Field Analysis on Magnetic Transmission Mechanism of Downhole Tur- bine Generator

New downhole turbine generator can transmit the high speed rotation of the turbine to the rotor of the generator without contact by magnetic transmission mechanism to provide continuous power. Driving torque on magnetic transmission mechanism is a key parameter. This paper mainly studies the field on magnetic transmission mechanism of downhole turbine generator by using ANSYS software. The effects of thickness of permanent magnets, thickness of distance sleeve, the average radius of working field, air gaps and rotating speed on torque were quantitatively analyzed, and eddy current in distance sleeve with different structure parameters were also analyzed. Through the analysis, it can be shown that the influence of the eddy current in distance sleeve should be considered when designing the transmission mechanism to avoid reducing large torque. The size of magnetic transmission mechanism should be optimized for the design goal of large torque and low eddy current, avoiding overheating and making sure that the generator works normally.