High-precision magnetic ring assembly structure of hub motor

Abstract

The utility model discloses a high-precision wheel hub motor magnetic ring assembling structure, which comprises a rotor shell and a magnetic ring unit, a coupling sleeve is formed in the center of the rotor shell, at least two protruding positioning bosses are formed on the bottom surface of an inner cavity of the rotor shell, each positioning boss is formed through a stamping process, and the magnetic ring unit is connected with the coupling sleeve. The forming specifications of the positioning bosses are the same, the positioning bosses are distributed at intervals in the circumferential direction with the coupling sleeve as the center, an arc-shaped limiting part is formed on the inner side of each positioning boss, the limiting parts of the positioning bosses are located on the same circular track and surround to form a magnetic ring clamping and embedding position, and the outer diameter of the magnetic ring unit is matched with the magnetic ring clamping and embedding position. The magnet ring unit is clamped and assembled in the magnet ring clamping position, and the side face of the magnet ring unit is tightly matched with the bottom face of the rotor shell. The assembly stability of the magnetic ring unit is improved, the positioning precision of the magnetic ring unit is ensured, and the induction accuracy is remarkably improved.

Description

Technical Field

[0001] This utility model relates to the field of hub motor technology, and in particular to a high-precision magnetic ring assembly structure for a hub motor. Background Technology

[0002] In existing technologies, the assembly of the rotor housing and the magnetic ring typically relies on manual calibration or simple positioning structures, which can easily lead to magnetic ring eccentricity, resulting in magnetic field signal deviation (such as Hall sensor detection errors). Furthermore, insufficient concentricity between the stator and the shaft (generally greater than 0.05 mm) further amplifies the sensing error, affecting equipment performance. For example, in motors or encoders, magnetic ring eccentricity and insufficient stator concentricity can lead to inaccurate speed detection and distorted control signals. Therefore, there is an urgent need for an assembly structure that can simultaneously address both magnetic ring positioning and stator concentricity. Utility Model Content

[0003] To address the shortcomings of existing technologies, the purpose of this invention is to provide a high-precision magnetic ring assembly structure for a hub motor. By utilizing the recessed positioning feature of the rotor housing, the positioning accuracy and concentricity of the magnetic ring are ensured, thereby significantly improving the induction accuracy.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a high-precision magnetic ring assembly structure for a hub motor, comprising a rotor housing and a magnetic ring unit. A shaft sleeve is formed at the center of the rotor housing, and at least two protruding positioning bosses are formed on the bottom surface of the inner cavity of the rotor housing. Each positioning boss is formed by a stamping process, and the forming specifications of each positioning boss are the same. They are distributed at intervals along the circumferential direction with the shaft sleeve as the center. An arc-shaped limiting part is formed on the inner side of the positioning boss. The limiting parts of each positioning boss are respectively located on the same circular trajectory and surround to form a magnetic ring insertion position. The outer diameter of the magnetic ring unit matches the magnetic ring insertion position. The magnetic ring unit is inserted and assembled in the magnetic ring insertion position, and the side of the magnetic ring unit is tightly fitted with the bottom surface of the rotor housing.

[0005] In a further technical solution, the positioning boss also includes an outer arc edge and two side edges. The outer arc edge and the limiting part are concentrically arranged, and the outer arc edge is located outside the limiting part. The radius difference between the two is 3mm-20mm. The side edges are respectively arranged along the radial direction of the rotor housing. The two ends of the side edges are respectively formed and connected to the outer arc edge and the limiting part. The two side edges of the same positioning boss are symmetrically arranged.

[0006] In a further technical solution, the projected shape of the positioning boss is arranged in a fan-shaped ring, and the number of positioning bosses is more than three.

[0007] In a further technical solution, the edges of the positioning boss are formed with rounded corners or chamfers to facilitate the insertion and assembly of the magnetic ring unit.

[0008] In a further technical solution, the protrusion height d of the positioning boss is 1mm-3mm; the arc length L of the limiting part is 2mm-5mm.

[0009] In a further technical solution, the thickness of the magnetic ring unit is greater than the protrusion height d of the positioning boss, but less than three times the protrusion height d of the positioning boss.

[0010] In a further technical solution, the outer surface of the rotor housing is formed with multiple stamped recesses relative to the positions of each positioning boss, which are used to increase the attachment points of the externally injection-molded tire and improve the connection strength between the tire and the rotor housing.

[0011] In a further technical solution, a shaft connection hole for inserting a rotating shaft unit is provided at the center of the shaft connection sleeve. The shaft connection hole and the magnetic ring insertion position are concentrically set, and the length of the shaft connection hole is 5mm-15mm.

[0012] In a further technical solution, the wall thickness of the shaft sleeve is 0.2mm-1mm; the diameter of the shaft connection channel of the shaft sleeve is 5mm-12mm.

[0013] The advantages of this invention compared to the prior art after adopting the above structure are:

[0014] 1. High positioning accuracy of the magnetic ring: The magnetic ring is embedded in the positioning boss, ensuring that the radial offset of the magnetic ring is ≤0.02mm, which significantly reduces the deviation of the sensing signal.

[0015] 2. Improved concentricity: The shaft is fixed by a sleeve, which makes the concentricity between the magnetic ring unit and the shaft reach 0.01mm, ensuring that the PCB board can uniformly sense the magnetic field.

[0016] 3. High assembly efficiency: The chamfered guide design of the positioning boss simplifies the assembly process and reduces manual calibration costs. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is an exploded view of the present invention.

[0019] Figure 2 yes Figure 1 Enlarged view of point A in the image.

[0020] Figure 3 This is a cross-sectional view of a hub motor using the magnetic ring assembly structure provided by this utility model.

[0021] Figure 4 This is a cross-sectional view of the present invention. Detailed Implementation

[0022] The following are merely preferred embodiments of the present invention and do not limit the scope of protection of the present invention.

[0023] To solve the problem of assembling the magnetic ring on the rotor housing of hub motors in the prior art, the inventors proposed a simple magnetization assembly structure.

[0024] like Figures 1 to 4 A high-precision hub motor magnetic ring assembly structure includes a rotor housing 1 and a magnetic ring unit 3. A shaft sleeve is formed at the center of the rotor housing 1. At least two protruding positioning bosses 2 are formed on the bottom surface of the inner cavity of the rotor housing 1. Each positioning boss 2 is formed by a stamping process. The forming specifications of each positioning boss 2 are the same, and they are distributed at intervals along the circumferential direction with the shaft sleeve as the center. An arc-shaped limiting part 21 is formed on the inner side of the positioning boss 2. The limiting part 21 of each positioning boss 2 is located on the same circular trajectory and surrounds to form a magnetic ring insertion position. The outer diameter of the magnetic ring unit 3 matches the magnetic ring insertion position. The magnetic ring unit 3 is inserted and assembled in the magnetic ring insertion position. The side of the magnetic ring unit 3 is tightly fitted with the bottom surface of the rotor housing 1.

[0025] The magnetic ring unit 3 is assembled by using two or more stamped positioning bosses 2 to form a magnetic ring insertion position, which simplifies the assembly steps of the magnetic ring unit 3, eliminates the need for magnetic ring assembly fixtures, and improves its assembly speed and assembly strength.

[0026] The magnetic ring unit 3 is installed by snapping it into the magnetic ring, so that the radial offset of the magnetic ring unit 3 is ≤0.02mm, which significantly reduces the deviation of the sensing signal.

[0027] Specifically, the positioning boss 2 also includes an outer arc edge 22 and two side edges 23. The outer arc edge 22 is concentrically arranged with the limiting part 21, and the outer arc edge 22 is located outside the limiting part 21, with a radius difference of 4mm between them. The side edges 23 are respectively arranged along the radial direction of the rotor housing 1, and the two ends of the side edges 23 are respectively formed and connected to the outer arc edge 22 and the limiting part 21. The two side edges 23 of the same positioning boss 2 are symmetrically arranged. The projected shape of the positioning boss 2 is fan-shaped, and the number of positioning bosses 2 is three or more. In this embodiment, the number of positioning bosses 2 is three, which are distributed at intervals along the circumferential direction.

[0028] Specifically, the edge of the positioning boss 2 is formed with rounded corners 24 to facilitate the insertion and assembly of the magnetic ring unit 3.

[0029] Specifically, the protrusion height d of the positioning boss 2 is 2mm; the arc length L of the limiting part 21 is 5mm.

[0030] Specifically, the thickness of the magnetic ring unit 3 is greater than the protrusion height d of the positioning boss 2, but less than three times the protrusion height d of the positioning boss 2.

[0031] Specifically, the outer side of the rotor housing 1 is formed with multiple stamped recesses 20 relative to the positions of each positioning boss 2, which are used to increase the attachment points of the externally injection-molded tire 9 and improve the connection strength between the tire 9 and the rotor housing 1.

[0032] Specifically, a shaft connection hole (10) for inserting a rotating shaft unit is provided at the center of the shaft connection sleeve. The shaft connection hole (10) and the magnetic ring insertion position are concentrically arranged, and the length of the shaft connection hole (10) is 12mm.

[0033] The shaft sleeve fixes the rotating shaft 8, so that the concentricity between the magnetic ring unit 3 and the rotating shaft 8 reaches 0.01mm, ensuring that the PCB board is uniformly induced by the magnetic field.

[0034] Specifically, the wall thickness of the shaft sleeve is 0.7 mm; the diameter of the shaft connection hole (10) of the shaft sleeve is 10 mm.

[0035] This embodiment also provides a stator structure with two positioning bearings 71. The stator structure has positioning bearings 71 spaced vertically at its center. The two positioning bearings 71 are spaced 8mm apart and are respectively sleeved on the rotating shaft 8 to further improve the concentricity of the rotating shaft 8.

[0036] The above description is only a preferred embodiment of this utility model. For those skilled in the art, there will be changes in the specific implementation method and application scope based on the idea of ​​this utility model. The content of this specification should not be construed as a limitation of this utility model.

Claims

1. A high-precision magnetic ring assembly structure for a hub motor, characterized in that: The device includes a rotor housing (1) and a magnetic ring unit (3). A shaft sleeve is formed at the center of the rotor housing (1). At least two protruding positioning bosses (2) are formed on the bottom surface of the inner cavity of the rotor housing (1). Each positioning boss (2) is formed by a stamping process. The forming specifications of each positioning boss (2) are the same, and they are distributed at intervals along the circumferential direction with the shaft sleeve as the center. Among them, an arc-shaped limiting part (21) is formed on the inner side of the positioning boss (2), and the limiting part (21) of each positioning boss (2) is located on the same circular trajectory and surrounds to form the magnetic ring locking position. The outer diameter of the magnetic ring unit (3) matches the magnetic ring insertion position. The magnetic ring unit (3) is inserted and assembled at the magnetic ring insertion position. The side of the magnetic ring unit (3) is in close contact with the bottom surface of the rotor housing (1).

2. The magnetic ring assembly structure for a high-precision hub motor according to claim 1, characterized in that: The positioning boss (2) also includes an outer arc edge (22) and two side edges (23). The outer arc edge (22) and the limiting part (21) are concentrically arranged. The outer arc edge (22) is located outside the limiting part (21), and the radius difference between the two is 3mm-20mm. The side edges (23) are respectively arranged along the radial direction of the rotor housing (1). The two ends of the side edges (23) are respectively formed and connected to the outer arc edge (22) and the limiting part (21). The two side edges (23) of the same positioning boss (2) are respectively symmetrically arranged.

3. The magnetic ring assembly structure for a high-precision hub motor according to claim 2, characterized in that: The projection shape of the positioning boss (2) is arranged in a fan-shaped ring, and the number of positioning bosses (2) is more than three.

4. The magnetic ring assembly structure for a high-precision hub motor according to claim 3, characterized in that: The positioning boss (2) has rounded corners (24) or chamfers on its edges to facilitate the fitting and assembly of the magnetic ring unit (3).

5. The magnetic ring assembly structure for a high-precision hub motor according to claim 4, characterized in that: The protrusion height d of the positioning boss (2) is 1mm-3mm; the arc length L of the limiting part (21) is 2mm-5mm.

6. The magnetic ring assembly structure for a high-precision hub motor according to claim 5, characterized in that: The thickness of the magnetic ring unit (3) is greater than the protrusion height d of the positioning boss (2) and less than three times the protrusion height d of the positioning boss (2).

7. The magnetic ring assembly structure for a high-precision hub motor according to claim 1, characterized in that: The outer side of the rotor housing (1) is formed with a plurality of stamped recesses (20) relative to the positions of each of the positioning bosses (2), which are used to increase the attachment points of the externally injection-molded tire (9) and improve the connection strength between the tire (9) and the rotor housing (1).

8. The magnetic ring assembly structure for a high-precision hub motor according to claim 1, characterized in that: The center of the shaft sleeve is provided with a shaft connection hole (10) for inserting the rotating shaft unit. The shaft connection hole (10) is concentric with the magnetic ring insertion position. The length of the shaft connection hole (10) is 5mm-15mm.

9. The magnetic ring assembly structure for a high-precision hub motor according to claim 8, characterized in that: The wall thickness of the shaft sleeve is 0.2mm-1mm; the diameter of the shaft connection hole (10) of the shaft sleeve is 5mm-12mm.

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