A small motor external rotor structure

Abstract

This utility model provides a small motor external rotor structure, belonging to the field of mechanical technology. It solves the problem of complex existing external rotor structures. This small motor external rotor structure includes an external rotor body and a rotating shaft. The external rotor body includes a cylinder for mounting magnets, and the rotating shaft is coaxially disposed within the cylinder. The external rotor body is an integral structure. The external rotor body also includes a positioning block coaxially disposed above the cylinder, and the side wall of the positioning block is connected to the cylinder via a ring of spokes. A vertical through hole is formed in the positioning block, and the rotating shaft is threaded into the through hole. The upper end of the rotating shaft passes through the through hole, and a first external thread is provided on the outer wall of the upper end of the rotating shaft. A limiting structure for axially limiting the rotating shaft is also provided between the positioning block and the rotating shaft. This small motor external rotor structure is simple in design.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical technology and relates to an electric motor, particularly an external rotor structure for a small electric motor. Background Technology

[0002] Existing motor products can be divided into internal rotor motors and external rotor motors according to the arrangement of the stator and rotor. In an internal rotor motor, the rotor is rotatably mounted inside the stator, while in an external rotor motor, the rotor is rotatably mounted outside the stator.

[0003] An existing motor structure, such as an external rotor motor disclosed in the Chinese Patent Database (application number: 201320779173.9), includes a rotor, a stator, and a rotating shaft. The rotating shaft is installed at the center of the rotor and engages with the stator through two bearings installed in the center hole of the stator. The characteristic feature is that the rotating shaft is connected to the rotor through a bushing fixed on the rotor, and the two bearings are single-row tapered roller bearings of different sizes.

[0004] When the aforementioned motor is connected to the driven component, the rotor is connected to the driven component through the drive shaft. This means that during assembly, the rotor and the driven component need to be fixed to each end of the drive shaft, which is not only inconvenient to assemble and complex in structure, but also affects coaxiality and transmission accuracy. Utility Model Content

[0005] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a simple external rotor structure for motors.

[0006] The objective of this utility model can be achieved through the following technical solution: A small motor outer rotor structure, comprising an outer rotor body and a rotating shaft, the outer rotor body comprising a barrel for mounting magnets, the rotating shaft being coaxially disposed within the barrel, characterized in that the outer rotor body is an integral structure, the outer rotor body further comprising a positioning block coaxially disposed above the barrel, and the side wall of the positioning block being connected to the barrel by a ring of spokes; a through hole is vertically penetrating the positioning block, the rotating shaft being threadedly connected within the through hole, the upper end of the rotating shaft passing through the through hole, and a first external thread being provided on the outer wall of the upper end of the rotating shaft; a limiting structure for axially limiting the rotating shaft is also provided between the positioning block and the rotating shaft.

[0007] A first external thread is provided on the outer wall of the upper end of the shaft so that the driven component can be directly connected using the first external thread in actual use. This effectively eliminates the need for intermediate transmission components, which not only simplifies the structure but also improves the coaxiality between the shaft and the driven component, thereby improving transmission accuracy.

[0008] In the aforementioned small motor outer rotor structure, the aforementioned limiting structure can release the restriction on the axial movement of the rotating shaft. Thus, after removing the limiting structure, the upper and lower rotating outer rotor body can be disassembled and assembled, facilitating motor maintenance.

[0009] In the aforementioned small motor external rotor structure, the through hole is a stepped hole, consisting of a smaller upper hole and a larger lower hole. The upper hole is threaded to the shaft. The inner wall of the lower hole is a tapered surface (I) whose diameter gradually increases from top to bottom. The outer wall of the shaft has a tapered surface (II) that matches tapered surface (I) and is tightly fitted onto tapered surface (I). The fit between tapered surface (I) and tapered surface (II) can forcibly correct the relative position of the external rotor body and the shaft, effectively improving the coaxiality of the external rotor body and the shaft, and enhancing transmission accuracy.

[0010] In the aforementioned small motor external rotor structure, the limiting structure includes a threaded hole 1 horizontally penetrating the positioning block, and a corresponding threaded hole 2 on the outer wall of the shaft. Both threaded holes 1 and 2 are internally threaded with the same positioning pin. The cooperation of the positioning pin, threaded hole 1, and threaded hole 2 ensures the shaft is stably limited.

[0011] In the above-mentioned small motor external rotor structure, a heat dissipation channel is formed between two adjacent spokes, and the above-mentioned positioning pin is set directly opposite one of the heat dissipation channels.

[0012] In the aforementioned small motor external rotor structure, the external rotor body is a cast integral piece.

[0013] Compared with existing technologies, the external rotor structure of this small motor has the following advantages:

[0014] 1. A first external thread is provided on the outer wall of the upper end of the shaft so that the driven component can be directly connected using the first external thread in actual use. This effectively eliminates the need for intermediate transmission components, which not only simplifies the structure but also improves the coaxiality between the shaft and the driven component, thereby improving transmission accuracy.

[0015] 2. The combination of conical surface one and conical surface two can forcibly correct the relative position of the outer rotor body and the shaft, effectively improving the coaxiality of the outer rotor body and the shaft, and improving the transmission accuracy. Attached Figure Description

[0016] Figure 1 This is a 3D schematic diagram of a small motor.

[0017] Figure 2 This is a cross-sectional schematic diagram of a small motor.

[0018] Figure 3 This is a cross-sectional schematic diagram of the outer rotor body.

[0019] In the figure, 1. Outer rotor body; 1a. Machine barrel; 1b. Positioning block; 1c. Spoke; 1d. Heat dissipation channel; 1e. Through hole; 1e1. Upper hole; 1e2. Lower hole; 1e3. Conical surface one; 1e4. Threaded hole one; 2. Shaft; 2a. First external thread; 2b. Annular protrusion; 3. Positioning pin. Detailed Implementation

[0020] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0021] like Figure 1 As shown, the external rotor structure of this small motor includes an external rotor body 1 and a rotating shaft 2.

[0022] in,

[0023] The outer rotor body 1 is a one-piece structure, and preferably a cast integral part. The outer rotor body 1 consists of a barrel 1a, a positioning block 1b, and a ring of spokes 1c. In actual use, the motor magnet is bonded and fixed to the inner wall of the barrel 1a; the positioning block 1b is located above the barrel 1a and is coaxial with the barrel 1a; the spokes 1c are located between the positioning block 1b and the barrel 1a, and the ring of spokes 1c is evenly distributed around the circumference of the barrel 1a, forming a heat dissipation channel 1d between adjacent spokes 1c. Both ends of each spoke 1c are connected to the outer wall of the positioning block 1b and the barrel 1a, respectively. Preferably, the spokes 1c are L-shaped, and the ends of the spokes 1c away from the positioning block 1b are located on the top wall of the barrel 1a.

[0024] like Figure 1 and Figure 2 As shown, the rotating shaft 2 is vertically installed inside the machine barrel 1a, and the central axes of the rotating shaft 2 and the machine barrel 1a are collinear. A through hole 1e is vertically inserted through the positioning block 1b, and the through hole 1e and the rotating shaft 2 are coaxially arranged. A first external thread 2a and a second external thread are provided on the outer wall of the rotating shaft 2, and the first external thread 2a and the second external thread are distributed along the axial direction of the rotating shaft 2. An internal thread that mates with the second external thread is provided in the through hole 1e, and the rotating shaft 2 is threadedly connected to the through hole 1e. The upper end of the rotating shaft 2 passes through the through hole 1e, and the aforementioned first external thread 2a is provided on the outer wall of the upper end of the rotating shaft 2. A limiting structure for axially limiting the rotating shaft 2 is also provided between the positioning block 1b and the rotating shaft 2.

[0025] A first external thread 2a is provided on the outer wall of the upper end of the rotating shaft 2 so that the driven component can be directly connected using the first external thread 2a in actual use. This effectively eliminates the need for intermediate transmission components, which not only simplifies the structure but also improves the coaxiality between the rotating shaft 2 and the driven component, thereby improving the transmission accuracy.

[0026] To further explain, the limiting structure can release the restriction on the axial movement of the rotating shaft 2. Thus, after removing the limiting structure, the upper and lower rotating outer rotor body 1 can be disassembled and assembled, which is convenient for motor maintenance.

[0027] In this embodiment,

[0028] like Figure 2 and Figure 3 As shown, the limiting structure includes a threaded hole 1e4 horizontally penetrating the positioning block 1b, and a corresponding threaded hole 2 on the outer wall of the rotating shaft 2. The same positioning pin 3 is screwed into both threaded holes 1e4 and 1e4. With the cooperation of the positioning pin 3, threaded hole 1e4, and threaded hole 2, the rotating shaft 2 can be stably limited. Preferably, the positioning pin 3 is positioned directly opposite one of the heat dissipation channels 1d.

[0029] To further explain, such as Figure 2 and Figure 3 As shown, the through hole 1e is a stepped hole, consisting of a smaller upper hole 1e1 and a larger lower hole 1e2, with the upper hole 1e1 positioned above the lower hole 1e2. The upper hole 1e1 is threaded to the shaft 2. The inner wall of the lower hole 1e2 is a tapered surface 1e3 whose diameter gradually increases from top to bottom. The outer wall of the shaft 2 has a tapered surface 2 that matches the tapered surface 1e3, and the tapered surface 2 is tightly fitted onto the tapered surface 1e3. The cooperation of the tapered surface 1e3 and the tapered surface 2 can forcibly correct the relative position of the outer rotor body 1 and the shaft 2, effectively improving the coaxiality of the outer rotor body 1 and the shaft 2, and enhancing transmission accuracy.

[0030] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A small motor external rotor structure, comprising an external rotor body (1) and a rotating shaft (2), wherein the external rotor body (1) includes a casing (1a) for mounting magnets, and the rotating shaft (2) is coaxially disposed within the casing (1a), characterized in that, The outer rotor body (1) is an integral structure. The outer rotor body (1) also includes a positioning block (1b) coaxially arranged above the barrel (1a), and the side wall of the positioning block (1b) is connected to the barrel (1a) through a ring of spokes (1c). A through hole (1e) is vertically penetrating the positioning block (1b), and the rotating shaft (2) is threaded in the through hole (1e). The upper end of the rotating shaft (2) passes through the through hole (1e), and the outer wall of the upper end of the rotating shaft (2) is provided with a first external thread (2a). A limiting structure for axially limiting the rotating shaft (2) is also provided between the positioning block (1b) and the rotating shaft (2).

2. The small motor external rotor structure according to claim 1, characterized in that, The aforementioned limiting structure can release the restriction on the axial movement of the rotating shaft (2).

3. The small motor external rotor structure according to claim 1 or 2, characterized in that, The through hole (1e) is a stepped hole. The through hole (1e) consists of an upper hole (1e1) with a smaller diameter and a lower hole (1e2) with a larger diameter. The upper hole (1e1) is threaded to the shaft (2). The inner wall of the lower hole (1e2) is a tapered surface (1e3) with a diameter that gradually increases from top to bottom. The outer wall of the shaft (2) has a tapered surface (2) that matches the tapered surface (1e3) and the tapered surface (2) is close to the tapered surface (1e3).

4. The small motor external rotor structure according to claim 2, characterized in that, The limiting structure includes a threaded hole 1 (1e4) that runs horizontally through the positioning block (1b), and a corresponding threaded hole 2 on the outer wall of the rotating shaft (2). The same positioning pin (3) is screwed into the threaded hole 1 (1e4) and the threaded hole 2.

5. The small motor external rotor structure according to claim 4, characterized in that, A heat dissipation channel (1d) is formed between two adjacent spokes (1c), and the aforementioned positioning pin (3) is positioned directly opposite one of the heat dissipation channels (1d).

6. The small motor external rotor structure according to claim 1, characterized in that, The outer rotor body (1) is a cast integral part.

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