Direct-current brushless outer rotor motor

Abstract

The utility model provides a direct-current brushless external rotor motor, which comprises a base and an external rotor assembly rotationally connected to the base, and the lower end of a rotating shaft in the external rotor assembly is rotationally connected with the base through a bearing; a concave cavity is formed in the middle of the outer bottom of the base, a supporting ring made of a metal material is embedded in the concave cavity, the bearing is embedded in the supporting ring and is in close fit with the supporting ring, the supporting ring is fastened to the base, and the lower end of the rotating shaft is inserted into the bearing and is rotationally connected with the supporting ring through the bearing; according to the utility model, the displacement of the bearing and the support ring can be avoided, so that the eccentricity of the rotating shaft can be avoided, and the coaxiality of the rotating shaft can be ensured when the direct-current brushless outer rotor motor works.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, and more specifically, to a DC brushless external rotor motor. Background Technology

[0002] Brushless DC external rotor motors are commonly used drive components, such as those used in air fryers to drive cooling fan blades. Currently, commercially available brushless DC external rotor motors consist of a base and an external rotor assembly rotatably connected to the base. The lower end of the rotor shaft in the external rotor assembly is rotatably connected to the base via a bearing, and the shaft is embedded in a cavity located on the bottom of the base. However, in existing brushless DC external rotor motor structures, the base is generally made of plastic. When applied to air fryers, the high temperature environment during operation causes significant temperature rise in the bearings. Furthermore, the plastic base can deform at the bearing location, leading to bearing displacement and subsequent shaft eccentricity, making it difficult to ensure the coaxiality of the rotor shaft in the brushless DC external rotor motor. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a DC brushless external rotor motor that can avoid displacement of the bearings and support rings, thereby avoiding eccentricity of the rotor shaft and ensuring the coaxiality of the rotor shaft during operation.

[0004] This utility model provides a DC brushless external rotor motor, including a base and an external rotor assembly rotatably connected to the base. The lower end of the rotating shaft in the external rotor assembly is rotatably connected to the base through a bearing. A cavity is provided in the middle of the outer bottom of the base, and a support ring made of metal material is embedded in the cavity. The bearing is embedded in the support ring and tightly fitted with the support ring. The support ring is fixed to the base, and the lower end of the rotating shaft is inserted into the bearing and rotatably connected to the support ring through the bearing.

[0005] By adopting the above structure, this utility model ensures that the bearing is embedded in the support ring and tightly fitted with it, and the support ring is firmly fixed to the base. Even if the bearing and support ring experience a temperature rise, the firm structure between the support ring and the base can prevent displacement of the bearing and support ring, thereby preventing eccentricity of the rotating shaft and ensuring the coaxiality of the rotating shaft of the DC brushless external rotor motor during operation.

[0006] In one possible implementation, the outer wall of the support ring is provided with at least one lug, and the side wall of the cavity is provided with a notch for engaging with the lug. The lug is provided with a connecting hole, and the support ring is fastened to the base by a screw. The screw passes through the connecting hole and is threaded onto the base. With this structure, when the screw shank passes through the connecting hole on the lug and is threaded onto the base, the lug can be fastened to the base at the notch, that is, the support ring can be fastened to the cavity on the base. In addition, multiple lugs can be provided, and the multiple lugs are distributed at intervals along the circumferential direction of the support ring. The number of notches is the same as the number of lugs. Each lug is fitted into the notch at the corresponding position, and each lug is fastened to the base by a screw. Furthermore, the support ring is made of zinc alloy, which is a currently available material on the market.

[0007] In one possible implementation, the screw is also used to press the grounding wire onto the lug; with this structure, when fixing the lug to the base, the screw can simultaneously fix the grounding wire onto the lug, thereby simplifying the grounding wire connection structure of the brushless DC external rotor motor. At the same time, it has the advantage of convenient grounding of the brushless DC external rotor motor, since the external rotor assembly, bearings and support ring are all made of metal materials, thus enabling grounding of the brushless DC external rotor motor.

[0008] In one possible implementation, the outer wall of the base is integrally formed with several support feet, each of which is provided with a fixing hole. With this structure, when using a brushless DC external rotor motor, the brushless DC external rotor motor can be easily fixed to the target accessory. That is, after the screw part of the fastening bolt passes through the fixing hole on the support foot, the brushless DC external rotor motor can be easily fixed to the target accessory, such as the shell of an air fryer.

[0009] In one possible implementation, reinforcing ribs are integrally formed on both sides of the bottom of each support foot and the outer wall of the base; by adopting this structure, the fracture resistance between each support foot and the base can be improved. Attached Figure Description

[0010] Figure 1 This is the first three-dimensional structural schematic diagram of the present invention;

[0011] Figure 2 This is a second three-dimensional structural diagram of the present invention. Detailed Implementation

[0012] First, those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the embodiments of this application and are not intended to limit the scope of protection of the embodiments of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0013] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0014] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0015] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0016] See Figure 1-2 As shown in the figure, this application discloses a DC brushless external rotor motor, including a base 1 and an external rotor assembly 2 rotatably connected to the base 1. The lower end of the rotating shaft 21 in the external rotor assembly 2 is rotatably connected to the base 1 through a bearing 3. A cavity 11 is provided in the middle of the outer bottom of the base 1. A support ring 4 made of metal material is embedded in the cavity 11. The bearing 3 is embedded in the support ring 4 and is tightly fitted with the support ring 4. The support ring 4 is fastened to the base 1. The lower end of the rotating shaft 21 is inserted into the bearing 3 and is rotatably connected to the support ring 4 through the bearing 3.

[0017] The outer wall of the support ring 4 is provided with at least one lug 41, and the side wall of the cavity 11 is provided with a notch 12 for engaging with the lug 41. The lug 41 is provided with a connecting hole 42. The support ring 4 is fastened to the base 1 by a screw, which passes through the connecting hole 42 and is threadedly fastened to the base 1. With this structure, when the screw thread passes through the connecting hole on the lug and is threadedly fastened to the base, the lug can be fastened to the base located at the notch, that is, the support ring can be fastened to the cavity on the base. In addition, multiple lugs can be provided, and multiple lugs are distributed at intervals along the circumferential direction of the support ring. The number of notches is the same as the number of lugs. Each lug is fitted into the notch at the corresponding position, and each lug is fastened to the base by a screw. Furthermore, the support ring is made of zinc alloy material, which is a currently available material on the market.

[0018] The screw is also used to press the grounding wire onto the lug 41. With this structure, when fixing the lug to the base, the screw can simultaneously fix the grounding wire onto the lug, thereby simplifying the grounding wire connection structure of the brushless DC external rotor motor. At the same time, it has the advantage of convenient grounding of the brushless DC external rotor motor. Since the external rotor assembly, bearings and support rings are all made of metal materials, grounding of the brushless DC external rotor motor can be achieved.

[0019] The outer wall of the base 1 is integrally formed with several support feet 13, and each support foot 13 is provided with a fixing hole 14. With this structure, when using a DC brushless external rotor motor, the DC brushless external rotor motor can be easily fixed to the target accessory. That is, after the screw part of the fastening bolt passes through the fixing hole on the support foot, the DC brushless external rotor motor can be easily fixed to the target accessory, such as fixed to the shell of an air fryer.

[0020] Each support leg 13 has an integrally formed reinforcing rib 15 between its bottom two sides and the outer side wall of the base 1; by adopting this structure, the fracture resistance between each support leg and the base can be improved.

[0021] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A DC brushless external rotor motor, comprising a base (1) and an external rotor assembly (2) rotatably connected to the base (1), wherein the lower end of the rotating shaft (21) in the external rotor assembly (2) is rotatably connected to the base (1) via a bearing (3); characterized in that: The outer bottom middle of the base (1) is provided with a recess (11), the recess (11) is embedded with a support ring (4) made of metal material, the bearing (3) is embedded in the support ring (4) and tightly matched with the support ring (4), the support ring (4) is fastened with the base (1), the lower end of the rotating shaft (21) is inserted into the bearing (3) and is rotationally connected with the support ring (4) through the bearing (3).

2. A brushless DC external rotor electric motor according to claim 1, characterized in that: The outer wall of the support ring (4) is provided with at least one lug (41), the side wall of the recess (11) is provided with a notch (12) for embedding the lug (41), the lug (41) is provided with a connecting hole (42), the support ring (4) is fastened with the base (1) through a screw, the screw is threaded in the connecting hole (42) and is threadedly fastened with the base (1).

3. A brushless DC external rotor electric motor according to claim 2, characterised in that: The screw is also used for pressing a grounding wire on the lug (41).

4. A brushless DC external rotor electric motor according to any one of claims 1 to 3, characterised in that: The outer wall of the base (1) is circumferentially integrally formed with a plurality of supporting legs (13), each of the supporting legs (13) is provided with a fixing hole (14).

5. A brushless DC external rotor electric motor as claimed in claim 4, characterised in that: The two sides of the bottom of each supporting leg (13) and the outer side wall of the base (1) are integrally formed with a reinforcing rib plate (15).

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