Shaft seal assembly, especially for high-pressure turbocompressors

A shaft seal assembly for a turbocompressor, comprising:

• a shaft
• a housing surrounding said shaft and formed with a pressurized gas space to be sealed from the atmosphere;
• a gas-side axially sealing slide ring surrounding said shaft, received in said housing and angularly fixed therein;
• an atmosphere-side axially sealing slide ring surrounding said shaft, received in said housing and angularly fixed therein;
• means for mounting said atmosphere-side slide ring for axial and radial movement relative to said housing at an axially extending functional gap defined between said atmosphere-side slide ring and said housing, and including:
• an O-ring sealing said functional gap relative to said housing without exerting centering forces upon said atmosphere-side slide ring, and
• a further O-ring and springs acting upon said atmosphere-side slide ring for centering same relative to said housing along an inner diameter of said atmosphere-side slide ring;
• a rotor ring on said shaft between said slide rings and having opposite sealing surfaces respectively juxtaposed with sealing surfaces of said slide rings;
• a respective blocking-liquid compartment formed in said housing and open toward each of said slide rings outwardly thereof;
• an annular passage formed in said housing around a periphery of said rotor ring and interconnecting said compartments, said atmosphere-side slide ring sealing the respective compartment against the atmosphere and said gas-side slide ring sealing the respective compartment against said gas space;
• and
• means for connecting both of said compartments in a blocking-liquid circulation path including a pump and a cooler,
• said atmosphere-side slide ring having a surface-area ratio K between substantially 0.45 to 0.60 between an area A1 constituting the numerator of said ratio and formed by a net effective area of said atmosphere-side slide ring biased by said blocking liquid and an are A2 constituting the denominator of said ratio and constituting a sealing area of said atmosphere-side slide ring against said rotor ring, said rings are composed of a material having a modulus of elasticity of at least 250,000 N/mm.sup.2.