Patent ID: 7210687

Claim:
A shaft seal assembly for providing a seal between a housing and a rotary shaft, said shaft seal assembly comprising: a) a first seal portion located at a first end of said rotary shaft and disposed between said housing and said rotary shaft in a radial direction relative to a longitudinal axis of said rotary shaft; b) a second seal portion located at a second end of said rotary shaft opposite to said first seal portion and disposed between said housing and said rotary shaft in said radial direction relative to said longitudinal axis of said rotary shaft process fluid side relative to said first seal portion; c) a fluid chamber defined between said first seal portion and said second seal portion in an axial direction relative to said longitudinal axis of said rotary shaft; d) an intake passage in communication with a communication passage, said intake and communication passages being defined and located between a first end of said fluid chamber and said first seal portion relative to said longitudinal axis of said rotary shaft; e) a floating ring that is axially movable with respect to both the rotary shaft and the housing and includes a pressure reduction inner surface that defines a pressure reduction gap between an inner diameter surface of said floating ring and said rotary shaft, wherein said fluid chamber is defined between an outer diameter surface of said floating ring and an inner diameter surface of said housing; f) an outlet passage communicating with said pressure reduction gap; g) a sleeve formed directly on the rotary shaft, wherein said first and second seal portions are located directly on an outer circumferential surface of the sleeve and are between an inner circumferential surface of the housing and the outer circumferential surface of the sleeve; and h) a biasing member disposed between an inner radial wall portion of said floating ring and an inner radial wall portion of said housing, wherein said biasing member urges said floating ring to contact said inner radial wall portion of said housing.