A drum motor assembly

Abstract

The present invention belongs to the technical field of logistics transportation, and particularly relates to a roller motor assembly, comprising: a cylinder shell; a motor reducer assembly, the motor reducer assembly includes a power output unit, an expansion mechanism is provided on the outer peripheral surface of the power output unit, and the power output unit is in interference connection with a first area on the inner wall of the cylinder shell through the expansion mechanism, and the first area is an area close to the center of the cylinder shell in the axial direction of the cylinder shell. The present invention provides three radial support points on the inner side of the cylinder shell, that is, two end covers support both ends of the cylinder shell, and the power output unit supports the middle part of the cylinder shell. Compared with the traditional solution, the present invention reduces the axial span between two adjacent support points, and improves the overall strength of the cylinder shell without adding additional reinforcement structures; the present invention arranges the power output unit in the middle of the cylinder shell, and the torsional stress generated by the driving load is evenly transmitted from the center of the cylinder shell to both ends, reducing the risk of deformation of the cylinder shell and improving the reliability of power transmission.

Description

Technical Field

[0001] The present invention belongs to the technical field of logistics transportation, and particularly relates to a drum motor assembly. Background Art

[0002] The electric drum is one of the important components of the conveyor line. Its function is to drive the flow of goods, and sometimes it is also used to drive other non-powered drums to rotate. The electric drum generally includes a cylinder body. A driving element is provided inside the cylinder body. The driving element is fixedly connected to the frame outside the drum through a fixed shaft. The power output end of the driving element is connected to the cylinder body to drive the cylinder body to rotate relative to the fixed shaft. The cylinder body in the prior art is generally made of thin-walled steel pipe. In order to ensure the smoothness and integrity of the cylinder body surface, generally no fasteners such as bolts are provided between the power output end of the driving element and the cylinder body. A common practice is to connect the power output end to the end cover at one end of the cylinder body, and then use the connection between the end cover and the cylinder body to achieve the power transmission between the power output end and the cylinder body. This method can meet the use requirements when facing a shorter drum. However, when the drum is longer, the following defects will exist: First, the driving load at the power output end only acts on one end of the cylinder body. When the goods on the cylinder body are heavy or the goods are biased towards the other end of the cylinder body, a large torsional stress will be generated between the two ends of the cylinder body. And because the axial span of the cylinder body is large, this torsional stress is likely to cause the cylinder body to deform. Second, when the cylinder body is long, due to the lack of effective radial support in the middle of the cylinder body, the cylinder body itself is prone to deformation under the heavy pressure of the goods. Summary of the Invention

[0003] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a drum motor assembly that can effectively improve the structural strength of the drum and the reliability of power transmission.

[0004] To achieve the above purpose and other related purposes, the present invention provides a drum motor assembly, including:

[0005] A cylinder shell;

[0006] An electric motor reducer assembly, the electric motor reducer assembly is received in the cylinder shell. The electric motor reducer assembly includes a power output unit. An expansion mechanism is provided on the outer peripheral surface of the power output unit. The power output unit is in interference connection with a first area on the inner wall of the cylinder shell through the expansion mechanism. The first area is an area close to the center of the cylinder shell in the axial direction of the cylinder shell;

[0007] A first fixed shaft and a second fixed shaft, the first fixed shaft and the second fixed shaft are respectively circumferentially fixedly connected to both ends of the electric motor reducer assembly, and the first fixed shaft and the second fixed shaft respectively abut against the electric motor reducer assembly from both ends of the electric motor reducer assembly;

[0008] The first end cover is rotatably connected to the first fixed shaft, and the first end cover abuts against the first fixed shaft from the end of the first fixed shaft away from the motor reducer assembly. The first end cover is in interference connection with the inner wall of the first end of the cylindrical shell;

[0009] The second end cover is rotatably connected to the second fixed shaft, and the second end cover abuts against the second fixed shaft from the end of the second fixed shaft away from the motor reducer assembly. The second end cover is in interference connection with the inner wall of the second end of the cylindrical shell.

[0010] In an alternative embodiment of the present invention, a disc-shaped flange is provided on the outer peripheral surface of the power output unit. The expansion mechanism includes an annular elastic member and an annular rigid member stacked in sequence along the axial direction of the power output unit from one end surface of the disc-shaped flange. At least two annular elastic members and annular rigid members are respectively provided. The annular elastic members and the annular rigid members are alternately arranged along the axial direction of the power output unit, and the end closest to the disc-shaped flange is an annular elastic member, and the end farthest from the disc-shaped flange is an annular rigid member; a locking mechanism is provided between the annular rigid member farthest from the disc-shaped flange and the power output unit. The locking mechanism is configured to be able to hold the annular rigid member in a state of pressing the annular elastic member and causing the annular elastic member to deform. When the annular elastic member deforms, the outer peripheral surface of the annular elastic member protrudes from the outer peripheral surface of the disc-shaped flange.

[0011] In an alternative embodiment of the present invention, a clearance fit is formed between the inner peripheral surface of the annular rigid member and the outer peripheral surface of the power output unit. A ring groove is provided on the outer peripheral surface of the power output unit. The locking mechanism includes a circlip, the circlip is clamped in the ring groove, and the circlip protrudes from the outer peripheral surface of the power output unit. The annular rigid member farthest from the disc-shaped flange abuts against the circlip.

[0012] In an alternative embodiment of the present invention, the first end cover is provided with a first through hole for the first fixed shaft to pass through. A first counterbore is provided at one end of the first through hole facing the motor reducer assembly. A first bearing is provided between the first end cover and the first fixed shaft. The outer ring of the first bearing abuts against the first counterbore, and the inner ring of the first bearing abuts against a first step provided on the first fixed shaft.

[0013] In an alternative embodiment of the present invention, a first sliding sealing ring is provided between the inner wall of the first through hole and the first fixed shaft. A second counterbore is provided at one end of the first through hole away from the motor reducer assembly. A first sealing end cover is provided in the second counterbore.

[0014] In an alternative embodiment of the present invention, the second end cover is provided with a second through hole for the second fixed shaft to pass through. One end of the second through hole facing the motor reducer assembly is provided with a third counterbore. A second bearing is provided between the second end cover and the second fixed shaft. The outer ring of the second bearing abuts against the third counterbore, and the inner ring of the second bearing abuts against a second step provided on the second fixed shaft.

[0015] In an alternative embodiment of the present invention, a second sliding sealing ring is provided between the inner wall of the second through hole and the second fixed shaft. One end of the second through hole away from the motor reducer assembly is provided with a fourth counterbore, and a second sealing end cover is provided in the fourth counterbore.

[0016] In an alternative embodiment of the present invention, the motor reducer assembly includes a motor and a reducer. The reducer includes a housing, a first gear, a second gear, a third gear, and a fourth gear. The first gear, the second gear, the third gear, and the fourth gear are rotatably connected to the housing. An output gear is provided on the main shaft of the motor. The power output unit includes an output gear ring. The first gear and the second gear are coaxially and fixedly arranged. The third gear and the fourth gear are coaxially and fixedly arranged. The first gear meshes with the output gear, the second gear meshes with the third gear, and the fourth gear meshes with the output gear ring.

[0017] In an alternative embodiment of the present invention, a first jack is provided at one end of the housing away from the motor, and a second jack is provided at one end of the motor away from the reducer. The first fixed shaft passes through the output gear ring and is inserted into the first jack. A first key is provided between the first fixed shaft and the first jack. The second fixed shaft is inserted into the second jack, and a second key is provided between the second fixed shaft and the second jack. A third step for abutting against the end face of the housing is provided on the first fixed shaft, and a fourth step for abutting against the end face of the motor is provided on the second fixed shaft.

[0018] In an alternative embodiment of the present invention, a wire harness channel is provided inside the second fixed shaft. One end of the wire harness channel is located on the side end face of the second fixed shaft away from the motor reducer assembly, and the other end of the wire harness channel is located on the circumferential surface of the second fixed shaft inside the second end cover. The cable of the motor reducer assembly is guided to the outside of the cylinder shell through the wire harness channel.

[0019] The technical effects of the present invention are as follows: Three radial support points are provided inside the cylindrical shell of the present invention, that is, two end covers support both ends of the cylindrical shell, and the power output unit supports the middle of the cylindrical shell. Compared with the traditional solution, the present invention reduces the axial span between two adjacent support points, and improves the overall strength of the cylindrical shell without adding additional reinforcement structures; The present invention arranges the power output unit in the middle of the cylindrical shell, and the torsional stress generated by the driving load is evenly transmitted from the center of the cylindrical shell to both ends, reducing the risk of deformation of the cylindrical shell and improving the reliability of power transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the front view of the drum motor assembly provided by the embodiment of the present invention;

[0021] Figure 2 is Figure 1 the A-A sectional view of

[0022] Figure 3 is Figure 2 the partial enlarged view I of

[0023] Figure 4 is Figure 2 the partial enlarged view II of

[0024] Figure 5 is Figure 2 the partial enlarged view III of

[0025] Figure 6 is the perspective view of the power output unit provided by the embodiment of the present invention;

[0026] Figure 7 is the exploded view of the power output unit provided by the embodiment of the present invention;

[0027] Figure 8 is the exploded view of the motor reducer assembly and the power output unit provided by the embodiment of the present invention;

[0028] Figure 9 is the assembly drawing of the motor reducer assembly and the power output unit provided by the embodiment of the present invention;

[0029] Figure 10 is the exploded view of the first end cover and the first fixed shaft provided by the embodiment of the present invention;

[0030] Figure 11 is the exploded view of the second end cover and the second fixed shaft provided by the embodiment of the present invention;

[0031] Description of the reference numerals: 10, cylindrical shell; 11, first end cover; 111, first sliding sealing ring; 112, first sealing end cover; 12, second end cover; 121, second sliding sealing ring; 122, second sealing end cover; 13, first fixed shaft; 131, first step; 132, third step; 14, second fixed shaft; 141, wire harness channel; 142, second step; 143, fourth step; 15, first bearing; 16, second bearing; 17, first key body; 18, second key body; 20, motor reducer assembly; 21, motor; 22, housing; 23, output gear; 24, first gear; 25, second gear; 26, third gear; 27, fourth gear; 28, power output unit; 281, disc-shaped flange; 282, annular groove; 30, expansion mechanism; 31, annular elastic member; 32, annular rigid member; 33, snap ring. Detailed implementation manners

[0032] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0033] It should be noted that the drawings provided in the following embodiments only schematically illustrate the basic concept of the present invention. Therefore, only the components related to the present invention are shown in the drawings, rather than being drawn according to the number, shape, and size of the components in actual implementation. The types, quantities, and ratios of the components in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0034] Please refer to Figures 1-11As shown in the figure, the drum motor assembly provided by the embodiment of the present invention includes a drum shell 10, a motor reducer assembly 20, a first fixed shaft 13, a second fixed shaft 14, a first end cover 11 and a second end cover 12. In a specific embodiment, the drum shell 10 can be made of a thin-walled steel pipe, and the outer surface of the drum shell 10 can also be coated with rubber to make the surface of the drum have a large frictional force; the motor reducer assembly 20 is received in the drum shell 10, and the motor reducer assembly 20 includes a power output unit 28. An expansion mechanism 30 is provided on the outer peripheral surface of the power output unit 28. The power output unit 28 is in interference connection with the first area of the inner wall of the drum shell 10 through the expansion mechanism 30. The first area is the area close to the center of the drum shell 10 in the axial direction of the drum shell 10; the first fixed shaft 13 and the second fixed shaft 14 are respectively circumferentially and fixedly connected to both ends of the motor reducer assembly 20, and the first fixed shaft 13 and the second fixed shaft 14 respectively abut against the motor reducer assembly 20 from both ends of the motor reducer assembly 20; it should be understood that during the operation of the drum, the first fixed shaft 13, the second fixed shaft 14 and the motor reducer assembly 20 are fixedly connected to the frame outside the drum, that is, the first fixed shaft 13, the second fixed shaft 14 and the motor reducer assembly 20 themselves do not rotate. The first fixed shaft 13, the second fixed shaft 14 and the motor reducer assembly 20 together form a support shaft for supporting the drum shell 10.

[0035] The first end cover 11 is rotatably connected to the first fixed shaft 13, and the first end cover 11 abuts against the first fixed shaft 13 from the end of the first fixed shaft 13 away from the motor reducer assembly 20. The first end cover 11 is in interference connection with the inner wall of the first end of the drum shell 10; the second end cover 12 is rotatably connected to the second fixed shaft 14, and the second end cover 12 abuts against the second fixed shaft 14 from the end of the second fixed shaft 14 away from the motor reducer assembly 20. The second end cover 12 is in interference connection with the inner wall of the second end of the drum shell 10. The present invention provides three radial support points on the inner side of the drum shell 10, that is, two end covers support both ends of the drum shell 10, and the power output unit 28 supports the middle of the drum shell 10. Compared with the traditional scheme, the present invention reduces the axial span between adjacent two support points and improves the overall strength of the drum shell 10 without adding additional reinforcement structures; the present invention arranges the power output unit 28 in the middle of the drum shell 10, and the torsional stress generated by the driving load is evenly transmitted from the center of the drum shell 10 to both ends, reducing the risk of deformation of the drum shell 10 and improving the reliability of power transmission. In addition, the present invention uses the interference connection between the expansion mechanism 30 and the inner wall of the drum shell 10 to achieve power transmission between the power output unit 28 and the drum shell 10, avoiding the setting of fasteners on the drum shell 10 and ensuring the appearance quality of the drum shell 10.

[0036] Please refer to Figure 3 、 Figure 6 、 Figure 7As shown, in an alternative embodiment of the present invention, a disc-shaped flange 281 is provided on the outer peripheral surface of the power output unit 28. The expansion mechanism 30 includes an annular elastic member 31 and an annular rigid member 32 that are sequentially stacked along the axial direction of the power output unit 28 from one end surface of the disc-shaped flange 281. At least two annular elastic members 31 and annular rigid members 32 are respectively provided. The annular elastic members 31 and annular rigid members 32 are alternately arranged along the axial direction of the power output unit 28. The end closest to the disc-shaped flange 281 is the annular elastic member 31, and the end farthest from the disc-shaped flange 281 is the annular rigid member 32. A locking mechanism is provided between the annular rigid member 32 farthest from the disc-shaped flange 281 and the power output unit 28. The locking mechanism is configured to be able to hold the annular rigid member 32 in a state of pressing the annular elastic member 31 and causing the annular elastic member 31 to deform. When the annular elastic member 31 deforms, the outer peripheral surface of the annular elastic member 31 protrudes from the outer peripheral surface of the disc-shaped flange 281. The present invention utilizes the expansion of the annular elastic member 31 to achieve a fixed connection between the power output unit and the inner wall of the cylinder shell 10. Since the annular elastic member 31 is continuously distributed along the outer peripheral surface of the power output unit 28, after the annular elastic member 31 expands, its outer peripheral surface can uniformly contact the inner wall of the cylinder shell 10, thereby ensuring the coaxiality between the power output unit 28 and the inner wall of the cylinder shell 10 and further improving the reliability of power transmission. It should be noted that since the power output unit 28 is installed at a relatively deep position inside the cylinder shell 10, the power output unit 28 cannot directly form an interference fit with the inner wall of the cylinder shell 10 using its outer peripheral surface. In a specific embodiment, for example, the outer peripheral surface of the power output unit 28 and the inner wall of the cylinder shell 10 can form a clearance fit to ensure that the power output unit 28 can smoothly slide to the designated position. Then, the two ends of the power output unit 28 are pressed using a long rod tool to expand the annular elastic member 31, and the locking mechanism is used to hold the annular elastic member 31 in the expanded state, thereby achieving a fixed connection between the power output unit 28 and the cylinder shell 10.

[0037] Please refer to Figure 3 、 Figure 6 、 Figure 7As shown, in an alternative embodiment of the present invention, a clearance fit is formed between the inner peripheral surface of the annular rigid member 32 and the outer peripheral surface of the power output unit 28. A ring groove 282 is provided on the outer peripheral surface of the power output unit 28. The locking mechanism includes a circlip 33. The circlip 33 is clamped in the ring groove 282 and protrudes from the outer peripheral surface of the power output unit 28. The annular rigid member 32 farthest from the disc-shaped flange 281 abuts against the circlip 33. The circlip 33 can easily lock the position of the annular rigid member 32. The specific operation process is as follows: Before the power output unit 28 is installed into the cylinder housing 10, the circlip 33 can be first sleeved on the outer peripheral surface of the power output unit 28 and spaced a certain distance from the ring groove 282 to ensure that the annular elastic member 31 is not squeezed. When the power output unit 28 is installed in the designated position of the cylinder housing 10, a long rod tool is used to squeeze the disc-shaped flange 281 and the annular rigid member 32, so that the outer peripheral surface of the annular elastic member 31 expands outward, and at the same time, the circlip 33 is pushed towards the direction close to the ring groove 282 until the circlip 33 is snapped into the ring groove 282 to lock the position of the annular rigid member 32.

[0038] Please refer to Figure 2 、 Figure 4 、 Figure 5 、 Figure 10 、 Figure 11 As shown, in an alternative embodiment of the present invention, the first end cover 11 is provided with a first through hole for the first fixed shaft 13 to pass through. A first counterbore is provided at one end of the first through hole facing the motor reducer assembly 20. A first bearing 15 is provided between the first end cover 11 and the first fixed shaft 13. The outer ring of the first bearing 15 abuts against the first counterbore, and the inner ring of the first bearing 15 abuts against a first step 131 provided on the first fixed shaft 13. A first sliding seal ring 111 is provided between the inner wall of the first through hole and the first fixed shaft 13. A second counterbore is provided at one end of the first through hole away from the motor reducer assembly 20. A first sealing end cover 112 is provided in the second counterbore. The second end cover 12 is provided with a second through hole for the second fixed shaft 14 to pass through. A third counterbore is provided at one end of the second through hole facing the motor reducer assembly 20. A second bearing 16 is provided between the second end cover 12 and the second fixed shaft 14. The outer ring of the second bearing 16 abuts against the third counterbore, and the inner ring of the second bearing 16 abuts against a second step 142 provided on the second fixed shaft 14. A second sliding seal ring 121 is provided between the inner wall of the second through hole and the second fixed shaft 14. A fourth counterbore is provided at one end of the second through hole away from the motor reducer assembly 20. A second sealing end cover 122 is provided in the fourth counterbore. The present invention utilizes the mutual abutment between the end cover, the fixed shaft, and the motor reducer, and finally realizes the axial position fixation of each component through the interference connection force between the end cover and the cylinder housing 10, simplifies the assembly process, and improves the assembly efficiency.

[0039] Please refer to Figure 8 、 Figure 9As shown, in an alternative embodiment of the present invention, the motor reducer assembly 20 includes a motor 21 and a reducer. The reducer includes a housing 22, a first gear 24, a second gear 25, a third gear 26, and a fourth gear 27. The first gear 24, the second gear 25, the third gear 26, and the fourth gear 27 are rotatably connected to the housing 22. An output gear 23 is provided on the main shaft of the motor 21. The power output unit 28 includes an output gear ring. The first gear 24 and the second gear 25 are coaxially and fixedly arranged. The third gear 26 and the fourth gear 27 are coaxially and fixedly arranged. The first gear 24 meshes with the output gear 23. The second gear 25 meshes with the third gear 26. The fourth gear 27 meshes with the output gear ring. The present invention can achieve a three-stage deceleration function, that is, the deceleration transmission between the output gear 23 and the first gear 24, the deceleration transmission between the second gear 25 and the third gear 26, and the deceleration transmission between the fourth gear 27 and the output gear ring, enabling the power output unit 28 to obtain a larger output torque. On the premise of ensuring the power output performance of the drum, the power and size parameters of the motor 21 can be reduced, realizing the miniaturized design of the drum, and at the same time reducing the manufacturing cost.

[0040] Please refer to Figure 2 、 Figure 10 、 Figure 11 As shown, in an alternative embodiment of the present invention, a first jack is provided at one end of the housing 22 away from the motor 21, and a second jack is provided at one end of the motor 21 away from the reducer. A first fixed shaft 13 passes through the output gear ring and is inserted into the first jack, and a first key body 17 is provided between the first fixed shaft 13 and the first jack. A second fixed shaft 14 is inserted into the second jack, and a second key body 18 is provided between the second fixed shaft 14 and the second jack. A third step 132 abutting against the end face of the housing 22 is provided on the first fixed shaft 13, and a fourth step 143 abutting against the end face of the motor 21 is provided on the second fixed shaft 14. In the present invention, the two fixed shafts are connected through the housing 22 of the motor 21 and the reducer. The housing 22 of the motor 21 and the reducer serves as a part of the entire fixed shaft, ensuring the structural strength while saving the internal space of the drum.

[0041] Please refer to Figure 5 、 Figure 11 As shown, in an alternative embodiment of the present invention, a wire harness channel 141 is provided inside the second fixed shaft 14. One end of the wire harness channel 141 is located on the end face of the second fixed shaft 14 away from the motor reducer assembly 20, and the other end of the wire harness channel 141 is located on the circumferential surface of the second fixed shaft 14 inside the second end cover 12. The cable of the motor reducer assembly 20 is guided to the outside of the drum shell 10 through the wire harness channel 141, avoiding interference of the cable with the rotational movement of the drum.

[0042] In summary, the present invention provides three radially supporting points inside the cylindrical shell 10. That is, two end caps support both ends of the cylindrical shell 10, and the power output unit 28 supports the middle part of the cylindrical shell 10. Compared with the traditional solution, the present invention reduces the axial span between two adjacent supporting points, and improves the overall strength of the cylindrical shell 10 without adding additional reinforcement structures. The present invention arranges the power output unit 28 in the middle of the cylindrical shell 10, and the torsional stress generated by the driving load is evenly transmitted from the center of the cylindrical shell 10 to both ends, reducing the risk of deformation of the cylindrical shell 10 and improving the reliability of power transmission. The present invention uses the expansion of the annular elastic member 31 to achieve the fixed connection between the power output end and the inner wall of the cylindrical shell 10. Since the annular elastic member 31 is continuously distributed along the outer peripheral surface of the power output unit 28, after the annular elastic member 31 expands, its outer peripheral surface can evenly contact the inner wall of the cylindrical shell 10, thereby ensuring the coaxiality between the power output unit 28 and the inner wall of the cylindrical shell 10, and further improving the reliability of power transmission. The present invention utilizes the mutual abutment between the end cap, the fixed shaft, and the motor 21 reducer, and finally realizes the fixation of the axial positions of each component through the interference connection force between the end cap and the cylindrical shell 10, simplifies the assembly process, and improves the assembly efficiency. The present invention can achieve a three-stage deceleration function, enabling the power output unit 28 to obtain a large output torque. On the premise of ensuring the power output performance of the drum, the power and size parameters of the motor 21 can be reduced, realizing the miniaturized design of the drum, and at the same time reducing the manufacturing cost.

[0043] The above embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

[0044] In the description herein, numerous specific details are provided, such as examples of components and / or methods, to provide a complete understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention may be practiced without one or more of the specific details or with other devices, systems, components, methods, components, materials, parts, etc. In other instances, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

Claims

1. A drum motor assembly, characterized in that: include: A cylindrical shell (10); A motor reducer assembly (20), the motor reducer assembly (20) being accommodated in the cylindrical shell (10), the motor reducer assembly (20) comprising a power output unit (28), an expansion mechanism (30) being provided on the outer peripheral surface of the power output unit (28), the power output unit (28) being interference-connected with a first area of ​​the inner wall of the cylindrical shell (10) via the expansion mechanism (30), the first area being an area close to the center of the cylindrical shell (10) in the axial direction of the cylindrical shell (10); A first fixed shaft (13) and a second fixed shaft (14), wherein the first fixed shaft (13) and the second fixed shaft (14) are respectively circumferentially fixedly connected to two ends of the motor reducer assembly (20), and the first fixed shaft (13) and the second fixed shaft (14) are respectively pressed against the motor reducer assembly (20) from two ends of the motor reducer assembly (20); A first end cover (11) is rotatably connected to the first fixed shaft (13), and the first end cover (11) is pressed against the first fixed shaft (13) from one end of the first fixed shaft (13) away from the motor reducer assembly (20), and the first end cover (11) is interference-connected with the inner wall of the first end of the cylindrical shell (10); A second end cover (12) is rotatably connected to the second fixed shaft (14), and the second end cover (12) is pressed against the second fixed shaft (14) from one end of the second fixed shaft (14) away from the motor reducer assembly (20), and the second end cover (12) is interference-connected with the inner wall of the second end of the cylindrical shell (10); The power output unit (28) is provided with a disc-shaped flange (281) on its outer peripheral surface, and the expansion mechanism (30) comprises an annular elastic member (31) and an annular rigid member (32) stacked in sequence along the axial direction of the power output unit (28) from one end surface of the disc-shaped flange (281), and at least two of the annular elastic members (31) and the annular rigid member (32) are provided respectively, and the annular elastic members (31) and the annular rigid member (32) are alternately arranged along the axial direction of the power output unit (28), and the end closest to the disc-shaped flange (281) is an annular elastic member (31). An annular elastic member (31) is provided, and the end farthest from the disc-shaped flange (281) is an annular rigid member (32); a locking mechanism is provided between the annular rigid member (32) farthest from the disc-shaped flange (281) and the power output unit (28), the locking mechanism being configured to be able to keep the annular rigid member (32) in a state of pressing the annular elastic member (31) and causing the annular elastic member (31) to deform, and when the annular elastic member (31) is deformed, the outer peripheral surface of the annular elastic member (31) protrudes from the outer peripheral surface of the disc-shaped flange (281).

2. The drum motor assembly according to claim 1, characterized in that: The inner circumference of the annular rigid member (32) forms a clearance fit with the outer circumference of the power output unit (28); an annular groove (282) is provided on the outer circumference of the power output unit (28); the locking mechanism comprises a retaining spring (33); the retaining spring (33) is clamped in the annular groove (282), and the retaining spring (33) protrudes from the outer circumference of the power output unit (28); the annular rigid member (32) farthest from the disc-shaped flange (281) abuts against the retaining spring (33).

3. The drum motor assembly according to claim 1, characterized in that: The first end cover (11) is provided with a first through hole for the first fixed shaft (13) to pass through, and a first sinking platform is provided at one end of the first through hole facing the motor reducer assembly (20). A first bearing (15) is provided between the first end cover (11) and the first fixed shaft (13), and an outer ring of the first bearing (15) abuts against the first sinking platform, and an inner ring of the first bearing (15) abuts against a first step (131) provided on the first fixed shaft (13).

4. The drum motor assembly according to claim 3, characterized in that: A first sliding sealing ring (111) is provided between the inner wall of the first through hole and the first fixed shaft (13), a second sink is provided at one end of the first through hole away from the motor reducer assembly (20), and a first sealing end cover (112) is provided in the second sink.

5. The drum motor assembly according to claim 1, characterized in that: The second end cover (12) is provided with a second through hole for the second fixed shaft (14) to pass through, and a third sink is provided at one end of the second through hole facing the motor reducer assembly (20). A second bearing (16) is provided between the second end cover (12) and the second fixed shaft (14), and the outer ring of the second bearing (16) abuts against the third sink, and the inner ring of the second bearing (16) abuts against a second step (142) provided on the second fixed shaft (14).

6. The drum motor assembly according to claim 5, characterized in that: A second sliding sealing ring (121) is provided between the inner wall of the second through hole and the second fixed shaft (14), and a fourth sink is provided at one end of the second through hole away from the motor reducer assembly (20), wherein a second sealing end cover (122) is provided in the fourth sink.

7. The drum motor assembly according to claim 1, characterized in that: The motor reducer assembly (20) comprises a motor (21) and a reducer, wherein the reducer comprises a housing (22), a first gear (24), a second gear (25), a third gear (26) and a fourth gear (27), wherein the first gear (24), the second gear (25), the third gear (26) and the fourth gear (27) are rotatably connected to the housing (22), an output gear (23) is provided on the main shaft of the motor (21), and the power output unit (28) comprises an output gear ring, wherein the first gear (24) and the second gear (25) are coaxially fixedly arranged, the third gear (26) and the fourth gear (27) are coaxially fixedly arranged, the first gear (24) is meshed with the output gear (23), the second gear (25) is meshed with the third gear (26), and the fourth gear (27) is meshed with the output gear ring.

8. The drum motor assembly according to claim 7, characterized in that: A first plug hole is provided at one end of the housing (22) away from the motor (21), and a second plug hole is provided at one end of the motor (21) away from the reducer. The first fixed shaft (13) passes through the output gear ring and is inserted into the first plug hole, and a first key body (17) is provided between the first fixed shaft (13) and the first plug hole. The second fixed shaft (14) is inserted into the second plug hole, and a second key body (18) is provided between the second fixed shaft (14) and the second plug hole. The first fixed shaft (13) is provided with a third step (132) abutting against an end surface of the housing (22), and the second fixed shaft (14) is provided with a fourth step (143) abutting against an end surface of the motor (21).

9. The drum motor assembly according to claim 5, characterized in that: A wiring harness channel (141) is provided inside the second fixed shaft (14), one end of the wiring harness channel (141) is located on an end surface of the second fixed shaft (14) away from the motor reducer assembly (20), and the other end of the wiring harness channel (141) is located on a circumferential surface of the second fixed shaft (14) inside the second end cover (12), and the cables of the motor reducer assembly (20) are guided to the outside of the cylindrical shell (10) through the wiring harness channel (141).

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