Ultrasmall DC electric motor capable of preventing fracture of root of wire

Abstract

The invention relates to an ultrasmall DC electric motor capable of preventing the fracture of the root of a wire. The electric motor comprises a rotor, a stator and a brush group, wherein the rotor comprises a rotor frame and a winding, the rotor frame comprises a rotation shaft, a fixing ring sleeved on one end of the rotation shaft and a commutator arranged on one end of the rotation shaft; the stator comprises a case and a magnetic steel combination arranged in the case, the magnetic steel combination comprises a bearing, a pull tube and a magnetic steel part which are sleeved on the rotation shaft; the brush group comprises a base plate arranged on one end of the case, and an upper brush and lower brush which are mounted on the base plate and arranged in the case; and the upper brushand lower brush are separately connected with a wire, a through-hole is arranged on the base plate, the wire passes through the through-hole and is leaded out from the through-hole, and the end surface of the base plate far away the case is provided with a wire fastener used for limiting the movement of the wire. By adopting the above structure, the wire can bend along one direction after leaded out from the base plate, and the displacement of the wire can be limited by using the wire fastener so as to avoid the fracture of the root of the wire caused by the friction of the root of the wire and the end surface of the base plate when the electric motor vibrates.

Description

technical field [0001] The invention belongs to the technical field of micro-motors, and in particular relates to an ultra-miniature direct-current motor capable of preventing wire roots from breaking. Background technique [0002] At present, micro DC motors are widely used in the fields of mobile communication and model aircraft, as the vibration source of mobile communication tools and the driving source of model aircraft. With the continuous development of mobile communication tools and aircraft model aircraft in the direction of stronger functions, smaller size, thinner and lighter weight, motors are also required to be smaller and more efficient. [0003] Such as figure 1 As shown, the existing micro-motor usually includes a rotor 1', a stator 2' and a brush group 3'. The rotor 1' includes a rotor frame 11' and a winding 12'. The rotor frame 11' includes a rotating shaft 111', a fixing ring 112' sleeved at one end of the rotating shaft 111', and a commutator 113' loc...

AI Technical Summary

Problems solved by technology

However, in actual operation, the scale of pressing down the brush 32' by manual operation is different. If the scale is small, the commutator 113' is easy to hang on the inclined part 323' of the upper brush 32', causing the deformation of the upper brush 32' , the scale is large, and it is easy to cause excessive deformation of the lower brush 32' ( image 3 The correct initial installation position of commutator 113' is shown in , while Figure 4 The initial installation position of the commutator 113' shown in is too low, the scale is relatively large during installation, and the lower brush 32' is prone to excessive deformation)

[0007] (2) In order to ensure the contact area between the pull tube 222' and the casing 21', as well as the adhesion between the pull tube 222' and the casing 21', the outer diameter of the pull tube 222' cannot be made too small. For small motors (such as ultra-miniature motors with a diameter of 3.2 mm), if the above structure is adopted, the wall thickness of the magnetic steel 223' is too thin and difficult to process. In addition, even if high magnetic NdFeB magnetic materials are used, the surface magnetism cannot reach According to the design requirements, the overall performance of the motor is too poor

However, because the existing brush 32' does not have a left and right limit structure, the assembly personnel often seek speed or other artificial reasons during assembly, causing the right-angle connection of the brush 32' not to be close to the boss 317' of the seat plate 31'. Right-angled edges (such as Figure 4 Middle III'), the brush distance of the product made in this way is B, B>A, it is a substandard product

[0009] (4) if Figure 5 As shown, the existing motor generally adopts three-pole commutation, and its commutator 113' has three commutator segments. Since the average voltage between the commutator segments is inversely proportional to the number of commutator segments, the potential difference is relatively large , the spark is large, which will affect the life of the motor and may generate electrical noise

[0010] (5) The existing motors generally use manual soldering to weld the brush 32' and the wire 4' together. However, the raw materials for soldering are not environmentally friendly, and the amount of tin used in manual soldering is too much, and the harmful gas discharged in the operation is relatively large. large, polluting the environment

On the other hand, since the brush 32' of the micro-motor is too small, the welding surface is very small, the operation of manual soldering is difficult and the efficiency is low

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