GB1193384A - Impeller Pump and Electric Motor Assembly - Google Patents

Abstract

1,193,384. Cooling electric motors driving pumps. BORG-WARNER CORP. 28 June, 1968 [2 Aug., 1967], No. 31009/68. Heading H2A. [Also in Divisions F1 and F2] A pump assembly for high temperature and pressure fluids, comprising main and auxiliary pumps 11, 13, Figs. 2 and 4, driven by an electric motor 12, has a thermal barrier plate 39 arranged between the main pump and motor to maintain the temperature of the motor within tolerable limits. A cooling fluid, e.g. the fluid being pumped, is delivered from an inlet 131, through a spiral-like passage or passages in the plate 39 and through shaft clearance 76 into the space below the main pump impeller 77 from where it is discharged into the main flow by supplementary impeller vanes 137. Cooling is also provided by delivering cooling fluid, e.g. water, through passages 104 in a member 17 between the main pump and motor, the adjacent passages 104 being joined alternately at their radially outer and inner ends so that the water flows in a zig-zag path towards and away from the shaft during its passage around the member 17 from an inlet 107 to an adjacent outlet (108), Fig. 8 (not shown). The upper surface of the member 17 has a layer of laminated stainless steel thereon (not shown). Further cooling is provided by a lubrication system for the bearings and for a shaft seal assembly 49. In this system oil is delivered by the auxiliary pump 13 through conduit 168 into an inlet region 201 of a series of longitudinal grooves 179 in the motor stator. The grooves 179 are arranged in a number of groups interconnected alternately at the upper and lower ends of the stator so that the oil passes from the inlet region 201 around the stator to an outlet region along a zig-zag path. Thereafter, the oil passes through passages 103 to the shaft seal assembly 49 where some of the oil flows via a spiral groove 64 or via stationary and rotary seal members 57, 72 to the shaft clearance 76, and the remainder flows through passage 86 into shaft bore 82 and back to the auxiliary pump 13 via tube 85, passage 87, rotor/stator clearance 215 and passage 169. Three terminals 184 are provided. Bearing 91 is lubricated by the returning oil flow. Make-up oil is delivered to the auxiliary pump 13 through a non-return valve 173 and passages 172, 171, 169. The auxiliary pump impeller comprises a ring 151 keyed to a thrust disc 138 of a thrust bearing assembly having floating bearing shoes 141, 142 at either side of the disc 138. The bearing assembly is lubricated by oil delivered through passages 164, 165 and returned through passages 217, 169 and 174, 171, 169. In a further cooling arrangement for the motor, cooling water is circulated through an annular space between the motor casing 16 and an outer shell 223. The annular space contains a spiral tube 225, and cooling water entering the space at 227 flows through the tube and between the coils of the tube to an outlet 226. The motor casing 16 may be made up in sections welded together as at 29 and 31.