basic structure:

The outer shell of the vacuum switch tube is made of inorganic insulating materials such as glass, ceramics or glass-ceramic, in the shape of a cylinder, and the two ends are sealed with metal cover plates to form a sealed container.

There is a pair of contacts inside the shell, the static contact is fixed on the end of the static conductive rod, the moving contact is fixed on the end of the movable conductive rod, and the movable conductive rod extends out of the vacuum switch tube through the central hole of the bellows and the metal cover. outside. The movable conductive rod is welded with one port of the bellows in the middle.

The other port of the bellows is welded with the metal cover plate. The bellows is an elastic element, and the sidewall is a metal tube with a wave-like shape, which can expand and contract longitudinally. Due to the introduction of a bellows between the movable conductive rod and the metal cover plate, the shell of the vacuum switch tube is completely sealed, and the movable conductive rod can move forward and backward without destroying the sealing performance of the shell.

Category of use

Vacuum switch tubes can be divided into circuit breakers, load switches, contactors and special purposes according to their uses.

1. The vacuum switch tube for circuit breakers is required to have the ability to break short-circuit current. It is used for overload and short-circuit protection of circuits and electrical equipment. Generally, it is not operated frequently, and the number of short-circuit current breaking times can reach more than 30 times.

2. The vacuum switch tube for load switch only needs to break the load current, that is, break the rated working current. It is often combined with a fuse, and the fuse is used for short-circuit protection.

3. The vacuum switch tube used in the contactor requires frequent operation under a certain load current, and its operation times can reach 500,000 times to 1 million times, or even more. It is also often used in series with fuses.

4. The special vacuum switch tube refers to the vacuum switch tube that operates under specific conditions, such as the vacuum switch tube for breaking high-voltage DC, the vacuum switch tube for triggering ignition and the vacuum switch tube for cutting off high-frequency current, etc. .