Electric Motors for Powering Downhole Tools
An electric motor, for powering downhole tools, comprises a stator and a rotor connectable to a rotatable device, a permanent magnet and a series of coiled windings or laminations having a connection to a DC supply, the permanent magnet and the laminations being arranged annularly with respect to each other, characterised in that the laminations and coil windings are potted in a potting material impervious to wellbore fluids. The potting material are introduced under a vacuum, and the motor housing confines the potting material, acting as a mould.
1 . An electric motor, for powering downhole tools, the motor comprising:
a stators;
a rotor connectable to a rotatable devices;
a permanent magnets;
a series of coiled windings or laminations having a connection to a DC supply, the permanent magnet and the laminations being arranged annularly with respect to each other; and
a potting material impervious to wellbore fluids, the laminations and coil windings being potted in the material.
2 . An electric motor according to claim 1 , wherein the potting material is introduced under a vacuum.
3 . An electric motor according to claim 1 , further comprising
a motor housing which confines the potting material.
4 . An electric motor according to claim 1 , further comprising
wiring that exits from the potted material through a metal clad tube, onto which an O ring seal can be used.
5 . An electric motor assembly comprising two or more electric motors according to claim 1 secured in series.
6 . An electric motor assembly according to claim 5 , wherein the two or more electric motors are secured together before the potting material is introduced.