An outer rotor electric motor and a bearing replacement method

Abstract

This application provides an external rotor motor and a bearing replacement method. The external rotor motor includes a rotor assembly, a stator assembly, a first bearing, and a locking member. The stator assembly is disposed within the rotor assembly. The first bearing is disposed between the stator assembly and the rotor assembly along the radial direction of the external rotor motor. The locking member is configured to lock the stator assembly and the rotor assembly when the external rotor motor is in a maintenance state, thereby facilitating the removal and installation of the first bearing. The external rotor motor provided in this application embodiment can achieve relative fixation between the stator assembly and the rotor assembly in a maintenance state, and can achieve the replacement of the first bearing without completely disassembling the external rotor motor, thereby reducing maintenance costs and maintenance cycles.

Description

Technical Field

[0001] This application relates to the field of motor technology, and in particular to an external rotor motor and a bearing replacement method. Background Technology

[0002] Low-altitude aircraft are affected by multiple key factors such as flight performance, energy efficiency, safety, and economy, resulting in extremely stringent weight requirements for each component. As the power source for low-altitude aircraft, the propulsion motor's dimensions and weight directly affect the aircraft's performance, range, and payload capacity. Furthermore, considering reliability, safety, lifespan management, and regulatory compliance, the propulsion motors of low-altitude aircraft require regular inspection and maintenance, especially addressing issues such as bearing mechanical wear and fatigue, and blockages in air gaps and ducts.

[0003] Compared with traditional internal rotor motors, external rotor motors are widely used in low-altitude aircraft due to their comprehensive advantages in structural efficiency, space adaptability, and heat dissipation optimization.

[0004] In related technologies, when low-altitude aircraft use external rotor motors as propulsion motors, the maintenance of external rotor motors is difficult, and they usually need to be returned to the factory for disassembly of parts, resulting in high maintenance costs and long maintenance cycles. Summary of the Invention

[0005] In view of this, the embodiments of this application aim to provide a method for replacing an external rotor motor and its bearings, so as to reduce the difficulty of maintaining an external rotor motor.

[0006] To achieve the above objectives, one embodiment of this application provides an external rotor motor, comprising: Rotor assembly; A stator assembly is disposed within the rotor assembly; A first bearing is disposed between the stator assembly and the rotor assembly along the radial direction of the outer rotor motor; A locking element is configured to lock the stator assembly and the rotor assembly when the outer rotor motor is in a maintenance state, in order to allow for the removal and installation of the first bearing.

[0007] In some embodiments, the locking element includes an end cap, the stator assembly and the rotor assembly are spaced apart at one end of the axial direction of the outer rotor motor to define a spacer cavity, the end cap is movably disposed within the spacer cavity, and the end cap is used to radially limit the engagement with the rotor assembly and the stator assembly respectively in the maintenance state.

[0008] In some embodiments, the end cover has a limiting block and a first limiting portion formed at both ends along the axial direction, the stator assembly has a stepped portion formed along the axial direction, the limiting block abuts against the stepped portion in the radial direction, and the rotor assembly has a second limiting portion formed on one side along the axial direction. The first limiting portion is used to move along the axial direction in the maintenance state and to limit and cooperate with the second limiting portion in the radial direction.

[0009] In some embodiments, one of the first limiting portion and the second limiting portion is a plug, and the other of the first limiting portion and the second limiting portion is a slot, wherein the plug is inserted into the slot.

[0010] In some embodiments, the stator assembly includes a stator support and a first bearing housing, the rotor assembly includes a rotor support and a shaft, the inner ring of the first bearing is sleeved on the shaft, the stator support and the rotor support define the spacer cavity at one end of the axial direction of the outer rotor motor, and the outer rotor motor also has an operating state, in which the end cover is spaced apart from the rotor assembly along the axial direction. In the operating state, the rotor support is locked to the shaft, the stator support, the end cover and the first bearing housing are locked, and the first bearing housing and the end cover define a limiting groove along the axial direction to clamp the outer ring of the first bearing; In the maintenance state, the end cover is locked to the rotor support and the stator support respectively, the first bearing housing can be unlocked and separated from the stator support, the shaft can be unlocked and separated from the rotor support, and the end cover can be axially limited to the end face of the outer ring of the first bearing so that the first bearing can be removed along with the first bearing housing and / or the shaft.

[0011] In some embodiments, in the operating state, the inner ring of the first bearing is interference-fitted with the shaft, the outer ring of the first bearing is transition-fitted with the limiting groove, and the inner diameter of the end cap is smaller than the outer diameter of the outer ring of the first bearing. In the maintenance state, the shaft can move along the axial direction from the stator support to the rotor support, thereby causing the outer ring of the first bearing to abut against the end cover and separating the first bearing from the shaft.

[0012] In some embodiments, the stator assembly includes a first fixing member, the rotor assembly includes a second fixing member, and the locking member further includes a first fastener and a second fastener; In the operating state, the end cover, the stator support, and the first bearing housing are locked by the first fixing member, and the rotor support and the rotating shaft are locked by the second fixing member; In the maintenance state, the first fastener and the second fastener are removed, the end cover is locked to the rotor support by the first fastener, and the end cover is locked to the stator support by the second fastener.

[0013] In some embodiments, the locking member further includes a third fastener for being inserted into the stator support in the maintenance state and abutting against the first fastener.

[0014] In some embodiments, the stator support includes a first sleeve, a second sleeve, and a web, the outer rotor motor includes a second bearing, the second sleeve is located inside the first sleeve, the web is radially connected to the first sleeve and the second sleeve, the second sleeve and the rotor support define the spacer cavity at one end of the axial direction of the outer rotor motor, the second sleeve is used to lock with the end cover and the first bearing seat in the operating state, and the second bearing is sleeved on the outside of the first sleeve.

[0015] In some embodiments, the first bearing and the second bearing are arranged spaced apart along the axial direction.

[0016] In some embodiments, the external rotor motor includes a second bearing housing and an outer cover. In the operating state, the second bearing housing is connected to the rotor support and located outside the first sleeve. The outer cover is disposed at one end of the second bearing housing and the first sleeve along the axial direction. The outer cover and the second bearing housing limit the outer ring of the second bearing, and the outer cover and the first sleeve limit the inner ring of the second bearing. In the maintenance state, the outer cover can be removed from the first sleeve so that the second bearing can be removed along with the second bearing housing and / or the first sleeve.

[0017] In some embodiments, the first sleeve includes a cylindrical body and a sealing plate, the stator assembly includes a stator core, the cylindrical body is connected to the web plate, the cylindrical body forms a receiving cavity and an opening communicating with the receiving cavity, and the stator core is disposed in the receiving cavity; In the operating state, one end of the sealing plate covers the opening, and the other end of the sealing plate is connected to the outer cover. The second bearing is sleeved on the sealing plate, and the sealing plate has a first flange formed on the side away from the outer cover along the axial direction. The first flange and the outer cover clamp the inner ring of the second bearing.

[0018] In some embodiments, a second flange is formed on the inner side of the second bearing housing, the second flange being used to limit the outer ring of the second bearing in the operating state.

[0019] In some embodiments, the outer cover has a first sealing tooth, and the second bearing seat has a second sealing tooth, with the first sealing tooth and the second sealing tooth engaging in a mating fit.

[0020] In some embodiments, a plurality of second sealing teeth are arranged along the radial direction, a plurality of first sealing teeth are arranged along the radial direction, a first sealing groove is formed between two adjacent first sealing teeth, a second sealing groove is formed between two adjacent second sealing teeth, the first sealing teeth cooperate with the second sealing groove, the second sealing teeth cooperate with the first sealing groove, and at least one second sealing groove has its groove wall recessed along the radial direction away from the central axis of the outer rotor motor to form a collection groove.

[0021] In some embodiments, the collection groove is formed at least within the second sealing groove along the radial direction closest to the central axis of the outer rotor motor.

[0022] In some embodiments, the first bearing housing has a sealing portion on the end face away from the rotor support along the axial direction, for forming a sealed connection between the first bearing housing and components other than the external rotor motor.

[0023] Another aspect of this application provides a bearing replacement method for an external rotor motor, applied to the external rotor motor described above. The locking member includes an end cover. The stator assembly and the rotor assembly are spaced apart at one end of the axial direction of the external rotor motor to define a spacer cavity. The end cover is movably disposed within the spacer cavity. The bearing replacement method includes: Remove the first fastener to unlock the end cap and the stator assembly; The rotor assembly is connected to the end cap by a first fastener; The stator assembly is connected to the end cap by a second fastener; The third fastener is passed through the stator assembly and abuts against the first fastener axially to lock the stator assembly and the rotor assembly.

[0024] In some embodiments, the stator assembly includes a stator support and a first bearing housing, the rotor assembly includes a rotor support and a shaft, the inner ring of the first bearing is fitted onto the shaft, and the stator support and the rotor support define the spacer cavity at one end of the axial direction of the external rotor motor. The bearing replacement method also includes: Remove the first bearing housing axially away from the rotor support; Remove the second fastener to unlock the rotor bracket from the shaft; The rotating shaft is removed axially away from the stator support, and the end cap abuts against the outer ring of the first bearing axially, thereby separating the inner ring of the first bearing from the rotating shaft or separating the outer ring of the first bearing from the inner ring.

[0025] In some embodiments, the external rotor motor includes a second bearing, the stator support includes a first sleeve, the external rotor motor includes a second bearing housing and an outer cover, the first sleeve includes a cylindrical body and a sealing plate, and the second bearing is sleeved on the sealing plate; The bearing replacement method also includes: Unlock the connection between the outer cover and the sealing plate, and remove the outer cover; Remove the sealing plate and the second bearing from the cylinder; or... Disconnect the second bearing housing from the rotor support, remove the second bearing housing from the rotor support, and abut the outer ring of the second bearing along the axial direction through the second flange formed on the inner side of the second bearing housing, so that the inner ring of the second bearing is separated from the sealing plate or the outer ring of the second bearing is separated from the inner ring.

[0026] The external rotor motor provided in this application embodiment has a locking component configured to lock the stator assembly and rotor assembly when the external rotor motor is in maintenance mode, so as to allow for the disassembly and assembly of the first bearing. In this way, the relative fixation between the stator assembly and rotor assembly can be achieved in maintenance mode, and the first bearing can be replaced without completely disassembling the external rotor motor, thereby reducing maintenance costs and maintenance cycle. Attached Figure Description

[0027] Figure 1 This is a cross-sectional view of the assembly of the external rotor motor, propeller, and controller provided in one embodiment of this application. Figure 2 This is a schematic cross-sectional view of an external rotor motor provided in one embodiment of this application; Figure 3 for Figure 2 Side view of the end face after removing the second fastener; Figure 4 for Figure 3 A partial sectional view at AA after the second fastener has been installed and the device is in operation; Figure 5 In maintenance mode, Figure 3 A partial sectional view at point BB; Figure 6 In maintenance mode, Figure 3 A partial sectional view at point CC; Figure 7This is a schematic diagram of the structure of a rotating shaft provided in one embodiment of this application; Figure 8 This is a schematic diagram of the structure of a stator support provided in one embodiment of this application; Figure 9 This is a schematic diagram of the structure of a first bearing housing provided in an embodiment of this application; Figure 10 This is a schematic diagram of the structure of an end cap provided in one embodiment of this application; Figure 11 for Figure 2 A magnified view of the area located at the second bearing; Figure 12 A cross-sectional view of the second bearing housing and the outer cover provided in an embodiment of this application; Figure 13 This is a bearing replacement method provided in one embodiment of the present application; Figure 14 This is a bearing replacement method for the first bearing provided in one embodiment of the present application; Figure 15 This is a bearing replacement method for the second bearing provided in one embodiment of this application.

[0028] Explanation of reference numerals in the attached figures 10. External rotor motor; 10a. Spacing cavity; 11. Rotor assembly; 11a. Limiting groove; 111. Rotor bracket; 111a. Second limiting part; 111b. Fourth through hole; 111c. Second threaded hole; 111d. Weight reduction hole; 112. Shaft; 112a. Flange; 112b. Third through hole; 112c. First notch; 112d. Sixth threaded hole; 113. Second fixing part; 14. Magnet; 12. Stator assembly; 121. Stator bracket; 121a. Stepped portion; 121b. First through hole; 121c. Fifth through hole; 121d. Fifth threaded hole; 1211. First sleeve; 12111. Cylinder; 12111a. Receiving cavity; 12111b. Opening; 12112. Sealing plate; 12112a. First flange; 1212. Second sleeve; 1213. Abdomen Plate; 122, First bearing housing; 122a, Second through hole; 122b, Second notch; 122c, Third notch; 123, First fixing member; 124, Stator core; 13, First bearing; 14, Locking member; 141, End cover; 141a, Limiting block; 141b, First limiting part; 141c, First threaded hole; 141d, Third threaded hole; 141e, Fourth threaded hole; 142, First fastener; 143, Second fastener; 144, Third fastener; 145, Bearing nut; 146, Retaining ring; 15, Second bearing; 16, Second bearing housing; 16a, Second flange; 16b, Second sealing tooth; 16c, Second sealing groove; 16d, Collection groove; 17, Outer cover; 17a, First sealing tooth; 17b, First sealing groove; 18, Sealing part; 20, Controller; 30, Propeller. Detailed Implementation

[0029] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but should not be used to limit the scope of this application.

[0030] In the description of the embodiments of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "top," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0032] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature and the second feature are in direct contact, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0033] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0034] In related technologies, when low-altitude aircraft use external rotor motors as propulsion motors, the maintenance of external rotor motors is difficult, and they usually need to be returned to the factory for disassembly of parts, resulting in high maintenance costs and long maintenance cycles.

[0035] Based on the above, the first aspect of this application provides an external rotor motor 10. Please refer to [link to relevant documentation]. Figures 1 to 12 The external rotor motor 10 includes a rotor assembly 11, a stator assembly 12, a first bearing 13, and a locking member 14. The stator assembly 12 is disposed within the rotor assembly 11. The first bearing 13 is disposed between the stator assembly 12 and the rotor assembly 11 radially between the external rotor motor 10. The locking member 14 is configured to lock the stator assembly 12 and the rotor assembly 11 in a maintenance state to allow for the removal and installation of the first bearing 13.

[0036] It should be noted that the external rotor motor 10 in this application can be a permanent magnet synchronous motor or an asynchronous motor, and no restriction is made here.

[0037] The stator assembly 12 is disposed inside the rotor assembly 11, that is, the rotor assembly 11 of the external rotor motor 10 is external, and the stator assembly 12 is internal.

[0038] In this embodiment of the application, it should be noted that, unless otherwise explicitly specified and limited, the terms "axial", "radial", and "circumferential" refer to the axial, radial, and circumferential directions of the external rotor motor 10, respectively. In this embodiment of the application, the axial, radial, and circumferential directions of the external rotor motor 10, the stator assembly 12, and the rotor assembly 11 are all consistent.

[0039] In this context, the axial direction is along the axis of the external rotor motor 10, the radial direction is along the radius of the cross-section (perpendicular to the axis and passing through the center of the circle), and the circumferential direction refers to the "circumferential direction," that is, the direction around the axis of the external rotor motor 10 (perpendicular to the axis and also perpendicular to the radius of the cross-section). Together with the axial and radial directions, they constitute the three orthogonal directions of the cylindrical coordinate system.

[0040] It should be noted that bearings are an important component in mechanical equipment. Their main function is to support rotating mechanical parts, reduce the coefficient of friction during their movement, and ensure their rotational accuracy.

[0041] The first bearing 13 is disposed between the stator assembly 12 and the rotor assembly 11 along the radial direction of the outer rotor motor 10. Specifically, the inner ring of the first bearing 13 may mate with the rotor assembly 11 and the outer ring of the first bearing 13 may mate with the stator assembly 12, or the inner ring of the first bearing 13 may mate with the stator assembly 12 and the outer ring of the first bearing 13 may mate with the rotor assembly 11. No limitation is made here.

[0042] It should be noted that the maintenance state can be the state when the motor is being repaired or maintained. In the maintenance state, the 10 components of the external rotor motor can be disassembled and replaced.

[0043] The external rotor motor 10 provided in this application embodiment has a locking member 14 configured to lock the stator assembly 12 and the rotor assembly 11 when the external rotor motor 10 is in a maintenance state, so as to allow for the disassembly and assembly of the first bearing 13. In this way, the relative fixation between the stator assembly 12 and the rotor assembly 11 can be achieved in the maintenance state, and the first bearing 13 can be replaced without completely disassembling the external rotor motor 10, thereby reducing maintenance costs and maintenance cycle.

[0044] In some embodiments, please refer to Figures 1 to 6 as well as Figure 10The locking element 14 includes an end cap 141. The stator assembly 12 and the rotor assembly 11 are spaced apart at one end of the outer rotor motor 10 along the axial direction to define a spacer cavity 10a. The end cap 141 is movably disposed within the spacer cavity 10a. The end cap 141 is used to radially limit the engagement with the rotor assembly 11 and the stator assembly 12 respectively in the maintenance state.

[0045] For example, the external rotor motor 10 also has an operating state. In the operating state, the end cover 141 is sleeved on a portion of the stator assembly 12, and the end cover 141 is spaced apart from the rotor assembly 11 along the axial direction. The rotor assembly 11 can rotate relative to the stator assembly 12 and the end cover 141. In the maintenance state, the end cover 141 moves axially toward the rotor assembly 11 and is sleeved on a portion of the rotor assembly 11 to radially limit the rotor assembly 11. At the same time, the end cover 141 is still sleeved on a portion of the stator assembly 12, so that the end cover 141 can be radially limited and engaged with the rotor assembly 11 and the stator assembly 12 respectively.

[0046] In maintenance mode, the end cover 141 radially limits the rotor assembly 11 and stator assembly 12, respectively. This allows for simultaneous radial limiting of both the rotor assembly 11 and stator assembly 12 without completely disassembling the external rotor motor 10 or using additional tooling. This improves the reliability and stability of the relative fixation of the stator assembly 12 and rotor assembly 11, facilitating subsequent replacement of the first bearing 13 and reducing maintenance costs and cycles. Simultaneously, the end cover 141 also serves as the end cover for the first bearing 13, pre-tightening at least the outer ring of the first bearing 13 during operation. In other words, by separating the original end cover 141 structure at the first bearing 13 from the stator assembly 12, the structure becomes more rational, and the overall weight of the external rotor motor 10 is reduced as much as possible.

[0047] In some embodiments, please refer to Figures 1 to 6 as well as Figure 10 The end cover 141 has a limiting block 141a and a first limiting portion 141b formed at both ends along the axial direction. The stator assembly 12 has a stepped portion 121a formed along the axial direction. The limiting block 141a abuts against the stepped portion 121a radially. The rotor assembly 11 has a second limiting portion 111a formed on one side along the axial direction. The first limiting portion 141b is used to move axially in the maintenance state and is radially limited and engaged with the second limiting portion 111a.

[0048] The stator assembly 12 and the rotor assembly 11 are spaced apart at one end of the axial direction of the outer rotor motor 10 to define a spacer cavity 10a. In this way, the stator assembly 12 and the rotor assembly 11 can rotate relative to each other without interference, which can improve the stability and reliability of motor operation.

[0049] The end cap 141 is movably disposed within the spacer cavity 10a, thus enabling the end cap 141 to move within the spacer cavity 10a.

[0050] The end cover 141 has a limiting block 141a and a first limiting part 141b formed at both ends along the axial direction, wherein the limiting block 141a is located on the side closer to the stator assembly 12, and the first limiting part 141b is located on the side closer to the rotor assembly 11.

[0051] The form and structure of the limiting block 141a and the first limiting part 141b are not limited; they can be ring-shaped, block-shaped, etc.

[0052] For example, the limiting block 141a and the first limiting part 141b both extend in opposite directions along the axial direction.

[0053] The stator assembly 12 has a stepped portion 121a formed along the axial direction, and the limiting block 141a abuts against the stepped portion 121a in the radial direction, so that the end cover 141 and the stator assembly 12 are radially limited. For example, the limiting block 141a is sleeved outside the stepped portion 121a, so that the end cover 141 and the stator assembly 12 are at least radially limited.

[0054] The first limiting part 141b is used to move axially in the maintenance state and to limit and cooperate with the second limiting part 111a. This means that in the maintenance state, the second limiting part 111a formed on one side of the rotor assembly 11 along the axial direction moves axially relative to the end cover 141, that is, the end cover 141 moves axially toward the rotor assembly 11, so that the first limiting part 141b on the end cover 141 moves closer to the second limiting part 111a and at least partially cooperates radially.

[0055] For example, the first limiting part 141b is sleeved outside the second limiting part 111a, such that at least a radial limit is formed between the end cover 141 and the rotor assembly 11.

[0056] In this embodiment, the limiting block 141a abuts against the step portion 121a, and the first limiting portion 141b and the second limiting portion 111a cooperate to limit the end cover 141 so that the two ends along the axial direction can respectively limit the stator assembly 12 and the rotor assembly 11. By using the end cover 141 as an intermediate transition, the relative position between the stator assembly 12 and the rotor assembly 11 can be fixed without completely disassembling the motor or using additional tooling. This is beneficial for the subsequent replacement of the first bearing 13 and reduces maintenance costs and cycle time.

[0057] For example, the limiting block 141a and the first limiting part 141b are both sleeve structures. The two sleeve structures are respectively sleeved on the step part 121a and the second limiting part 111a, thereby achieving mutual limiting at least in the radial direction.

[0058] The end cover 141 has a T-shaped cross section passing through the central axis of the outer rotor motor 10.

[0059] In some embodiments, one of the first limiting portion 141b and the second limiting portion 111a is a plug, and the other of the first limiting portion 141b and the second limiting portion 111a is a slot. The plug and the slot are inserted and engaged.

[0060] For example, the first limiting part 141b is an insert block and the second limiting part 111a is a slot.

[0061] The inserts can be arranged in a ring or spaced apart circumferentially, and correspondingly, the slots can also be arranged in a ring or spaced apart circumferentially.

[0062] The insertion block and the slot are connected and engaged, which makes the structure of the first limiting part 141b and the second limiting part 111a simpler, and they can be connected or disconnected by moving closer to each other along the axial direction.

[0063] In some embodiments, please refer to Figures 1 to 6 The stator assembly 12 includes a stator support 121 and a first bearing housing 122. The rotor assembly 11 includes a rotor support 111 and a shaft 112. The inner ring of the first bearing 13 is fitted onto the shaft 112. The stator support 121 and the rotor support 111 define a spacer cavity 10a at one end of the outer rotor motor 10 along the axial direction. The outer rotor motor 10 also has an operating state, in which the end cover 141 is spaced apart from the rotor assembly 11 along the axial direction. In the operating state, the rotor support 111 is locked to the shaft 112, and the stator support 121, end cover 141, and first bearing housing 122 are locked. The first bearing housing 122 and the end cover 141 define a limiting groove 11a along the axial direction for clamping the outer ring of the first bearing 13. In the maintenance state, the end cover 141 is locked to the rotor support 111 and the stator support 121 respectively. The first bearing housing 122 can be unlocked and separated from the stator support 121, the rotating shaft 112 can be unlocked and separated from the rotor support 111, and the end cover 141 can be axially limited to the end face of the outer ring of the first bearing 13 so that the first bearing 13 can be removed along with the first bearing housing 122 and / or the rotating shaft 112.

[0064] It should be noted that the operating state in this application refers to the state of the external rotor motor 10 when it has not been disassembled, replaced, or maintained. Specifically, it can be the normal state of the external rotor motor 10. It can be a state of being stopped, a state of being rotated, or a non-maintenance state.

[0065] For example, the inner ring of the first bearing 13 may be interference-fitted or transition-fitted with the rotating shaft 112. The outer ring of the first bearing 13 may be transition-fitted or interference-fitted with the first bearing housing 122.

[0066] In operation, the rotor support 111 is locked to the shaft 112, and the stator support 121, end cover 141 and first bearing housing 122 are locked. The first bearing housing 122 and end cover 141 define a limiting groove 11a along the axial direction to clamp the outer ring of the first bearing 13. At this time, the end cover 141 is spaced apart from the rotor assembly 11 along the axial direction, and the rotor support 111 and shaft 112 can rotate relative to the stator support 121 and end cover 141.

[0067] In the maintenance state, the end cover 141 is locked to the rotor support 111 and the stator support 121 respectively. That is, while the end cover 141 is fixedly connected to the stator support 121, it is also fixed to the rotor support 111, so that the rotor support 111 and the stator support 121 can be fixed together.

[0068] The first bearing housing 122 can be unlocked and separated from the stator support 121, that is, the first bearing housing 122 can be removed from the stator support 121. The fact that the rotating shaft 112 can be unlocked and separated from the rotor support 111 means that the rotating shaft 112 can be removed from the rotor support 111.

[0069] The end cap 141 can be axially positioned against the end face of the outer ring of the first bearing 13 so that the first bearing 13 can be removed along with the first bearing housing 122 and / or the shaft 112. This means that if the inner ring of the first bearing 13 is interference-fitted with the shaft 112 and the outer ring of the first bearing 13 is transition-fitted with the first bearing housing 122, then the first bearing 13 will not be removed along with the first bearing housing 122. Instead, during the removal of the shaft 112 from the side of the rotor support 111 away from the stator support 121, the shaft 112 can carry the first bearing 13 axially against the end cap 141. 41. The contact occurs when the end face of the outer ring of the first bearing 13 abuts against the end face of the end cover 141. If the inner and outer rings of the first bearing 13 are not easily separated, the end cover 141 removes the first bearing 13 from the shaft 112 by pushing against the outer ring of the first bearing 13. If the inner and outer rings of the first bearing 13 are easily separated, the end cover 141 removes the outer ring of the first bearing 13 from the shaft 112 by pushing against the outer ring of the first bearing 13, and the inner ring of the first bearing 13 is removed along with the shaft 112. Subsequently, a tool can be used to remove the inner ring of the first bearing 13 from the shaft 112. If the inner ring of the first bearing 13 has an interference fit with the shaft 112, and the outer ring of the first bearing 13 has an interference fit with the first bearing housing 122, then the first bearing 13 can be removed by removing the first bearing housing 122, and then a tool can be used to remove the first bearing 13 from the first bearing housing 122.

[0070] Here, the first bearing 13 can be removed by disassembling the rotating shaft 112 and the first bearing housing 122, which can reduce the number of parts to be disassembled when replacing the bearing and reduce the difficulty of disassembling the first bearing 13.

[0071] For example, in operation, the end cap 141 is attached to and fixed to the stator bracket 121, and together with the first bearing housing 122, defines a first bearing 13 chamber for mounting the first bearing 13.

[0072] For example, a weight reduction hole 111d is formed on the rotor support 111, which is beneficial to reduce the weight of the rotor assembly 11 and improve the performance of the external rotor motor 10.

[0073] In some embodiments, please refer to Figures 1 to 6 In operation, the inner ring of the first bearing 13 is interference-fitted with the shaft 112, and the outer ring of the first bearing 13 is transition-fitted with the limiting groove 11a. The inner diameter of the end cover 141 is smaller than the outer diameter of the outer ring of the first bearing 13. In maintenance mode, the shaft 112 can move axially from the stator support 121 towards the rotor support 111, thereby causing the outer ring of the first bearing 13 to abut against the end cover 141, thus separating the first bearing 13 from the shaft 112.

[0074] Here, by limiting the inner ring of the first bearing 13 to be interference fit with the shaft 112, and the outer ring to be transition fit or clearance fit with the first bearing housing 122, when the shaft 112 moves axially, the first bearing 13 can be removed from the shaft 112 by pushing the outer ring of the first bearing 13 with the end cover 141. This reduces the tooling required to disassemble the first bearing 13 and lowers the difficulty of disassembling and assembling the first bearing 13.

[0075] In some embodiments, please refer to Figures 1 to 6 The stator assembly 12 includes a first fixing member 123. The rotor assembly 11 includes a second fixing member 113. The locking member 14 further includes a first fastener 142 and a second fastener 143. In the operating state, the end cover 141, the stator support 121, and the first bearing housing 122 are locked by the first fixing member 123, and the rotor support 111 and the shaft 112 are locked by the second fixing member 113. In the maintenance state, the first fixing member 123 and the second fixing member 113 are removed, and the end cover 141 is locked to the rotor support 111 by the first fastener 142, and the end cover 141 is locked to the stator support 121 by the second fastener 143.

[0076] The first fixing member 123 and the second fixing member 113 are installed on the external rotor motor 10 in the operating state. The first fixing member 123 fixes the end cover 141, the stator bracket 121 and the first bearing seat 122, and the second fixing member 113 fixes the rotor bracket 111 and the rotating shaft 112. The first fixing member 123 and the second fixing member 113 are removed from the external rotor motor 10 in the maintenance state, so that the rotating shaft 112 and the first bearing seat 122 can be removed.

[0077] The number of the first fastener 123, the second fastener 113, the first fastener 142, and the second fastener 143 is unlimited; there can be one, two, three, four, five, six, seven, or eight, etc. The arrangement of the first fastener 123, the second fastener 113, the first fastener 142, and the second fastener 143 is also unlimited; they can be evenly distributed circumferentially or randomly distributed. Understandably, the arrangement depends on the threaded holes that mate with the first fastener 123, the second fastener 113, the first fastener 142, and the second fastener 143.

[0078] The first fastener 123, the second fastener 113, the first fastener 142, and the second fastener 143 can be any type of fastener, such as bolts, studs, screws, etc.

[0079] The locking mentioned in this application includes at least axial locking limits, and may also include circumferential and radial locking limits, without limitation herein.

[0080] For example, the stator support 121 has a first through hole 121b, the first bearing housing 122 has a second through hole 122a, and the end cover 141 has a first threaded hole 141c. The first fixing member 123 passes through the first through hole 121b of the stator support 121 and the second through hole 122a of the first bearing housing 122, and engages with the first threaded hole 141c of the end cover 141 to achieve locking between the end cover 141, the stator support 121, and the first bearing housing 122. The first through hole 121b, the second through hole 122a, and the first threaded hole 141c correspond one-to-one, and the number is unlimited. The second through hole 122a of the first bearing housing 122 corresponds to the first threaded hole 141c, which is beneficial for fixing the end cover 141, for pre-tightening the first bearing 13, and for assisting in the disassembly of the first bearing 13.

[0081] For example, a flange 112a is formed on the rotating shaft 112, a third through hole 112b is formed on the flange 112a, and a second threaded hole 111c is formed on the rotor support 111. The second fastener 113 passes through the third through hole 112b on the rotating shaft 112 and engages with the second threaded hole 111c on the rotor support 111 to achieve locking between the rotor support 111 and the rotating shaft 112. The third through hole 112b and the second threaded hole 111c correspond one-to-one, and the number is unlimited.

[0082] For example, a flange 112a is formed on the rotating shaft 112, a first notch 112c is formed on the flange 112a, a fourth through hole 111b is formed on the rotor support 111, and a third threaded hole 141d is formed on the end cover 141. A first fastener 142 passes through the first notch 112c and the fourth through hole 111b in sequence and engages with the third threaded hole 141d to lock the end cover 141 and the rotor support 111. At the same time, by providing the first notch 112c on the rotating shaft 112, the first notch 112c can avoid the first fastener 142, preventing the first fastener 142 from fixing the rotating shaft 112 to the rotor support 111, which is beneficial for subsequent disassembly and assembly of the rotating shaft 112. In addition, the first notch 112c can also be used for positioning and is beneficial for reducing the weight of components. The first notch 112c, the fourth through hole 111b and the third threaded hole 141d correspond one-to-one, and the number is unlimited.

[0083] For example, the first bearing housing 122 has a second notch 122b, the stator support 121 has a fifth through hole 121c, and the end cover 141 has a fourth threaded hole 141e. The second fastener 143 passes through the second notch 122b and the fifth through hole 121c in sequence and engages with the fourth threaded hole 141e to lock the end cover 141 and the stator support 121. Simultaneously, by providing the second notch 122b on the first bearing housing 122, the second notch 122b can avoid the second fastener 143, preventing the second fastener 143 from fixing the first bearing housing 122 to the stator support 121, which facilitates subsequent disassembly and assembly of the first bearing housing 122. The second notch 122b, the fifth through hole 121c, and the fourth threaded hole 141e correspond one-to-one, and their number is unlimited.

[0084] Here, by connecting the first fastener 142 and the second fastener 143 to the third threaded hole 141d and the fourth threaded hole 141e on the end cover 141 from both sides of the axial direction, the rotor support 111 and the stator support 121 can be unidirectionally limited in the axial direction, thereby achieving bidirectional axial limitation between the end cover 141, the stator support 121 and the rotor support 111, so that the stator support 121 and the rotor support 111 do not move relative to each other at least in the axial direction, and keep the gap between the stator and the rotor as unchanged as possible.

[0085] Fastener threads are typically classified as left-hand or right-hand. It can be understood that if viewed from one axial side of the end cap 141 towards the third threaded hole 141d and the fourth threaded hole 141e, and the thread directions of the third threaded hole 141d and the fourth threaded hole 141e are opposite, then the thread directions of the first fastener 142 and the second fastener 143 are the same. Similarly, if viewed from one axial side of the end cap 141 towards the third threaded hole 141d and the fourth threaded hole 141e, and the thread directions of the third threaded hole 141d and the fourth threaded hole 141e are the same, then the thread directions of the first fastener 142 and the second fastener 143 are opposite.

[0086] It should be noted that the first fastener 142 and the second fastener 143 in the locking member 14 may be components that are only installed on the external rotor motor 10 in the maintenance state. In the operating state, the first fastener 142 and the second fastener 143 are not installed on the external rotor motor 10, while the end cover 141 in the locking member 14 is installed on the external rotor motor 10 in both the operating and maintenance states. The end cover 141 may be movably installed in the partition cavity 10a or fixedly installed in the partition cavity 10a.

[0087] Specifically, the end cover 141 is movably disposed in the spacer cavity 10a, which allows the end cover 141 to move axially. This allows the end cover 141, which is originally spaced apart from the rotor support 111 in the operating state, to move axially toward the rotor support 111 in the maintenance state and contact the rotor support 111 to form a limiting fit. This is beneficial for fixing the rotor support 111 and the stator support 121, and improves the reliability of the fixation between the end cover 141, the rotor support 111 and the stator support 121.

[0088] In this embodiment, by removing the first fixing member 123 and the second fixing member 113 in the maintenance state, the end cover 141, the stator support 121 and the first bearing seat 122 are unlocked, and the rotor support 111 and the shaft 112 are unlocked, so that the shaft 112 and the first bearing seat 122 can be removed. The end cover 141 and the rotor support 111 are locked by the first fastener 142, and the end cover 141 and the stator support 121 are locked by the second fastener 143. In this way, before the shaft 112 and the first bearing seat 122 are removed, the rotor support 111 and the stator support 121 can be fixed to the end cover 141 by the first fastener 142 and the second fastener 143 respectively. This can improve the situation where relative movement easily occurs between the rotor support 111 and the stator support 121 during the process of removing the shaft 112 and the first bearing seat 122, and help reduce the difficulty of disassembling and assembling the shaft 112 and the first bearing seat 122.

[0089] In some embodiments, during maintenance, after the first fastener 123 is removed, the end cover 141 is in an unlocked state. The first fastener 142 passes through the rotor support 111 and is threaded into the end cover 141. When the end face of the rotor support 111 restricts the axial displacement of the first fastener 142, the end cover 141 is driven to move axially toward the rotor support 111 by continuing to rotate the first fastener 142 until the first limiting portion 141b and the second limiting portion 111a are axially limited. At this time, the limiting block 141a still maintains a limiting engagement with the step portion 121a. Thus, the end cover 141 forms at least radial limits with the rotor support 111 and the stator support 121 at both ends along the axial direction.

[0090] In some embodiments, please refer to Figure 3 and Figure 5 The locking member 14 also includes a third fastener 144, which is used to pass through the stator bracket 121 in the maintenance state and abut against the first fastener 142.

[0091] The third fastener 144 abuts against the first fastener 142 in an axial manner, which can improve the axial limiting strength between the stator support 121 and the end cover 141, and improve the stability and reliability of the fixation between the rotor support 111 and the stator support 121.

[0092] For example, the first bearing housing 122 has a third notch 122c, and the stator support 121 has a fifth threaded hole 121d. The third fastener 144 passes through the third notch 122c and engages with the fifth threaded hole 121d until the third fastener 144 abuts against the first fastener 142 that engages with the third threaded hole 141d of the end cover 141. This achieves axial one-way limiting between the stator support 121 and the end cover 141, preventing the end cover 141 and the stator support 121 from approaching each other axially. In addition, the fifth threaded hole 121d can also be used to install a temperature sensor to measure the temperature at the first bearing 13. The third notch 122c, the fifth threaded hole 121d, and the third threaded hole 141d are one-to-one corresponding, and the number is unlimited.

[0093] In other embodiments, in the maintenance state, the third fastener 144 passes through the stator support 121 and abuts against the end face of the end cap 141 axially toward the end face of the stator support 121.

[0094] In some embodiments, please refer to Figures 1 to 6 as well as Figure 8The stator support 121 includes a first sleeve 1211, a second sleeve 1212, and a web 1213. The outer rotor motor 10 includes a second bearing 15. The second sleeve 1212 is located inside the first sleeve 1211. The web 1213 is radially connected to the first sleeve 1211 and the second sleeve 1212. The second sleeve 1212 and the rotor support 111 define a spacer cavity 10a at one end of the outer rotor motor 10 in the axial direction. The second sleeve 1212 is used to lock with the end cover 141 and the first bearing seat 122 in the operating state. The second bearing 15 is sleeved on the outside of the first sleeve 1211.

[0095] Here, the stator support 121 has a double-sleeve single-web plate 1213 structure. The second sleeve 1212 is located inside the first sleeve 1211. The outer circumferential surface of the first sleeve 1211 located on the outer side is used to install the stator core 124, and the second sleeve 1212 located on the inner side is used to install the first bearing 13.

[0096] The second sleeve 1212 is used to lock with the end cover 141 and the first bearing housing 122 in the operating state. That is, the first fastener 123 passes through the first bearing housing 122, the second sleeve 1212, and the end cover 141 to fix the end cover 141, the stator support 121, and the first bearing housing 122. In addition, the second sleeve 1212 can also be used to cooperate with the second fastener 143 to achieve locking between the end cover 141 and the stator support 121.

[0097] For example, a first through hole 121b and a fifth through hole 121c are formed on the second sleeve 1212.

[0098] The second bearing 15 is sleeved on the outside of the first sleeve 1211, meaning the first sleeve 1211 can also be used to install the second bearing 15, at least fixing the inner ring of the second bearing 15. Meanwhile, the inner ring of the first bearing 13 mates with the rotating shaft 112 and is located inside the second sleeve 1212. In other words, the second bearing 15 and the first bearing 13 are separated at least radially, and the second bearing 15 is larger than the first bearing 13, at least in both outer and inner diameters. This reduces the size of the first shaft... The heat transfer between the bearing 13 and the second bearing 15 improves the situation of high local temperature in the external rotor motor 10. At the same time, the second bearing 15 and the stator core 124 are both located in the first sleeve 1211, which can be used to cool the second bearing 15 by means of cooling the stator core 124, thereby improving the cooling efficiency of the second bearing 15. In addition, when the second bearing 15 is located at the end of the stator coil, the redundant space at the end of the stator coil can be used to install the second bearing 15, thereby improving the space utilization of the external rotor motor 10.

[0099] It should be noted that the first bearing 13 located in the second sleeve 1212 bears the main radial and axial loads. There can be one first bearing 13 and one second bearing 15. Compared with the related technology, which sets two bearings in series in the second sleeve 1212, setting a single first bearing 13 in the second sleeve 1212 can reduce the space occupied by the first bearing 13 on the rotating shaft 112, which is beneficial to provide more space for the controller 20 or other components of the external rotor motor 10, thereby reducing the overall size of the external rotor motor 10 and improving the structural compactness of the external rotor motor 10.

[0100] In some embodiments, please refer to Figure 1 and Figure 2 The first bearing 13 and the second bearing 15 are arranged at intervals along the axial direction.

[0101] Meanwhile, the second bearing 15 is larger than the first bearing 13 in at least its outer and inner diameters.

[0102] Thus, the first bearing 13 and the second bearing 15 are radially and axially separated, forming an inner and outer oblique angle support. The forces acting on them are at a certain angle, enabling them to work together to resist combined loads, such as radial loads, axial loads, or bending moments, or one, two, or three of these. The oblique angle support formed by the first bearing 13 and the second bearing 15 enhances the bending stiffness of the external rotor motor 10 and also strengthens the suppression of shaft vibration during high-speed operation.

[0103] In some embodiments, please refer to Figure 1 , Figure 2 , Figure 11 and Figure 12 The external rotor motor 10 includes a second bearing housing 16 and an outer cover 17. In operation, the second bearing housing 16 is connected to the rotor support 111 and located outside the first sleeve 1211. The outer cover 17 is disposed at one axial end of the second bearing housing 16 and the first sleeve 1211. The outer cover 17 and the second bearing housing 16 limit the outer ring of the second bearing 15, and the outer cover 17 and the first sleeve 1211 limit the inner ring of the second bearing 15. In maintenance mode, the outer cover 17 can be removed from the first sleeve 1211 so that the second bearing 15 can be removed along with the second bearing housing 16 and / or the first sleeve 1211.

[0104] For example, the second bearing housing 16 is sleeve-shaped.

[0105] A portion of the rotor support 111 is sleeve-shaped and connected to the second bearing housing 16, located outside the first sleeve 1211. The magnet 114 is disposed on the inner wall surface of the sleeve-shaped rotor support 111.

[0106] Another part of the rotor support 111 extends radially outward from the sleeve-shaped portion along the central axis of the rotor motor 10 and is connected to the shaft 112.

[0107] The outer cover 17 is disposed at one end of the second bearing seat 16 and the first sleeve 1211 along the axial direction. In this way, the outer cover 17 can seal the space between the rotor support 111 and the first sleeve 1211 of the stator support 121 to protect the stator coil, magnet 114 and second bearing 15, and improve the protection performance of the outer rotor motor 10.

[0108] The outer cover 17 and the second bearing housing 16 limit the outer ring of the second bearing 15, meaning that the outer cover 17 and the second bearing housing 16 can define a space for accommodating the outer ring of the second bearing 15. Specifically, the outer cover 17 and the outer ring of the second bearing 15 are spaced apart along the axial direction, and the outer diameter of the second bearing housing 16 is matched with the outer ring of the second bearing 15, which is conducive to the outer ring of the second bearing 15 rotating relative to the outer cover 17. The outer diameter matching between the second bearing housing 16 and the outer ring of the second bearing 15 can be an interference fit, a clearance fit, or a transition fit.

[0109] Meanwhile, when the rotor rotates, the second bearing housing 16 and the second bearing 15 work together to resist the deformation of the rotor support 111 caused by centrifugal force. Through the dual effects of mechanical limiting and stiffness enhancement, the rotor deformation problem during the operation of the external rotor motor 10 can be solved.

[0110] The outer cover 17 and the first sleeve 1211 limit the inner ring of the second bearing 15, and together they define a space for accommodating the inner ring of the second bearing 15. Specifically, the outer cover 17 and the inner ring of the second bearing 15 abut axially, and the first sleeve 1211 and the inner ring of the second bearing 15 abut axially, to achieve the installation and fixation between the inner ring of the second bearing 15 and the stator bracket 121. The inner ring of the second bearing 15 and the outer diameter of the first sleeve 1211 are fitted, which can be an interference fit, a clearance fit, or a transition fit.

[0111] For example, the inner ring of the second bearing 15 is interference-fitted with the first sleeve 1211, and the outer ring of the second bearing 15 is clearance-fitted with the second bearing housing 16.

[0112] In the maintenance state, the outer cover 17 can be removed from the first sleeve 1211 so that the second bearing 15 can be removed along with the second bearing housing 16 and / or the first sleeve 1211. That is, in the operating state, the outer cover 17 is connected to the first sleeve 1211. At the same time, after removing the outer cover 17, the second bearing 15 can be removed by removing the second bearing housing 16, removing the first sleeve 1211, or removing the second bearing housing 16 and the first sleeve 1211 at the same time.

[0113] Here, the second bearing 15 can be removed by removing the second bearing housing 16, the first sleeve 1211, or both the second bearing housing 16 and the first sleeve 1211 at the same time. No additional tooling or complete disassembly of the entire external rotor motor 10 is required. Removing the second bearing 15 is simpler and can reduce the cost and time required to replace the second bearing 15.

[0114] For example, the second bearing housing 16 is bolted to the rotor support 111.

[0115] In some embodiments, please refer to Figure 1 , Figure 2 , Figure 11 and Figure 12 The first sleeve 1211 includes a cylinder 12111 and a sealing plate 12112. The stator assembly 12 includes a stator core 124. The cylinder 12111 is connected to the web plate 1213. The cylinder 12111 forms a receiving cavity 12111a and an opening 12111b communicating with the receiving cavity 12111a. The stator core 124 is disposed in the receiving cavity 12111a. In the operating state, one end cap 141 of the sealing plate 12112 is disposed at the opening 12111b, and the other end of the sealing plate 12112 is connected to an outer cover 17. The second bearing 15 is sleeved on the sealing plate 12112. The sealing plate 12112 forms a first flange 12112a on the side away from the outer cover 17 along the axial direction. The first flange 12112a and the outer cover 17 clamp the inner ring of the second bearing 15.

[0116] The receiving cavity 12111a is used to receive the stator core 124. Exemplarily, the cooling medium can enter the receiving cavity 12111a to exchange heat with the stator core 124, thereby cooling the stator core 124.

[0117] One end cap 141 of the sealing plate 12112 is located at the opening 12111b, thereby sealing the receiving cavity 12111a and isolating the receiving cavity 12111a from the outside world, thus protecting the stator core 124.

[0118] For example, one end of the cylinder 12111 is connected to the web 1213 along the axial direction, and the other end has an opening 12111b.

[0119] The other end of the sealing plate 12112 is connected to the outer cover 17, that is, the side of the sealing plate 12112 that is axially away from the receiving cavity 12111a is connected to the outer cover 17.

[0120] The second bearing 15 is sleeved on the sealing plate 12112, which means that the inner ring of the second bearing 15 is fitted with the sealing plate 12112.

[0121] The sealing plate 12112 has a first flange 12112a formed on the side away from the outer cover 17 along the axial direction. The first flange 12112a can limit the inner ring of the second bearing 15 when the second bearing 15 is assembled.

[0122] The first flange 12112a and the outer cover 17 clamp the inner ring of the second bearing 15, thereby improving the reliability of fixing the inner ring of the second bearing 15.

[0123] Here, by splitting the first sleeve 1211 into a cylinder 12111 and a sealing plate 12112, the inner ring of the second bearing 15 is fitted onto the sealing plate 12112. Thus, when disassembling the second bearing 15, the second bearing 15 can be removed by removing the sealing plate 12112, which can reduce the number of parts to be disassembled and assembled during the disassembly of the second bearing 15 and reduce the difficulty of disassembly and assembly.

[0124] For example, the sealing plate 12112 is connected to the cylinder 12111 by bolts.

[0125] For example, the outer cover 17 is connected to the sealing plate 12112 by bolts.

[0126] In some embodiments, please refer to Figure 11 and Figure 12 A second flange 16a is formed on the inner side of the second bearing housing 16. The second flange 16a is used to limit the outer ring of the second bearing 15 during operation.

[0127] The second flange 16a can contact or be spaced apart from the outer ring of the second bearing 15 in the axial direction, so that during operation, the outer ring of the second bearing 15 is limited and the reliability of the installation and fixation of the second bearing 15 is improved.

[0128] Here, the second flange 16a, together with the outer cover 17, defines the space for mounting the outer ring of the second bearing 15.

[0129] For example, the second flange 16a and the outer ring of the second bearing 15 are spaced apart in the axial direction. For example, the axial gap between the second flange 16a and the outer ring of the second bearing 15 is between 0.1mm and 0.2mm, such as 0.1mm, 0.12mm, 0.15mm, 0.18mm or 0.2mm, etc. This can improve the situation where the second flange 16a easily abuts against the outer ring of the second bearing 15 in the axial direction when the second bearing seat 16 expands in the direction of the outer cover 17 due to the thermal stress generated by the heating of the magnet 114, which can easily cause the inner and outer rings of the second bearing 15 to jam.

[0130] In some embodiments, please refer to Figure 11 and Figure 12The outer cover 17 has a first sealing tooth 17a. The second bearing housing 16 has a second sealing tooth 16b, and the first sealing tooth 17a and the second sealing tooth 16b are inserted into each other.

[0131] Here, the first sealing tooth 17a and the second sealing tooth 16b can be annular sealing teeth. After the first sealing tooth 17a and the second sealing tooth 16b are inserted and engaged, a labyrinth seal is formed. There can be multiple first sealing teeth 17a and second sealing teeth 16b.

[0132] In this application, "multiple" refers to two or more items.

[0133] A series of intercepting gaps and expansion cavities are formed between multiple sealing teeth. When the sealed medium passes through the gaps of the tortuous labyrinth, a throttling effect is generated to achieve the purpose of preventing leakage.

[0134] The first sealing tooth 17a and the second sealing tooth 16b can form a radial labyrinth seal or an axial labyrinth seal, which is not limited here.

[0135] The insertion fit between the first sealing tooth 17a and the second sealing tooth 16b is a non-contact labyrinth seal fit, which requires no lubrication, is simple to maintain, has a reasonable operation mode, and a long service life.

[0136] For example, the second bearing 15 is a self-sealing bearing with an integrated sealing lip. The dual design of the labyrinth seal and the self-sealing bearing can effectively prevent residual foreign objects from entering the interior of the external rotor motor 10, improve the overall sealing performance of the external rotor motor 10, achieve active interception of foreign objects, and significantly improve the reliability of the external rotor motor 10 in harsh environments.

[0137] In some embodiments, please refer to Figure 11 and Figure 12 Multiple second sealing teeth 16b are arranged radially, and multiple first sealing teeth 17a are arranged radially. A first sealing groove 17b is formed between two adjacent first sealing teeth 17a. A second sealing groove 16c is formed between two adjacent second sealing teeth 16b. The first sealing teeth 17a mate with the second sealing grooves 16c. The second sealing teeth 16b mate with the first sealing grooves 17b. At least one second sealing groove 16c has a groove wall recessed radially away from the central axis of the outer rotor motor 10 to form a collection groove 16d.

[0138] Multiple second sealing teeth 16b are arranged radially, and multiple first sealing teeth 17a are arranged radially. That is to say, a radial labyrinth seal is formed between the first sealing teeth 17a and the second sealing teeth 16b.

[0139] For example, the first sealing tooth 17a and the second sealing tooth 16b cooperate to form a triple seal, that is, there are three of each of the first sealing tooth 17a and the second sealing tooth 16b.

[0140] It should be noted that the first sealing tooth 17a and the second sealing groove 16c are in clearance fit, and the second sealing tooth 16b and the first sealing groove 17b are in clearance fit, so that when the second bearing seat 16 rotates relative to the outer cover 17, there will be no frictional interference between the first sealing tooth 17a and the second sealing tooth 16b.

[0141] For example, the radial gap between adjacent first sealing teeth 17a and second sealing teeth 16b is between 0.5mm and 0.6mm. For example, it can be 0.5mm, 0.52mm, 0.55mm, 0.58mm, or 0.6mm, etc.

[0142] At least one second sealing groove 16c has a groove wall recessed radially away from the central axis of the outer rotor motor 10 to form a collection groove 16d. That is, the second sealing groove 16c located on the second bearing housing 16 has a collection groove 16d formed on the groove wall radially away from the central axis of the outer rotor motor 10. In this way, the collection groove 16d can effectively capture residual particles that enter through the tooth gap. When the second bearing housing 16 rotates with the rotor assembly 11, the particles located in the collection groove 16d can be discharged radially by centrifugal force. This can improve the dustproof, waterproof and anti-pollution capabilities of the outer rotor motor 10, making the outer rotor motor 10 suitable for applications with harsh environments or high reliability requirements.

[0143] For example, the collection tank 16d is spoon-shaped, specifically, the rate of curvature change of the tank walls from the center of the collection tank 16d to the surrounding area is different.

[0144] The number of collection grooves 16d is unlimited. A collection groove 16d can be formed on the groove wall of each second sealing groove 16c in a radial direction away from the central axis of the outer rotor motor 10.

[0145] In some embodiments, please refer to Figure 11 and Figure 12 The collection groove 16d is formed at least in the second sealing groove 16c that is radially closest to the central shaft of the outer rotor motor 10.

[0146] In this way, a collection groove 16d can be formed in at least the innermost second sealing groove 16c to capture residual particles that enter through the tooth gap, thereby improving the protection performance of the outer rotor motor 10.

[0147] In some embodiments, please refer to Figure 1A sealing portion 18 is provided on the end face of the first bearing housing 122 away from the rotor support 111 along the axial direction. This sealing portion is used to form a sealed connection between the first bearing housing 122 and components other than the external rotor motor 10. For example, the sealing portion 18 is used to abut against the controller 20, thereby forming a seal at the end of the first bearing housing 122 away from the rotor support 111 along the axial direction. This improves the situation where dust, foreign objects, etc., enter the space where the first bearing 13 is located from the side of the first bearing housing 122 away from the rotor support 111 along the axial direction, and then enter between the stator support 121 and the rotor support 111, causing damage to the coils or magnets 114. This improves the stability and reliability of the operation of the external rotor motor 10.

[0148] For example, the stator support 121 is formed with a first through hole 121b, a fifth through hole 121c and a fifth threaded hole 121d, the first bearing housing 122 is formed with a second through hole 122a, a second notch 122b and a third notch 122c, the end cover 141 is formed with a first threaded hole 141c, a third threaded hole 141d and a fourth threaded hole 141e, the rotating shaft 112 is formed with a flange 112a, the flange 112a is formed with a third through hole 112b and a first notch 112c, and the rotor support 111 is formed with a fourth through hole 111b and a second threaded hole 111c.

[0149] Among them, such as Figure 8 As shown, the number of first through holes 121b on the stator support 121 can be six, the number of fifth through holes 121c can be four, and the number of fifth threaded holes 121d can be two. The first through holes 121b, the fifth through holes 121c, and the fifth threaded holes 121d are on the same distribution circle. The first through holes 121b are evenly distributed circumferentially, and the fifth through holes 121c and the fifth threaded holes 121d are also evenly distributed circumferentially and are alternately arranged with the first through holes 121b.

[0150] like Figure 9 As shown, the number of second notches 122b on the first bearing housing 122 can be four, the number of third notches 122c can be two, and the number of second through holes 122a can be six. The second through holes 122a, the second notches 122b, and the third notches 122c are on the same distribution circle. The second notches 122b and the third notches 122c have the same shape and size and are evenly distributed along the circumference. The second through holes 122a are also evenly distributed along the circumference and are alternately arranged with the second notches 122b or the third notches 122c.

[0151] like Figure 10As shown, the number of first threaded holes 141c on the end cap 141 can be six, the number of third threaded holes 141d can be two, and the number of fourth threaded holes 141e can be four. The first threaded holes 141c, the third threaded holes 141d, and the fourth threaded holes 141e are on the same distribution circle. The third threaded holes 141d and the fourth threaded holes 141e are evenly distributed circumferentially. The first threaded holes 141c are also evenly distributed circumferentially and are alternately arranged with the third threaded holes 141d or the fourth threaded holes 141e.

[0152] like Figure 7 As shown, on the flange 112a of the rotating shaft 112, there can be two first notches 112c, which are evenly distributed circumferentially; there can be six third through holes 112b, which are also evenly distributed circumferentially; and a sixth threaded hole 112d can also be formed on the flange 112a of the rotating shaft 112 for mounting the propeller 30. There can be four sixth threaded holes 112d. The first notches 112c, the third through holes 112b, and the sixth threaded holes 112d are generally evenly distributed circumferentially.

[0153] The rotor support 111 can have two fourth through holes 111b and six second threaded holes 111c. The second threaded holes 111c are evenly distributed circumferentially, and the fourth through holes 111b are evenly distributed circumferentially.

[0154] The above-mentioned circumferentially distributed arrangement allows the holes on the flange 112a, first bearing housing 122, end cover 141, stator support 121, and rotor support 111 of the rotating shaft 112 to be evenly arranged, which makes the force more uniform, balances the structural strength, improves the stress concentration, optimizes space utilization, and improves the convenience of bearing maintenance.

[0155] For example, the locking member 14 also includes a bearing nut 145 and a retaining ring 146. The bearing nut 145 and the retaining ring 146 are disposed at the end of the first bearing 13 away from the end cover 141, for locking and limiting the first bearing 13 at least in the operating state.

[0156] In this application, the end cap 141, the first bearing housing 122, the second bearing housing 16, and the outer cover 17 can all be machined from alloy steel. The stator support 121 can be made using 3D printing or casting, and the material can be integral high-strength alloy steel. The sealing plate 12112 can be machined from high-strength alloy steel. The rotating shaft 112 can be machined using forging, and the material can be high-strength alloy steel. The rotor support 111 can be made using 3D printing or casting, and the material can be integral high-strength alloy steel.

[0157] The second aspect of this application provides a bearing replacement method for an external rotor motor 10, applicable to the external rotor motor 10 provided in any embodiment of this application. Please refer to... Figures 1 to 13 The locking element 14 includes an end cap 141. The stator assembly 12 and rotor assembly 11 are spaced apart at one end of the outer rotor motor 10 along its axial direction to define a spacer cavity 10a. The end cap 141 is movably disposed within the spacer cavity 10a. Bearing replacement methods include: S10: Remove the first fastener to unlock the end cover and stator assembly; S20: Connect the rotor assembly to the end cover via the first fastener; S30: Connect the stator assembly to the end cap via a second fastener; S40: Pass the third fastener through the stator assembly and abut against the first fastener axially to lock the stator assembly and rotor assembly together.

[0158] Step S10 specifically involves removing the first fastener 142 and unlocking the connection between the end cover 141, the stator bracket 121, and the first bearing seat 122.

[0159] Step S20 specifically involves passing the first fastener 142 sequentially through the first notch 112c on the flange 112a of the rotating shaft 112, the fourth through hole 111b on the rotor support 111, and engaging with the third threaded hole 141d on the end cover 141. When the end face of the rotor support 111 restricts the axial displacement of the first fastener 142, the end cover 141 is driven to move axially toward the rotor support 111 by continuing to rotate the first fastener 142 until the first limiting part 141b and the second limiting part 111a engage axially. In this way, the end cover 141 can be moved axially toward the rotor support 111, achieving radial and axial limiting between the end cover 141 and the rotor support 111.

[0160] Step S30 specifically involves inserting the second fastener 143 from the stator bracket 121 side, sequentially passing through the second notch 122b of the first bearing seat 122, the fifth through hole 121c of the stator bracket 121, and engaging with the fourth threaded hole 141e on the end cover 141, thereby achieving axial positioning between the stator bracket 121 and the end cover 141. Simultaneously, since the end cover 141 moves axially to engage with the first limiting part 141b and the second limiting part 111a, the limiting block 141a remains in contact with the stepped part 121a, thus maintaining radial positioning between the end cover 141 and the stator bracket 121. In this way, both radial and axial positioning between the end cover 141 and the stator bracket 121 can be achieved.

[0161] Step S40 specifically involves passing the third fastener 144 through the third notch 122c of the first bearing housing 122 and engaging with the fifth threaded hole 121d on the stator bracket 121 until the third fastener 144 abuts against the first fastener 142 engaging with the third threaded hole 141d of the end cover 141, thereby achieving axial one-way limiting between the stator bracket 121 and the end cover 141 and preventing the end cover 141 and the stator bracket 121 from approaching each other axially.

[0162] In this embodiment, the above method can improve the reliability and stability of the locking between the stator assembly 12 and the rotor assembly 11, which is beneficial for subsequent disassembly and assembly of the first bearing 13 or the second bearing 15. At the same time, the first bearing 13 can be replaced without completely disassembling the external rotor motor 10, reducing maintenance costs and maintenance cycle.

[0163] In some embodiments, please refer to Figures 1 to 14 The stator assembly 12 includes a stator support 121 and a first bearing housing 122. The rotor assembly 11 includes a rotor support 111 and a shaft 112. The inner ring of the first bearing 13 is fitted onto the shaft 112. The stator support 121 and the rotor support 111 define a spacer cavity 10a at one end of the axial direction of the outer rotor motor 10.

[0164] Bearing replacement methods also include: S50: Remove the first shaft bearing seat axially away from the rotor support; S60: Remove the second fastener to unlock the rotor bracket and shaft; S70: Remove the shaft axially away from the stator support, and use the end cover to abut against the outer ring of the first bearing axially, so that the inner ring of the first bearing is separated from the shaft or the outer ring of the first bearing is separated from the inner ring.

[0165] Before step S70, step S69 is also included: removing the bearing nut 145 and retaining ring 146 provided at the end of the first bearing 13.

[0166] Step S69 can be performed before step S50, before step S60, or before step S70; the specific operation is not limited.

[0167] In step S70, after the outer ring and inner ring of the first bearing are separated, the process further includes: after the shaft is removed along with the inner ring of the first bearing, the inner ring of the first bearing is removed from the shaft using a tool.

[0168] Here, by disassembling the rotating shaft 112 and the first bearing housing 122, the first bearing 13 can be removed, which reduces the number of parts to be disassembled when replacing the bearing and lowers the difficulty of disassembling the first bearing 13. At the same time, the first bearing 13 can be removed by pushing the outer ring of the first bearing 13, without the need for additional tooling, which helps to reduce the maintenance cycle and cost.

[0169] In some embodiments, please refer to Figures 1 to 15 The external rotor motor 10 includes a second bearing 15. The stator support 121 includes a first sleeve 1211. The external rotor motor 10 includes a second bearing housing 16 and an outer cover 17. The first sleeve 1211 includes a cylinder 12111 and a sealing plate 12112. The second bearing 15 is sleeved on the sealing plate 12112.

[0170] Bearing replacement methods also include: S80: Unlock the connection between the outer cover and the sealing plate, and remove the outer cover; S90: Remove the sealing plate and second bearing from the cylinder; or... S100: Disconnect the connection between the second bearing seat and the rotor support, remove the second bearing seat from the rotor support, and abut against the outer ring of the second bearing along the axial direction through the second flange formed on the inner side of the second bearing seat, so that the inner ring of the second bearing is separated from the sealing plate or the outer ring of the second bearing is separated from the inner ring.

[0171] Specifically, step S90 includes: removing the sealing plate 12112 and the second bearing 15 from the cylinder 12111. The second bearing 15 is removed along with the sealing plate 12112, and the inner ring of the second bearing 15 is separated from the sealing plate 12112 using a tooling.

[0172] In step S100, after the outer ring and inner ring of the second bearing are separated, the steps further include: the second bearing housing takes out the outer ring of the second bearing, the sealing plate is removed from the cylinder, and the inner ring of the second bearing is separated from the sealing plate using a tool.

[0173] In this embodiment, the second bearing 15 can be removed by disassembling the second bearing housing 16 and the first sleeve 1211 without additional tooling or complete disassembly of the entire external rotor motor 10. Removing the second bearing 15 is simpler and can reduce the cost and time required to replace the second bearing 15.

[0174] The various embodiments / implementations provided in this application can be combined with each other without creating contradictions.

[0175] The above description is merely a preferred embodiment of this application and is not intended to limit the application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. An external rotor electric machine characterized by, include: Rotor assembly; A stator assembly is disposed within the rotor assembly; A first bearing is disposed between the stator assembly and the rotor assembly along the radial direction of the outer rotor motor; A locking element is configured to lock the stator assembly and the rotor assembly when the external rotor motor is in a maintenance state, in order to allow for the removal and installation of the first bearing; The locking element includes an end cap. The stator assembly and the rotor assembly are spaced apart at one end of the axial direction of the external rotor motor to define a spacer cavity. The end cap is movably disposed within the spacer cavity. The end cap is used to radially limit the engagement with the rotor assembly and the stator assembly respectively in the maintenance state. The stator assembly includes a stator bracket and a first bearing housing, the rotor assembly includes a rotor bracket and a rotating shaft, the inner ring of the first bearing is sleeved on the rotating shaft, the stator bracket and the rotor bracket define the spacer cavity at one end of the axial direction of the outer rotor motor, the outer rotor motor also has an operating state, in which the end cover is spaced apart from the rotor assembly along the axial direction; In the operating state, the rotor support is locked to the shaft, the stator support, the end cover and the first bearing housing are locked, and the first bearing housing and the end cover define a limiting groove along the axial direction to clamp the outer ring of the first bearing; In the maintenance state, the end cover is locked to the rotor support and the stator support respectively, the first bearing housing can be unlocked and separated from the stator support, the shaft can be unlocked and separated from the rotor support, and the end cover can be axially limited to the end face of the outer ring of the first bearing so that the first bearing can be removed along with the first bearing housing and / or the shaft.

2. An external rotor electric machine according to claim 1, characterized in that The end cap has a limiting block and a first limiting part formed at both ends along the axial direction, the stator assembly has a stepped part formed along the axial direction, the limiting block abuts against the stepped part in the radial direction, and the rotor assembly has a second limiting part formed on one side along the axial direction. The first limiting part is used to move along the axial direction in the maintenance state and to limit and cooperate with the second limiting part in the radial direction.

3. An external rotor electric machine according to claim 2, characterized in that One of the first limiting part and the second limiting part is a plug, and the other of the first limiting part and the second limiting part is a slot, and the plug is inserted into the slot.

4. The external rotor electric machine of claim 1, wherein In the operating state, the inner ring of the first bearing is interference-fitted with the shaft, the outer ring of the first bearing is transition-fitted with the limiting groove, and the inner diameter of the end cover is smaller than the outer diameter of the outer ring of the first bearing. In the maintenance state, the rotating shaft can move along the axial direction from the stator support to the rotor support, thereby causing the outer ring of the first bearing to abut against the end cover, thus separating the first bearing from the rotating shaft; and / or, The first bearing housing has a sealing portion on its end face away from the rotor support along the axial direction, which is used to form a sealed connection between the first bearing housing and components other than the external rotor motor.

5. The external rotor motor according to claim 1, characterized in that, The stator assembly includes a first fixing member, the rotor assembly includes a second fixing member, and the locking member further includes a first fastener and a second fastener. In the operating state, the end cover, the stator support, and the first bearing housing are locked by the first fixing member, and the rotor support and the rotating shaft are locked by the second fixing member; In the maintenance state, the first fastener and the second fastener are removed, the end cover is locked to the rotor support by the first fastener, and the end cover is locked to the stator support by the second fastener.

6. The external rotor motor according to claim 5, characterized in that, The locking component further includes a third fastener, which is used to pass through the stator support in the maintenance state and abut against the first fastener.

7. The external rotor motor according to claim 1, characterized in that, The stator support includes a first sleeve, a second sleeve, and a web. The outer rotor motor includes a second bearing. The second sleeve is located inside the first sleeve. The web is radially connected to the first sleeve and the second sleeve. The second sleeve and the rotor support define the spacer cavity at one end of the axial direction of the outer rotor motor. The second sleeve is used to lock with the end cover and the first bearing seat in the operating state. The second bearing is sleeved on the outside of the first sleeve.

8. The external rotor motor according to claim 7, characterized in that, The first bearing and the second bearing are arranged at a distance along the axial direction.

9. The external rotor motor according to claim 7, characterized in that, The external rotor motor includes a second bearing housing and an outer cover. In the operating state, the second bearing housing is connected to the rotor support and located outside the first sleeve. The outer cover is disposed at one end of the second bearing housing and the first sleeve along the axial direction. The outer cover and the second bearing housing limit the outer ring of the second bearing, and the outer cover and the first sleeve limit the inner ring of the second bearing. In the maintenance state, the outer cover can be removed from the first sleeve so that the second bearing can be removed along with the second bearing housing and / or the first sleeve.

10. The external rotor motor according to claim 9, characterized in that, The first sleeve includes a cylindrical body and a sealing plate, the stator assembly includes a stator core, the cylindrical body is connected to the web plate, the cylindrical body forms a receiving cavity and an opening communicating with the receiving cavity, and the stator core is disposed in the receiving cavity; In the operating state, one end of the sealing plate covers the opening, and the other end of the sealing plate is connected to the outer cover. The second bearing is sleeved on the sealing plate, and the sealing plate has a first flange formed axially away from the outer cover. The first flange and the outer cover clamp the inner ring of the second bearing; and / or, The inner side of the second bearing housing has a second flange, which is used to limit the outer ring of the second bearing in the operating state.

11. The external rotor motor according to claim 9, characterized in that, The outer cover has a first sealing tooth, and the second bearing seat has a second sealing tooth, with the first sealing tooth and the second sealing tooth interlocking.

12. The external rotor motor according to claim 11, characterized in that, A plurality of second sealing teeth are arranged along the radial direction, a plurality of first sealing teeth are arranged along the radial direction, a first sealing groove is formed between two adjacent first sealing teeth, a second sealing groove is formed between two adjacent second sealing teeth, the first sealing teeth cooperate with the second sealing groove, the second sealing teeth cooperate with the first sealing groove, and at least one second sealing groove has its groove wall recessed along the radial direction away from the central axis of the outer rotor motor to form a collection groove.

13. The external rotor motor according to claim 12, characterized in that, The collection groove is formed at least in the second sealing groove that is closest to the central axis of the outer rotor motor along the radial direction.

14. A bearing replacement method, applied to the external rotor motor of claim 1, characterized in that, The locking element includes an end cap. The stator assembly and the rotor assembly are spaced apart at one end of the axial direction of the outer rotor motor to define a spacer cavity. The end cap is movably disposed within the spacer cavity. The bearing replacement method includes: Remove the first fastener to unlock the end cap and the stator assembly; The rotor assembly is connected to the end cap by a first fastener; The stator assembly is connected to the end cap by a second fastener; The third fastener is passed through the stator assembly and abuts against the first fastener axially to lock the stator assembly and the rotor assembly.

15. The bearing replacement method according to claim 14, characterized in that, The stator assembly includes a stator support and a first bearing housing, the rotor assembly includes a rotor support and a rotating shaft, the inner ring of the first bearing is sleeved on the rotating shaft, and the stator support and the rotor support define the spacer cavity at one end of the axial direction of the external rotor motor. The bearing replacement method also includes: Remove the first bearing housing axially away from the rotor support; Remove the second fastener to unlock the rotor bracket from the shaft; The rotating shaft is removed axially away from the stator support, and the end cap abuts against the outer ring of the first bearing axially, thereby separating the inner ring of the first bearing from the rotating shaft or separating the outer ring of the first bearing from the inner ring.

16. The bearing replacement method according to claim 15, characterized in that, The external rotor motor includes a second bearing, the stator support includes a first sleeve, the external rotor motor includes a second bearing housing and an outer cover, the first sleeve includes a cylindrical body and a sealing plate, and the second bearing is sleeved on the sealing plate; The bearing replacement method also includes: Unlock the connection between the outer cover and the sealing plate, and remove the outer cover; Remove the sealing plate and the second bearing from the cylinder; or... Disconnect the second bearing housing from the rotor support, remove the second bearing housing from the rotor support, and abut the outer ring of the second bearing along the axial direction through the second flange formed on the inner side of the second bearing housing, so that the inner ring of the second bearing is separated from the sealing plate or the outer ring of the second bearing is separated from the inner ring.

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