Gas laser blower

A gas laser blower for compulsorily circulating a laser gas used in a gas laser oscillation apparatus, comprising:

• a circulation-path-side casing constituting a circulation path for the laser gas;
• a motor-side housing separated from said circulation-path-side casing by a partition wall;
• a shaft penetrating said partition wall so that a portion projecting on the side of the circulation-path-side casing is fitted with an impeller and a portion projecting on the side of said motor-side housing is integral with or connected to an output shaft of a motor;
• and
• a bearing for supporting said shaft, which is provided in such region of said partition wall as is penetrated by said shaft,
• wherein,
• said shaft is passed through a through hole formed axially in the center of an intermediate member, having one or more annular grooves with a given depth and a given width on the outer periphery thereof, so that one of the axial end faces of the intermediate member is in contact with said impeller while the other is in contact with an inner ring of said bearing;
• rings are fitted individually in the annular grooves of said intermediate member;
• and
• a ring holder constituting part of said partition wall is arranged so that the inner wall thereof is normally in contact with the rings fitted individually in the annular grooves of said intermediate member;
• so that said rings fitted in said annular grooves prevent impurities, such as gas and vapor, from said motor-side casing from getting into the circulation-path-side casing through said partition wall.