DOUBLE MECHANICAL SEAL, MOTOR, AND PUMP SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a double mechanical seal capable of maintaining sealing performance on movement of a shaft. SOLUTION: An outer diameter D1 of a non-rotary driven ring 2 is equal to an inner diameter D2 of a backup ring 40. The volume P of an enclosed liquid space 6 is not changed in spite of movement of a motor shaft 50, and pressure V1 in the liquid space is also not changed. Even though the motor shaft moves to a left-hand side in a drawing on starting of the motor, the volume of the enclosed liquid space 6 is not changed, and its sealing performance can be maintained. A flushing hole 91 is formed on a seal flange 9, and the liquid pressurized by a pump system A is flushed in the vicinity of an outer periphery of a seal surface S1 and an outer periphery of the non-rotary driven ring 2. COPYRIGHT: (C)2005,JPO&NCIPI