The utility model discloses a
cylindrical grinding machine main shaft, including the axle body, the shell, the inner cover, the outer cover, the air curtain hole, the drain hole, the axle body is coaxially loaded in the shell, the both ends of shell are covered with the inner cover, the outer cover is stacked with the inner cover outside, be provided with first water
retaining ring on the axle body, the inner cover is provided with the integrative second water
retaining ring, the second water
retaining ring installs in the port inner wall of shell, first water retaining ring, second water retaining ring mutually cooperate and form the zigzag water retaining joint, the inner cover is provided with the air curtain hole in the outer end port of water retaining joint, the outer cover is cooperated in the axle body outer
peripheral surface and forms the water inlet joint. Through above -mentioned mode, the utility model provides a
cylindrical grinding machine main shaft, forms the quick drainage channel through the air curtain hole and the drain hole, and realizes directional control and arranges simultaneously with air seal groove and guide angle, and the bearing distribution structure is optimized to the
grinding wheel load simultaneously, thereby significantly improved the waterproof sealing performance and running stability of main shaft whole.