GB768871A - Improvements in motor driven pumps - Google Patents

Abstract

768,871. Centrifugal pumps. CHEMPUMP CORPORATION. Feb. 21, 1955, No. 5161/55. Class 110 (1). A motor-driven pump comprises a housing 12 extending between spaced end plates 10, 11, a pump housing 63 mounted on the plate 11, a cylindrical sleeve 25 axially extending between the plates 10, 11 within the housing 12 to provide separate chambers for the motor rota 80 and the motor stator 29, and closure plates 30, 50 carried by the plates 10, 11 and extending into the sleeve 25. Packing rings 35, 55 are provided. Shaft bearings 40 of graphite or tetrafluoroethylene are carried by the plates 30, 50. The motor rotor 80 may be protected from the pumped liquid by a cylindrical cover 83 and end covers 84 and, preferably, by flanges 81 which extend into recesses in the plates 30, 50. The radial faces 82 of the flanges 81 may each bear against a thrust ring 76 which is interposed between the end face of the adjacent bearing 40 and a shoulder 75 on the driving shaft. The sleeve 25 and the cover 83, 84 may be of stainless steel. The flanges 81 have close clearances with the adjacent bearing-supporting flanges 36, 57 to form flame traps. A small quantity of pumped liquid may be passed through a pipe 45 to cool and lubricate the right-hand bearing 40, and thence around the adjacent flange 81, along the outside of the rotor 80, and around the other flange 81 to cool and lubricate the other bearing 40, returning through a bore 56 to the pump impeller 71. If the pumped liquid contains abrasive material, a valve 47 can be turned to cut off the supply from the pump and admit instead a supply of abrasive-free liquid from a pipe 46.