Integrated dual pump system

An integral combination of two motor pumps wherein two pumps 12, 14 are operated preferably from the motor shafts 41, 43 of a centrally located, pancake-type, d.c., brushless electric motor 10, the entire combination being housed in a unitary casing. The stator 22 is located within a central peripheral cavity between a pair of rotor faces 26, 28 in which are set spaced permanent mangets 32, 34 which react with the commutated d.c. fields of the stator coils to rotate the rotors 36, 38. Each rotor, e.g. 38, is integral with a motor shaft section which is integrally coupled with a pump shaft, e.g., 44. The pump shaft 44 supports an inducer 46 and an impeller 48 which pump a fluid that is also sent through passages in the motor 10 to lubricate the sleeve bearings 54 and to cool the motor components. The speeds of the rotor 36, 38 can be individually adjusted, for example, by adjusting the number of permanent magnets 32, 34 in each rotor face 26, 28. Counterrotation of the rotors 36, 38 can be achieved by proper orientation of the permanent magnets 32, 34 relative to the positions of the stator coils 24 and by stator current switching control. The pump shafts 42, 44 can be made to rotate together mechanically at the same speed by connecting the motor shafts 41, 43 together by means such as a splined bar 90, or electrically by synchronizing the rotor/shafts through the controller.