Mechanical seal with blade-like sealing end

摘要

The present invention relates to a mechanical seal for a shaft, having a rotary seal ring and a stationary seal ring which slide on and come in contact with each other for sealing a fluid. A blade-like sealing end portion formed at one seal ring is resiliently pressed, through a coil spring or a flat leaf spring, to a flat sealing end surface formed at the other seal ring. The blade-like sealing end portion is symmetrical at the inner and outer peripheral surfaces thereof with respect to the edge surface thereof, and the angles formed by the inner and outer peripheral surfaces of the sealing end portion with respect to the edge surface thereof are set to 90 DEG or more, and preferably in the range from 105 DEG to 150 DEG . This facilitates the machining of the sealing end portion and prevents the sealing end portion from being broken, thus assuring a stable sealing performance for a long period of time. Further, the spring surface pressure is increased to assure an excellent sealing performance even though the pressure greatly varies.