GB954883A - Rotary face seal - Google Patents

Abstract

954,883. Mechanical seals. CONTINENTAL ILLINOIS NATIONAL BANK & TRUST CO. OF CHICAGO. March 5, 1963 [March 23, 1962], No. 8795/63. Heading F2B. In a mechanical seal 10 for a rotary shaft 11 comprising a non-rotatable sealing ring 30 sealed to the shaft housing 13 and urged into facial sealing contact with a sealing ring 20 secured to the shaft, means are provided to convert the frictional torque at the sealing faces 26, 31 into a force tending to separate those faces and thereby prevent excessive frictional contact. The ring 30 is slidably sealed, by means of an O-ring 35, in a cup housing 32 fitted in a bore 12 in the shaft housing 13. A thrust bearing 50 is disposed between the ring 20 and a pivot ring 47 held against rotation in the cup 32 by a pair of projections 48 on the ring engaging slots 49 in the cup. Axially-inclined pins 45 extend through holes 62 and 55 in a guide 61 and a spacer 56 respectively and bear at one end against a washer 57 and engage at the other end in sockets 46 in the ring 47. The washer 57 is clamped between a flange 58 on the ring 30 and the spacer 56 which is fixed to the ring 30. The ring 47 is urged away from the bearing 50 by a leaf spring 65 abutting a ring 66 locked to the ring 30 which latter is urged by the pressure of the sealed fluid and a leaf spring 60 into contact with the surface 26 of a carbon insert 25 in the ring 20. The cup 32 is sealed to the housing 13 by an 0-ring 33 and outward movement of the parts in the cup is limited by a retaining circlip 37. In operation, the shaft rotates in the direction 14 and excessive frictional drag at the sealing surfaces 26, 31 rotates the ring 30 in the cup 32 in a direction to straighten the inclined pins 45 and thus move the ring 30 away from the ring 20 to thereby reduce the drag to an allowable amount. In a modification, Figs. 3-5 (not shown), the frictional drag tends to separate the sealing faces by means comprising a cam follower which is secured to the ring 30 and engages a cam surface on a ring rotationally fixed in the cup 32.