Outer rotor brushless motor

Abstract

The present invention relates to the technical field of brushless motors, and in particular to an outer rotor brushless motor. The motor comprises a housing (1), a magnet (2), an end cover (3) and a retaining ring (4). A plurality of isolation mounting parts are evenly arranged on the inner wall of the housing (1), and the plurality of isolation mounting parts are integrally formed with the housing (1). A mounting groove (6) for mounting the magnet (2) is arranged between two adjacent isolation mounting parts. The magnet is arranged in the mounting groove and is axially limited by the end cover and the retaining ring. The brushless motor has high assembly efficiency and good reliability.

Description

Technical Field

[0001] The invention relates to the technical field of brushless motors, and in particular to an outer rotor brushless motor. Background Art

[0002] Compared with the structure of inner rotor motor, outer rotor motor has certain advantages in noise, moment of inertia and enameled wire cost. In addition, outer rotor motor has the advantages of high power density, compact structure, long life and safety and reliability. Therefore, outer rotor motor is used by more and more manufacturers.

[0003] However, in the prior art outer rotor motor, such as the Chinese invention patent with authorization announcement number CN206922549U, its magnets are separated and fixed by magnet fixing parts arranged on the inner wall of the casing. However, because its magnet fixing parts need to be installed on the inner wall of the casing through an additional fixing structure, the assembly efficiency is low and the reliability is also low. For example, in the Chinese invention patent with authorization announcement number CN 208028674U, it separates and fixes the magnets by setting a mounting structure on the end cover, but this form of assembly is not very convenient. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an outer rotor brushless motor with high assembly efficiency and good reliability.

[0005] The technical solution adopted by the present invention is: an outer rotor brushless motor, which includes a casing, a magnet, an end cover and a retaining ring. A plurality of isolation mounting parts are evenly arranged on the inner wall of the casing, and the plurality of isolation mounting parts are integrally formed with the casing, and an installation groove for installing the magnet is provided between two adjacent isolation mounting parts. The magnet is arranged in the installation groove and is axially limited by the end cover and the retaining ring.

[0006] Preferably, the isolation mounting member is a single rib.

[0007] Preferably, the isolation mounting members are two ribs arranged side by side.

[0008] Preferably, the length of the rib is smaller than the length of the magnet.

[0009] Preferably, the cross section of the rib is trapezoidal.

[0010] Preferably, the cross-sectional height of the rib is greater than the cross-sectional height of the magnet.

[0011] Preferably, after the retaining ring is installed in one end of the casing, the outer surface of the retaining ring is flush with the outer surface of the one end of the casing.

[0012] Preferably, the distance between the rib and one end of the casing is smaller than the distance between the rib and the other end of the casing.

[0013] Compared with the prior art, the present invention has the following advantages: an isolation mounting piece is integrally formed on the inner wall of the casing, and then the magnet is installed in the mounting groove formed between the two isolation mounting pieces, and the axis is limited by the end cover and the retaining ring. The outer rotor brushless motor of this structure does not need to be assembled with the isolation mounting piece when it is first assembled, so the assembly efficiency is higher, and the magnet is positioned and fixed by the isolation mounting piece, the retaining ring and the end cover, and the reliability is better.

[0014] A rib is used as an isolation mounting piece, which has a simple structure and is convenient for one-piece molding.

[0015] Two ribs arranged side by side are used as isolation mounting parts, which makes the isolation effect better.

[0016] The length of the rib is made smaller than that of the magnet. In this way, when the magnet is installed between two ribs, a portion of the two ends of the rib will extend out of the installation slot, that is, the retaining ring and the end cover can resist the magnet extending out of the installation slot, so that the axial limiting effect is better.

[0017] The cross section of the rib is made into a trapezoid, which not only can well match the shape of the magnet, but also can better fix the magnet.

[0018] The cross-sectional height of the rib is made higher than the cross-sectional height of the magnet, so that the rib can well separate the two magnets and play a good isolation role.

[0019] Make the outer surface of the retaining ring flush with the outer surface of the housing, so that the reliability of the motor is higher after assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a partial structural schematic diagram of a specific embodiment 1 of the outer rotor brushless motor of the present invention.

[0021] Figure 2 It is a schematic structural diagram of the casing in the first specific embodiment of the outer rotor brushless motor of the present invention.

[0022] Figure 3 It is a partial structural diagram of a specific embodiment 2 of the outer rotor brushless motor of the present invention.

[0023] Figure 4 It is a schematic diagram of the structure of the housing in the second specific embodiment of the outer rotor brushless motor of the present invention.

[0024] As shown in the figure: 1. Casing; 2. Magnet; 3. End cover; 4. Retaining ring; 5. Rib; 6. Mounting groove. DETAILED DESCRIPTION

[0025] The present invention is further described below through specific implementation modes, but the present invention is not limited to the following specific implementation modes.

[0026] Specific embodiment 1: Figure 1 and Figure 2 As shown, an outer rotor brushless motor includes a stator part and a rotor part, wherein the rotor part includes a housing 1, a magnet 2, an end cover 3, and a retaining ring 4, wherein:

[0027] The inner wall of the casing 1 is formed with equally divided ribs 5 which are integral with the casing 1, and a mounting groove 6 is formed between two adjacent ribs 5 and the inner wall of the casing 1. In the present application, 14 ribs 5 are evenly arranged on the inner wall of the casing 1, and the cross-sectional shape of the ribs 5 is a trapezoid, which can well match the shape of the magnet 2, and the length of the ribs 5 is slightly smaller than the magnet 2. Here, the length refers to the vertical height of the ribs. After the magnet 2 is installed in the mounting groove 6 between the two ribs 5, the two ends of the magnet 2 can extend slightly, so that the retaining ring 4 and the end cover 3 can resist the two ends of the magnet 2, thereby axially limiting the magnet 2, and the cross-sectional height of the ribs 5 is greater than the cross-sectional height of the magnet 2, so that the magnets 2 on both sides of the ribs 5 can be well isolated;

[0028] The magnet 2 is a conventional magnet used in the prior art outer rotor brushless motor, and is installed in the mounting groove 6. After the magnet 2 is installed in the mounting groove 6, the left and right sides are completely blocked by the ribs 5, that is, the ribs 5 can well isolate the magnets 2 in the adjacent mounting grooves 6. In the present application, the number of the magnets 2 matches the number of the ribs 5, which is also 14.

[0029] The retaining ring 4 is arranged at one end of the housing 1 and is mainly used to resist one end of the magnet 2. When the retaining ring 4 is installed in one end of the housing 1, the outer surface of the retaining ring 4 is flush with the outer surface of the one end of the housing 1.

[0030] The end cover 3, in the present application, has the structures of the limiting magnets 2 cancelled, that is, the contact portion between the end cover 3 and the magnet 2 has only one circle of protrusions, so that the end cover 3 is installed at the other end of the casing 1, and the circle of protrusions abuts against the other end of the magnet 2, and the distance between the rib 5 and the other end of the casing 1 is greater than the distance between the rib 5 and one end of the casing 1, that is, the installation position left for the retaining ring 4 is much smaller than the safe position left for the end cover 3, because the retaining ring 4 is small in size and does not require such a large installation position, while the end cover 3 is large in size, and in order to ensure the firmness of the end cover 3 after installation, a large space needs to be left for the end cover 3 to extend into and install;

[0031] The stator part includes a shaft, and the shaft and the end cover 3 use interference fit due to the physical characteristics of stainless steel and aluminum having a large friction coefficient, so that the shaft and the end cover 3 fit more firmly and have stable quality.

[0032] Specific embodiment 2, as Figure 3and Figure 4 As shown, the difference from the specific embodiment 1 is that a group of equally divided ribs that are integral with the housing 1 is formed on the inner wall of the housing 1, and each group of ribs includes two ribs 5 arranged side by side. The structure of each rib 5 in the rib group is similar to that of a single rib in the specific embodiment, and the cross-section is also trapezoidal. In addition, the gap between the two ribs 5 in a rib group can allow one rib 5 to be flipped and installed, which is equivalent to dividing the ribs in the specific embodiment 1 into three parts and then peeling off the middle part. This arrangement does not require larger and wider ribs to be set due to the need to expand the isolation distance, thereby reducing part of the cost. In addition, because the magnet 2 is isolated by two ribs 5, the isolation effect is better.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An outer rotor brushless motor, characterized in that: It comprises a casing (1), a magnet (2), an end cover (3) and a retaining ring (4); a plurality of isolating mounting parts are evenly arranged on the inner wall of the casing (1); the plurality of isolating mounting parts are integrally formed with the casing (1); and a mounting groove (6) for mounting the magnet (2) is arranged between two adjacent isolating mounting parts; the magnet (2) is arranged in the mounting groove (6) and is axially limited by the end cover (3) and the retaining ring (4).

2. The outer rotor brushless motor according to claim 1, characterized in that: The isolation mounting piece is a single rib (5).

3. The outer rotor brushless motor according to claim 1, characterized in that: The isolation mounting parts are two ribs (5) arranged side by side.

4. The outer rotor brushless motor according to claim 2 or 3, characterized in that: The length of the rib (5) is smaller than the length of the magnet (2).

5. The outer rotor brushless motor according to claim 2 or 3, characterized in that: The cross section of the rib (5) is trapezoidal.

6. The outer rotor brushless motor according to claim 2 or 3, characterized in that: The cross-sectional height of the rib (5) is greater than the cross-sectional height of the magnet (2).

7. The outer rotor brushless motor according to claim 1, characterized in that: After the retaining ring (4) is installed in one end of the casing, the outer surface of the retaining ring (4) is flush with the outer surface of one end of the casing (1).

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