Patent ID: 8509280

Claim:
A gas laser oscillator apparatus comprising: a discharge section for exciting laser gas as a laser medium; a bellows section for feeding the laser gas further including: a rotating shaft having an impeller at a tip end; a driver for rotating the rotating shaft; a plurality of bearings connected to the rotating shaft; and a temperature-detecting mechanism with a controller, the temperature-detecting mechanism having temperature sensors, the temperature sensors contacting with the bearings; and a laser-gas flow passage as a circulation path between the discharge section and the bellows section, wherein, a grease made of a volatile substance is applied to the bearings for lubrication, the temperature sensors detect temperature of the bearings, and the controller of the temperature-detecting mechanism outputs a signal that indicates a replacement cycle of the bellows section according to temperature of the bearings with reference to a data on relationship between rise of the temperature and a lifetime of the bearings, the data is stored in the controller, and the temperature-detecting mechanism has a sensor on a tip end of a spring having a pressure force smaller than a load applied to the bearings, and the sensor detects temperature of the bearings in a manner that the spring is wrapped around with heat insulating material so as not to be exposed to outside temperature.