Circuit breakers for motor protection

Abstract

A circuit breaker for motor protection includes a contact support installed in a housing, a static contact assembly and a movable contact assembly mounted on the contact support, and also includes a rotary handle and a linkage mechanism connected with the rotary handle. The linkage mechanism comprises a gear swing rod and a push rod. The rotary handle rotatably drives the linkage mechanism to drive the push rod to make the movable contact group on the contact support come into contact with and separate from the static contact group. One end of the rotary handle is provided with an upper gear intermeshed with the gear swing rod. The upper gear comprises teeth. A tooth groove is formed between every two adjacent teeth. The gear swing rod is provided with swing rod teeth corresponding to the tooth grooves. Swing rod tooth grooves corresponding to the teeth are formed between the swing rod teeth. The teeth gradually narrow from the inside to the outside. First inclined surfaces are formed on both sides, and second inclined surfaces corresponding to the first inclined surfaces are disposed on both sides of the swing rod tooth grooves.

Description

technical field [0001] The invention relates to the field of low-voltage electrical appliances, in particular to a circuit breaker for motor protection. Background technique [0002] Circuit breakers, as a basic low-voltage electrical appliance, are mainly used for overload, short circuit, loss of voltage, undervoltage and leakage protection of lines. It can be used not only for the protection of power distribution system, but also for the protection of frequently started motors. When used for motor protection, the requirements for product reliability and sensitivity, as well as mechanical life and electrical life are higher and more stringent. The circuit breaker for motor mainly drives the opening and closing of the contact device through the operating mechanism, and then realizes the breaking and closing of the circuit. The quality of the operating mechanism directly affects the performance and service life of the circuit breaker. The traditional mechanism currently us...

AI Technical Summary

Problems solved by technology

The traditional mechanism currently used for motor protection circuit breakers has the following problems: 1. The gears of the operating mechanism are not well matched, resulting in a large force required for the user to operate the rotary handle and a low service life of the product; 2. The volume of the existing product cannot be unchanged. In the case of a large opening distance between contacts, the short-circuit breaking capacity is limited

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