Double-drive wet type electric bridge

Abstract

The utility model discloses a double-drive wet type electric axle which comprises motors, a brake device and a hub assembly, the motors are fixed to the left end and the right end of the brake device, and the outer ends of the motors are fixedly connected with a shell of the hub assembly through bolts; the brake device comprises two sub-shells which are symmetrically arranged and abut against each other, and the outer wall surfaces of the sub-shells abut against the end surfaces of the end plates on the inner sides of the corresponding motors; the inner end of a motor shaft of the motor extends out of the end face of an end plate on the inner side of the motor and is provided with an inner friction plate and an outer friction plate. The brake device is arranged between the two motors, the installation and processing are convenient, the structure is simple, the manufacturing difficulty is greatly reduced, and the manufacturing cost is reduced.

Description

Technical field:

[0001] The utility model relates to the technical field related to drive axles, and more specifically to a dual-drive wet electric axle. Background technology:

[0002] With the development of the domestic forklift industry, the design and manufacture of wet drive axles have gradually matured. As one of the main drive systems of forklifts, drive axles are used in various types of forklifts. Their braking systems are generally divided into service brakes and parking brakes. The function of service brakes is to apply braking force to the wheels, thereby slowing down or stopping the vehicle; the function of parking brakes is to ensure that the vehicle can be parked on flat ground or on a slope, and can also be used for braking in emergency situations.

[0003] A wet drive axle with Chinese patent application number 202311424336.6 comprises a motor, a bridge housing, a differential and a hub assembly; two bridge housings are respectively fixed on both sides of the motor, two hub assemblies are respectively installed in two bridge housings, and a differential is installed in the bridge housing, the differential is connected to the motor and transmits the power of the motor to the two hub assemblies respectively; the two ends of the motor shaft extend into the two bridge housings respectively, one end of the motor shaft is connected to the differential, and a parking brake assembly is arranged between the other end of the motor shaft and the bridge housing; a driving gear shaft, a sun gear shaft and a planet carrier are rotatably installed in the bridge housing, wherein the differential is connected to 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 from the bridge housing to be used as a hub; a service brake mechanism is arranged between the sun gear shaft and the bridge housing; the drive axle has two functions of service brake and parking brake, and the motor is centrally placed, the power source brakes, and the structure inside the drive axle is fuller and more functional.

[0004] However, it is only driven by a single motor. For some existing forklifts, dual motors are required. For dual motor drive axles, the existing braking systems are all on the wheel hub assemblies at both ends of the bridge body, which are connected to the transmission system, making it difficult to manufacture, with many structural components and high cost. Utility model content:

[0005] The purpose of the utility model is to overcome the deficiencies of the prior art and provide a dual-drive wet electric bridge, which places a brake device between two motors, is easy to install and process, has a simple structure, greatly reduces manufacturing difficulty, and reduces manufacturing costs.

[0006] The solution of the utility model to solve the technical problem is:

[0007] A dual-drive wet electric bridge comprises a motor, a brake device and a wheel hub assembly, wherein the motor is fixed to both left and right ends of the brake device, and the outer end of the motor is fixedly connected to the housing of the wheel hub assembly by bolts;

[0008] The brake device comprises two sub-housings, the outer wall surfaces of the sub-housings being pressed against the end surfaces of the end plates at the inner sides of the corresponding motors;

[0009] The inner end of the motor shaft of the motor extends out of the end surface of the end plate at the inner side of the motor and is installed with an inner friction plate and an outer friction plate;

[0010] An outer stepped through hole is formed on a side of the middle of the sub-shell close to the motor, and an inner stepped through hole is formed on a side of the middle of the sub-shell away from the motor, wherein the inner end of the outer stepped through hole is connected to the outer end of the inner stepped through hole;

[0011] A service brake piston is installed in the outer stepped through hole, and the outer end surface of the service brake piston is pressed against the outer friction plate. A parking brake piston and a butterfly spring seat are installed in the inner stepped through hole, and a butterfly spring is provided between the parking brake piston and the butterfly spring seat. One end of the butterfly spring forces the butterfly spring seat, and the other end forces the inner end of the parking brake piston. The outer end surface of the parking brake piston presses against the inner end surface of the service brake piston.

[0012] A groove is formed in the middle of the end surface of the end plate at the inner side of the motor, and a main annular groove is formed on the inner wall of the groove close to one end of the sub-shell. The edge of the fixed end plate is inserted into the main annular groove and fixedly connected to the end plate at the inner side of the motor through positioning bolts, and one end surface edge of the fixed end plate is pressed against the end surface of the annular groove.

[0013] A pressure plate, an inner friction plate and an outer friction plate are inserted and sleeved on the inner end of the motor shaft of the motor, the inner friction plate is clamped between the pressure plate and the outer friction plate, the other side wall surface of the pressure plate is closely attached to one end surface of the fixed end plate, and the other side wall surface of the outer friction plate is pressed against the outer end surface of the service brake piston;

[0014] The outer edges of the pressure plate and the outer friction plate are formed with a plurality of positioning grooves, the rods of the corresponding positioning bolts are inserted into the corresponding positioning grooves, a rotating part is fixed on the inner end of the motor shaft of the motor, the inner friction plate is inserted into the rotating part, a tooth-shaped groove is formed on the outer wall of the rotating part, a tooth-shaped protrusion is formed on the inner wall of the middle through hole of the inner friction plate, the tooth-shaped protrusion is inserted into the tooth-shaped groove, and the two cooperate with each other;

[0015] The outer stepped through hole comprises a first outer hole section, a second outer hole section and a third outer hole section extending from the outside to the inside in sequence;

[0016] The inner stepped through hole comprises a first inner hole section and a second inner hole section which are sequentially extended from the outside to the inside.

[0017] A radially extending edge is formed on the outer side wall of the outer end face of the service brake piston, and the radially extending edge is inserted into the corresponding first outer hole section, and the outer side face of the radially extending edge is pressed against the corresponding end face of the corresponding outer friction plate; a radially extending reinforcing ring is formed on the outer side wall of the middle part of the service brake piston, and the radially extending reinforcing ring is inserted into the second outer hole section, and the outer side wall of the radially extending reinforcing ring is close to the inner side wall of the second outer hole section, and a sealing groove is formed on the outer side wall of the radially extending reinforcing ring, and the first sealing ring is nested in the sealing groove, and the outer side wall of the first sealing ring is pressed against the inner side wall of the second outer hole section; the inner end of the service brake piston is inserted into the third outer hole section, and the outer side wall of the inner end of the service brake piston is close to the inner side wall of the third outer hole section, and the second sealing ring is nested in the sealing groove formed on the outer side wall of the inner end of the service brake piston, and the outer side wall of the second sealing ring is pressed against the inner side wall of the third outer hole section;

[0018] A first oil through hole is formed on the inner side wall of the outer stepped through hole between the first sealing ring and the second sealing ring, and the outer end of the first oil through hole extends out of the outer wall surface of the sub-shell.

[0019] A first radial extension is formed on the outer side wall of the inner end of the parking brake piston, the outer section of the parking brake piston is inserted into the first inner hole section, the inner section of the parking brake piston and the first radial extension are inserted into the second inner hole section, the outer wall surface of the outer section of the parking brake piston is close to the inner side wall of the first inner hole section, a third sealing ring is nested in the sealing groove on the outer wall surface of the outer section of the parking brake piston, the outer wall surface of the third sealing ring is pressed against the inner side wall of the first inner hole section, the outer wall surface of the first radial extension is close to the inner side wall of the second inner hole section, a fourth sealing ring is nested in the sealing groove on the outer side wall of the first radial extension, the outer wall surface of the fourth sealing ring is pressed against the inner side wall of the second inner hole section, a second oil through hole is formed on the inner side wall of the inner stepped through hole between the third sealing ring and the fourth sealing ring, and the outer end of the second oil through hole extends out of the outer wall surface of the sub-housing.

[0020] An inner mounting hole is formed in the middle of the inner end surface of the parking brake piston, and a radially extending annular groove is formed on the inner side wall of the inner mounting hole near the inner end surface of the parking brake piston. The butterfly spring seat is inserted into the radially extending annular groove, and the butterfly spring seat is fixedly connected to the sub-housing by a fixing bolt, and the rod body of the fixing bolt is inserted into the positioning through hole formed on the end surface of the radially extending annular groove.

[0021] The outstanding effects of the utility model are:

[0022] 1. It uses two motors to drive the corresponding wheel hub assemblies separately, so that it can meet the steering needs of the vehicle and achieve steering through the different rotation speeds of the wheels installed on the left and right wheel hub assemblies;

[0023] 2. The brake device is placed between two motors, which is easy to install and process, has a simple structure, greatly reduces the manufacturing difficulty, and reduces the manufacturing cost. Description of the drawings:

[0024] Figure 1 It is a partial structural schematic diagram of the utility model;

[0025] Figure 2 yes Figure 1 A partial enlarged view of

[0026] Figure 3 yes Figure 2 A partial enlarged view of . Specific implementation method:

[0027] For example, see Figures 1 to 3 As shown, a dual-drive wet electric bridge includes a motor 10, a brake device 20 and a wheel hub assembly 30, wherein the motor 10 is fixed to both left and right ends of the brake device 20, and the outer end of the motor 10 is fixedly connected to the housing of the wheel hub assembly 30 by bolts, and the motor 10 and the wheel hub assembly 30 are both conventional structures, which are not described in detail here, wherein the wheel hubs of the corresponding wheels of the forklift are installed on the wheel hub assembly 30, and the corresponding wheel hub assembly 30 is driven separately by two motors 10, so that it can achieve steering through the different rotation speeds of the wheels installed on the left and right wheel hub assemblies 30.

[0028] The brake device 20 includes two sub-shells 21 symmetrically arranged and pressed against each other, and the outer wall surface of the sub-shell 21 is pressed against the end surface of the end plate at the inner side of the corresponding motor 10; the two sub-shells 21 and the two motors 10 are fixedly connected by bolts;

[0029] An annular groove is formed on the edge of the end surface of the end plate at the inner side of the two motors 10, and an annular protrusion is formed on the edge of the outer wall surface of the corresponding sub-shell 21. The annular protrusion is inserted into the annular groove, and the inner side wall of the annular groove is tightly attached to or close to the inner side wall of the annular protrusion.

[0030] Furthermore, the inner end of the motor shaft 11 of the motor 10 extends out of the end surface of the end plate at the inner side of the motor 10 and is installed with an inner friction plate 12 and an outer friction plate 13;

[0031] An outer stepped through hole 211 is formed on a side of the middle of the sub-shell 21 close to the motor 10, and an inner stepped through hole 212 is formed on a side of the middle of the sub-shell 21 away from the motor 10. The inner end of the outer stepped through hole 211 is connected to the outer end of the inner stepped through hole 212.

[0032] A service brake piston 22 is installed in the outer stepped through hole 211, and the outer end surface of the service brake piston 22 is pressed against the outer friction plate 13. A parking brake piston 23 and a butterfly spring seat 24 are installed in the inner stepped through hole 212. A butterfly spring 25 is provided between the parking brake piston 23 and the butterfly spring seat 24. One end of the butterfly spring 25 works on the butterfly spring seat 24, and the other end works on the inner end of the parking brake piston 23. The outer end surface of the parking brake piston 23 is pressed against the inner end surface of the service brake piston 22.

[0033] Furthermore, a groove is formed in the middle of the end surface of the end plate at the inner side of the motor 10, and a main annular groove is formed on the inner wall of the groove close to one end of the sub-shell 21. The edge of the fixed end plate 213 is inserted into the main annular groove and fixedly connected to the end plate at the inner side of the motor 10 by positioning bolts, and one end surface edge of the fixed end plate 213 is pressed against the end surface of the annular groove.

[0034] A pressure plate 14, an inner friction plate 12 and an outer friction plate 13 are inserted and sleeved on the inner end of the motor shaft 11 of the motor 10, the inner friction plate 12 is clamped between the pressure plate 14 and the outer friction plate 13, the other side wall surface of the pressure plate 14 is closely attached to one end surface of the fixed end plate 213, and the other side wall surface of the outer friction plate 13 is pressed against the outer end surface of the service brake piston 22;

[0035] The outer edges of the pressure plate 14 and the outer friction plate 13 are formed with a plurality of positioning grooves, and the rods of the corresponding positioning bolts are inserted into the corresponding positioning grooves. A rotating member 15 (which is fixed by a key connection) is fixed on the inner end of the motor shaft 11 of the motor 10, and the inner friction plate 12 is inserted into the rotating member 15. A tooth-shaped groove is formed on the outer wall of the rotating member 15, and a tooth-shaped protrusion is formed on the inner wall of the middle through hole of the inner friction plate 12. The tooth-shaped protrusion is inserted into the tooth-shaped groove, and the two cooperate with each other;

[0036] Furthermore, the outer stepped through hole 211 includes a first outer hole section 2111, a second outer hole section 2112 and a third outer hole section 2113 extending from the outside to the inside in sequence, the inner diameter of the first outer hole section 2111 is larger than that of the second outer hole section 2112, and the inner diameter of the second outer hole section 2112 is larger than that of the third outer hole section 2113;

[0037] The inner stepped through hole 212 includes a first inner hole section 2121 and a second inner hole section 2122 extending from the outside to the inside in sequence. The inner diameter of the second inner hole section 2122 is larger than the inner diameter of the first inner hole section 2121 . The third outer hole section 2113 is connected to the corresponding first inner hole section 2121 .

[0038] Further, a radially extending edge portion 221 is formed on the outer wall of the outer end surface of the service brake piston 22, and the radially extending edge portion 221 is inserted into the corresponding first outer hole section 2111, and the outer end surface of the radially extending edge portion 221 is pressed against the corresponding end surface of the corresponding outer friction plate 13, and a radially extending reinforcing ring portion 222 is formed on the middle outer wall of the service brake piston 22, and the radially extending reinforcing ring portion 222 is inserted into the second outer hole section 2112, and the outer wall of the radially extending reinforcing ring portion 222 is close to the inner wall of the second outer hole section 2112, and the radial A sealing groove is formed on the outer side wall of the extending reinforcing ring portion 222, the first sealing ring 1 is nested in the sealing groove, the outer wall surface of the first sealing ring 1 is pressed against the inner side wall of the second outer hole section 2112, the inner end of the service brake piston 22 is inserted into the third outer hole section 2113, the outer side wall of the inner end of the service brake piston 22 is close to the inner side wall of the third outer hole section 2113, the second sealing ring 2 is nested in the sealing groove formed on the outer side wall of the inner end of the service brake piston 22, and the outer wall surface of the second sealing ring 2 is pressed against the inner side wall of the third outer hole section 2113;

[0039] A first oil through hole 26 is formed on the inner side wall of the outer stepped through hole 211 between the first sealing ring 1 and the second sealing ring 2 (i.e., a first oil through hole 26 is formed on the inner end surface of the second outer hole section 2112 and the inner side wall at the inner end surface), and the outer end of the first oil through hole 26 extends out of the outer wall surface of the sub-shell 21.

[0040] Furthermore, a first radial extension portion 231 is formed on the outer wall of the inner end of the parking brake piston 23, the outer section of the parking brake piston 23 is inserted into the first inner hole section 2121, the inner section of the parking brake piston 23 and the first radial extension portion 231 are inserted into the second inner hole section 2122, the outer wall surface of the outer section of the parking brake piston 23 is close to the inner wall of the first inner hole section 2121, and the third sealing ring 3 is embedded in the sealing groove on the outer wall surface of the outer section of the parking brake piston 23, and the outer wall surface of the third sealing ring 3 is pressed against the inner wall of the first inner hole section 2121 The outer wall surface of the first radial extension portion 231 is close to the inner wall of the second inner hole section 2122, and the fourth sealing ring 4 is nested in the sealing groove on the outer wall of the first radial extension portion 231. The outer wall surface of the fourth sealing ring 4 is pressed against the inner wall of the second inner hole section 2122. A second oil through hole 27 is formed on the inner wall of the inner stepped through hole 212 between the third sealing ring 3 and the fourth sealing ring 4 (that is, the second oil through hole 27 is formed on the outer end surface of the second inner hole section 2122 and the inner wall at the outer end surface), and the outer end of the second oil through hole 27 extends out of the outer wall surface of the sub-shell 21.

[0041] Furthermore, an inner mounting hole 232 is formed in the middle of the inner end surface of the parking brake piston 23, and a radially extending annular groove 233 is formed on the inner side wall of the inner mounting hole 232 near the inner end surface of the parking brake piston 23, and the butterfly spring seat 24 is inserted into the radially extending annular groove 233. The butterfly spring seat 24 is fixedly connected to the sub-housing 21 by a fixing bolt, and the rod body of the fixing bolt is inserted into the positioning through hole formed on the end surface of the radially extending annular groove 233;

[0042] A butterfly spring 25 is inserted into the inner mounting hole 232 , one end of the butterfly spring 25 is pressed against the end surface of the inner mounting hole 232 , and the other end of the butterfly spring 25 is pressed against the butterfly spring seat 24 .

[0043] Furthermore, a plurality of return spring support pins 6 are fixed on the end face of the main annular groove, and a return spring 7 is inserted on the return spring support pin 6. One end of the return spring 7 is applied to the end face of the main annular groove, and the other end is applied to the edge of the corresponding end face of the outer friction plate 13.

[0044] Furthermore, the return spring support pin 6 is inserted into the through hole corresponding to the edge of the outer friction plate 13. The return spring 7 can ensure that when the parking brake piston 23 is not pressed against the service brake piston 22, the outer friction plate 13 is pushed open so that it does not contact the inner friction plate 12, thereby ensuring the normal rotation of the motor shaft 11.

[0045] Working principle: When this embodiment is in use, its first oil through hole 26 and the second oil through hole 27 are connected to the control valve of the external oil pump through a connecting pipe, and the flow of oil is realized through the operation of the control valve (it is a conventional structure and will not be described in detail here); wherein, the outer ends of the first oil through hole 26 and the second oil through hole 27 are connected to plugs when leaving the factory, which has a protective function.

[0046] The two motors 10 can be controlled separately, so that the motor shafts 11 of the two motors 10 can run at different rotation speeds, so that the hub rotation speeds of the corresponding hub assembly 30 are different, and the wheels thereon can turn by rotating at different speeds. The control is precise and the effect is good.

[0047] When this embodiment is in use, during driving, oil is continuously passed into the second oil through hole 27, so that the parking brake piston 23 moves inward, that is, the parking brake piston 23 no longer presses against the service brake piston 22. At this time, the butterfly spring 25 is compressed, and the elastic restoring force of the return spring 7 pushes the outer friction plate 13 away, so that it does not contact the inner friction plate 12, thereby ensuring the normal rotation of the motor shaft 11.

[0048] When service braking is needed, the oil enters the first oil through hole 26, causing the service brake piston 22 to move outward, so that the outer end face of its radially extending edge 221 presses against the corresponding end face of the corresponding outer friction plate 13 and pushes outward, so that the return spring 7 is compressed, so that the inner friction plate 12 is clamped between the pressure plate 14 and the outer friction plate 13, so that the motor shaft 11 of the motor 10 cannot rotate, thereby achieving service braking.

[0049] When parking brake is needed, that is, after the forklift stops running, the oil in the second oil through hole 27 is returned. At this time, the butterfly spring 25 returns to its original position, pressing the parking brake piston 23 against the service brake piston 22, so that the service brake piston 22 is pressed against the corresponding end surface of the outer friction plate 13 and pushed outward, so that the return spring 7 is compressed, so that the inner friction plate 12 is clamped between the pressure plate 14 and the outer friction plate 13, so that the motor shaft 11 of the motor 10 cannot rotate, thereby realizing parking brake.

[0050] In this embodiment, the brake device 20 is placed between the two motors 10, which is convenient for installation and processing, has a simple structure, greatly reduces the manufacturing difficulty, and reduces the manufacturing cost.

Claims

1. A dual-drive wet electric axle, comprising a motor (10), a brake device (20) and a hub assembly (30), characterized in that: Motors (10) are fixed to both left and right ends of the brake device (20), and the outer end of the motor (10) is fixedly connected to the housing of the wheel hub assembly (30) by bolts; The braking device (20) comprises two sub-shells (21) which are symmetrically arranged and pressed against each other, and the outer wall surfaces of the sub-shells (21) are pressed against the end surfaces of the end plates at the inner sides of the corresponding motors (10); The inner end of the motor shaft (11) of the motor (10) extends out of the end surface of the end plate at the inner side of the motor (10) and is installed with an inner friction plate (12) and an outer friction plate (13); An outer stepped through hole (211) is formed on a side of the middle of the sub-housing (21) close to the motor (10), and an inner stepped through hole (212) is formed on a side of the middle of the sub-housing (21) away from the motor (10), and the inner end of the outer stepped through hole (211) is in communication with the outer end of the inner stepped through hole (212); A service brake piston (22) is installed in the outer stepped through hole (211), and the outer end surface of the service brake piston (22) is pressed against the outer friction plate (13). A parking brake piston (23) and a butterfly spring seat (24) are installed in the inner stepped through hole (212). A butterfly spring (25) is provided between the parking brake piston (23) and the butterfly spring seat (24). One end of the butterfly spring (25) is applied to the butterfly spring seat (24), and the other end is applied to the inner end of the parking brake piston (23). The outer end surface of the parking brake piston (23) is pressed against the inner end surface of the service brake piston (22).

2. The dual-drive wet electric axle according to claim 1, characterized in that: A groove is formed in the middle of the end surface of the end plate at the inner side of the motor (10), and a main annular groove is formed on the inner side wall of the groove at one end close to the sub-housing (21). The edge of the fixed end plate (213) is inserted into the main annular groove and fixedly connected to the end plate at the inner side of the motor (10) by means of positioning bolts, and an end surface edge of the fixed end plate (213) is pressed against the end surface of the annular groove. A pressure plate (14), an inner friction plate (12) and an outer friction plate (13) are inserted and sleeved on the inner end of the motor shaft (11) of the motor (10); the inner friction plate (12) is clamped between the pressure plate (14) and the outer friction plate (13); the other side wall of the pressure plate (14) is in close contact with one end surface of the fixed end plate (213); and the other side wall of the outer friction plate (13) is pressed against the outer end surface of the service brake piston (22); A plurality of positioning grooves are formed on the outer edges of the pressure plate (14) and the outer friction plate (13), and the rod bodies of the corresponding positioning bolts are inserted into the corresponding positioning grooves. A rotating member (15) is fixed on the inner end of the motor shaft (11) of the motor (10), and the inner friction plate (12) is inserted into the rotating member (15). A tooth-shaped groove is formed on the outer wall of the rotating member (15), and a tooth-shaped protrusion is formed on the inner wall of the middle through hole of the inner friction plate (12). The tooth-shaped protrusion is inserted into the tooth-shaped groove, and the two cooperate with each other.

3. The dual-drive wet electric axle according to claim 1, characterized in that: The outer stepped through hole (211) comprises a first outer hole section (2111), a second outer hole section (2112) and a third outer hole section (2113) which are sequentially extended from the outside to the inside, the inner diameter of the first outer hole section (2111) is larger than that of the second outer hole section (2112), and the inner diameter of the second outer hole section (2112) is larger than that of the third outer hole section (2113); The inner stepped through hole (212) comprises a first inner hole section (2121) and a second inner hole section (2122) which are extended from the outside to the inside in sequence, the inner diameter of the second inner hole section (2122) is larger than the inner diameter of the first inner hole section (2121), and the third outer hole section (2113) is connected to the corresponding first inner hole section (2121).

4. The dual-drive wet electric axle according to claim 3, characterized in that: A radially extending edge portion (221) is formed on the outer wall of the outer end surface of the service brake piston (22), the radially extending edge portion (221) is inserted into the corresponding first outer hole section (2111), and the outer end surface of the radially extending edge portion (221) is pressed against the corresponding end surface of the corresponding outer friction plate (13); a radially extending reinforcing ring portion (222) is formed on the middle outer wall of the service brake piston (22), the radially extending reinforcing ring portion (222) is inserted into the second outer hole section (2112), the outer wall of the radially extending reinforcing ring portion (222) is close to the inner wall of the second outer hole section (2112), and the radially extending A sealing groove is formed on the outer wall of the reinforcing ring portion (222), the first sealing ring (1) is nested in the sealing groove, the outer wall surface of the first sealing ring (1) is pressed against the inner wall of the second outer hole section (2112), the inner end of the service brake piston (22) is inserted into the third outer hole section (2113), the outer wall of the inner end of the service brake piston (22) is close to the inner wall of the third outer hole section (2113), the second sealing ring (2) is nested in the sealing groove formed on the outer wall of the inner end of the service brake piston (22), and the outer wall surface of the second sealing ring (2) is pressed against the inner wall of the third outer hole section (2113); A first oil through hole (26) is formed on the inner side wall of the outer stepped through hole (211) between the first sealing ring (1) and the second sealing ring (2), and the outer end of the first oil through hole (26) extends out of the outer wall surface of the sub-shell (21).

5. The dual-drive wet electric axle according to claim 4, characterized in that: A first radial extension portion (231) is formed on the outer wall of the inner end of the parking brake piston (23); the outer section of the parking brake piston (23) is inserted into the first inner hole section (2121); the inner section of the parking brake piston (23) and the first radial extension portion (231) are inserted into the second inner hole section (2122); the outer wall surface of the outer section of the parking brake piston (23) is close to the inner wall of the first inner hole section (2121); a third sealing ring (3) is embedded in the sealing groove on the outer wall surface of the outer section of the parking brake piston (23); the outer wall surface of the third sealing ring (3) is pressed against the outer wall surface of the third sealing ring (3). The first radial extension portion (231) is adjacent to the inner wall of the first inner hole section (2121), the outer wall of the first radial extension portion (231) is adjacent to the inner wall of the second inner hole section (2122), a fourth sealing ring (4) is embedded in the sealing groove on the outer wall of the first radial extension portion (231), the outer wall of the fourth sealing ring (4) is pressed against the inner wall of the second inner hole section (2122), a second oil through hole (27) is formed on the inner wall of the inner stepped through hole (212) between the third sealing ring (3) and the fourth sealing ring (4), the outer end of the second oil through hole (27) protrudes from the outer wall of the sub-shell (21).

6. The dual-drive wet electric axle according to claim 5, characterized in that: An inner mounting hole (232) is formed in the middle of the inner end surface of the parking brake piston (23); a radially extending annular groove (233) is formed on the inner side wall of the inner mounting hole (232) near the inner end surface of the parking brake piston (23); the butterfly spring seat (24) is inserted into the radially extending annular groove (233); the butterfly spring seat (24) is fixedly connected to the sub-housing (21) by a fixing bolt; and the rod body of the fixing bolt is inserted into a positioning through hole formed on the end surface of the radially extending annular groove (233); A butterfly spring (25) is inserted into the inner mounting hole (232), one end of the butterfly spring (25) is pressed against the end surface of the inner mounting hole (232), and the other end of the butterfly spring (25) is pressed against the butterfly spring seat (24).

7. The dual-drive wet electric axle according to claim 2, characterized in that: A plurality of return spring support pins (6) are fixed on the end surface of the main annular groove, a return spring (7) is inserted on the return spring support pin (6), one end of the return spring (7) is applied to the end surface of the main annular groove, and the other end is applied to the edge of a corresponding end surface of the outer friction plate (13).

8. The dual-drive wet electric axle according to claim 7, characterized in that: The return spring support pin (6) is inserted into a through hole corresponding to the edge of the outer friction plate (13).

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