Grinder e.g. pneumatic grinder, has main body with bottom end that is inwardly recessed to form space, and sealing unit disposed between plane face of rotary shaft and cover to seal both cover and plane face

摘要

The grinder has a main body with a bottom end that is inwardly recessed to form a space, and a driving unit mounted on the body. A bottom end of a rotary shaft connected with the unit has a plane face (52) facing downward. A bottom cover (60) with a through hole is disposed at the bottom end of the body for sealing the space. A sealing unit disposed between the face and the cover seals both the cover and the face.