Drum motor

Abstract

This disclosure relates to the field of drum motors, which include: a rotor assembly with an annular cross-section; a stator assembly disposed inside the rotor assembly; and a rotating end cover located at one end of the rotor assembly. The rotor assembly, stator assembly, and rotating end cover are coaxially arranged, and the rotating end cover is directly or indirectly fixedly connected to the rotor assembly to rotate synchronously with it. The rotating end cover is also connected to the stator assembly in a manner rotatable relative to each other. The drum motor of this disclosure, through its specially structured rotating end cover, provides a structural basis for the externalization and standardization of backstops, and also provides a structural basis for special bearing arrangements.

Description

Technical Field

[0001] This disclosure relates to a drum motor. Background Technology

[0002] As a drive device that integrates a motor and a roller, the roller motor has advantages such as compact structure, convenient installation, and simple maintenance, and is widely used in logistics transportation, automated production lines, warehousing equipment, food packaging, and electronics manufacturing.

[0003] A conventional drum motor has components such as a rotor assembly, a solid stator assembly surrounded by the rotor assembly, a backstop configured to limit the direction of the rotor to a predetermined single direction, and a junction box for electrical wiring and electrical connections.

[0004] However, existing roller motors still have various problems.

[0005] For example, existing drum motors require customized non-standard backstops based on the specific model of the motor and the specific dimensions of components such as the rotor, which leads to complex production processes and increased production costs.

[0006] For example, existing drum motors are generally heavy and have low heat dissipation efficiency.

[0007] For example, existing drum motors typically require two support bearings located between the rotor and stator. Due to the constraints of the rotor and stator dimensions, the required two bearings are relatively large and costly.

[0008] For example, in the existing technology, the electrical wiring of the drum motor faces the problem of limited space and difficult wiring. It is usually necessary to drill deep holes in the solid stator spindle to pass the lead wires of the junction box. This process is not only complicated and costly, but the deep holes can also have an adverse effect on the structural strength of the spindle. At the same time, it is difficult to arrange and fix the lead wires in the holes, which brings inconvenience to installation and maintenance. Summary of the Invention

[0009] This disclosure discloses a drum motor comprising: a rotor assembly having an annular cross-section; a stator assembly disposed inside the rotor assembly; and a rotating end cover located at one end of the rotor assembly. The rotor assembly, stator assembly, and rotating end cover are coaxially arranged, and the rotating end cover is directly or indirectly fixedly connected to the rotor assembly to rotate synchronously with it, and the rotating end cover is connected to the stator assembly in a manner rotatable relative to each other.

[0010] According to the example scheme, the rotary end cap has a plate-shaped end cap body and a rotor assembly connection located at the edge of the end cap body.

[0011] According to an example embodiment, the rotor assembly connection portion of the rotary end cap includes an edge portion of the rotary end cap and an annular flange extending perpendicular to the edge portion and toward the rotor assembly. The end of the rotor assembly is fixed to the rotor assembly connection portion and abuts against both the annular flange and the edge portion.

[0012] According to the example embodiment, the stator assembly has a stator shaft extending toward the rotary end cap. The rotary end cap has a plate-shaped end cap body and a stator assembly connecting portion having an annular cross-section extending from the end cap body toward the stator assembly, the stator shaft portion and the stator assembly connecting portion being rotatably connected together relative to each other.

[0013] According to the example design, the rotary end cap has a plurality of first reinforcing ribs extending from the end cap body to the outer surface of the stator assembly connection.

[0014] According to the example scheme, the stator shaft and the stator assembly connection are connected by a stator fixed bearing.

[0015] According to an example embodiment, the rotary end cap has a plate-shaped end cap body and an end cap shaft extending from the end cap body away from the stator assembly. The drum motor also has a backstop configured to define the rotational direction of the rotor assembly, the backstop surrounding and mounted to the end cap shaft.

[0016] According to the example scheme, the end cap shaft portion of the rotary end cap has an elongated backstop mounting groove that extends radially through the end cap shaft portion.

[0017] According to the example scheme, the end cap shaft of the rotary end cap has several shaft segments, including a first shaft segment for mounting the end cap shaft bearing and a second shaft segment for mounting the backstop, the second shaft segment being further away from the stator assembly than the first shaft segment.

[0018] According to the example scheme, the diameter of the second shaft segment is smaller than that of the first shaft segment.

[0019] According to the example design, the rotary end cap has a plurality of second reinforcing ribs extending from the end cap body to the outer surface of the end cap shaft.

[0020] According to the example scheme, the stator assembly includes: an outer cylinder having a hollow cylindrical structure; and an inner cylinder having a hollow cylindrical structure. The inner cylinder is located within the hollow portion of the outer cylinder and is coaxially arranged with the outer cylinder. The inner surface of the outer cylinder and the outer surface of the inner cylinder are spaced apart to define an annular space. The hollow portion of the inner cylinder forms a first airflow channel, and the annular space between the inner and outer cylinders forms a second airflow channel. The outlet of the first airflow channel is connected to the inlet of the second airflow channel, such that airflow travels in a first direction within the first airflow channel and in a second direction opposite to the first direction within the second airflow channel.

[0021] According to the example scheme, the drum motor further includes a fan connected to the first end of the inner cylinder, which serves as the inlet of the first airflow channel.

[0022] According to the example scheme, the inner cylinder has a first portion extending from the first end and a second portion extending to a second end opposite to the first end, wherein the inner diameter of the first portion is smaller than the inner diameter of the second portion.

[0023] According to the example scheme, the inner cylinder also has a transition portion connecting the first part and the second part, the transition portion having a shape that gradually expands from the first part to the second part.

[0024] According to the example design, the outer cylinder has an open end and a closed end. A second airflow channel outlet is formed between the open end of the outer cylinder and a first end of the inner cylinder. The closed end is closed by an end structure spaced apart from a second end of the inner cylinder to allow airflow from the first airflow channel to the second airflow channel.

[0025] According to the example scheme, the end structure has a central structure portion located at the center and a flow guiding structure portion extending from the central structure portion, the flow guiding structure portion having a flow guiding surface that is at least partially curved.

[0026] According to the example scheme, the flow guiding structure includes: an inclined flow guiding wall extending from the central structure in an axial direction relative to the stator assembly away from the open end of the outer cylinder, and an arcuate flow guiding wall extending from the inclined flow guiding wall to the outer cylinder, the arcuate flow guiding wall being recessed away from the open end of the outer cylinder.

[0027] According to the example scheme, the inner surface of the inclined guide wall is tangent to the inner surface of the arc-shaped guide wall.

[0028] According to the example scheme, the angle between the inclined guide wall and the axial direction of the stator assembly is between 30° and 60°.

[0029] According to the example scheme, the thickness of the flow guiding structure is less than the thickness of the central structure.

[0030] The drum motor disclosed herein features a specially structured rotating end cover, offering two key technical advantages. Firstly, it provides a structural basis for the externalization and standardization of the backstop. Specifically, this design moves the backstop from the narrow space inside the traditional drum motor rotor to a spacious external location on the end cover shaft, freeing it from the constraints of the rotor's inner diameter. This allows for the direct selection of mature and reliable standard backstop models. This not only eliminates the high customization costs and complex installation procedures of non-standard parts but also eliminates the need to disassemble the motor body for maintenance, repair, or replacement of the backstop, significantly improving equipment maintainability, simplifying the overall structure, and enhancing the reliability of the transmission system. Secondly, it provides a structural basis for the unique bearing arrangement in this design. Specifically, this solution introduces a rotating end cover with an end cover shaft. A large bearing can be installed between the end cover shaft and the corresponding support seat. At the other end, a large-diameter bearing is installed between the rotor assembly and the stator assembly. The two bearings are used to bear the main load, and a small bearing is installed inside the rotating end cover and between the stator assembly for support. While ensuring overall rigidity and operational accuracy, this solution significantly reduces the overall procurement cost of bearings and the installation space requirements. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments of this disclosure will be briefly described below. The drawings are merely illustrative of some embodiments of this disclosure and are not intended to limit all embodiments of this disclosure to them.

[0032] Figure 1 This is a perspective view of a drum motor according to an embodiment of the present disclosure;

[0033] Figure 2 yes Figure 1 Cross-sectional view along line AA;

[0034] Figure 3 This is a side view of a drum motor according to an embodiment of the present disclosure;

[0035] Figure 4 This is another side view of a drum motor according to an embodiment of the present disclosure;

[0036] Figure 5 This is a cross-sectional view of a drum motor according to an embodiment of the present disclosure;

[0037] Figure 6 This is another cross-sectional view of a drum motor according to an embodiment of the present disclosure;

[0038] Figure 7This is a partial cross-sectional view of the stator assembly of a drum motor according to an embodiment of the present disclosure;

[0039] Figure 8 This is a partial side view of the stator assembly of a drum motor according to an embodiment of the present disclosure;

[0040] Figure 9 This is a cross-sectional view of the inner and outer cylinder assemblies of the stator assembly of a drum motor according to an embodiment of the present disclosure;

[0041] Figure 10 This is a side view of the inner and outer cylinder assemblies of the stator assembly of a drum motor according to an embodiment of the present disclosure;

[0042] Figure 11 This is an end view of the stator assembly of a drum motor according to an embodiment of the present disclosure;

[0043] Figure 12 This is a partial cross-sectional view of a drum motor according to an embodiment of the present disclosure;

[0044] Figure 13 This is a schematic diagram of a rotary end cap for a drum motor according to an embodiment of the present disclosure;

[0045] Figure 14 This is a side view of a rotating end cap of a drum motor according to an embodiment of the present disclosure;

[0046] Figure 15 This is an end view of a rotating end cap of a drum motor according to an embodiment of the present disclosure;

[0047] Figure 16 This is a partial enlarged view of the stator assembly of a drum motor according to an embodiment of the present disclosure;

[0048] Figure 17 This is a schematic diagram of the first end of a drum motor according to an embodiment of the present disclosure;

[0049] Figure 18 This is a schematic diagram of the second end of a drum motor according to an embodiment of the present disclosure.

[0050] List of reference numerals

[0051] 100. Drum motor; 10. Rotor assembly; 19. Filter structure; 20. Stator assembly; 21. Stator winding; 22. Lamination; 23. Outer cylinder; 231. Open end; 232. Closed end; 233. End structure; 234. First section; 235. Second section; 2331. Central structure; 23311. Stator shaft; 2332. Guide structure; 23321. Inclined guide wall; 23322. Arc-shaped guide wall; 24. Inner cylinder; 241. First end; 242. Second end; 243. First part; 244. Second part; 245. Transition part; 25. First airflow channel; 251. First airflow channel inlet; 252. First airflow channel outlet; 26. Second airflow channel; 261. Second airflow channel inlet; 2 62. Second airflow channel outlet; 27. Connector; 28. Heat sink; 29. ​​Temperature sensor; 291. Signal line; 30. Rotary end cover; 31. End cover body; 32. Rotor assembly connection; 321. Edge; 322. Annular flange; 33. Stator assembly connection; 34. First reinforcing rib; 35. Second reinforcing rib; 36. End cover shaft; 361. Backstop mounting slot; 362. First shaft section; 363. Second shaft section; 40. Backstop; 41. Fixing arm; 50. Junction box; 51. Hollow tube; 512. First section; 513. Second section; 52. First through hole; 53. Second through hole; 60. Fan; 70. First support base; 80. Second support base; 85. First bearing; 86. Second bearing; 87. Third bearing Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. The same reference numerals in the drawings represent the same components. It should be noted that the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0053] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships, which may change accordingly when the absolute position of the described object changes.

[0054] The following describes in detail the specific structure of the drum motor and its components and assemblies proposed in this disclosure by referring to the accompanying drawings and exemplary embodiments. Figure 1 This is a three-dimensional structural schematic diagram of a drum motor according to an embodiment of the present disclosure. Figure 2 yes Figure 1 Cross-sectional view along line AA. Figure 3 and Figure 4 These are side views of a drum motor from different angles according to an embodiment of the present disclosure. Figure 5 This is a cross-sectional view of a drum motor according to an embodiment of the present disclosure. Figure 6 This is another cross-sectional view of a drum motor according to an embodiment of the present disclosure. Figure 7 This is a partial cross-sectional view of the stator assembly of a drum motor according to an embodiment of the present disclosure. Figure 8 This is a partial side view of the stator assembly of a drum motor according to an embodiment of the present disclosure. Figure 9 This is a cross-sectional view of the stator assembly of a drum motor according to an embodiment of the present disclosure. Figure 10 This is a side view of the stator assembly of a drum motor according to an embodiment of the present disclosure. Figure 11 This is an end view of the stator assembly of a drum motor according to an embodiment of the present disclosure. Figure 12 This is a partial cross-sectional view of a drum motor according to an embodiment of the present disclosure. Figure 13 This is a schematic diagram of a rotating end cap for a drum motor according to an embodiment of the present disclosure. Figure 14 This is a side view of a rotating end cap of a drum motor according to an embodiment of the present disclosure. Figure 15 This is an end view of the rotating end cap of a drum motor according to an embodiment of the present disclosure. Figure 16 This is a partial enlarged view of the stator assembly of a drum motor according to an embodiment of the present disclosure. Figure 17 This is a schematic diagram of the first end of a drum motor according to an embodiment of the present disclosure. Figure 18 This is a schematic diagram of the second end of a drum motor according to an embodiment of the present disclosure. The drum motor of the present disclosure is, for example, an air-cooled permanent magnet drum motor.

[0055] like Figure 1 , Figure 3 and Figure 4 As shown, the drum motor 100 generally has an elongated structure with two ends spaced apart along the axial direction. A fan 60 and a junction box 50 are provided at one end, and a rotating end cover 30 and a backstop 40 are provided at the opposite end. In addition, a first support 70 and a second support 80 for supporting the drum motor 100 are provided at both ends.

[0056] like Figure 2 As shown, the rotor assembly 10 of the drum motor 100 has a cylindrical structure with an annular cross-section, such as a circular annulus. The cylindrical structure of the rotor assembly 10 defines a hollow portion located at the center. Before assembly with other components, both the first end 241 and the second end 242 of the rotor assembly 10 are open. After assembly, one end of the rotor assembly 10 is closed by a swivel end cap 30. When the drum motor 100 is running, the rotor assembly 10 is able to rotate about its axis of rotation.

[0057] like Figure 2 As shown, the stator assembly 20 of the drum motor 100 is disposed within the hollow portion of the rotor assembly 10 and surrounds the rotor assembly 10. The stator assembly 20 and the rotor assembly 10 are arranged coaxially, with a gap between them. When the drum motor 100 is running, the stator assembly 20 is stationary, while the rotor assembly 10 rotates relative to the stator assembly 20. Unlike the solid stator of a conventional drum motor 100, this disclosure designs the stator assembly 20 as a cylindrical structure, i.e., a structure with an annular cross-section, such as a ring. In other words, the stator assembly 20 has a hollow portion located at its center. By designing the stator assembly 20 as a hollow structure, the overall weight of the stator assembly 20 and the entire drum motor 100 can be reduced, saving materials and lowering costs. Furthermore, the hollow stator assembly 20 can bring more advantages when combined with other features of this disclosure, which will be detailed below.

[0058] The following is in conjunction with the accompanying drawings, especially as shown below. Figure 2 , 5Sections 6, 9, 10, and 11 describe the specific structure of the stator assembly 20. As shown in the figure, the stator assembly 20 includes an outer cylinder 23 and an inner cylinder 24. The inner cylinder 24 of the stator assembly 20 has two open ends, referred to as the first end 241 and the second end 242, respectively. The outer cylinder 23 of the stator assembly 20 has one open end and one closed end, referred to in this disclosure as the open end 231 and the closed end 232, respectively.

[0059] Figure 10 and Figure 11 The external view and end view of the stator assembly 20 are shown respectively. It can be seen that the outer cylinder 23 of the stator assembly 20 is provided with laminations 22 and stator windings 21.

[0060] The outer cylinder 23 of the stator assembly 20 has a hollow cylindrical structure, preferably with an annular cross-section. The laminations 22 and stator windings 21 can be located outside the outer cylinder 23. The inner cylinder 24 of the stator assembly 20 has a hollow cylindrical structure, preferably with an annular cross-section. The inner cylinder 24 is located within the hollow portion of the outer cylinder 23 and is coaxially arranged with the outer cylinder 23.

[0061] like Figure 9 As shown, the stator assembly 20 of this disclosure has a dual heat dissipation channel design.

[0062] The hollow portion of the inner cylinder 24 of the stator assembly 20 forms a first airflow channel 25. The first end 241 of the inner cylinder 24 is open to form an inlet 251 of the first airflow channel. A fan 60 can be installed at the first end 241 of the inner cylinder 24 to blow airflow from the first end 241 to the second end 242 of the inner cylinder 24. The second end 242 of the inner cylinder 24 is open to form an outlet 252 of the first airflow channel.

[0063] The inner surface of the outer cylinder 23 and the outer surface of the inner cylinder 24 of the stator assembly 20 are spaced apart to define an annular space, which forms a second airflow channel 26. Preferably, a second airflow channel outlet 262 is formed between the open end 231 of the outer cylinder 23 and the first end 241 of the inner cylinder 24.

[0064] like Figure 9 As shown, the first airflow channel outlet 252 is connected to the second airflow channel inlet 261, so that the airflow travels in the first airflow channel 25 along the first direction D1 and in the second airflow channel 26 along the second direction D2 opposite to the first direction.

[0065] As can be seen, the stator assembly 20 of this disclosure forms a unique dual heat dissipation channel design, different from existing solutions, through the inner cylinder 24 and the outer cylinder 23. The inner cylinder 24 itself is a hollow structure, forming a first airflow channel 25; at the same time, the annular space between the inner cylinder 24 and the outer cylinder 23 constitutes a second airflow channel 26. This design constructs an efficient "U-shaped" heat dissipation path inside the stator, allowing the cooling medium to flow through it, thereby achieving efficient and uniform heat dissipation of the stator and simultaneously reducing the overall weight.

[0066] like Figure 7 As shown, the inner cylinder 24 of the stator assembly 20 preferably includes a first portion 243, a second portion 244, and a transition portion 245 located between the first portion 243 and the second portion 244. The first portion 243 extends from a first end 241 of the inner cylinder 24 toward a second end 242, and has a first inner diameter. The second portion 244 extends to the second end 242 of the inner cylinder 24, and has a second inner diameter larger than the first inner diameter. The transition portion 245 connects the first portion 243 and the second portion 244, and has a shape that gradually widens from the first portion 243 to the second portion 244.

[0067] Preferably, the first portion 243 of the inner cylinder 24 extends from the outer cylinder 23. Since the portion of the inner cylinder 24 extending from the outer cylinder 23 has a smaller inner diameter, it facilitates the installation of the fan 60. Furthermore, the smaller size of the portion of the inner cylinder 24 extending from the outer cylinder 23 facilitates the installation of the first support 70, meaning the first support 70 does not need to be large; rather, it can be similar in size to the second support 80, thus contributing to the balance and stability of the overall structure. Figure 17 and 18 The two ends of the roller motor are shown separately. The first end has a first support base 70, and the second end has a second support base 80. The two supports provide stable support for the roller motor.

[0068] As mentioned above, the outer cylinder 23 of the stator assembly 20 has an open end 231 and a closed end 232. Figure 16 An enlarged view of the closed end 232 of the outer cylinder 23 is shown.

[0069] The closed end 232 of the outer cylinder 23 is closed by an end structure 233, which is spaced apart from the second end 242 of the inner cylinder 24 to allow airflow from the first airflow channel 25 to the second airflow channel 26.

[0070] The end structure 233 has a central structure portion 2331 located at the center and a flow guiding structure portion 2332 extending from the central structure portion 2331. The flow guiding structure portion 2332 has a flow guiding surface that is at least partially curved to smoothly guide the airflow of the first airflow channel 25 to the second airflow channel 26.

[0071] The flow guiding structure 2332 preferably includes two parts: an inclined flow guiding wall 23321 and an arc-shaped flow guiding wall 23322. The inclined flow guiding wall 23321 extends from the central structure 2331 of the end structure 233 at an angle away from the open end 231 of the outer cylinder 23 relative to the axial direction of the stator assembly 20. The arc-shaped flow guiding wall 23322 extends from the inclined flow guiding wall 23321 to the cylindrical sidewall of the outer cylinder 23, and the arc-shaped flow guiding wall 23322 is recessed away from the open end 231 of the outer cylinder 23. The inclined flow guiding wall 23321 and the arc-shaped flow guiding wall 23322 together form a flow guiding structure that effectively guides the airflow of the first airflow channel 25 toward the inlet of the second airflow channel 26.

[0072] Preferably, the inner surface of the inclined guide wall 23321 is tangent to the inner surface of the arc-shaped guide wall 23322.

[0073] Preferably, the angle between the inclined guide wall 23321 and the axial direction of the stator assembly 20 is between 30° and 60°, for example, 35°, 40°, 45°, 50°, 55°, etc.

[0074] In this disclosure, the hollow portion of the inner cylinder 24 of the stator assembly 20 forms a first airflow channel 25, and the annular space between the inner cylinder 24 and the outer cylinder 23 forms a second airflow channel 26. During operation, the fan 60 drives the cooling airflow to enter from the first end 241 of the inner cylinder 24 and flow through the entire first airflow channel 25 in a first direction. After reaching the second end 242 of the inner cylinder 24, the airflow is smoothly guided into the second airflow channel 26 by the guide structure 2332 through the gap between the inner cylinder 24 and the closed end 232 of the outer cylinder 23, flows back in the opposite second direction, and is finally discharged from the outlet 262 of the second airflow channel. This "U-shaped" reciprocating flow channel design allows the cooling medium to penetrate the core area of ​​the stator, achieving simultaneous cooling of the inner cylinder 24 and the outer cylinder 23. In addition, the arc-shaped guide wall 23322 and the inclined guide wall 23321 of the guide structure 2332 can effectively reduce airflow eddies and pressure loss, ensuring that the airflow passes smoothly and evenly through the entire heat dissipation path, thereby improving heat dissipation efficiency.

[0075] According to an exemplary embodiment, the central structural portion 2331 of the stator assembly 20 further has a stator shaft portion 23311 extending from the central structural portion 2331 toward the open end 231 away from the outer cylinder 23. The stator shaft portion 23311 is configured for mounting to the rotary end cap 30, which will be described below. The design of the flow-guiding structure of the stator assembly 20 causes the central structural portion 2331 of the end structure 233 to be recessed toward the interior of the stator assembly 20, thereby leaving space for the stator shaft portion 23311 on the other side of the end structure 233. Thus, the stator assembly 20 has a compact construction.

[0076] According to an exemplary embodiment, the thickness of the flow guiding structure 2332 is less than the thickness of the central structure 2331. In other words, the central structure 2331 has a larger thickness, thereby providing a stable support and mounting structure, while the flow guiding structure 2332 has a smaller thickness, thereby reducing overall weight and saving materials.

[0077] like Figure 2 As shown, the stator assembly 20 also includes connectors 27. The connectors 27 extend from the inner surface of the outer cylinder 23 to the outer surface of the inner cylinder 24. One end of each connector 27 is connected to the outer surface of the inner cylinder 24, and the other end is connected to the inner surface of the outer cylinder 23. According to an alternative embodiment, the connectors 27 are integrally formed with the inner cylinder 24 and the outer cylinder 23. According to another alternative embodiment, the inner cylinder 24, the outer cylinder 23, and the connectors 27 are separate components and are subsequently fixed together. By connecting the inner cylinder 24 and the outer cylinder 23 with the connectors 27, the integration of the stator assembly 20 can be improved, resulting in a compact overall structure of the stator assembly 20.

[0078] According to an exemplary embodiment, the connector 27 of the stator assembly 20 is plate-shaped, with its length direction aligned with the axial direction of the stator assembly 20, and the connector 27 extends radially from the inner cylinder 24 to the outer cylinder 23. Preferably, the connector 27 has an elongated rectangular cross-section.

[0079] According to an exemplary embodiment, the number of connectors 27 in the stator assembly 20 is from 2 to 10. For example, in an exemplary embodiment, the stator assembly 20 has 5 connectors 27. Preferably, the connectors 27 are evenly distributed around the axis of the stator assembly 20.

[0080] like Figure 2 As shown, the stator assembly 20 also includes a heat sink 28. The heat sink 28 extends from one of the inner cylinder 24 and the outer cylinder 23 toward the other. The heat sink 28 may be plate-shaped, with its length direction aligned with the axial direction of the stator assembly 20. By dissipating heat from the stator assembly 20 through the heat sink 28, the performance of the stator assembly 20 and the entire drum motor 100 can be improved.

[0081] According to an exemplary embodiment, the heat sink 28 extends radially from one of the inner cylinder 24 and the outer cylinder 23 toward the other. For example... Figure 2 As shown in the preferred embodiment, the heat sink 28 extends from the inner surface of the outer cylinder 23 toward the inner cylinder 24. Preferably, the end of the heat sink 28 is spaced apart from the outer surface of the inner cylinder 24 by a distance. Preferably, the heat sink 28 is integrally formed with the outer cylinder 23.

[0082] The simultaneous inclusion of connector 27 and heat sink 28 can improve the integration and compactness of stator assembly 20, reduce the overall structural complexity, and enhance the heat dissipation effect of stator assembly 20.

[0083] According to an exemplary embodiment, the thickness of the heat sink 28 is less than the thickness of the connector 27.

[0084] like Figure 2 As shown in the preferred embodiment, a plurality of heat dissipation components 28 are arranged between each pair of adjacent connectors 27. In other words, the multiple heat dissipation components 28 of the drum motor 100 are arranged in groups, with one group of heat dissipation components 28 arranged between each pair of adjacent connectors 27. This arrangement divides the annular heat dissipation channel into multiple independent flow channel units. While serving as structural support, the connectors also act as grouping partitions, guiding airflow through each group of heat dissipation components in a more orderly manner, thus enhancing heat exchange efficiency; while the densely arranged heat dissipation components maximize the heat dissipation area, thereby maximizing heat dissipation performance while ensuring the overall structural integrity. Preferably, 5 to 10 heat dissipation components 28 are arranged between each pair of adjacent connectors 27.

[0085] like Figure 5 or Figure 16 As shown, at the closed end 232 of the outer cylinder 23, the heat dissipation component 28 extends beyond the end of the inner cylinder 24. Thus, the extended heat dissipation component 28 not only enhances the heat dissipation effect but also serves as a flow guide.

[0086] like Figure 5As shown, the outer cylinder 23 of the stator assembly 20 has a first section 234 and a second section 235. The second section 235 is the main body portion of the outer cylinder 23 and has a constant diameter. The second section 235 is disposed at least around the second portion 244 of the inner cylinder 24. Preferably, the connector 27 and the heat sink 28 are also disposed in the second section 235. The first section 234 is a small-diameter section extending from the second section 235. In other words, the outer diameter of the first section 234 is smaller than the outer diameter of the second section 235. In an exemplary embodiment, the first section 234 may have a shape that gradually expands toward the second section 235. The first section 234 surrounds at least a portion of the first portion 243 and the transition portion 245 of the inner cylinder 24 to form the end portion of the second airflow channel 26.

[0087] A bearing is provided on the outer side of the first section 234. To distinguish it from the other bearings described below, this bearing is referred to as the first bearing 85. The first bearing 85 is disposed between the outer cylinder 23 of the stator assembly 20 and the rotor assembly 10, specifically around the smaller first section 234 of the outer cylinder 23 of the stator assembly 20. This design allows for the use of bearings with smaller inner diameters, thereby reducing costs.

[0088] As mentioned above, the drum motor 100 also has a rotating end cover 30. The rotating end cover 30 is located at one end of the rotor assembly 10, and the rotor assembly 10, stator assembly 20, and rotating end cover 30 are coaxially arranged. The arrangement of the rotor assembly 10, stator assembly 20, and rotating end cover 30 is, for example, in… Figure 5 , 6 As shown in Figure 12, the specific structure of the rotating end cap 30 is, for example, in... Figure 13 , 14 As shown in 15.

[0089] The rotary end cap 30 has a plate-shaped end cap body 31. The end cap body 31 may have a circular shape.

[0090] The rotary end cap 30 is directly or indirectly fixedly connected to the rotor assembly 10 to rotate synchronously with it. The rotary end cap 30 may have a rotor assembly connection portion 32 located at the edge of the end cap body 31. According to an exemplary embodiment, as... Figure 12 and 14As shown, the rotor assembly connecting portion 32 of the rotary end cap 30 includes an edge portion 321 of the rotary end cap 30 and an annular flange 322 extending perpendicular to the edge portion 321 and toward the rotor assembly 10. The thickness of the edge portion 321 may be less than the thickness of the end cap body 31 of the rotary end cap 30. The end of the rotor assembly 10 is fixed to the rotor assembly connecting portion 32 and abuts against both the annular flange 322 and the edge portion. The edge portion 321 may be provided with a through hole through which bolts or similar fasteners pass to secure the rotor assembly 10 to the edge portion 321.

[0091] The rotary end cap 30 is connected to the stator assembly 20 in a manner that allows them to rotate relative to each other. The rotary end cap 30 may have a stator assembly connecting portion 33 with an annular cross-section extending from the end cap body 31 toward the stator assembly 20, and the stator shaft portion 23311 of the stator assembly 20 and the stator assembly connecting portion 33 are connected together in a manner that allows them to rotate relative to each other.

[0092] In an exemplary embodiment, such as Figure 12 As shown, the stator shaft portion 23311 and the stator assembly connection portion 33 are connected by a stator fixed bearing (hereinafter also referred to as the second bearing 86). The stator assembly connection portion 33 has an annular cylindrical structure in which a portion of the stator shaft portion 23311 and the second bearing 86 are received.

[0093] In an alternative embodiment, the stator assembly connection 33 is a solid or hollow shaft structure, while the stator shaft 23311 is a hollow shaft. A portion of the stator assembly connection 33 extends into the stator shaft 23311, and a second bearing 86 is provided between the stator assembly connection 33 and the stator shaft 23311.

[0094] According to an exemplary embodiment, the rotary end cap 30 further has an end cap shaft 36 extending from the end cap body 31 away from the stator assembly 20, and a backstop 40 for defining the rotation direction of the rotor assembly 10 surrounds and is mounted to the end cap shaft 36.

[0095] The core advantage of placing the backstop 40 on the end cover shaft 36 of the rotating end cover 30 lies in its externalization and standardization. Specifically, this design moves the backstop 40 from the narrow space inside the rotor of the traditional drum motor 100 to the spacious external position of the end cover shaft 36, freeing it from the constraints of the rotor's inner diameter. This allows for the direct selection of mature and reliable standard backstop models. This not only eliminates the high customization costs and complex installation procedures of non-standard parts but also eliminates the need to disassemble the motor body for maintenance, repair, or replacement of the backstop 40, significantly improving equipment maintainability, simplifying the overall structure, and enhancing the reliability of the transmission system.

[0096] The backstop 40 may include a rotating part and a fixing part. The rotating part is fixed to the end cover shaft 36 to rotate synchronously with the end cover shaft 36. The fixing part is at least partially disposed around the rotating part and includes a radially extending fixing arm 41.

[0097] Figure 14 As shown, the end cap shaft portion 36 of the rotary end cap 30 may have an elongated backstop mounting groove 361, which penetrates the end cap shaft portion 36 in a radial direction and extends in a direction perpendicular to the axis of the end cap shaft portion 36.

[0098] According to an exemplary embodiment, the end cap shaft 36 of the rotary end cap 30 has a plurality of shaft segments, including but not limited to a first shaft segment 362 for mounting an end cap shaft bearing (here also referred to as a third bearing 87) and a second shaft segment 363 for mounting the backstop 40, the second shaft segment 363 being further away from the stator assembly 20 than the first shaft segment 362. Preferably, the diameter of the second shaft segment 363 is smaller than that of the first shaft segment 362.

[0099] By setting a smaller diameter second shaft segment 363, a clear axial positioning reference is provided for the backstop 40 mounted on it. The difference in diameter naturally forms a stepped structure, which allows the backstop 40 to be positioned quickly and accurately during installation and effectively prevents axial movement caused by vibration during operation, improving the convenience of installation and operational reliability. At the same time, this "thicker at the front and thinner at the back" stepped shaft design optimizes the force distribution and space utilization. The thicker first shaft segment 362 ensures sufficient contact area with the bearing to stably withstand radial loads; while the thinner second shaft segment 363 precisely matches the inner diameter of the standard backstop 40, achieving compact installation. This not only avoids material waste and structural weight increase caused by adapting to a single shaft diameter, but also makes the overall structure lighter and more rational.

[0100] like Figure 13 , 14As shown, the rotary end cap 30 preferably has a plurality of first reinforcing ribs 34 extending from the end cap body 31 to the outer surface of the stator assembly connection portion 33. The rotary end cap 30 may also have a plurality of second reinforcing ribs 35 extending from the end cap body 31 to the outer surface of the end cap shaft portion 36. For example... Figure 15 As shown, the second reinforcing rib 35 is preferably arranged radially in the radial direction. Similarly, the first reinforcing rib 34 is also preferably arranged radially in the radial direction. This reinforcing rib design can significantly enhance the structural rigidity and strength of the end cover body 31, effectively preventing its deformation or vibration under load, thereby ensuring the connection accuracy and transmission stability with the rotor and stator assembly 20.

[0101] Figure 5 and Figure 6 The overall bearing arrangement of this disclosure is shown. As mentioned above, the drum motor 100 of this disclosure includes a first bearing 85, a second bearing 86, and a third bearing 87.

[0102] A first bearing 85 is disposed between the rotor assembly 10 and the stator assembly 20 at the end of the stator assembly 20 and the rotor assembly 10 away from the rotating end cover 30. In an exemplary embodiment, the first bearing 85 is mounted on the outside of a first section 234 of the outer cylinder 23. This first section 234 is a smaller section of the outer cylinder 23, and arranging the first bearing 85 on this first section 234 means that a standard bearing with a smaller inner diameter and lower cost can be used. This directly reduces manufacturing costs without sacrificing support performance. As the main support point of the rotor, the first bearing 85 bears the main radial load and ensures a uniform air gap between the rotor and the stator, laying the foundation for efficient and stable operation of the motor.

[0103] The second bearing 86 is disposed between the stator assembly connecting portion 33 of the rotary end cover 30 and the stator shaft portion 23311 of the stator assembly 20. The second bearing 86 enables a relative rotational connection between the rotary end cover 30 and the stator assembly 20. As mentioned above, the stator assembly connecting portion 33 preferably has an annular cylindrical structure, in which a portion of the stator shaft portion 23311 and the second bearing 86 are received.

[0104] The third bearing 87 is disposed around the end cover shaft portion 36 of the rotary end cover 30. As described above, the drum motor 100 includes a first support 70 and a second support 80 located at both ends of the drum motor 100. Preferably, the third bearing 87 is installed between the end cover shaft portion 36 and the second support 80. The third bearing 87 provides a second external support point for the rotary end cover 30 and the rotor assembly 10 fixedly connected thereto, forming a stable "two-point support" system together with the first bearing 85 to support the rotor assembly 10 and prevent vibration during high-speed operation.

[0105] According to an exemplary embodiment, the dimensions of the second bearing 86 are smaller than those of the first bearing 85 and the third bearing 87. For example, the outer diameter of the second bearing 86 is less than half the outer diameter of the first bearing 85. According to an exemplary embodiment, the dimensions of the third bearing 87 are smaller than those of the first bearing 85; for example, the outer diameter of the third bearing 87 is less than half the outer diameter of the first bearing 85.

[0106] Compared to the traditional double-bearing design, the bearing arrangement proposed in this solution achieves significant performance optimization and cost savings. Traditional solutions lack a rotating end cover 30 with an end cap shaft portion 36, requiring both support bearings to be installed between the rotor and stator. Limited by the dimensions of the rotor and stator, two large bearings must be used, resulting in high costs. This solution introduces a rotating end cover 30 with an end cap shaft portion 36, decomposing the support function: only one large bearing is used at one end of the rotor assembly 10 and stator assembly 20 to bear the main load. Space is cleverly utilized near the other end of the rotor assembly 10 and stator assembly 20 to design two smaller bearings, allowing these two smaller bearings to replace the traditional large bearing. This significantly reduces the overall bearing procurement cost and installation space requirements while ensuring overall rigidity and operational accuracy.

[0107] As shown in the figure, the drum motor 100 has a junction box 50 and a hollow tube 51. The junction box 50 is provided with leads electrically connected to the stator winding 21. The hollow tube 51 extends from the junction box 50 and surrounds at least a portion of the length of the leads. Figure 8 As shown, the stator assembly 20 has a first through hole 52 and a second through hole 53 through which the hollow tube 51 passes. The hollow tube 51 includes a first section 512 located between the junction box 50 and the first through hole 52 and outside the stator assembly 20, and a second section 513 located between the first through hole 52 and the second through hole 53 and inside the hollow portion of the stator assembly 20.

[0108] This wiring structure leads the wires out of the junction box 50 and places them inside the hollow tube 51, which isolates and protects the wire ducts, improving the reliability and safety of the electrical connection. Meanwhile, this disclosure features a hollow design for the stator assembly 20, with the wires passing through the hollow portion of the stator assembly 20. This avoids the complex process of drilling deep holes in solid components, simplifies the assembly process, and effectively prevents structural strength reduction caused by openings.

[0109] In an embodiment not shown, the hollow tube 51 may also have a third section extending from the second through-hole 53 beyond the stator assembly 20.

[0110] According to an exemplary embodiment, the junction box 50 is located at one end of the stator assembly 20 and offset relative to the axis of the stator assembly 20. In other words, the junction box 50 is not arranged on the axis of the stator assembly 20. According to an exemplary embodiment, the fan 60 of the drum motor 100 and the junction box 50 are located at the same end of the stator assembly 20, so that the other end of the stator assembly 20 can be provided with the aforementioned rotating end cover 30 and backstop 40. The fan 60 can be directly installed to the first end 241 of the inner cylinder 24 of the stator assembly 20 and centered on the axis of the stator assembly 20, while the junction box 50 is radially offset relative to the fan 60. The centrally mounted fan 60 ensures that the cooling airflow is evenly delivered along the axis, guaranteeing heat dissipation efficiency. The radial offset of the junction box 50 effectively avoids interference with the central air duct, compressing the axial length of the motor, making external wiring more convenient, and resulting in a more compact and reasonable overall structure.

[0111] As described above, the inner cylinder 24 has a first portion 243 extending from the first end 241 and a second portion 244 extending to the second end 242. The fan 60 is connected to the first portion 243, and the inner diameter of the first portion 243 is smaller than the inner diameter of the second portion 244. According to an exemplary embodiment, the first through hole is located in the portion of the first portion 243 that extends from the outer cylinder 23.

[0112] As described above, the inner cylinder 24 also has a transition portion 245 connecting the first portion 243 and the second portion 244, the transition portion 245 having a shape that gradually expands from the first portion 243 to the second portion 244. According to an exemplary embodiment, the second through hole is disposed in the transition portion 245.

[0113] like Figure 2 and 6As shown, the drum motor 100 may further include a temperature sensor 29, which is located within the hollow portion of the stator assembly 20 and has its end inserted into the end structure 233. Preferably, a signal line 291 extending from the temperature sensor 29 passes through the hollow tube 51.

[0114] like Figure 17 As shown, a filter structure 19 may be provided at the end of the drum motor, especially at the end without a rotating end cap, to prevent impurities from entering the drum motor.

[0115] The exemplary implementation of the solution proposed in this disclosure has been described in detail above with reference to preferred embodiments. However, those skilled in the art will understand that various modifications and alterations can be made to the above specific embodiments without departing from the spirit of this disclosure, and various combinations can be made to the various technical features and structures proposed in this disclosure without exceeding the protection scope of this disclosure.

Claims

1. A drum motor, characterized by Comprising: a rotor assembly (10) having a cross section in the shape of a ring; a stator assembly (20) disposed inside the rotor assembly (10); a rotary end cover (30) located at one end of the rotor assembly (10); wherein the rotor assembly (10), the stator assembly (20), and the rotary end cover (30) are coaxially disposed, and wherein the rotary end cover (30) is directly or indirectly fixedly connected to the rotor assembly (10) to rotate in synchronization with the rotor assembly (10), and the rotary end cover (30) is connected to the stator assembly (20) in a manner that allows rotation relative to each other; wherein the stator assembly (20) comprises: an outer cylinder (23) having a hollow cylindrical structure; an inner cylinder (24) having a hollow cylindrical structure, the inner cylinder (24) being located inside the hollow portion of the outer cylinder (23) and arranged coaxially with the outer cylinder (23), wherein the inner surface of the outer cylinder (23) and the outer surface of the inner cylinder (24) are spaced apart to define an annular space; wherein the hollow portion of the inner cylinder (24) forms a first airflow passage (25), and the annular space between the inner cylinder (24) and the outer cylinder (23) forms a second airflow passage (26); wherein the outlet of the first airflow passage (25) is connected to the inlet of the second airflow passage (26), so that the airflow travels in a first direction in the first airflow passage (25) and travels in a second direction opposite to the first direction in the second airflow passage (26); the outer cylinder (23) has an open end (231) and a closed end (232); a second airflow passage outlet (262) is formed between the open end (231) of the outer cylinder (23) and the first end (241) of the inner cylinder (24) as the inlet of the first airflow passage (25); the closed end (232) is closed by an end structure (233) which is spaced apart from the second end (242) of the inner cylinder (24) to allow airflow to flow from the first airflow passage (25) to the second airflow passage (26).

2. The drum motor according to claim 1, wherein: the rotary end cover (30) has a plate-shaped end cover body (31) and a rotor assembly connecting portion (32) located at the edge of the end cover body (31).

3. The drum motor according to claim 2, wherein: the rotor assembly connecting portion (32) of the rotary end cover (30) includes an edge portion (321) of the rotary end cover (30) and an annular flange (322) extending perpendicular to the edge portion (321) and toward the rotor assembly (10); the end portion of the rotor assembly (10) is fixed to the rotor assembly connecting portion (32) and abuts both the annular flange (322) and the edge portion (321).

4. The drum motor according to claim 1, wherein: the stator assembly (20) has a stator shaft portion (23311) extending toward the rotary end cover (30); The rotary end cover (30) has a plate-shaped end cover body (31) and a stator assembly connecting portion (33) having an annular cross section extending from the end cover body (31) toward the stator assembly (20), and the stator shaft portion (23311) and the stator assembly connecting portion (33) are connected together in a rotatable manner relative to each other.

5. The drum motor of claim 4, wherein The rotary end cover (30) has a plurality of first reinforcing ribs (34) extending from the end cover body (31) to an outer surface of the stator assembly connecting portion (33).

6. The drum motor of claim 4, wherein The stator shaft portion (23311) and the stator assembly connecting portion (33) are connected by a stator fixed bearing.

7. The drum motor of claim 1, wherein The rotary end cover (30) has a plate-shaped end cover body (31) and an end cover shaft portion (36) extending from the end cover body (31) away from the stator assembly (20); The drum motor (100) further has a backstop (40) configured to define a rotation direction of the rotor assembly (10), the backstop (40) surrounding and mounted to the end cover shaft portion (36).

8. The drum motor of claim 7, wherein The end cover shaft portion (36) of the rotary end cover (30) has an elongated backstop mounting groove (361) extending through the end cover shaft portion (36) in a radial direction.

9. The drum motor of claim 7, wherein The end cover shaft portion (36) of the rotary end cover (30) has a plurality of shaft sections including a first shaft section (362) for mounting an end cover shaft portion bearing and a second shaft section (363) for mounting the backstop (40), the second shaft section (363) being farther away from the stator assembly (20) than the first shaft section (362).

10. The drum motor of claim 9, wherein The second shaft section (363) has a smaller diameter than the first shaft section (362).

11. The drum motor of claim 7, wherein The rotary end cover (30) has a plurality of second reinforcing ribs (35) extending from the end cover body (31) to an outer surface of the end cover shaft portion (36).

12. The drum motor of claim 1, wherein The drum motor (100) further includes a blower (60) connected to the first end (241) of the inner drum (24).

13. The drum motor of claim 1, wherein The inner drum (24) has a first portion (243) extending from the first end (241) and a second portion (244) extending to a second end (242) opposite the first end, the first portion (243) having a smaller inner diameter than the second portion (244).

14. The drum motor of claim 13, wherein The inner cylinder (24) further has a transition portion (245) connecting the first portion (243) and the second portion (244), the transition portion (245) having a shape that is diverging from the first portion (243) to the second portion (244).

15. The drum motor of claim 1, wherein, The end structure (233) has a central structure portion (2331) located at the center and a flow guide structure portion (2332) extending from the central structure portion (2331), the flow guide structure portion (2332) having a flow guide surface that is at least partially curved.

16. The drum motor of claim 15, wherein, The flow guide structure portion (2332) includes: a slanted flow guide wall (23321) extending from the central structure portion (2331) away from the open end (231) of the outer cylinder (23) obliquely with respect to an axial direction of the stator assembly (20), and an arc-shaped flow guide wall (23322) extending from the slanted flow guide wall (23321) to the outer cylinder (23), the arc-shaped flow guide wall (23322) being concave away from the open end (231) of the outer cylinder (23).

17. The drum motor of claim 16, wherein, an inner surface of the slanted flow guide wall (23321) is tangent to an inner surface of the arc-shaped flow guide wall (23322).

18. The drum motor of claim 16, wherein, an included angle of the slanted flow guide wall (23321) with respect to the axial direction of the stator assembly (20) is between 30° and 60°.

19. The drum motor of claim 15, wherein, a thickness of the flow guide structure portion (2332) is smaller than a thickness of the central structure portion (2331).

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