GB1142327A - Improvements in rotary mechanical seals - Google Patents

Abstract

1,142,327. Mechanical seals. UNITED STATES METALLIC PACKING CO. Ltd. 8 June, 1967, No. 26418/67. Addition to 1,142,326. Heading F2B. In a mechanical seal 10 for a rotary shaft 11 of the type described in the parent Specification and comprising a split wear ring 17 of selflubricating material, e.g. graphite, urged into facial sealing contact with a metallic packing ring 15, the segments forming the ring 17 are held together by a spring 20 having a plurality of convolutions each encircling the ring which is sealed to the shaft by a resilient ring 18. The spring 20 is formed from flat metal strip. The ring 17 is urged against the ring 15 by springs 32 in recesses in a driving ring 19 clamped to the shaft by a set-screw 26 having a conical end 27 engaging a ball 28 in a radial bore 29 in the ring 19. Alternatively, the ring may be clamped to the shaft by a radial screw or tangential bolts. The ring 15 is secured by a ring 30 to the shaft casing 12. Rings 15,17, 19 and 30 are all formed in halves. Axial pegs (not shown) extend from the ring 19 to engage bores in the ring 17 to rotate the latter with the shaft. The two halves (42, 43), Fig. 3 (not shown), of the ring 15 are aligned by C-section locators (46) received in grooves (47, 48) in the ring halves. In a modification, Fig. 6, the compression springs are omitted and the driving ring 55 has a nose 56 engaging the ring 18 so that the wear ring 17 is urged into contact with the ring 60 by the resilience of the ring 18. A sealing ring 76 housed in a disc 73 engages the shaft 11 and provides a seal when the mechanical seal is removed for maintenance.