| 摘要 |
1,109,489. Mechanical seals. BORG-WARNER CORPORATION. 16 Aug., 1965 [17 Aug., 1964], No. 35066/65. Heading F2B. A rotary pump shaft 11 is sealed by means comprising first and second mechanical seals 14 and 15 axially separated by an enclosed chamber 30c and each by-passed by a pressure reducing cell 63b and 63c respectively providing an open fluid conduit. In the embodiment shown for a high pressure pump the shaft is sealed by four mechanical seals 12, 13, 14 and 15 arranged in series. The seal 12 comprises a rotary sealing ring 35 sealed to the shaft by a cup packing 34 and having a face 36 urged by springs 32 in a sleeve member 26 into facial sealing contact with face 37 of a stationary sealing ring 38 housed in a back-up member 23. The members 23 and 26 are located in a housing 22 tightly fitted in a counterbore 18 in the pump housing 10. The seals 13, 14 and 15 are identical with seal 12 except that the sealing faces are by-passed by a pressure reducing cell 63, 63b, 63c formed by a helical groove 64 in the back-up member 23a, 23b, 23c. The fluid in chamber 30 is at substantially pump pressure and is cooled by being circulated by an impeller 61 through a heat exchanger 57. The seal chamber 30a is supplied with fluid which is cooled in a heat exchanger 70 and has its pressure reduced in a reducer 71 fed by a pipe 72 communicating with the pump chamber. A pressure less than that in chamber 30a is provided in chamber 30b due to the cell 63. Similarly, the pressure differential across seals 14 and 15 is controlled by cells 63b and 63c and fluid escaping past the last cell 63c is communicated to atmosphere, pump inlet or any low pressure zone. The seals 12 and 13 may be omitted.
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