| 摘要 |
1,254,237. Pump motors. KLEIN, SCHANZLIN & BECKER A.G. 16 Dec., 1969 [17 Dec., 1968], No. 61274/69. Heading H2A. [Also in Division F1] The rotor 9 of an electric motor driving a pump impeller 4 through a shaft 3 is enclosed in a rotor chamber formed by a cylindrical stator plate 8 and bulkheads 11, 12; thrust bearings at each end of the rotor chamber each comprise a bearing part 15 or 22 having a face directed towards a face of the respective bulkhead 11 or 12 on the side of the bulkhead remote from the rotor chamber; the arrangement is such that pressurized fluid supplied from the pump output via a duct 5 to the rotor chamber can escape through the opposed faces of the thrust bearings. The fluid passes from the end 6 of the rotor chamber through a restrictor gap 20 and then passes through the lower thrust bearing, a radial bearing 23 and a restrictor gap 24 into a chamber 25 behind the impeller 4. The fluid also passes from the end 6 of the rotor chamber to the other end 10 via the gap 7 between the rotor 9 and the stator plate 8, thereby exerting an upthrust R on the rotor. Thence, the fluid passes through a restrictor gap-13, the upper thrust bearing and a radial bearing 16 to the end of the shaft 3, where it exerts a downthrust W on the shaft. After flowing through a drilled screw 17, a bore 18 in the shaft 3 and a further drilled screw 19, the fluid returns to the eye of the pump. The net upthrust R-W counteracts the downthrust exerted by the impeller 4. In the event of an imbalance occurring between the impeller downthrust and the counteracting upthrust, the resultant axial displacement of the shaft 3 reduces the gap between the opposed faces of one of the two thrust bearings, thereby producing an axial thrust on the thrust bearing to remove the imbalance: Radial grooves may be provided in the thrust bearing faces of the bulk- heads 11, 12 to ensure a minimum flow which is sufficient for cooling and lubrication. |
