A brushless motor rotor assembly with a buffer structure

Abstract

The utility model discloses a brushless motor rotor subassembly with buffer structure, including magnetic cylinder and pivot, the shaft hole is set up to magnetic cylinder along the axial direction, and the magnetic cylinder is rotated and is equipped with in the pivot outer, and the pivot is matched with the clearance of inner wall of shaft hole, still include elastic tension structure, and the edge of shaft hole is arranged with several rotor bullet in the circumference of magnetic cylinder, and elastic tension structure has the radial contraction of the inner wall of drive several rotor bullet and the elastic abutment of the outer wall of pivot, to make the axis of pivot and shaft hole keep or move to coincide position. Have the effect that can effectively buffer when producing radial deviation between pivot and rotor shell, reduce the noise when the brushless motor operates, prolong the service life, and elastic ring is convenient to dismount.

Description

Technical Field

[0001] This utility model relates to the field of brushless motor technology, and in particular to a brushless motor rotor assembly with a buffer structure. Background Technology

[0002] A Chinese patent with publication number CN210927419U discloses a high-heat-dissipation permanent magnet brushless motor with cohesive magnetic properties, including a stator assembly, an armature assembly, a rotor assembly, and a heat dissipation assembly. The stator assembly includes a base and a main bearing disposed on the base. The armature assembly includes an armature frame and an annular winding. The armature frame is fixedly mounted on the base, and the annular winding is mounted on the armature frame. The rotor assembly includes a shaft, a housing, and an annular permanent magnet. The shaft is mounted on the base via the main bearing. The housing is fixedly mounted on the shaft. The annular permanent magnet is fixedly fitted onto the inner wall of the housing and coaxially arranged with the shaft. The annular permanent magnet surrounds the annular winding.

[0003] However, the aforementioned brushless motor has the following drawbacks: Like most brushless motors on the market, there is a tiny gap between the outer shell and the outer circumference of the shaft in the rotor assembly of this brushless motor. When the brushless motor is working, the outer shell will rotate around the shaft. However, during the continuous rotation of the outer shell, the inner wall of the outer shell will continuously collide with the outer wall of the shaft, thus generating continuous noise. Therefore, it is urgent to develop a brushless motor rotor assembly that can eliminate the noise generated by the collision between the outer shell and the shaft. Utility Model Content

[0004] The purpose of this invention is to provide a brushless motor rotor assembly with a buffer structure, which can effectively buffer radial offset between the shaft and the magnetic cylinder, reduce noise during operation of the brushless motor, and extend its service life.

[0005] The above-mentioned technical objective of this utility model is achieved through the following technical solution: a brushless motor rotor assembly with a buffer structure, including a magnetic cylinder and a rotating shaft, wherein the magnetic cylinder has a shaft hole along the axial direction, the magnetic cylinder is rotatably sleeved on the outside of the rotating shaft through the shaft hole, and the rotating shaft is clearance-fitted with the inner wall of the shaft hole, and further includes an elastic tensioning structure, wherein the magnetic cylinder has a plurality of rotating bullet pieces arranged circumferentially on the edge of the shaft hole, and the elastic tensioning structure has a radial contraction force that drives the inner wall of the plurality of rotating bullet pieces to elastically resist the outer wall of the rotating shaft, so as to keep or move the axis of the rotating shaft and the shaft hole to a coincident position.

[0006] By adopting the above technical solution, when the magnetic cylinder rotates relative to the shaft, the elastic deformation force of the rotor bullet can buffer the impact caused by the radial offset between the shaft and the magnetic cylinder. At the same time, the elastic tensioning structure provides radial tension to the rotor bullet, ensuring that the magnetic cylinder and the shaft maintain a high degree of concentricity. This avoids resonance caused by continuous shaking between the shaft and the magnetic cylinder, effectively suppressing the noise during brushless motor operation, reducing the wear rate between the shaft and the magnetic cylinder, and extending the service life of the rotor assembly. It effectively buffers radial offset between the shaft and the magnetic cylinder, reduces the noise during brushless motor operation, and extends the service life.

[0007] A further feature of this invention is that the elastic tensioning structure is configured as an elastic ring, which is sleeved around a plurality of the rotating bullet pieces.

[0008] By adopting the above technical solution, the elastic contraction force at each position of the elastic ring is more uniform, the radial tightening force at each position along the length of the rotating bullet is uniform and consistent, and the deformation controllability and fatigue resistance are higher. This can significantly reduce the risk of local stress concentration caused by abrupt changes in cross-section and avoid the occurrence of microcracks on the surface of the elastic ring when the brushless motor is working under high load.

[0009] A further feature of this invention is that the elastic ring is made of an elastic polymer material.

[0010] A further feature of this invention is that the inner surface of the rotating bullet is provided with a rotating contact surface corresponding to the outer wall of the rotating shaft, the rotating contact surface extends from the free end toward the fixed end, and the rotating bullet rotates in cooperation with the rotating shaft through the rotating contact surface; The rotating shaft has a state of being ready to be assembled and a state of being assembled relative to the shaft hole. When the rotating shaft is in the state of being ready to be assembled relative to the shaft hole, the distance between the rotating contact surfaces of any two rotating bullet pieces gradually decreases from the fixed end to the free end. When the rotating shaft and the shaft hole are in the assembled state, the rotating shaft squeezes several rotating bullet pieces to open radially outward, so that the several rotating bullet pieces squeeze the rotating shaft radially inward, and drive the rotating shaft and the shaft hole to maintain or move to a concentric position.

[0011] By adopting the above technical solution, when the rotating shaft is inserted into the shaft hole, the rotating bullets located around the shaft hole are squeezed outward by the rotating shaft, causing the rotating bullets to undergo elastic deformation. The rotating bullets have an elastic force that elastically returns inward. This elastic force acts on the outer wall of the rotating shaft. By utilizing the combined squeezing force of multiple sets of rotating bullets acting on the outer wall of the rotating shaft simultaneously, the axis of the rotating shaft and the shaft hole can be maintained or moved to a concentric position, thereby effectively suppressing the radial displacement of the rotor housing relative to the rotating shaft.

[0012] A further feature of this invention is that the inner wall of the rotating bullet on the free end side is provided with a guide slope, and the rotating shaft is guided and engaged with the rotating contact surface through the guide slope.

[0013] By adopting the above technical solution, the addition of the guide slope allows the rotating shaft to slide quickly through the guide slope to the rotating contact surface of the rotating bullet without precise alignment, and finally be inserted into the shaft hole.

[0014] A further feature of this invention is that at least two rotating bullet pieces are provided, and a plurality of rotating bullet pieces are arranged at equal intervals along the circumference of the shaft hole, with a deformation gap provided between adjacent rotating bullet pieces.

[0015] By adopting the above technical solution, multiple rotating bullet pieces are evenly spaced around the rotating shaft, which can improve the elastic clamping force of the rotating bullet pieces on the rotating shaft, avoid stress concentration caused by uneven stress distribution, and ensure that adjacent rotating bullet pieces do not interfere with each other when they undergo elastic deformation.

[0016] A further feature of this invention is that the magnetic cylinder includes a rotor housing and a magnet, the magnet being coaxially arranged on the rotor housing, the rotor housing including a sleeve portion fixedly connected to the rotating bullet, the sleeve portion having an axially formed receiving cavity, and the elastic tensioning structure and a plurality of the rotating bullets being disposed in the receiving cavity.

[0017] By adopting the above technical solution, both the rotor bullet and the sleeve are set in the receiving cavity, which effectively improves the structural compactness of the rotor assembly.

[0018] A further feature of this invention is that the inner wall of the sleeve portion has a connecting portion extending inwardly corresponding to the fixed end, and the fixed end is fixedly connected to the inner wall of the sleeve portion through the connecting portion.

[0019] By adopting the above technical solution, the connecting part serves as the connection point for fixing the rotor bullet, which can improve the machining position accuracy of the rotor bullet. In addition, the rotor bullet can also transfer the load to the sleeve part through the connecting part, eliminating local stress concentration and reducing the risk of rotor shell deformation.

[0020] A further feature of this invention is that the connection between the fixed end of the rotating bullet piece and the connecting part adopts an arc transition.

[0021] By adopting the above technical solution, the arc transition connection method can effectively avoid stress concentration at the connection position.

[0022] A further feature of this invention is that: the outer wall of the rotor housing is provided with an circumferential mounting groove; the magnet is provided with an annular structure; the magnet is embedded in the mounting groove; the magnet is provided with an anti-rotation protrusion; the rotor housing is provided with an anti-rotation groove communicating with the mounting groove; and the anti-rotation protrusion cooperates with the anti-rotation groove to prevent rotation.

[0023] By adopting the above technical solution, the magnet anti-rotation is installed in the mounting groove of the rotor housing, thus preventing the magnet from shifting when the rotor housing rotates at high speed.

[0024] In summary, this utility model has the following beneficial effects: This design employs a system where several rotating bullets are integrally installed within the sleeve portion of the rotor housing. The rotating shaft passes through the shaft hole of the rotor housing, and an elastic ring is fitted over the rotating bullets. When the rotor housing drives the magnet to rotate relative to the rotating shaft, the elastic deformation force of the rotating bullets buffers the impact caused by radial displacement between the rotating shaft and the rotor housing. Simultaneously, the tension force of the elastic ring on the rotating bullets in the radial direction ensures a high degree of concentricity between the rotor housing and the rotating shaft, thus preventing resonance caused by continuous shaking between the rotating shaft and the rotor housing. This effectively suppresses noise during brushless motor operation, reduces the wear rate between the rotating shaft and the rotor housing, and extends the service life of the rotor assembly. Furthermore, the elastic ring is installed in a detachable, sleeved manner, facilitating replacement after prolonged use when elastic fatigue occurs. Since both the rotating bullets and the elastic ring are located within a receiving cavity, this effectively improves the structural compactness of the rotor assembly. The design effectively buffers radial displacement between the rotating shaft and the rotor housing, reduces noise during brushless motor operation, extends service life, and facilitates easy installation and removal of the elastic ring. Attached Figure Description

[0025] Figure 1 This is a structural diagram of the rotor assembly of this utility model.

[0026] Figure 2 This is a utility model Figure 1 Top view.

[0027] Figure 3 This is a utility model Figure 2 A sectional view of section AA in the middle.

[0028] Figure 4 This is a utility model Figure 1 Exploded view.

[0029] Figure 5 This is a top view of the rotor assembly of this utility model after the rotor has been removed from the shaft.

[0030] Figure 6 This is the present invention. Figure 5 A sectional view of section BB in the middle.

[0031] In the diagram: 1. Magnetic cylinder; 2. Rotor housing; 20. Shaft hole; 21. Sleeve section; 211. Mounting groove; 212. Anti-rotation groove; 213. Receiving cavity; 214. Clearance space; 215. Annular anti-detachment part; 22. Connecting part; 23. Rotating bullet piece; 230. Deformation gap; 231. Fixed end; 232. Free end; 2321. Guide slope; 233. Rotation contact surface; 24. Gear section; 3. Magnet; 31. Anti-rotation protrusion; 4. Elastic ring; 5. Rotating shaft. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings.

[0033] A brushless motor rotor assembly with a buffer structure, such as Figures 1-4As shown, the device includes a magnetic cylinder 1 and a rotating shaft 5. The magnetic cylinder 1 includes a rotor housing 2 and a magnet 3. The rotor housing 2 has a shaft hole 20 corresponding to the rotating shaft 5, and the rotating shaft 5 passes through the shaft hole 20. The magnet 3 is coaxially arranged on the rotor housing 2. The rotor housing 2 includes a sleeve portion 21 with a receiving cavity 213 and an elastic support structure integrally connected to the sleeve portion 21 and located in the receiving cavity 213. The elastic support structure includes three rotating bullet pieces 23 evenly spaced along the circumference of the rotating shaft 5. One end of the rotating bullet piece 23 is fixedly connected to the sleeve portion 21, and there is a deformation gap 230 between adjacent rotating bullet pieces 23. The cavity 213 contains an elastic ring 4 with radial elastic tension. The elastic ring 4 is fitted around several rotating bullet pieces 23, causing the inner wall of the rotating bullet pieces 23 to elastically abut against the outer wall of the rotating shaft 5. The outer wall of the rotor housing 2 has a circumferentially circumferentially formed mounting groove 211. The magnet 3 is an annular structure and is embedded in the mounting groove 211. The upper and lower ends of the rotor housing 2 extend radially outward to form annular anti-detachment parts 215. The mounting groove 211 is formed between the two annular anti-detachment parts 215 on the outer wall of the rotor housing 2. The magnet 3 is an annular structure and is fitted into the mounting groove 211, causing... The magnet 3 is prevented from detaching at both ends by corresponding annular anti-detachment parts 215, and the magnet 3 is anti-rotationally fitted with the mounting groove 211, so that the magnet 3 is installed in the mounting groove 211 of the rotor housing 2 without rotation, thus preventing the magnet 3 from shifting when the rotor housing 2 rotates at high speed. The upper and lower ends of the rotor housing 2 extend radially outward to form annular anti-detachment parts 215, and the mounting groove 211 is formed on the outer wall of the rotor housing 2 between the two annular anti-detachment parts 215. The magnet 3 is designed as an annular structure and is fitted into the mounting groove 211, so that the magnet 3 is prevented from detaching at both ends by corresponding annular anti-detachment parts 215. The magnet 3 is anti-rotationally fitted with the mounting groove 211, so that the magnet 3 is anti-rotationally installed in the mounting groove 211 of the rotor housing 2, which prevents the magnet 3 from shifting when the rotor housing 2 rotates at high speed. The magnet 3 is provided with an anti-rotation protrusion 31, and the rotor housing 2 is provided with an anti-rotation groove 212 that communicates with the mounting groove 211. The anti-rotation protrusion 31 and the anti-rotation groove 212 are anti-rotationally positioned, so that the magnet 3 is anti-rotationally installed in the mounting groove 211 of the rotor housing 2, which prevents the magnet 3 from shifting when the rotor housing 2 rotates at high speed. In addition, in this embodiment, a gear part 24 is integrally provided at the output end of the rotor housing 2.

[0034] like Figures 3-6As shown, the rotor spring 23 includes a fixed end 231 and a free end 232. A connecting portion 22 extends inward from the inner wall of the sleeve portion 21 corresponding to the fixed end 231. The connecting portion 22 and the rotor spring 23 are connected by an arc transition to avoid stress concentration. The fixed end 231 is fixedly connected to the inner wall of the sleeve portion 21 through the connecting portion 22. The connecting portion 22 serves as the connection point for the fixed end 231 of the rotor spring 23, improving the machining position accuracy of the rotor spring 23. Furthermore, the rotor spring 23 can transfer the load to the sleeve portion 21 through the connecting portion 22, eliminating local stress concentration and reducing the risk of rotor housing 2 deformation. The inner surface of the spring piece 23 is provided with a rotating contact surface 233 corresponding to the outer wall of the rotating shaft 5. The rotating contact surface 233 extends from the free end 232 toward the fixed end 231. The rotating spring piece 23 rotates and engages with the rotating shaft 5 through the rotating contact surface 233. The rotating shaft 5 has a state of being ready for assembly and a state of being assembled relative to the shaft hole 20. When the rotating shaft 5 is in the state of being ready for assembly relative to the shaft hole 20, the distance between the rotating contact surfaces 233 of any two rotating spring pieces 23 gradually decreases from the fixed end 231 toward the free end 232. When the rotating shaft 5 is in the state of being assembled with the shaft hole 20, the rotating shaft 5 squeezes several rotating spring pieces 23 to open radially outward, so that several rotating spring pieces 23 radially open... The internal compression shaft 5 is used to drive the shaft 5 to maintain or move to a concentric position with the shaft hole 20. When the shaft 5 is inserted into the shaft hole 20, the rotating bullet pieces 23 located around the shaft hole 20 are compressed outward by the shaft 5, causing the rotating bullet pieces 23 to undergo elastic deformation. The rotating bullet pieces 23 have an elastic force that elastically returns inward. This elastic force acts on the outer wall of the shaft 5. By utilizing the combined compression force of multiple sets of rotating bullet pieces 23 acting simultaneously on the outer wall of the shaft 5, the axis of the shaft 5 and the shaft hole 20 can be maintained or moved to a concentric position, thereby effectively suppressing the radial displacement of the rotor housing 2 relative to the shaft 5; the rotating pad located on one side of the fixed end 231 The end of the mating surface 233 is smoothly connected to the edge of the shaft hole 20. This smooth transition makes it easier for the rotating shaft 5 to be inserted into the shaft hole 20 through the rotating mating surface 233. The inner wall of the rotating bullet piece 23 located on the free end 232 side is provided with a guide slope 2321. The inclination angle α of the guide slope 2321 relative to the rotating shaft 5 is set between 5-40°. The rotating shaft 5 is guided and engaged with the rotating mating surface 233 through the guide slope 2321. The addition of the guide slope 2321 allows the rotating shaft 5 to slide quickly through the guide slope 2321 onto the rotating mating surface 233 of the rotating bullet piece 23 without precise alignment, and finally be inserted into the shaft hole 20.

[0035] like Figures 1-4As shown, the elastic ring 4 is designed as a cylindrical structure with a uniform wall thickness. This uniform wall thickness ensures consistent stiffness at all points, resulting in uniform radial tightening force along the length of the rotating bullet piece 23. This enhances deformation control and fatigue resistance, significantly reducing the risk of localized stress concentration caused by abrupt changes in cross-section and preventing micro-cracks from appearing on the surface of the elastic ring 4 under high loads. The elastic ring 4 is made of elastic polymer material. A clearance space 214 is provided between the outer wall of the elastic ring 4 and the inner wall of the receiving cavity 213. This clearance space 214 improves the ease of installation and disassembly of the elastic ring 4 within the receiving cavity 213.

[0036] The basic working principle of this invention is as follows: A plurality of rotating bullet plates 23 are integrally arranged inside the sleeve portion 21 of the rotor housing 2. The rotating shaft 5 is inserted into the shaft hole 20 of the rotor housing 2, and an elastic ring 4 is sleeved on the rotating bullet plates 23. When the rotor housing 2 drives the magnet 3 to rotate relative to the rotating shaft 5, the elastic deformation force of the rotating bullet plates 23 can be used to buffer the impact caused by the radial displacement between the rotating shaft 5 and the rotor housing 2. At the same time, the tension force of the elastic ring 4 on the rotating bullet plates 23 in the radial direction ensures that the rotor housing 2 and the rotating shaft 5 always maintain a high degree of concentricity, thereby avoiding continuous shaking between the rotating shaft 5 and the rotor housing 2. This design effectively suppresses resonance, thereby reducing noise during brushless motor operation and decreasing the wear rate between the shaft 5 and the rotor housing 2, extending the service life of the rotor assembly. Furthermore, the elastic ring 4 is installed in a detachable, sleeved manner, facilitating replacement after prolonged use when elastic fatigue occurs. Both the rotor clip 23 and the elastic ring 4 are located within the receiving cavity 213, effectively improving the structural compactness of the rotor assembly. This design effectively buffers radial offset between the shaft and the rotor housing, reduces noise during brushless motor operation, extends service life, and facilitates easy installation and removal of the elastic ring.

[0037] The above description is only a preferred embodiment of the present utility model. Therefore, all equivalent changes or modifications made to the structure, features and principles described in the claims of the present utility model patent application are included in the scope of the present utility model patent application.

Claims

1. A brushless motor rotor assembly with a buffer structure, comprising a magnetic cylinder (1) and a rotating shaft (5), wherein the magnetic cylinder (1) has an axially formed shaft hole (20), the magnetic cylinder (1) is rotatably sleeved on the rotating shaft (5) through the shaft hole (20), and the rotating shaft (5) is clearance-fitted with the inner wall of the shaft hole (20), characterized in that: It also includes an elastic tensioning structure, wherein the magnetic cylinder (1) has a plurality of rotating bullet pieces (23) arranged circumferentially on the edge of the shaft hole (20), and the elastic tensioning structure has a radial contraction force that drives the inner wall of the plurality of rotating bullet pieces (23) to elastically resist the outer wall of the rotating shaft (5), so that the axis of the rotating shaft (5) and the shaft hole (20) are kept or moved to coincide.

2. The brushless motor rotor assembly with a buffer structure according to claim 1, characterized in that: The elastic tensioning structure is configured as an elastic ring (4), which is sleeved on the outside of several of the rotating bullet pieces (23).

3. The brushless motor rotor assembly with a buffer structure according to claim 2, characterized in that: The elastic ring (4) is made of elastic polymer material.

4. The brushless motor rotor assembly with a buffer structure according to claim 1, characterized in that: The rotating bullet (23) includes a fixed end (231) and a free end (232). The rotating bullet (23) is connected to the magnetic cylinder (1) through the fixed end (231). The inner surface of the rotating bullet (23) is provided with a rotating contact surface (233) corresponding to the outer wall of the rotating shaft (5). The rotating contact surface (233) extends from the free end (232) toward the fixed end (231). The rotating bullet (23) is rotatably engaged with the rotating shaft (5) through the rotating contact surface (233). The rotating shaft (5) has a state of being ready to be assembled and a state of being assembled relative to the shaft hole (20). When the rotating shaft (5) is in the state of being ready to be assembled relative to the shaft hole (20), the distance between the rotating contact surfaces (233) of any two rotating bullet pieces (23) gradually decreases from the fixed end (231) toward the free end (232). When the rotating shaft (5) and the shaft hole (20) are in the assembled state, the rotating shaft (5) squeezes a number of rotating bullet pieces (23) to open radially outward, so that the number of rotating bullet pieces (23) squeeze the rotating shaft (5) radially inward, and drives the rotating shaft (5) and the shaft hole (20) to remain or move to a concentric position.

5. A brushless motor rotor assembly with a buffer structure according to claim 4, characterized in that: The inner wall of the rotating bullet piece (23) located on the free end (232) side is provided with a guide slope (2321), and the rotating shaft (5) is guided and engaged with the rotating contact surface (233) through the guide slope (2321).

6. A brushless motor rotor assembly with a buffer structure according to claim 1, characterized in that: At least two rotating bullet pieces (23) are provided, and a plurality of rotating bullet pieces (23) are arranged at equal intervals along the circumference of the shaft hole (20), and a deformation gap (230) is provided between adjacent rotating bullet pieces (23).

7. A brushless motor rotor assembly with a buffer structure according to claim 4, characterized in that: The magnetic cylinder (1) includes a rotor housing (2) and a magnet (3). The magnet (3) is coaxially arranged on the rotor housing (2). The rotor housing (2) includes a sleeve portion (21) fixedly connected to the rotating bullet (23). The sleeve portion (21) has an axially opened receiving cavity (213). The elastic tensioning structure and a plurality of the rotating bullets (23) are all disposed in the receiving cavity (213).

8. A brushless motor rotor assembly with a buffer structure according to claim 7, characterized in that: The inner wall of the sleeve portion (21) extends inward to the fixed end (231) with a connecting portion (22), and the fixed end (231) is fixedly connected to the inner wall of the sleeve portion (21) through the connecting portion (22).

9. A brushless motor rotor assembly with a buffer structure according to claim 8, characterized in that: The connection between the fixed end (231) of the rotating bullet piece (23) and the connecting part (22) adopts an arc transition.

10. A brushless motor rotor assembly with a buffer structure according to any one of claims 7-8, characterized in that: The outer wall of the rotor housing (2) is provided with an mounting groove (211) in the circumferential direction. The magnet (3) is designed as a ring structure. The magnet (3) is embedded in the mounting groove (211) and the magnet (3) is provided with an anti-rotation protrusion (31). The rotor housing (2) is provided with an anti-rotation groove (212) that communicates with the mounting groove (211). The anti-rotation protrusion (31) and the anti-rotation groove (212) are anti-rotation engaged.

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