GB1339540A - Motor driven centrifugal pumps - Google Patents

Abstract

1339540 Electric motors driving centrifugal pumps via magnetic couplings STANDARD MAGNET AG 1 Dec 1970 [1 Dec 1969] 57074/70 Heading H2A [Also in Division F1] In a motor, e.g. electric motor, driven centrifugal pump having a magnetic transmission coupling, the pump impeller 2 forms with a soft magnetic first pole ring 3 a unit enclosed in a pump housing 1 and a magnetically pervious shell 25, a permanent magnet second pole ring 12, arranged adjacent and at the other side of the shell from the first pole ring is drivable by the motor to transmit the motor torque to the first pole ring 3, and means are provided for varying the transmitted torque by varying the amount of flux passing through the shell 25. In the embodiment shown, the means effects variation of the air gap between the two pole rings 3, 12 and comprises a screw 21 which upon turned axially outwardly from the minimum gap position shown moves the assembly comprising the motor shaft 13 and armature 9 and hence pole ring 12 from the pole ring 3, whilst in Fig. 2, not shown, a pre-set adjustment may be made by a cammed connection of the shaft to the ring 12, and in Figs. 3 and 4 the adjustment is made by axial movement of the entire motor relative to the pump. The Specification states that the variation of flux alternatively may be provided by varying eddy currents in the shell 25, short-circuiting poles by soft Fe or permanent magnets, or by increasing the reluctance of a yoke between adjacent poles. The pole ring 3 may have an eddy current and protective copper shell 4. The motor is cooled by a fan ring 26 which draws air in at 29 and discharges it at apertures 30.