the structure of the drive axle is more compact, and the braking effect is better; in the structure, the primary speed reduction structure of the driving between the driven gear and the driving gear shaft forms a secondary speed reduction structure, so that the vehicle can obtain larger torque, and the driving gear shaft and the sun gear shaft are arranged in parallel, so that the partial structure of the parking brake assembly and the partial structure of the driving brake assembly can be overlapped in the axial direction of the motor shaft, and the structure of the driving axle is more compact on the premise that the driving axle has two braking modes of parking brake and driving brake

Further preferably, the ring gear 69 is integrally formed with the axle housing 2. So set up, ring gear and planet carrier adopt the integrated design, and part intensity is high. It is further preferred that the planet wheels 62 are mounted on planet wheel shafts fixed to the planet carrier 63 by means of double row needle bearings.

In this embodiment, in order to make the structure of the driving axle more compact, in this embodiment, the motor shaft is a hollow shaft, the motor shaft is sleeved on the rotating shaft in an empty manner, one driving gear shaft is directly connected with the differential mechanism, and the other driving gear shaft is connected with the differential mechanism through the rotating shaft. Specifically, reference may be made to patent technical literature such as CN113883252A, CN110145584a and CN115264023a for specific structure of the differential; in this embodiment, the differential 3 includes a differential case 31, a left side shaft gear 33, a right side shaft gear 34 and a star gear 32, the differential case 31 is rotatably connected with the axle case 2, the left side shaft gear 33, the right side shaft gear 34 and the star gear 32 are rotatably mounted on the differential case 31, the left side shaft gear 33 and the right side shaft gear 34 are disposed opposite to each other, the left side shaft gear 33 and the right side shaft gear 34 are located on both sides of the star gear 32 and are engaged with each other for transmission, a drive gear shaft 71 located on the left side of the differential 3 is inserted into and spline-fitted with the left side shaft gear 33, a rotary shaft 72 located on the right side of the differential 3 is inserted into and spline-fitted with the right side shaft gear 34, and the right end of the rotary shaft 72 is rotatably connected with a drive gear shaft 71 located on the right side of the differential 3 through a spline housing 73.

In order to facilitate the assembly of the drive axle, in this embodiment, as shown in fig. 1 to 4, the axle housing 2 includes a first housing 21, a second housing 22 and a third housing 23 that are sequentially and fixedly connected, the first housing 21 is fixedly connected with the motor 1, the first housing 12, the second housing 22 and the third housing 23 are buckled to form a first cavity and a second cavity, the driving gear shaft 71 is installed in the first cavity, the parking brake assembly 4 and the differential 3 are respectively installed in the first cavities of the two axle housings 2, and the service brake assembly 5 and the hub assembly 6 are disposed in the second cavity. So set up, the equipment of the transaxle of being convenient for.

In order to simplify the assembly of the drive axle, in the present embodiment, as shown in fig. 2 to 4, two ends of a motor shaft 11 of the motor 1 extend into first housings 21 of two axle housings 2, respectively, a differential 2 and a parking brake assembly 4 are mounted in the two first housings 21, respectively, and a drive gear shaft 71 is rotatably mounted in a second housing 22; the service brake piston 51 is mounted on the first housing 21, the sun gear shaft 61 is rotatably mounted on the second housing 22, and the planet carrier 63 is mounted on the third housing 23. So set up, can assemble the transaxle after installing each component on corresponding casing, and then make the equipment of transaxle easier to also be convenient for later maintenance more. Further preferably, as shown in fig. 3, the intermediate position of the drive gear shaft 71 is rotatably connected to the second housing 22 through a third bearing 711, and one end of the drive gear shaft 71 protrudes from the second housing 22 and is rotatably connected to the third housing 23 through a fourth bearing 712. The driving gear shaft adopts a double-support structure, reduces errors caused by gear transmission, and meets the requirement of light load and high rotating speed.

In the present embodiment, as shown in fig. 2, both ends of the first housing 21 in which the differential 3 is mounted are provided with a first opening and a second opening communicating with the inside thereof, the first opening being provided toward the motor 1, the second opening being provided toward the second left housing 22, the inner diameter of the first opening being larger than the inner diameter of the second opening and the outer diameter of the differential 3, the inner diameter of the second opening being smaller than the outer diameter of the differential 3; the differential case 32 is provided with two opposite step surfaces, a first step is protruded in a first opening of the first case 21, a second step is protruded in a second opening of the first case 21, a first bearing 35 and a second bearing 36 are respectively installed on the two step surfaces of the differential case 31, the first bearing 35 is located in the first opening, the second bearing 36 is located in the second opening, the left end of an outer ring of the first bearing 35 abuts against the first step in the first opening, the right end of the outer ring of the first bearing 35 abuts against a clamping ring clamped in the first opening, and the left end of the outer ring of the second bearing 36 abuts against the second step in the second opening. By the arrangement, the differential can be quickly arranged in the first shell.

In this embodiment, as shown in fig. 3, the first housing 21 on which the parking brake assembly 4 is mounted has a cylinder portion 211 protruding therefrom, the parking brake piston 41 has a parking abutment portion 411 protruding therefrom, the parking abutment portion 411 extends into the cylinder portion 211, and the axle housing 2, the cylinder portion 211, the parking abutment portion 411, and the parking brake piston 41 enclose to form a parking oil chamber 42.

Further preferably, the cylinder portion 211 is provided with a first brake groove, and the inner parking friction plate 43 and the outer parking friction plate 44 are both disposed in the first brake groove, and the parking contact portion 411 of the parking brake piston 41 can extend into the first brake groove and contact the friction plate. By the arrangement, the structure of the driving axle is more compact.

Further preferably, the first brake groove is in spline connection with the parking outer friction plate 44, the parking brake end plate 45 is fixed in the axle housing 2, and the parking inner friction plate 53 and the parking outer friction plate 44 are located between the parking brake end plate 45 and the parking brake piston 41. So set up, the parking brake subassembly of being convenient for installs in the axle housing. It is further preferred that a parking brake end plate 45 is provided in the first housing 21 near one end of the motor 1. By the arrangement, the length of the motor shaft can be better limited, so that the structure of the driving axle is more compact.

Further preferably, as shown in fig. 3, a return bolt seat 47 is fixed in the axle housing 2, and a parking brake return bolt 46 is arranged between the parking brake piston 41 and the return bolt seat 47; the parking brake piston 41 is provided with a first accommodating groove, the return bolt seat 47 is provided with a second accommodating groove, and two ends of the parking brake return bolt 46 extend into the first accommodating groove and the second accommodating groove respectively. So arranged, the return bolt can move more stably, and the structure of the drive axle is more compact

In this embodiment, as shown in fig. 3, the first housing 21 is provided with an oil groove facing the second housing 22, one end of the service brake piston 51 is inserted into the oil groove, and the service brake piston 51 and the inner wall of the oil groove enclose a service oil chamber 52. So set up, make the structure of transaxle simpler.

Further preferably, the installation part 58 is protruded on the service brake piston 51, the installation part 58 is penetrated with a plurality of guide pins 53, the guide pins 53 are arranged around the axis of the service brake piston 51, the guide pins 53 are in sliding fit with the installation part 58, one end of each guide pin 53 penetrates through the installation part 58 to be in threaded connection with the first shell 21, the other end of each guide pin 53 is protruded with a head part, the guide pins 53 are sleeved with return bolts 54, one ends of the return bolts 54 are propped against the heads of the guide pins 53, and the other ends of the return bolts 54 are propped against the installation part 58. Further preferably, the mounting portion 58 is provided with a plurality of third accommodating grooves, the third accommodating grooves are in one-to-one correspondence with the guide pins, the guide pins 53 penetrate through the third accommodating grooves, and one end of the return bolt 54 extends into the third accommodating grooves and abuts against the inner walls of the third accommodating grooves.

In this embodiment, the second housing 22 is provided with a second braking groove with an opening facing the first housing 21, and the inner friction plate 55 and the outer friction plate 56 are both disposed in the second braking groove, and the outer friction plate 56 is spline-connected with the second braking groove. By the arrangement, the mechanism of the drive axle is more compact.

Further preferably, a service brake end plate 47 is disposed in the second brake groove, the service brake end plate 47 is in spline connection with the second brake groove, a traveling abutment portion 511 for pushing the service brake end plate 57 is protruded on a mounting portion 58 of the service brake piston 51, and the service brake end plate 57 is located between the traveling abutment portion 511 and the friction plate.

In this embodiment, as shown in fig. 4, a connecting portion is provided on the driven gear 64, the connecting portion is sleeved and fixed on the sun gear shaft 61, the inner friction plate 55 for service brake and the outer friction plate 56 for service brake are both sleeved on the connecting portion, the inner friction plate 55 for service brake is in spline connection with the connecting portion, and the connecting portion is in rotational connection with the second housing 55 through the fifth bearing 65. By the arrangement, the sun gear shaft is installed more stably.

It is further preferred that one end of the sun gear shaft 61 protrudes into the planet carrier 63, and that the sun gear shaft 61 is rotatably connected to the planet carrier 63 by means of a sixth bearing 66. By this arrangement, the transaxle can be provided with a larger load. Further, the planet gears 62 and the ring gear 69 are driven by helical gearing. So set up, planetary gear both sides are supported through tapered roller bearing to adopt helical gear transmission, can effectually improve the bearing capacity of transaxle, noise reduction.

In this embodiment, the carrier 63 is rotatably mounted on the third housing 23 by two oppositely disposed tapered roller bearings 67; specifically, two tapered roller bearings 67 are separately disposed on two sides of the planet gear 62 and the ring gear 69, the ring gear 69 is clamped by outer rings of the two tapered roller bearings 67, a sealing portion protrudes from the planet carrier 63, a nut is connected to the planet carrier 63 in a threaded manner, the nut is disposed at a position close to the second housing 22, the two tapered roller bearings 67 are disposed between the nut 601 and the sealing portion, an inner ring of one tapered roller bearing 67 abuts against the sealing portion, and an inner ring of the other tapered roller bearing 67 abuts against the nut 601. By screwing the nuts 601 in this way, the distance between the nuts and the sealing part is shortened, and the outer rings of the two tapered roller bearings 67 clamp the ring gear 69, so that the position of the planet carrier 63 is fixed; and two large-size tapered roller bearings are arranged back to back between the gear ring and the planet carrier, so that the supporting rigidity of the drive axle is improved.

Further preferably, a locking piece 602 is fixed to the end of the planet carrier 63, and the locking piece 6002 abuts against the nut 601 and prevents the nut 601 from rotating.

In this embodiment, a sleeve 603 is provided over the seal portion, and a box seal 68 is suitably provided between the sleeve 603 and the third housing 23. So set up, make wheel hub subassembly's dirt resistance strong, long service life, seal lip is inside the oil blanket, reduces the requirement to casing roughness and practices thrift processing cost, and manufacturability is good, and the installation is simple, avoids the maloperation when the installation to damage the oil blanket lip and leads to the oil leak.

When the driving axle is in the driving process: the parking oil cavity 42 is filled with oil, pressure oil in the parking oil cavity 42 pushes the parking piston 41 to move, the parking return bolt 56 is compressed, and the parking inner friction plate 43 and the parking outer friction plate 44 are separated; the driving oil cavity 52 is not filled with oil, the driving return bolt 54 pushes the driving brake piston 51 to move, and the driving inner friction plate 55 and the driving outer friction plate 56 are separated; the motor 1 drives the motor shaft 11 to rotate, the motor shaft 11 drives the differential housing 31 and the parking inner friction plates 43 to rotate, the differential housing 31 drives the left half-shaft gear 33 and the right half-shaft gear 34 to rotate through the star gears 32, the left half-shaft gear 33 drives the driving gear shaft 71 positioned at the left side to rotate, the right half-shaft gear 34 drives the driving gear shaft 71 positioned at the right side to rotate through the rotating shaft 72 and the spline housing 73, the driving gear shaft 71 drives the driven gear 64 to rotate, the driven gear 64 drives the sun gear shaft 61 to rotate, the sun gear shaft 61 drives the planet gears 62 to rotate, and the planet gears 62 rotate and rotate around the axis of the sun gear shaft 61 under the action of the inner gear ring 69 so as to drive the planet carrier 63 to rotate;

when the drive axle is braked in the driving process: the parking oil cavity 42 is filled with oil, pressure oil in the parking oil cavity 42 pushes the parking piston 41 to move, the parking return bolt 56 is compressed, and the parking inner friction plate 43 and the parking outer friction plate 44 are separated; the driving oil cavity 52 is filled with oil, the pressure oil in the driving oil cavity 52 pushes the driving brake piston 51 to move, the driving return bolt 54 is compressed, the driving brake piston 51 drives the driving inner friction plate 55 and the driving outer friction plate 56 to be combined to lock the sun gear shaft 61, and the sun gear shaft 61 is braked;

when the driving axle is parked in the parking process: the parking return bolt 46 pushes the parking piston 41 to move, drives the parking oil cavity 42 to drain oil, drives the service brake piston 41 to drive the combination of the parking inner friction plate 43 and the parking outer friction plate 44 to lock the motor shaft 11, and brakes the motor shaft 11; the driving oil cavity 52 is not filled with oil, the driving return bolt 54 pushes the driving brake piston 51 to move, and the driving inner friction plate 55 and the driving outer friction plate 56 are separated.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives, and variations may be made in the above embodiments by those skilled in the art without departing from the spirit and principles of the invention.

Claims (10)

1. A wet drive axle comprises a motor (1), an axle housing (2), a differential mechanism (3) and a hub assembly (6); the method is characterized in that: the two axle housings (2) are respectively fixed at two sides of the motor (1), the two hub assemblies (6) are respectively arranged in the two axle housings (2), the differential mechanism (3) is arranged in the axle housings (2), and the differential mechanism (3) is connected with the motor (1) and respectively transmits the power of the motor (1) to the two hub assemblies (6); two ends of a motor shaft (11) respectively extend into the two axle housings (2), one end of the motor shaft (11) is connected with the differential mechanism (3), and a parking brake assembly (4) is arranged between the other end of the motor shaft (11) and the axle housings (2);

a driving gear shaft (71), a sun gear shaft (61) and a planet carrier (63) are rotatably arranged in the axle housing (2), wherein the differential mechanism (3) is connected with the sun gear shaft (61) through the driving gear shaft (71), the sun gear shaft (61) can drive the planet carrier (63) to rotate, and one end of the planet carrier (63) extends out of the axle housing (2) to serve as a hub; a service brake mechanism (5) is arranged between the sun gear shaft (61) and the axle housing (2);

the parking brake assembly (4) comprises a parking outer friction plate (44), a parking inner friction plate (43), a parking piston (41) and a parking return bolt (46), wherein the parking outer friction plate (44) and the parking inner friction plate (43) are sleeved on a motor shaft (11), the parking outer friction plate (44) is circumferentially fixed with an axle housing (2), the parking inner friction plate (43) is in sliding connection with the motor shaft (11) and circumferentially fixed, the parking outer friction plate (44) and the parking inner friction plate (43) are alternately arranged, the parking piston (41) is slidably mounted on the axle housing (2), a parking oil cavity (42) is arranged between the parking piston (41) and the axle housing (2), and the parking return bolt (46) is arranged between the parking piston (41) and the axle housing (2);

the driving brake assembly (5) comprises a driving inner friction plate (55), a driving brake piston (51) and a driving return bolt (54), wherein a driving outer friction plate (56) is circumferentially fixed with the axle housing (2), the driving inner friction plate (55) is slidably connected with the hub assembly (6) and circumferentially fixed, the driving brake piston (51) is slidably arranged on the axle housing (2), a driving oil cavity (52) is arranged between the driving brake piston (51) and the axle housing (2), and the driving return bolt (54) is arranged between the driving brake piston (51) and the axle housing (2);

when the driving axle is braked by running, the driving axle is braked by running: the parking oil cavity (42) is filled with oil, pressure oil in the parking oil cavity (42) pushes the parking piston (46) to move, the parking return bolt (46) is compressed, and the parking inner friction plate (43) and the parking outer friction plate (44) are separated; the driving oil cavity (52) is filled with oil, the pressure oil in the driving oil cavity (52) pushes the driving brake piston (51) to move, the driving return bolt (54) is compressed, the driving brake piston (51) drives the driving inner friction plate (53) and the driving outer friction plate (54) to be combined, and the sun gear shaft (61) is braked;

when the driving axle is parked: the parking oil cavity is drained, a parking return bolt (46) pushes a parking piston (41) to move, and drives a parking inner friction plate (43) and a parking outer friction plate (44) to be combined, so that braking is implemented on a motor shaft (11); the driving oil cavity (52) is not filled with oil, the driving return bolt (54) pushes the driving brake piston (51) to move, and the driving inner friction plate (53) is separated from the driving outer friction plate (54).

2. A wet drive axle as set forth in claim 1 wherein: the motor shaft (11) is sleeved on the rotating shaft (72), one driving gear shaft (71) is directly connected with the differential mechanism (3), and the other driving gear shaft (71) is connected with the differential mechanism (3) through the rotating shaft (72).

3. A wet drive axle as set forth in claim 2 wherein: the parking brake assembly (4) further comprises a parking brake end plate (45), the parking brake end plate (45) is fixedly connected with the axle housing (2), and the parking inner friction plate (43) and the parking outer friction plate (44) are located between the parking brake end plate (45) and the parking brake piston (41).

4. A wet drive axle as set forth in claim 1 wherein: the parking brake assembly (4) further comprises a return bolt seat (47), the return bolt seat (47) is fixedly connected with the axle housing (2), and two ends of the parking return bolt (46) are respectively abutted against the parking piston (41) and the return bolt seat (47).

5. A wet drive axle as set forth in claim 1 wherein: an oil cylinder part (211) protrudes in an axle housing (2) provided with a parking brake assembly (4), a parking abutting part (411) protrudes on a parking brake piston (41), the parking abutting part (411) stretches into the oil cylinder part (211), and the axle housing (2), the oil cylinder part (211), the parking abutting part (411) and the parking brake piston (41) enclose a parking oil cavity (42).

6. A wet drive axle as set forth in claim 5 wherein: a first brake groove is formed in the inner side wall of the oil cylinder part (211), and the parking inner friction plate (43) and the parking outer friction plate (44) are arranged in the first brake groove.

7. A wet drive axle as set forth in claim 1 wherein: an oil groove is formed in the inner wall of the axle housing (2), one end of the service brake piston (511) is inserted into the oil groove and is in sliding fit, and the inner wall of the oil groove and the service brake piston (51) enclose a service oil cavity (52).

8. A wet drive axle as set forth in claim 7 wherein: the driving brake piston (51) is provided with a mounting part (58) in a protruding mode, a plurality of guide pins (53) penetrate through the mounting part, the guide pins (53) are in sliding fit with the mounting part, one end of each guide pin (53) penetrates through the mounting part (58) to be in threaded connection with the axle housing (2), the other end of each guide pin (53) is provided with a head in a protruding mode, the guide pins (53) are sleeved with return bolts (54), one ends of the return bolts (54) are abutted to the heads of the guide pins (53), and the other ends of the return bolts (54) are abutted to the mounting part.

9. A wet drive axle as set forth in claim 8 wherein: a driving contact portion (511) for contacting the friction plate is protruded from a mounting portion (58) of the driving brake piston (51).

10. A wet drive axle as set forth in claim 9 wherein: a slidable service brake end plate (57) is also mounted in the axle housing, the service brake end plate (57) being located between the service abutment (511) and the friction plate.