JPS6449771A - Mechanical seal - Google Patents

Abstract

PURPOSE:To enable a long-time use by forming a minute gap which is opened on the inner periphery side of a sealed end face on either of the sealed end faces of a seat ring and a driven ring, providing spiral grooves on its surface, and forming lubricating grooves on the part of the sealed end face on which the minute gap is not formed. CONSTITUTION:A minute gap 23 which is opened on the inner periphery side of the sealed end face of a driven ring 2 side is formed on the end face, and spiral grooves 25 provided on its surface are inclined rearward in the relatively moving direction of the sealed end face. Due to these spiral grooves 25 provided on the sealed end face on which the minute gap 23 is formed, a pressure in the radial direction which can oppose to a leaking flow can be effectively generated utilizing the relative rotation of the sealed end face, with respect to a sealed fluid 14 existing in the minute gap 23 of the sealed end face 18. And, a nearly completely sealing fluid film can be formed on the sealed end face 18 due to lubricating grooves 26 provided on the part of the sealed end face 18 on which the minute gap 23 is not formed. Thereby, the captioned seal can stand a long-time use under a severe condition while suppressing the leakage of the sealed fluid 14 to be vary small.