Contact system of a circuit breaker

Abstract

The invention discloses a breaker contact system which comprises a static contact fixedly connected to a shell and a movable contact rotatably connected to the shell. The movable contact is driven by an operating mechanism to be communicated with and separated from the static contact. The operating mechanism comprises a handle, a contact gear, a contact support and a counter-force spring, wherein the handle and the contact gear are respectively pivoted to the shell and are in transmission connection through a gear, the contact support is fixedly connected to the movable contact, the counter-force spring is located between the shell and the movable contact, the contact gear is provided with a cam drive part, and the contact support is pressed against the cam drive part under the elasticity of the counter-force spring so as to achieve the linkage of the contact gear and the contact. By the breaker contact system, the technical problems that original breaker contact systems are complex in structure, large in space occupation, high in cost, complex in process and short in service life are solved.

Description

technical field [0001] The invention belongs to the technical field of small low-voltage circuit breakers, in particular to a contact system of a circuit breaker. Background technique [0002] A circuit breaker refers to a switching device that can close, carry and break current under normal circuit conditions and can close, carry and break current under abnormal circuit conditions within a specified time. Circuit breakers are divided into high-voltage circuit breakers and low-voltage circuit breakers according to their scope of use. [0003] Low-voltage circuit breakers, also known as automatic air switches, can be used to switch on and off load circuits, and can also be used to control motors that start infrequently. Low-voltage circuit breakers have multiple protection functions (overload, short circuit, undervoltage protection, etc.), adjustable operating value, high breaking capacity, convenient operation, safety, etc., so they are widely used. [0004] At present, ac...

AI Technical Summary

Problems solved by technology

The structure of the contact mechanism of this circuit breaker is relatively simple, but there are still the following technical problems: 1. Since the movable contact piece itself needs to be elastic to be able to realize reliable opening and closing, after long-term use, the breakage at the connecting part and the connecting part is relatively large Seriously, the service life is short; 2. Since the fracture distance of the circuit breaker is determined by the bounce height of the moving contact piece, the fracture distance will gradually become smaller after long-term use, resulting in poor dielectric strength of the circuit breaker; 3. Since the arc-shaped part of the moving contact piece is connected with the connecting part by spot welding, and the arc-shaped part needs to cooperate with the fan-shaped driving part, its arc-shaped height needs to meet certain requirements, which has a great impact on the forming process of the moving contact piece. Higher requirements are put forward, resulting in higher production costs of the moving contact piece

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