GB881439A - Rotary seal - Google Patents

Abstract

881,439. Stuffing-box substitutes. CRANE PACKING Ltd. June 29, 1960 [July 9, 1959], No. 23581/59. Class 122 (5). In a mechanical seal for a rotary shaft 1 and comprising a rotary seal ring 3 urged axially by a spring 1 into sealing contact with a stationary seal ring 4, the ring 3 is drivably connected to the shaft by at least one key 17 in the form of a flat strip, engaging a keyway 18 in the ring 3 and in a collar 15 secured to the shaft. Preferably, two diametrically-opposed keys which may be of tungsten carbide, are used. The ring 3 is sealed to the shaft by an 0-ring 12 and the spring 10 is compressed between a thrust ring 11 and a locating ring 14 having keyways 18 and a step portion 21. The keys 17 are axially located by a locking ring comprising two part-rings 20 that engage a groove 19 in a sleeve 9 and fit around the step 21 with one end of each part-ring engaging a notch 22 (Fig. 3), in one of the keys. The part-rings 20 are inserted or removed by pressing the locating ring 14 forward against the spring 10. The seal ring 4 is sealed to the shaft housing 2 by an 0-ring 5 and prevented from rotating by a pin 6. Cooling fluid is supplied through a bore 7 in the shaft housing. In a modification, Fig. 5 (not shown), the rotary seal ring 3 is replaced by a seal ring surrounded by a driving band having keyways therein for the keys 17. In a further modification, Fig. 7 (not shown), the 0-ring 12 is replaced by a wedge-section packing ring. The invention is stated to be applicable also when the ring 5 is sealed to the shaft by a flexible bellows in which case the band that clamps the bellows on to the shaft may be positively driven by the keys, for example by pegs on the band-engaging apertures 32 in the keys.