A pool cleaning machine

Abstract

The present invention discloses a pool cleaning machine, which comprises a body of the pool cleaning machine, a cover of the pool cleaning machine, a bottom cover plate, a detachable cotton swab sleeve assembly, a motor box body and a water flow channel. Compared with the prior art, the structure of the present invention is simple and reasonable in design. Without disassembling the transmission mechanism of the side cover, the cotton swab sleeve can be disassembled and maintained, which simplifies after-sales maintenance and user operation and is worthy of promotion.

Description

Technical Field

[0001] The present invention relates to the technical field of cleaning equipment, and particularly to a swimming pool cleaner. Background Art

[0002] A swimming pool cleaner is a cleaning device for meeting the cleaning needs of a swimming pool. It can crawl autonomously on the bottom of the swimming pool, circle around the perimeter, repeatedly clean the dirt in the pool, filter the pool water, and collect garbage, making the pool water clear as new. The operation of the swimming pool cleaner can be divided into two modes: manual control and automatic cleaning according to the usage needs, and the design is very user-friendly.

[0003] The cotton swab sleeve assembly of the existing swimming pool cleaners on the market cannot be easily disassembled. To replace the cotton swab sleeve, it is necessary to disassemble the side cover, which is not convenient for after-sales maintenance and user use. Therefore, it is necessary to propose a swimming pool cleaner. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems in the prior art and propose a swimming pool cleaner. The structure of the present invention is simple and reasonably designed. Without disassembling the transmission mechanism of the side cover, the cotton swab sleeve can be disassembled and maintained, simplifying after-sales maintenance and user use, and is worthy of promotion.

[0005] To achieve the above purpose, the present invention proposes a swimming pool cleaner, which includes a swimming pool cleaner body, a swimming pool cleaner cover, a bottom cover plate, a detachable cotton swab sleeve assembly, a motor box body, and a water flow channel. The top of the swimming pool cleaner body is provided with a swimming pool cleaner cover, and the swimming pool cleaner cover is provided with a water outlet. The bottom of the swimming pool cleaner body is provided with a bottom cover plate, and both sides of the bottom cover plate are provided with a detachable cotton swab sleeve assembly. The motor box body is fixedly arranged inside the swimming pool cleaner body, and a water pump motor and a traveling motor are arranged inside the motor box body. The traveling motor is located on both sides of the water pump motor. The output end of the water pump motor passes through the top wall of the motor box body, and an impeller is arranged at its upper end. The impeller is located inside the water outlet. The output end of the traveling motor is connected to the detachable cotton swab sleeve assembly on the same side through a synchronous belt or a gear. The bottom of the bottom cover plate is provided with a water inlet, and a filter bag support is arranged on the top of the bottom cover plate. A filter bag is arranged on the filter bag support. A water flow channel is arranged between the inner wall of the swimming pool cleaner body and the outer wall of the motor box body, and the upper and lower ends of the water flow channel are respectively connected to the water outlet and the water inlet.

[0006] Preferably, a power interface slot is further provided on the cover of the pool cleaner. The power interface slot is located on the front side of the water outlet. A root of a wire connector is provided inside the power interface slot. An integrally formed wire is provided on the root of the wire connector. A protective nut is sleeved outside the root of the wire connector. A handle is further provided on the top of the cover of the pool cleaner. The handle is located on the left side of the power interface slot. A through hole is provided at one end of the handle. The wire passes through the through hole. A cylindrical protrusion is provided on the top of the protective nut. The wire passes through the cylindrical protrusion. A rubber protective sleeve is provided inside the through hole. The rubber protective sleeve is fixedly installed inside the through hole. The rubber protective sleeve fixes the wire on the handle.

[0007] Preferably, locking components are further provided on both sides of the bottom surface of the bottom cover plate. An inlet baffle is further provided on the top surface of the bottom cover plate. A fixed end is provided on one side of the inlet baffle. The inlet baffle can rotate along the fixed end.

[0008] Preferably, the detachable cotton swab sleeve assembly includes a pool cleaner frame, a cotton swab sleeve, a connecting plate, a detachable cover, a first guide member, a second guide member, a buckle and a compression spring. The pool cleaner frame further includes a first transmission shaft, a second transmission shaft, a shaft sleeve fixing cover and transmission parts. A shaft sleeve fixing cover is provided on the right side of the first transmission shaft. A second transmission shaft arranged opposite to the first transmission shaft is provided on the shaft sleeve fixing cover. Transmission parts are provided outside the first transmission shaft. A cotton swab sleeve is provided between the first transmission shaft and the second transmission shaft. The cotton swab sleeve is a cylinder with an opening on the right side. A connecting plate is provided on the left side wall of the cotton swab sleeve. A first transmission shaft connection groove is provided on the connecting plate. The first transmission shaft connection groove is a D-shaped groove. A limiting groove extending leftward is provided at the opening edge of the cotton swab sleeve. A detachable cover is provided on the right opening of the cotton swab sleeve. The detachable cover further includes a first guide member, a second guide member, a buckle and a compression spring. A second guide member is provided at the bottom of the first guide member. The second transmission shaft passes through the first guide member and the second guide member. A buckle and a compression spring are provided on the second transmission shaft. The buckle is fixedly installed on the second transmission shaft and is located between the first guide member and the second guide member. The compression spring is located between the first guide member and the buckle. A guide groove corresponding to the limiting groove is provided on the first guide member. The upper end of the buckle passes through the guide groove and is located inside the limiting groove. A wrapping edge is provided at the edge of the left side wall of the second guide member. The inner diameter of the wrapping edge is equal to the outer diameter of the cotton swab sleeve. A fixing screw hole is provided on the right side wall of the second guide member. A fixing bolt is provided in the fixing screw hole. A coordination screw hole is provided on the right side wall of the upper end of the buckle. The coordination screw hole corresponds to the fixing bolt.

[0009] Preferably, the motor box body is composed of a motor box housing, a motor box cover plate and a sealing ring. A sealing ring is provided between the motor box housing and the motor box cover plate. On the outer side wall of the motor box housing, there are a motor fixing nut, a box body fixing part, a transmission shaft and a clearance compensation coupling. The motor fixing nut is fixedly installed on the output end of the traveling motor. The screw hole of the motor fixing nut is divided into a smooth through hole on the outer side and a threaded through hole on the inner side. A box body fixing part is sleeved inside the smooth through hole. The threaded through hole is connected to the output end of the traveling motor. The outer side of the box body fixing part is fixedly connected to the body of the pool cleaner. A transmission shaft is provided inside the box body fixing part. A clearance compensation coupling is provided at one end of the transmission shaft close to the output shaft of the traveling motor. The other end of the transmission shaft is connected to a transmission component.

[0010] The beneficial effects of the present invention: The structure of the present invention is simple and reasonably designed. By setting up a detachable cover composed of a first guiding part, a second guiding part, a buckle and a compression spring, and cooperating with the second transmission shaft and the shaft sleeve fixing cover, the disassembly operation of the cotton swab sleeve is simplified, and thus the after-sales maintenance and the use by users are simplified; by fixedly setting the first guiding part and the second guiding part, problems such as the inclination of the second transmission shaft during rotation are prevented; by setting up fixing bolts, fixing screw holes and coordinating screw holes, the installed buckle is fixed to the second guiding part to prevent the second transmission shaft from generating axial and radial displacements under force conditions such as when the pool cleaner turns or climbs the wall, ultimately resulting in the separation of the cotton swab sleeve from the first transmission shaft; by passing the wire through and fixing it on the handle, it is prevented that when the user does not fix the wire, the wire joint is pulled, resulting in the fracture of the wire joint and then burning out the circuit components inside the machine; by setting up a cylindrical protrusion, when the machine is inverted, it is prevented that the gravity directly acts on the root of the wire joint, resulting in the fracture of the wire inside the wire joint and burning out the internal circuit components; by setting up a motor fixing nut with a smooth through hole, and cooperating with the box body fixing part, the connection between the box body fixing part and the motor fixing nut is fixed by circumferential smoothness. On the premise of ensuring the connection stability and reliability between the motor box body and the body of the pool cleaner, the concentricity of the transmission on both sides of the machine is ensured to avoid mechanical problems such as transmission shaking and wear.

[0011] The features and advantages of the present invention will be described in detail through embodiments in conjunction with the drawings. Description of the Drawings

[0012] Figure 1 is the structural schematic diagram a of a pool cleaner of the present invention;

[0013] Figure 2 is the structural schematic diagram b of a pool cleaner of the present invention;

[0014] Figure 3 is the structural schematic diagram c of a pool cleaner of the present invention;

[0015] Figure 4 It is an enlarged schematic view of part A in schematic diagram c of the structure of a pool cleaning machine according to the present invention;

[0016] Figure 5 It is schematic diagram a of the structure of a detachable cotton swab sleeve assembly in a pool cleaning machine according to the present invention;

[0017] Figure 6 It is schematic diagram b of the structure of a detachable cotton swab sleeve assembly in a pool cleaning machine according to the present invention;

[0018] Figure 7 It is schematic diagram c of the structure of a detachable cotton swab sleeve assembly in a pool cleaning machine according to the present invention;

[0019] Figure 8 It is a schematic diagram of the structure of the motor box housing in a pool cleaning machine according to the present invention;

[0020] Figure 9 It is schematic diagram a of the structure of the bottom cover plate in a pool cleaning machine according to the present invention;

[0021] Figure 10 It is schematic diagram b of the structure of the bottom cover plate in a pool cleaning machine according to the present invention.

[0022] In the figure: 1 - body of the pool cleaning machine, 2 - cover of the pool cleaning machine, 21 - water outlet, 22 - power interface slot, 23 - root of the wire joint, 24 - wire, 25 - protective nut, 251 - cylindrical protrusion, 26 - handle, 261 - through hole, 262 - rubber protection sleeve, 3 - bottom cover plate, 31 - water inlet, 32 - filter bag support, 33 - filter bag, 34 - locking component, 35 - water inlet baffle, 36 - fixed end, 4 - detachable cotton swab sleeve assembly, 41 - frame of the pool cleaning machine, 411 - first transmission shaft, 412 - second transmission shaft, 413 - shaft sleeve fixing cover, 42 - cotton swab sleeve, 421 - limit groove, 43 - connecting plate, 431 - first transmission shaft connecting groove, 44 - detachable cover, 45 - first guiding member, 451 - guiding groove, 46 - second guiding member, 461 - edge wrapping, 462 - fixing screw hole, 463 - fixing bolt, 47 - buckle, 471 - coordinating screw hole, 48 - compression spring, 5 - motor box housing, 51 - water pump motor, 511 - impeller, 52 - traveling motor, 53 - motor box shell, 531 - motor fixing nut, 5311 - smooth through hole, 5312 - threaded through hole, 532 - box body fixing member, 533 - transmission shaft, 534 - clearance compensation coupling, 54 - motor box cover plate, 55 - sealing ring, 6 - water flow channel. Detailed implementation manners

[0023] Referring to the attached drawings, a pool cleaning machine of the present invention includes a pool cleaning machine body 1, a pool cleaning machine cover 2, a bottom cover plate 3, a detachable cotton swab sleeve assembly 4, a motor box body 5, and a water flow channel 6. A pool cleaning machine cover 2 is provided at the top of the pool cleaning machine body 1. An outlet 21 is provided on the pool cleaning machine cover 2. A bottom cover plate 3 is provided at the bottom of the pool cleaning machine body 1. Detachable cotton swab sleeve assemblies 4 are provided on both sides of the bottom cover plate 3. A motor box body 5 is fixedly provided inside the pool cleaning machine body 1. A water pump motor 51 and a traveling motor 52 are provided inside the motor box body 5. The traveling motor 52 is located on both sides of the water pump motor 51. The output end of the water pump motor 51 passes through the top wall of the motor box body 5 and an impeller 511 is provided at its upper end. The impeller 511 is located inside the outlet 21. The output end of the traveling motor 52 is connected to the detachable cotton swab sleeve assembly 4 on the same side through a synchronous belt or a gear. An inlet 31 is provided at the bottom of the bottom cover plate 3. A filter bag support 32 is provided on the top of the bottom cover plate 3. A filter bag 33 is provided on the filter bag support 32. A water flow channel 6 is provided between the inner wall of the pool cleaning machine body 1 and the outer wall of the motor box body 5. The upper and lower ends of the water flow channel 6 are respectively connected to the outlet 21 and the inlet 31.

[0024] Among them, a power interface slot 22 is further provided on the pool cleaning machine cover 2. The power interface slot 22 is located in front of the outlet 21. A wire joint root 23 is provided inside the power interface slot 22. An integrally formed wire 24 is provided on the wire joint root 23. A protective nut 25 is sleeved outside the wire joint root 23. A handle 26 is further provided on the top of the pool cleaning machine cover 2. The handle 26 is located on the left side of the power interface slot 22. A through hole 261 is provided at one end of the handle 26. The wire 24 passes through the through hole 261. A cylindrical protrusion 251 is provided on the top of the protective nut 25. The wire 24 passes through the cylindrical protrusion 251. A rubber protective sleeve 262 is provided inside the through hole 261. The rubber protective sleeve 262 is fixedly installed inside the through hole 261. The rubber protective sleeve 262 fixes the wire 24 on the handle 26.

[0025] Among them, lock components 34 are further provided on both sides of the bottom surface of the bottom cover plate 3. An inlet baffle 35 is further provided on the top surface of the bottom cover plate 3. A fixed end 36 is provided on one side of the inlet baffle 35. The inlet baffle 35 can rotate along the fixed end 36.

[0026] Among them, the detachable cotton swab sleeve assembly 4 includes a pool cleaning machine frame 41, a cotton swab sleeve 42, a connecting plate 43, a detachable cover 44, a first guide 45, a second guide 46, a buckle 47 and a compression spring 48. The pool cleaning machine frame 41 further includes a first transmission shaft 411, a second transmission shaft 412, a bushing fixing cover 413 and transmission parts. A bushing fixing cover 413 is provided on the right side of the first transmission shaft 411. A second transmission shaft 412 opposite to the first transmission shaft 411 is provided on the bushing fixing cover 413. Transmission parts are provided on the outer side of the first transmission shaft 411. A cotton swab sleeve 42 is provided between the first transmission shaft 411 and the second transmission shaft 412. The cotton swab sleeve 42 is a cylinder with an opening on the right side. A connecting plate 43 is provided on the left side wall of the cotton swab sleeve 42. A first transmission shaft connection groove 431 is provided on the connecting plate 43. The first transmission shaft connection groove 431 is a D-shaped groove. A limiting groove 421 extending leftward is provided at the opening edge of the cotton swab sleeve 42. A detachable cover 44 is provided on the right opening of the cotton swab sleeve 42. The detachable cover 44 further includes a first guide 45, a second guide 46, a buckle 47 and a compression spring 48. The second guide 46 is provided at the bottom of the first guide 45. The second transmission shaft 412 passes through the first guide 45 and the second guide 46. A buckle 47 and a compression spring 48 are provided on the second transmission shaft 412. The buckle 47 is fixedly installed on the second transmission shaft 412 and is located between the first guide 45 and the second guide 46. The compression spring 48 is located between the first guide 45 and the buckle 47. A guide groove 451 corresponding to the limiting groove 421 is provided on the first guide 45. The upper end of the buckle 47 passes through the guide groove 451 and is located inside the limiting groove 421. A wrapping edge 461 is provided at the edge of the left side wall of the second guide 46. The inner diameter of the wrapping edge 461 is equal to the outer diameter of the cotton swab sleeve 42. A fixing screw hole 462 is provided on the right side wall of the second guide 46. The fixing screw hole is provided with a fixing bolt 463. A coordination screw hole 471 is provided on the right side wall of the upper end of the buckle 47. The coordination screw hole 471 corresponds to the fixing bolt 463.

[0027] Among them, the motor box housing 5 is composed of a motor box shell 53, a motor box cover plate 54 and a sealing ring 55. A sealing ring 55 is provided between the motor box shell 53 and the motor box cover plate 54. On the outer side wall of the motor box shell 53, there are a motor fixing nut 531, a box body fixing part 532, a transmission shaft 533 and a clearance compensation coupling 534. The motor fixing nut 531 is fixedly installed on the output end of the traveling motor 52. The screw hole of the motor fixing nut 531 is divided into a smooth through hole 5311 on the outer side and a threaded through hole 5312 on the inner side. A box body fixing part 532 is sleeved inside the smooth through hole 5311. The threaded through hole 5312 is connected to the output end of the traveling motor 52. The outer side of the box body fixing part 532 is fixedly connected to the body 1 of the pool cleaner. A transmission shaft 533 is provided inside the box body fixing part 532. A clearance compensation coupling 534 is provided at one end of the transmission shaft 533 close to the output shaft of the traveling motor 52. The other end of the transmission shaft 533 is connected to a transmission component.

[0028] The working process of the present invention:

[0029] During the working process of a pool cleaner of the present invention, when it is necessary to disassemble and maintain the cotton swab sleeve 42, the fixing bolt 463 can be removed first, and then the cotton swab cover on the cotton swab sleeve 42 can be opened by hand. The button 47 is toggled to the left. The button 47 drives the second transmission shaft 412 to move to the left, and then separates from the sleeve fixing cover 413. Subsequently, the cotton swab sleeve 42 can be removed for maintenance and replacement.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows: By arranging the first guide member 45, the second guide member 46, the buckle 47 and the compression spring 48 to form the detachable cover 44, and cooperating with the second transmission shaft 412 and the bushing fixing cover 413, the disassembly operation of the cotton swab sleeve 42 is simplified, and thus the after-sales maintenance and the use by users are simplified; By fixedly arranging the first guide member 45 and the second guide member 46, problems such as inclination of the second transmission shaft 412 during rotation are prevented; By arranging the fixing bolt 463, the fixing screw hole 462 and the coordinating screw hole 471, the installed buckle 47 is fixed to the second guide member 46, preventing axial and radial displacement of the second transmission shaft 412 under force conditions such as turning and climbing the wall of the pool cleaning machine, which may ultimately cause the cotton swab sleeve 42 to be disengaged from the first transmission shaft 411; By passing and fixing the wire 24 on the handle 26, when the user does not fix the wire 24, pulling the wire joint is prevented, which may cause the wire joint to break and then burn out the circuit components inside the machine; By arranging the cylindrical protrusion 251, when the machine is inverted, the direct action of gravity on the root 23 of the wire joint is prevented, which may cause the wire inside the wire joint 23 to break and burn out the internal circuit components; By arranging the motor fixing nut 531 with a smooth through hole 5311, and cooperating with the box fixing member 532, the connection between the box fixing member 532 and the motor fixing nut 531 is fixed in a circumferential smooth manner. On the premise of ensuring the connection stability and reliability between the motor box body 5 and the body 1 of the pool cleaning machine, the concentricity of the transmission on both sides of the machine is ensured to avoid mechanical problems such as transmission shaking and wear.

[0031] The above embodiments are illustrative of the present invention and not restrictive thereof. Any solution obtained by simply transforming the present invention falls within the protection scope of the present invention.

Claims

1. A pool cleaning machine, characterized in that: It includes the body (1) of the pool cleaner, the cover (2) of the pool cleaner, the bottom cover plate (3), the detachable cotton swab sleeve assembly (4), the motor box body (5), and the water flow channel (6). The top of the body (1) of the pool cleaner is provided with the cover (2) of the pool cleaner. The cover (2) of the pool cleaner is provided with a water outlet (21). The bottom of the body (1) of the pool cleaner is provided with the bottom cover plate (3). The two sides of the bottom cover plate (3) are provided with the detachable cotton swab sleeve assembly (4). The motor box body (5) is fixedly arranged inside the body (1) of the pool cleaner. A water pump motor (51) and a traveling motor (52) are arranged inside the motor box body (5). The traveling motor (52) is located on both sides of the water pump motor (51). The output end of the water pump motor (51) passes through the top wall of the motor box body (5), and an impeller (511) is arranged at its upper end. The impeller (511) is located inside the water outlet (21). The output end of the traveling motor (52) is connected to the detachable cotton swab sleeve assembly (4) on the same side through a synchronous belt or a gear. The bottom of the bottom cover plate (3) is provided with a water inlet (31). The top of the bottom cover plate (3) is provided with a filter bag support (32). A filter bag (33) is arranged on the filter bag support (32). A water flow channel (6) is arranged between the inner wall of the body (1) of the pool cleaner and the outer wall of the motor box body (5). The upper and lower ends of the water flow channel (6) are respectively connected to the water outlet (21) and the water inlet (31). The detachable cotton swab sleeve assembly (4) includes a frame (41) of the pool cleaner, a cotton swab sleeve (42), a connecting plate (43), a detachable cover (44), a first guide (45), a second guide (46), a buckle (47), and a compression spring (48). The frame (41) of the pool cleaner further includes a first transmission shaft (411), a second transmission shaft (412), a sleeve fixing cover (413), and transmission parts. A sleeve fixing cover (413) is arranged on the right side of the first transmission shaft (411). A second transmission shaft (412) opposite to the first transmission shaft (411) is arranged on the sleeve fixing cover (413). Transmission parts are arranged outside the first transmission shaft (411). A cotton swab sleeve (42) is arranged between the first transmission shaft (411) and the second transmission shaft (412). The cotton swab sleeve (42) is a cylinder with an opening on the right side. A connecting plate (43) is arranged on the left side wall of the cotton swab sleeve (42). A first transmission shaft connection groove (431) is arranged on the connecting plate (43). The first transmission shaft connection groove (431) is a D-shaped groove. A limiting groove (421) extending leftward is arranged at the opening edge of the cotton swab sleeve (42). A detachable cover (44) is arranged on the right opening of the cotton swab sleeve (42). The detachable cover (44) further includes a first guide (45), a second guide (46), a buckle (47), and a compression spring (48). The bottom of the first guide (45) is provided with the second guide (46).The second transmission shaft (412) passes through the first guide member (45) and the second guide member (46). A buckle (47) and a compression spring (48) are provided on the second transmission shaft (412). The buckle (47) is fixedly installed on the second transmission shaft (412) and is located between the first guide member (45) and the second guide member (46). The compression spring (48) is located between the first guide member (45) and the buckle (47). A guide groove (451) corresponding to the limit groove (421) is provided on the first guide member (45). The upper end of the buckle (47) passes through the guide groove (451) and is located inside the limit groove (421). A wrapped edge (461) is provided at the edge of the left side wall of the second guide member (46). The inner diameter of the wrapped edge (461) is equal to the outer diameter of the sponge rubber sleeve (42). A fixing screw hole (462) is provided on the right side wall of the second guide member (46). The fixing screw hole is provided with a fixing bolt (463). A coordination screw hole (471) is provided on the right side wall of the upper end of the buckle (47). The coordination screw hole (471) corresponds to the fixing bolt (463).

2. The pool cleaner according to claim 1, characterized in that: The cover (2) of the pool cleaner is also provided with a power interface slot (22). The power interface slot (22) is located on the front side of the water outlet (21). Inside the power interface slot (22), there is a root (23) of a wire connector. An integrally formed wire (24) is provided on the root (23) of the wire connector. A protective nut (25) is sleeved outside the root (23) of the wire connector. On the top of the cover (2) of the pool cleaner, there is also a handle (26). The handle (26) is located on the left side of the power interface slot (22). A through hole (261) is provided at one end of the handle (26). The wire (24) passes through the through hole (261). A cylindrical protrusion (251) is provided on the top of the protective nut (25). The wire (24) passes through the cylindrical protrusion (251). A rubber protective sleeve (262) is provided inside the through hole (261). The rubber protective sleeve (262) is fixedly installed inside the through hole (261). The rubber protective sleeve (262) fixes the wire (24) on the handle (26).

3. A pool cleaning machine according to claim 1, characterized in that: On both sides of the bottom surface of the bottom cover plate (3), there are also locking components (34). On the top surface of the bottom cover plate (3), there is also a water inlet baffle (35). A fixed end (36) is provided on one side of the water inlet baffle (35). The water inlet baffle (35) can rotate along the fixed end (36).

4. A pool cleaning machine according to claim 1, wherein: The motor box body (5) is composed of a motor box housing (53), a motor box cover plate (54) and a sealing ring (55). A sealing ring (55) is provided between the motor box housing (53) and the motor box cover plate (54). On the outer side wall of the motor box housing (53), there are a motor fixing nut (531), a box body fixing part (532), a transmission shaft (533) and a clearance compensation coupling (534). The motor fixing nut (531) is fixedly installed on the output end of the traveling motor (52). The screw hole of the motor fixing nut (531) is divided into a smooth through hole (5311) on the outside and a threaded through hole (5312) on the inside. The box body fixing part (532) is sleeved inside the smooth through hole (5311). The threaded through hole (5312) is connected to the output end of the traveling motor (52). The outside of the box body fixing part (532) is fixedly connected to the body (1) of the pool cleaner. The transmission shaft (533) is provided inside the box body fixing part (532). A clearance compensation coupling (534) is provided at one end of the transmission shaft (533) close to the output shaft of the traveling motor (52). The other end of the transmission shaft (533) is connected to the transmission component.

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