Patent attributes
To stabilize frictional force to the reciprocating shaft without affecting sealing ability, a sealing device for a reciprocating shaft comprises a main lip 11, a whole periphery of which slidably and tightly contacts with an outer peripheral surface of a shaft 2 reciprocating in the axial direction; and a frictional lip 13, which extends to the sealed space A side from the main lip 11 and slidably and tightly contacts with the outer peripheral surface of the shaft 2 in the state of permitting circulation of sealed fluid, whereby the frictional force of the frictional lip 13 is not varied by pressure of the sealed fluid, while frictional force of the main lip 11 to the shaft 2 is varied by the pressure, the sliding surface is lubricated with the sealed fluid, and reduction of the frictional force by abrasion can be controlled.
