Gas-insulated high voltage puffer breaker comprising a puffer unit with a movable piston running in a puffer cylinder and delimiting a puffer volume. A piston and a first contact member are attached to a piston stem. A piston and a first contact member are attached to a piston stem. An electric arc is extinguishable in an arcing zone when the first contact member moves from a first position to a second position. The puffer volume is fluidly connected to a gas nozzle by a gas channel such that the puffer volume comprises the gas channel as well as a portion of the puffer cylinder. The gas channel is provided radially outside of the puffer cylinder between a puffer cylinder wall delimiting the puffer cylinder and a wall structure of the puffer unit.

Disclosed is an abrasion resistant material having low cost and excellent abrasion resistance, a puffer cylinder, and a puffer type gas circuit breaker. The abrasion resistant material includes: a base material which is formed of pure aluminum or aluminum alloy and has an unevenness structure formed on its surface; and an aluminum hydrated oxide film which is formed on the surface of the base material, wherein a surface of the aluminum hydrated oxide film is provided with an unevenness structure which is finer than the unevenness structure of the base material.

Disclosed is an abrasion resistant material having low cost and excellent abrasion resistance, a puffer cylinder, and a puffer type gas circuit breaker. The abrasion resistant material includes: a base material which is formed of pure aluminum or aluminum alloy and has an unevenness structure formed on its surface; and an aluminum hydrated oxide film which is formed on the surface of the base material, wherein a surface of the aluminum hydrated oxide film is provided with an unevenness structure which is finer than the unevenness structure of the base material.

Disclosed is a gas insulated circuit breaker having enhanced insulation properties. A gas insulated circuit breaker comprises: a fixed cylinder unit of which a movable contact point has an internal space; a movable piston unit which is slidably inserted into the inner space of the fixed cylinder unit; a fixing unit provided in a rear of the fixed cylinder unit in the internal space of the fixed cylinder unit; a puffer chamber which is formed by having the movable piston unit, fixed cylinder unit and fixing unit, surrounding the puffer chamber; and a gas inlet unit which forms a path, between the puffer chamber and the outer part of the fixed cylinder unit, through which a gas flows.

Disclosed is a gas insulated circuit breaker having enhanced insulation properties. A gas insulated circuit breaker comprises: a fixed cylinder unit of which a movable contact point has an internal space; a movable piston unit which is slidably inserted into the inner space of the fixed cylinder unit; a fixing unit provided in a rear of the fixed cylinder unit in the internal space of the fixed cylinder unit; a puffer chamber which is formed by having the movable piston unit, fixed cylinder unit and fixing unit, surrounding the puffer chamber; and a gas inlet unit which forms a path, between the puffer chamber and the outer part of the fixed cylinder unit, through which a gas flows.

The invention provides a switchgear that is capable of increasing a degree of freedom of a position of a moving arcing contact in a circuit breaker, does not require dimension management of components and a mechanism for adjusting a position of the moving arcing contact, and is capable of simplifying fabrication of components and assembly of devices and reducing cost. The switchgear according to the invention includes: a circuit breaker that is configured of a fixed arcing contact installed at a fixed-side conductor and a moving arcing contact installed at a moving electrode that opens and closes with respect to the fixed arcing contact; a linear motor that generates drive force for operating the moving arcing contact; a position detecting device that detects a position of a moving element of the linear motor; a contact detecting device that detects a contact state between the fixed arcing contact and the moving arcing contact; and a control device that sets a moving range of the moving arcing contact by controlling a voltage and a phase to be supplied to the linear motor based on the contact state between the fixed arcing contact and the moving arcing contact, which is detected by the contact detecting device, and position information of the moving element of the linear motor, which is detected by the position detecting device.

The invention provides a switchgear that is capable of increasing a degree of freedom of a position of a moving arcing contact in a circuit breaker, does not require dimension management of components and a mechanism for adjusting a position of the moving arcing contact, and is capable of simplifying fabrication of components and assembly of devices and reducing cost. The switchgear according to the invention includes: a circuit breaker that is configured of a fixed arcing contact installed at a fixed-side conductor and a moving arcing contact installed at a moving electrode that opens and closes with respect to the fixed arcing contact; a linear motor that generates drive force for operating the moving arcing contact; a position detecting device that detects a position of a moving element of the linear motor; a contact detecting device that detects a contact state between the fixed arcing contact and the moving arcing contact; and a control device that sets a moving range of the moving arcing contact by controlling a voltage and a phase to be supplied to the linear motor based on the contact state between the fixed arcing contact and the moving arcing contact, which is detected by the contact detecting device, and position information of the moving element of the linear motor, which is detected by the position detecting device.

A gas exhaust diffuser for a circuit breaker, comprising a first casing extending longitudinally along a principal axis with an open end to allow gas to enter and a closed end, and a second casing coaxial to the first casing, extending along the principal axis, with at least one outlet to allow gas to escape, the closed end of the first casing being arranged in the second casing and the first casing having at least two radial openings near its closed end to provide a fluid communication between the first and second casing. A plurality of incurved elements are positioned radially in the second casing at the at least one radial opening to create a rotation of an entering exhaust flow in a plan perpendicular to the principal axis, thereby generating a substantially helicoidally-shaped exhaust flow path in the second casing.

An insulation rod cover is fitted to an end portion of a puffer shaft and the insulation rod cover is fitted to a circuit-breaker side coupling pin coupling between a puffer shaft and an insulation rod, thereby allowing the insulation rod cover to be held at a joint between the puffer shaft and the insulation rod. In a first half of a circuit-breaking operation, the insulation rod cover is positioned in the exhaust cylinder and the exhaust of the hot gas from the puffer shaft is suppressed to increase the pressure of an extinguishing gas to be sprayed onto the arc. In a last half of the circuit-breaking operation, the insulation rod cover is positioned in a guard cylinder to promote the exhaust of the hot gas from the puffer shaft as well as to suppress the flow of the hot gas into the insulation cylinder.

An insulation rod cover is fitted to an end portion of a puffer shaft and the insulation rod cover is fitted to a circuit-breaker side coupling pin coupling between a puffer shaft and an insulation rod, thereby allowing the insulation rod cover to be held at a joint between the puffer shaft and the insulation rod. In a first half of a circuit-breaking operation, the insulation rod cover is positioned in the exhaust cylinder and the exhaust of the hot gas from the puffer shaft is suppressed to increase the pressure of an extinguishing gas to be sprayed onto the arc. In a last half of the circuit-breaking operation, the insulation rod cover is positioned in a guard cylinder to promote the exhaust of the hot gas from the puffer shaft as well as to suppress the flow of the hot gas into the insulation cylinder.