GB862553A - Improvements in or relating to seals for rotary shafts or the like - Google Patents

Abstract

862,553. Stuffing-box substitutes. UNIVERSAL METALLIC PACKING CO. Ltd. March 31,1959 [March 31, 1958], No. 10264/58. Class 122 (5). In a rubbing-collar type seal for a rotary shaft 1 comprising a rotatable packing-ring 7 cooperating with a non-rotatable packing-ring 2 and sealed to the shaft by a rubber &c. sealing- ring 15 axially-displaceably housed in an annular recess 8 in the rotatable ring, the sealing ring 15 is so compressed in the recess that it exerts a sufficient axial force between the rotatable ring and a clamping ring 11 or shoulder on the shaft to keep the sealing faces 9, 10 of the rotatable and non-rotatable rings in contact when the fluid pressures on both sides of the seal are equal. Clearance is provided between the rotatable and non-rotatable rings and the shaft and between the rotatable ring and the clamping-ring so that the sealing ring 15 is subjected to the fluid-pressures on opposite sides of the seal whereby, when a pressure differential exists across the seal, the contact pressure between the rings 2 and 7 is increased accordingly. A venting ring 16, formed in two parts held together by a garter spring 18, and radial vent grooves 17 in the recess face are provided on opposite sides of the sealing-ring 15. The rotatable ring is driven from the clamping-ring by means of pins 20 engaging slots 21. To facilitate dismantling the rings 2, 7 and 11 are formed in halves connected by bolts. The sealing-ring 15 is preferably of tubular form. In a modification (Fig. 2, not shown) the non-rotatable ring is axially movably connected to the casing 3 by pins on the latter engaging axial slots in the former. The venting ring 16 may be replaced by a collar on the clamping- ring 11 extending into the recess and having radial vent grooves on its end-face engaging the sealing-ring 15.