Dust-proof device for mechanical seal

摘要

A dust-proof device for preventing dust from entering into sliding surfaces from the inside thereof in a mechanical seal for avoiding the leakage of fluid from the outside into the inside of the sliding surfaces, which mechanical seal comprises a seating ring which receives therethrough a rotary shaft and a follower ring which is rotated together with the rotary shaft in sliding contact with the seating ring. The dust-proof device comprises a dust-proof disk which is attached to the rotary shaft. This disk is opposed to the end face of the seating ring with leaving a small clearance between them and the above end face is the opposite surface relative to the sliding surface of the seating ring. The dust-proof disk is rotated together with the rotary shaft to avoid the entering of dust into the clearance, thereby preventing the dust from entering into the sliding surfaces. Further, it is possible to seal up the clearance by bringing the peripheral portion of the dust-proof disk into contact with the end face of seating ring continuously or temporarily during the stoppage of the rotary shaft.