A switching device has at least one bellows made of a low-carbon nickel-chromium-molybdenum-niobium alloy. By using a low-carbon nickel-chromium-molybdenum-niobium alloy as a bellows material in the switching device, the buckling stiffness, i.e. the resistance to transverse deflection, and the mechanical service life of the bellows can be increased. The switching device can be a live-tank switching device, a dead-tank switching device, or else a gas-insulated switching device.

A medium voltage circuit breaker for the use in high pressure environments has a vacuum interrupter with a fixed contact side and a movable contract side with a movable rod, and a drive in pressure tight insulating housing, electrical terminals to the vacuum interrupter integrated into the pressure housing, and a further pressure tight housing attached pressure tightly at the insulating housing at the movable contact side of the vacuum interrupter with the movable rod, and that the inner volume of the insulating pressure tight housing gastightly separated from the inner volume of the further pressure tight housing by a bellow, through which the movable rod is guided through and mechanically coupled to a drive, which is arranged inside the further housing.

The present disclosure relates to a vacuum interrupter, and particularly, to a vacuum interrupter having enhanced performance of discharging air from the interior of a bellows in a breaking operation.

A circuit breaker comprises a vacuum chamber in which a fixed contact and a movable contact are located. A compensating reservoir comprising a counter-pressure element is provided for a good contacting.

The present disclosure is a vacuum circuit breaker 20. The vacuum circuit breaker 20 may be installed in an inner space 12 of an outer casing 10 or may be installed penetrating the outer casing 10. The vacuum circuit breaker 20 includes a vacuum interrupter 210 and a linkage mechanism 230. The linkage mechanism 230 includes a piston 246 that provides a force to offset the self-sealing force of the vacuum interrupter 210. The piston 246 may have a larger diameter than the driving rod 254 penetrating the outer casing 10, and may have a diameter equal to or similar to the effective diameter of a bellows 224 in the vacuum interrupter 210.

A circuit breaker including a bellows member having a sufficient fatigue life is obtained. The circuit breaker includes a fixed electrode, a movable electrode, a container, a movable shaft, a bellows member, and a resin layer. The bellows member is disposed so as to surround a periphery of the movable shaft. The resin layer is connected to the plurality of uneven portions of the bellows member. The resin layer includes a first part, a second part, and a third part. The first part is connected to a first recess and has a first thickness. The second part is connected to a second recess and has a second thickness. The third part is connected to at least one of a plurality of intermediate recesses and has a third thickness. The third thickness is thinner than the first thickness and the second thickness.

A vacuum circuit breaker includes a grounded tank in which an insulating gas is sealed, a vacuum valve, a movable-side electrode, a fixed-side electrode, a bellows fixed to the movable-side electrode allowed to pass therethrough, to expand and contract in the vacuum valve, a pressure valve regulating gas pressure between a first area enclosed by the bellows and a movable-side frame and a second area enclosed by the grounded tank outside the first area, a pressure release valve releasing the insulating gas from the first area to the outside of the grounded tank, and an anomaly determination unit determining leak of the insulating gas from the grounded tank, based on a gas pressure in the second area measured by a pressure sensor.

A bellows protector for a vacuum interrupter with an external bellows for low, medium or high voltages has a first region, which is configured tapered and to receive a moving contact rod such that the moving contact rod is guided out of the bellows protector from an inner side of the bellows protector onto a second side outside the bellows protector. The tapered first region of the bellows protector is configured to lie against the moving contact rod such that the moving contact rod is guided through the bellows protector. A second region adjoins the first region, the second region is enlarged relative to the first region such that the bellows to be protected is received in the second region. A holding region is configured to fasten the bellows protector on or to the vacuum interrupter such that the bellows protector forms a guide for the moving contact rod.