| 摘要 |
<p>1286432 Valves WESTINGHOUSE ELECTRIC CORP 19 April 1971 [9 March 1970] 23220/71 Heading F2V A butterfly valve, which is particularly suitable for use in controlling the flow of steam, comprises a disc having two spaced spherical faces of which only one, 6a, is shown, a shaft 9 which extends through the disc, and two selfaligning bearings 15 which are spaced from the flow being controlled and which allow bending of the shaft. The bearings are substantially sealed with respect to the valve flow channel by a sealing arrangement 50 which is comprised of two parts, one part being fixed to the housing whilst the other is fixed to, and is rotatable with, the shaft 9 (Fig. 3, not shown). Axial passages 25 and communicating radial passages 26 formed at the terminal portions of the shaft, serve to conduct atmospheric air around the bearings 15 (arrows E, Fig. 3). Part of such air is also fed outwardly from the bearings 15 whereat it mixes with any leakage flow past sealing arrangement 50 and thereafter leaves via a collection channel 71. Additional cooling of the bearings 15 is afforded by fins 23 formed on the bearing housing 20. The shaft 9 is secured to the disc by tapered pins (Fig. 4) which are threaded at their narrow ends only, the wider ends lying flush with that face (6b, not shown), which faces upstream in the valve closed position. The valve is operable within limits defined by fixed and adjustable stops (120, 122, Figs. 1 and 6, not shown) and is actuable in the closing direction by a spring arrangement (101, 102, Fig. 1) and in the opening direction by an hydraulic actuator (98, Fig. 1). The sealing arrangement 50 includes a dirt collecting baffle (53a, 54, Fig. 3).</p> |
