Rotary pump assembly

A rotary pump assembly comprising:

• a generally circular pump enclosure;
• a generally circular seal enclosure of reduced diameter to that of said pump enclosure and adapted to contain a lubricating fluid, said enclosures sharing a common wall, and said seal enclosure having a wall opposite to that of said common wall;
• a rotary pump positioned within said pump enclosure and having a driven shaft which passes through said walls;
• first and second stationary shaft sealing members positioned around said shaft in opposite walls of said seal enclosure, and said sealing members having facing planar seal surfaces;
• first and second spaced rotating seal members around and rotating with said shaft, said first rotating seal member having a planar surface positioned adjacent to and adapted to frictionally engage said first stationary seal member, and said second rotating seal member having a planar surface adjacent to and adapted to frictionally engage with the planar surface of said second stationary seal member;
• spring bias means for applying a bias to said rotating sealing members for biasing said rotating sealing members against said stationary sealing members;
• and
• an opening in said common wall, and an annular diaphragm positioned within said seal enclosure adjacent said common wall and said opening, and being between said shaft opening and the circumference of said seal enclosure, whereby the fluid pressure in said pump enclosure adjacent said opening, being a pressure in a basically inner diameter region of said pump enclosure, is directly transmitted through said opening to said diaphragm and by said diaphragm to a fluid containable in said seal enclosure, and thereby a coordinate pressure applied as an additional bias to said rotating seal members.