Mechanical seal for pulp pumps

Claim 1

A mechanical seal assembly comprising: a stuffing box, a shaft rotatable in said stuffing box, mechanical seal means for sealing said shaft in said stuffing box, said mechanical seal means including a stationary support, a stationary seal ring carried by said support and disposed about said shaft, a rotary seal ring disposed about said shaft, said stationary seal ring and said rotary seal ring having radial seal faces disposed in opposed sealing relation, a spring carrier having an annular body portion disposed about said shaft and an annular skirt portion radially spaced from the outer periphery of said shaft, said rotary seal ring being slidably disposed between said shaft and said skirt, said shaft, said body portion, said skirt and said rotary seal ring defining a substantially closed chamber, means providing a seal between said skirt portion and the outer periphery of said rotary seal ring, means providing a seal between the inner periphery of said rotary seal ring and said shaft, spring means within said chamber, carried by said spring carrier and engaged with said rotary seal ring to bias the latter toward said stationary seal ring, fluid pressure orifice means communicating said chamber with the interior of the stuffing box surrounding said spring carrier, and fluid passage means for conducting a flushing fluid between said radial seal faces.