GB925881A - Centrifugal pump with canned motor - Google Patents

Abstract

925,881. Bearings; lubricating. H. KRAEMER. Nov. 26, 1959, No. 40127/59. Classes 12 (1) and 12 (3). [Also in Groups XXVI and XXXV] A centrifugal pump is driven by an electric motor of the type in which the rotor is enclosed in a jacket 12 and the stator is shielded by a cylindrical liner 10. Liquid from the highpressure end of the pump enters the motor through passages 8 to cool the motor and lubricate the bearings. The liquid enters each bearing through the gap between the flanges 21 and 23 of stationary and rotary parts 17, 19 of the bearing and flows through longitudinal grooves 27 provided in either the stationary part 17 or the rotary part 19. On leaving the left-hand bearing, the liquid passes through holes 26 into the low-pressure side of the last stage of the pump, while the liquid leaving the right-hand bearing passes through the hollow shaft to the pump inlet 2. End movement of the shaft due to the thrust exerted by the pump increases the gap between one pair of bearing flanges 21, 23 and decreases the gap between the other pair, the resulting variations in the resistance to flow through the bearing causing a corresponding decrease in the fluid pressure in chamber 16 and a corresponding increase in the fluid pressure in chamber 9. The resultant differential end thrust on the motor rotor balances the end thrust of the pump. The diameter of the flanges 21, 23 of one bearing may differ from that of the other bearing or may be adjustable, as by means of removable rings. The cross-sectional area of the grooves 25 of one bearing may be different from that of the other bearing or may be adjustable, as by the use of inserts.