MAGNETIC ROTATIONAL TO LINEAR ACTUATOR FOR WELL PUMPS
A well pump includes a plunger reciprocally carried within a barrel between up stroke and down stroke positions. A tubular linear actuator housing located below the barrel has a rotatable rotor. An array of rotor magnets is mounted to the rotor, directing rotor magnetic fields in an outward direction. A cage is fixed against rotation relative to the housing and carried within the housing for axial movement relative to the rotor and the housing. The cage has a cylindrical inner sidewall surrounding the outer sidewall of the rotor. An array of cage magnets is mounted to the inner sidewall of the cage. The cage magnets direct cage magnetic fields in an inward direction relative to the axis. The cage and rotor magnetic fields interact such rotation of the rotor causes axial movement of the cage. A motor rotates the rotor.