Plastic bracket structure of motor with replaceable carbon brush

Abstract

The invention discloses a plastic bracket structure of a motor with a replaceable carbon brush, belonging to the technical field of motor parts and comprising two fully symmetrical external small cavities, wherein a plastic column, a brush box, a carbon brush spring, a carbon brush assembly and a terminal assembly are arranged in the small cavities; the carbon brush spring is located on the plastic column; the carbon brush assembly comprises a carbon brush, a brush cord and an insertion spring, and the tail part of the brush cord is fixedly connected with the insertion spring; the terminal assembly comprises a brush box bottom board, a plug terminal, a plug terminal connection hole and a lead, and the insertion spring of the carbon brush assembly is in splicing connection with the plug terminal of the terminal assembly; the terminal assembly is linked with the plastic bracket by a riveted way; the carbon brush spring is a constantforce spring, the contact part of the carbon spring andthe bottom of the carbon brush is in an arc shape; and the lead is in pressure welding connection with the plug terminal connection hole. The invention has the advantages that the carbon brush assembly can be rapidly replaced through inserting and pulling the insertion spring; the constantforce spring has stable effective force and no angle change after abrasion, can reduce the commutation spark and prolong the service life of the motor; the lead is in pressure welding connection with the plug terminal, thereby ensuring the connection intensity and keeping favorable conductivity.

Description

technical field [0001] The invention relates to a motor plastic bracket structure, in particular to a motor plastic bracket structure with replaceable carbon brushes, which belongs to the technical field of motor components. Background technique [0002] In the current market, equipment such as professional-grade DC power tools has higher and higher requirements for the use and life of the motors used. The two structural forms commonly used in the market can no longer fully meet the requirements of customers: [0003] Structure 1: As shown in Figure 1, it is a commonly used beryllium copper brush holder structure. This structure fixes the carbon brush through a beryllium bronze brush holder inside the motor and connects it to the external terminal. The beryllium copper brush holder is also a spring. Spring force can be applied to the carbon brush so that it touches the commutator. The characteristics of this structure are: small size, compact structure. The disadvantages ...

AI Technical Summary

Problems solved by technology

The disadvantages are: 1. The beryllium bronze sheet applies elastic force to the commutator by changing the angle, so the angle and elastic force of the carbon brush change from the beginning of the motor to the end of its life, which corresponds to the performance of the motor It also changes with the change of the carbon brush angle, which is not conducive to the stability of the motor speed and performance

2. When the carbon brush is worn out, the brush holder will continue to provide electricity until the beryllium bronze brush holder is worn out, and the carbon brush cannot be replaced

3. The carbon brush and the beryllium bronze brush holder are connected by a bayonet joint, and the contact is unreliable. When overloaded, due to the high density of the current contact surface, the beryllium bronze is prone to local overheating, the elasticity is reduced, and even the brush holder breaks, which affects the motor. overload capacity

But the disadvantages of this kind of motor are: 1. As the carbon brush wears and shortens during the use of the motor, the spring stretches out, the length lengthens, and the spring force will become smaller, so that the angle of the carbon brush will change after the wear and tear, and the commutation will be increased. Sparks seriously affect the life of the motor, and the performance of the motor will be reduced; 2. The compression spring usually needs to have a larger initial length, which increases the axial length, and the use of small-sized motors will cause the length of the carbon brush to decrease, resulting in a The service life of the auxiliary carbon brush cannot meet the customer's requirements

[0005] This kind of beryllium copper sheet structure with built-in carbon brush assembly, in the assembly process, the carbon brush assembly must be assembled first, and then the motor, so that the carbon brush is prone to cracking or loosening.

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