GB654660A - Improvements in or relating to sealing devices for pumps - Google Patents

Abstract

654,660. Stuffing-box substitutes. BORGWARNER CORPORATION. July 30, 1947, No. 20618. Convention date, July 31, 1946. [Class 122(v)] In a pressure loaded rotary liquid displacement device 10 having a housing 11, displacement means 12 within the housing 11, with an axially adjustable bushing 15 with a radially extending flange 16 provided at its rear surface with a liquid pressure responsive surface 16a for effecting, when liquid pressure is applied thereto, a sealing engagement of the bushing journal surface 16c with the adjacent side surface of the means 12, the bushing 15 being formed with a reduced axial tubular extension 19 received in a reduced bore 18 in the housing 11 while the extension 19 has an uninterrupted external surface 19b, there is provided a step 17 at the forward terminal of the bore 18, which embraces the extension 19 and locates a ring seal 20 in sealing contact with the surface 19b of the extension 19 and means is provided for directing pressure liquid to the surface 16a. The housing 11 from which an inlet 11b and an outlet 11c extend, comprises two cylindrical chambers having the reduced bores 18 formed in their end walls and each containing a toothed gear member having a journal extending from both sides thereof into the bores 18. The gears 12 which each have a bushing 15 provided on one side thereof, mesh at the junction of the cylindrical chambers. Each bushing surface 16a which forms a pressure chamber with the adjacent housing surface has a step 16d formed therein in telescopic relation with the step 17 to confine the seal 20. The forward face of the flange 16 has a radially outer face 16b open to the liquid in the pump chambers and a radially inner face 16c which engage the gear side face, while the latter side face has a relief recess 21 therein. The inlet 11b is connected to the recess 21 by passages 22, 23 and the outlet 11c is connected to the surface 16c by a passage 24. The areas of the surfaces 16a, b, c, are such that an overbalance force always exists in the sealing direction. A spring 25 is employed to promote initial sealing.