Outer rotor motor frame mounting device

Abstract

This utility model discloses an external rotor motor frame mounting device. By adding a tapered through-hole-tapered shaft structure and an external thread on the hollow shaft, with the rotation direction of the external thread opposite to the rotation direction of the external rotor, it replaces the existing frame through-hole radial section protrusion-hollow shaft forward and reverse rotation anti-rotation structure. This eliminates the problems of misalignment, loosening, and excessive structural noise caused by the missing tooth tip of the external thread and poor meshing with the nut. It also eliminates the need for materials and related production processes of the snap ring groove-snap ring axial limiting device, improving installation efficiency. During production, the nut is directly screwed into the external thread to drive the tapered through-hole of the frame and the tapered shaft of the hollow shaft to be axially and radially concentrically fixed. This forms an external rotor motor frame mounting device that can eliminate structural noise, loosening, and misalignment, is easy to install, and has low production cost.

Description

Technical Field

[0001] This utility model relates to electric motors, and more particularly to a frame mounting device for an external rotor electric motor. Background Technology

[0002] External rotor motors have advantages such as high electromechanical efficiency, energy saving, large torque, high speed, and small footprint. Existing technology, Chinese Patent Application No. 202222653945.6, describes an external rotor motor frame mounting device. This device includes an external rotor motor, a hollow shaft passing through the external rotor end cover, and a frame. A through hole is located in the middle of the frame, concentrically fitted with the hollow shaft. A radial section protrusion is located on one side of the through hole in the frame, and a radial section concave block is located on the hollow shaft. The radial section protrusion passes through the hollow shaft and forms a radially tight contact with the radial section concave block. An external thread is located on the hollow shaft, and the external thread connects to the external rotor end cover. An axial limiting device, consisting of a retaining ring groove and retaining ring or a hollow shaft with radially stacked end faces, is placed between the covers. The nut is screwed into the hollow shaft's external thread, causing the axial wall of the frame through hole to make axially tight contact with the axial limiting wall of the axial limiting device, thus forming a set of external rotor motor frame mounting devices, which has the advantage of easy installation. However, this type of external rotor motor frame mounting device, which uses a radially concave block on the hollow shaft and a radially protruding block through the frame through hole to make radially tight contact with the concave block, is limited by its small hollow shaft diameter, thin hollow wall, and small external thread module. This can lead to problems with the radially concave block on the hollow shaft. The concave section disrupts the overall full-thread structure of the hollow shaft's external thread, transforming it into a broken-thread structure with missing tooth tips. This leads to poor meshing between the nut and the external thread, resulting in misaligned threads, reduced mounting strength, and even occasional failure to secure the frame during production. This limits the application of small and medium-sized external rotor motors in small and medium-sized electromechanical products. Clearly, this mounting method, which uses a radially concave section on the hollow shaft and a radially protruding section in the frame's through-hole, needs improvement. Furthermore, a shaft consisting of a retaining ring groove and retaining ring, or a radially stacked end face of the hollow shaft, should be placed between the external thread and the external rotor end cover. The mounting method where the nut is screwed into the hollow shaft's external thread to drive the axial wall of the frame through hole to form an axially fixed contact with the axial limiting wall of the axial limiting device is limited by the small diameter of the hollow shaft, the thin wall, the small contact area of ​​the radially stacked end faces, and the small circlip groove. It also requires an assembly clearance that must exist when the axial wall of the frame through hole slides axially with the axial limiting wall of the axial limiting device. This method, which places an axial limiting device composed of a circlip groove and a circlip or composed of the radially stacked end faces of the hollow shaft between the external thread and the outer rotor end cover, is prone to structural noise and even loosening during high-speed operation of the outer rotor motor. This also needs improvement. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide an external rotor motor frame fixing device that can eliminate structural noise, loosening, and misaligned meshing, and is easy to install and has low production cost.

[0004] To solve the above-mentioned technical problems, the external rotor motor frame mounting device of this utility model includes an external rotor motor composed of an external rotor and a stator, a hollow shaft passing through the external rotor end cover and a frame, a through hole in the middle of the frame, and the frame through hole and the hollow shaft being concentrically fitted together. The external rotor motor is a unidirectional external rotor motor that rotates in one direction when energized. The frame through hole is a tapered through hole, and the hollow shaft has a tapered shaft body. The tapered wall of the frame tapered through hole passes through the hollow shaft and is in radial concentric close contact with the tapered wall of the hollow shaft tapered shaft body. An external thread is provided on the hollow shaft, and the rotation direction of the external thread is opposite to the rotation direction of the external rotor. The tapered slope of the frame tapered through hole is equal to the tapered slope of the hollow shaft tapered shaft body. A nut is screwed into the external thread of the hollow shaft to drive the tapered wall of the frame tapered through hole and the tapered wall of the hollow shaft tapered shaft body to be axially and radially concentrically and tightly fixed together.

[0005] This invention employs a method where the tapered wall of a frame tapered through-hole passes through a hollow shaft and forms a radially concentric, tight contact with the tapered wall of the hollow shaft's tapered shaft body. An external thread is placed on the hollow shaft, with the rotation direction of the external thread opposite to the rotation direction of the external rotor. The tapered slope of the frame tapered through-hole is equal to the tapered slope of the hollow shaft's tapered shaft body. A nut is screwed into the hollow shaft's external thread, driving the tapered wall of the frame tapered through-hole and the tapered wall of the hollow shaft's tapered shaft body to form an axially and radially concentric, tightly fixed assembly. This method replaces the existing technology where a radially concave block on the hollow shaft disrupts the overall full-thread structure of the hollow shaft's external thread, resulting in a fragmented external thread with the tooth tip forming an external thread. The broken-thread structure with missing tooth tips eliminates the problems of misalignment, loosening, and excessive structural noise caused by poor meshing between the nut and the external thread. On the other hand, it saves on the material cost and related production process cost of axial limiting devices composed of snap ring groove-snap ring or radially stacked end faces of hollow shafts. The nut can be directly screwed into the external thread of the hollow shaft to make the conical wall of the frame conical through hole concentric with the conical wall of the hollow shaft body in both axial and radial directions for tight fixing. This forms an external rotor motor frame fixing device that can eliminate structural noise, loosening, and misalignment, and is easy to install with low production cost. Attached Figure Description

[0006] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0007] Figure 1 This is a longitudinal sectional view of one embodiment of the external rotor motor frame mounting device of this utility model;

[0008] Figure 2 for Figure 1A magnified view of a portion of the text;

[0009] Figure 3 for Figure 1 Exploded view of the embodiment;

[0010] Label Explanation:

[0011] 1. Stator; 2. Outer rotor; Outer rotor end cover; 3. Hollow shaft; 4. Outer rotor end cover; 5. Tapered shaft body; 6. Frame; 7. Tapered through hole; 8. External thread; 9. Nut; Detailed Implementation

[0012] The following is combined Figures 1 to 3 This invention provides a detailed description of embodiments of the external rotor motor frame mounting device.

[0013] See Figures 1 to 3 An embodiment of the external rotor motor frame mounting device of this utility model includes an external rotor motor composed of an external rotor 2 (made of a stretched iron plate and a permanent magnet) and a stator 1, a hollow shaft 3 passing through an external rotor end cover 4, and a frame 6. A through hole 7 is provided in the middle of the frame 6, and the frame through hole 7 is concentrically fitted with the hollow shaft 3. The external rotor motor is a unidirectional external rotor motor that rotates when energized. The through hole 7 in the frame 6 is a tapered through hole 7, and the hollow shaft 3 has a tapered shaft body 5. The conical wall of the hollow shaft 3 passes through the conical wall of the hollow shaft 3 and is in radial concentric close contact with the conical wall of the conical shaft body 5. An external thread 8 is provided on the hollow shaft 3. The rotation direction of the external thread 8 is opposite to the rotation direction of the external rotor 2. The conical slope of the conical through hole 7 of the frame 6 is equal to the conical slope of the conical shaft body 5 of the hollow shaft 3. The nut 9 is screwed into the external thread 8 of the hollow shaft 3 to drive the conical wall of the conical through hole 7 of the frame 6 and the conical wall of the conical shaft body 5 of the hollow shaft 3 to be axially and radially concentrically fixed.

[0014] By employing a conical wall surface of the frame's conical through-hole 7 passing through the hollow shaft 3 and forming a radially concentric tight contact with the conical wall surface of the hollow shaft 3's conical shaft body 5, and by placing an external thread 8 on the hollow shaft 3, the rotation direction of the external thread 8 being opposite to the rotation direction of the external rotor 2, and by ensuring that the conical slope of the frame's conical through-hole 7 is equal to the conical slope of the hollow shaft 3's conical shaft body 5, and by screwing the nut 9 into the external thread 8 of the hollow shaft 3, the conical wall surface of the frame's conical through-hole 7 and the conical wall surface of the hollow shaft 3's conical shaft body 5 are axially and radially concentrically tightened and fixed, this technical solution replaces the existing technology where the hollow shaft has a radially concave section that destroys the overall full-thread structure of the hollow shaft's external thread, resulting in a fragmented external thread. The tooth tip forms a broken-thread structure with the tooth tip missing in the external thread section, thus eliminating the problems of easy misalignment, easy loosening, and excessive structural noise caused by poor meshing between the nut and the external thread. On the other hand, it saves the material cost and related production process cost of axial limiting devices composed of snap ring groove-snap ring or hollow shaft radially stacked end faces. The nut 9 can be directly screwed into the external thread 8 of the hollow shaft 3 to drive the tapered wall surface of the tapered through hole 7 of the frame 6 and the tapered wall surface of the tapered shaft body 5 of the hollow shaft 3 to be axially and radially concentrically fixed. This forms an external rotor motor frame fixing device that can eliminate structural noise, eliminate loosening, eliminate misalignment, is easy to install, and has low production cost.

[0015] Of course, the specific materials and manufacturing processes of the outer rotor of the external rotor of the external rotor motor frame mounting device of this utility model are not limited to the outer rotor composed of stretched iron plate and permanent magnet shown in the above embodiment. It can also be an outer rotor composed of silicon steel sheet cast aluminum, or an outer rotor composed of plate rolling machine housing and permanent magnet. Such specific local changes in the materials and manufacturing processes of the outer rotor all fall within the protection scope of this utility model.

Claims

1. A frame mounting device for an external rotor motor, comprising an external rotor motor consisting of an external rotor (2) and a stator (1), a hollow shaft (3) passing through an external rotor end cover (4) and a frame (6), wherein a through hole (7) is provided in the middle of the frame (6), and the through hole (7) of the frame is concentrically fitted with the hollow shaft (3), characterized in that: The external rotor motor is an external rotor motor that operates in one direction when energized. The through hole (7) of the frame (6) is a tapered through hole (7). The hollow shaft (3) is provided with a tapered shaft body (5). The tapered wall of the tapered through hole (7) of the frame passes through the hollow shaft (3) and is in radial concentric close contact with the tapered wall of the tapered shaft body (5). An external thread (8) is provided on the hollow shaft (3). The rotation direction of the external thread (8) is opposite to the rotation direction of the external rotor (2). The tapered slope of the tapered through hole (7) of the frame (6) is equal to the tapered slope of the tapered shaft body (5) of the hollow shaft (3). The nut (9) is screwed into the external thread (8) of the hollow shaft (3) to drive the tapered wall of the tapered through hole (7) of the frame (6) and the tapered wall of the tapered shaft body (5) of the hollow shaft (3) to be axially and radially concentrically fixed.

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