Patent ID: 8702400

Claim:
A motor direct drive rod ground screw pump device, comprising: a polished rod, a polished rod clip, a motor, a motor controller, a flange oil outlet, an oil well flange, a screw pump body, wherein the motor is a vertical three phase permanent magnet brushless direct current motor with a hollow shaft, the polished rod passes through said hollow shaft; wherein the motor controller comprises: a rectification circuit for rectifying a three phase alternating current into direct current; a converter circuit for converting the direct current into alternating current which can be adjusted; a Hall position sensor for detecting the rotary position of a rotor of the vertical three phase permanent magnet brushless direct current motor; a CPU for modulating the direct current brushless sine wave of mono-chip microcomputer with Hall sensor; a driving circuit for isolating the signal and magnifying the power, as well as acting on the converter circuit and adjusting the voltage and frequency of the vertical three phase permanent magnet brushless direct current motor thus realizing continuous speed adjustment; wherein the rectification circuit is a three phase semi-control bridge, the converter circuit is a three phase full-bridge converter output employing an insulated gate bipolar transistor, and the CPU has inputs of controller direct current bus voltage, motor current and temperature signal of a module radiator.