Abstract: The invention relates to an apparatus for evaluating the slippage of a mechanical seal comprising: a high frequency vibration sensor, attached to the outside of the mechanical seal of a rotary machine equipped with the mechanical seal, for measuring the high frequency vibration which is generated by the mechanical seal in the operating mode; and a microcomputer for receiving the output of the high frequency vibration sensor, for analyzing the high frequency vibration which is generated by the mechanical seal in each state of the slippage surfaces of the mechanical seal, and for outputting the evaluation value of the slippage of the mechanical seal.

Abstract: A shaft sealing device comprises a rotation shaft passing through a casing. A rotation ring mechanism is affixed to the rotation shaft within the casing, with a mechanical seal member located within the casing, with a mechanical seal member located within the casing and cooperating with one side of the rotation ring mechansim. A non-rotatable, floating seal member is also located in the casing, and is liquid-tightly fitted onto the outer circumference of the rotation ring mechanism. One side of the floating seal member contacts an inner surface of the casing, so that a sealing chamber for lubrication liquid is formed within the casing, by the rotation ring mechanism, mechanical and floating seal members.

Abstract: A mechanical seal is disclosed wherein an intermediate floating ring is employed between a seat sleeve and a rotary ring. Each of the rotary ring, intermediate floating ring and the seat sleeve are pressed against each other so as to be relatively rotatable at their respective abutting interfaces, each of the rotary ring, intermediate ring and the seat sleeve being separated from each other with proper clearances between the opposing surfaces thereof at places which are outward of the sliding interfaces and each of the opposing surfaces is provided with an annular groove and a cascade of blades therein so that a fluid coupling is formed between the adjacent opposing surfaces.