A motor plastic bracket structure with replaceable carbon brushes

Abstract

A motor plastic support structure with replaceable carbon brushes, belonging to the technical field of motor components, including two completely symmetrical external small cavities, plastic cylinders, brush boxes, carbon brush springs, carbon brush assemblies and terminal assemblies are arranged in the small cavities, The carbon brush spring is positioned on the plastic cylinder; the carbon brush assembly includes carbon brushes, brush braids and plug springs, and the tail of the brush braids is fixedly connected with the plug springs; the terminal assembly includes the bottom plate of the brush box, plug terminals, plug terminal connection holes and wires, carbon The insert spring of the brush assembly and the plug terminal of the terminal assembly are plug-in connections; the terminal assembly is connected with the plastic bracket by riveting; the carbon brush spring adopts a constant force torsion spring, and its contact with the bottom of the carbon brush is in the shape of an arc; the wire and The plug terminal connection holes are pressure-welded connections. The beneficial effects of the present invention are: the carbon brush assembly can be quickly replaced by plugging and unplugging the spring; the constant force torsion spring is effective and stable, and there is no angle change after wear, which can reduce commutation sparks and prolong the life of the motor; The terminal pressure welding connection ensures the connection strength and maintains good 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 on the contact surface, the beryllium bronze is easily overheated locally, the elasticity is reduced, and the brush holder is even broken, which affects 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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