A contact system of a low-voltage circuit breaker and the low-voltage circuit breaker

Abstract

The invention provides a contact terminal system of a low-voltage circuit breaker and the low-voltage circuit breaker. The contact terminal system of the low-voltage circuit breaker comprises a movable contact terminal which is rotatably connected to a rotary shaft and has a movable contact capable of being in contact with a stationary contact and a drive shaft located between a first shaft and the movable contact; a bracket rotatably connected to the rotary shaft and located on the side near the movable contact of the drive shaft and having a first arc surface facing the drive shaft, wherein the center of the first arc surface is on the side back on to the drive shaft of the first arc surface; and an elastic member abutted between the bracket and the rotary shaft and pushing and jacking the bracket against the drive shaft. The first arc surface is pressed against the drive shaft under the pushing of the elastic member in a state where the movable contact is in contact with the stationary contact and a torque is generated for the drive shaft to rotate the movable contact in the closing direction, and the drive shaft is located on the side, close to the movable contact, of a line connecting of a first shaft and a second shaft. The contact terminal system plays a role of compensating the contact pressure when a contact is burnt during work so that the temperature rise of the circuit breaker does not exceed a required value.

Description

technical field [0001] The invention relates to the technical field of low-voltage circuit breakers, in particular to a contact system of a low-voltage circuit breaker and the low-voltage circuit breaker. Background technique [0002] A low-voltage circuit breaker is mainly composed of a housing, a contact system, an arc extinguishing system and an operating mechanism, among which the contact system is an important part of a low-voltage circuit breaker. [0003] The circuit breaker must carry the current under normal circuit conditions and the temperature rise cannot exceed the required value. At present, the moving contact system of the low-voltage circuit breaker is burned out with the moving contact and static contact of the circuit breaker during work, and the deformation of the contact spring becomes smaller. , The contact spring force value becomes smaller, so that the contact pressure becomes smaller, and the contact resistance between the dynamic and static contacts ...

AI Technical Summary

Problems solved by technology

[0006] As the moving contact and static contact of the circuit breaker burn out during operation, the deformation of the contact spring 1' becomes smaller, that is, the force F6 of the contact spring 1' becomes smaller, and the first plane 21 of the bracket 2' The force arm L10 of the force F7 acting on the moving contact assembly 5' remains basically unchanged, so the moment M1 of the moving contact assembly 5' in the closing direction M1=F6*L8*L10 / L9 increases with the moving contact and The burning loss of the static contact decreases during work, that is, the contact pressure (contact pressure) of the moving contact system also becomes smaller, which increases the contact resistance between the moving and static contacts, resulting in an increase in the temperature rise of the circuit breaker

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