Design Of Drilling Mud Turbine Generator Based On Magnetic Transmission Technology

This article studies on the drilling mud turbine generator based on magnetic transmission technology, and the structure is designed, which can transmit the high speed rotating of the turbine to the rotor of the generator without contact by magnetic drive, and complete isolation between the generator and the power mud fluid can be realized; Based on the designed structure, the model of magnetic field can be established by using ANSYS software, and then it is concluded that the varied structure dimensions of magnetic transmission mechanism have effect on magnetic torque and the eddy in distance sleeve. The main works and the results of the research can be summarized by the following several aspects:Compared with the existing turbine generator, and based on the existing turbine generator, the structure of the new type compensating dynamic seal turbine generator is designed by using Kalsi seal and compensating spring. The new generator can isolate the motor from the drilling mud, which can improve the high speed bearing lubrication and the reliable of dynamic seal, and the requirement on motors is lowered.The structure dimensions of the magnets which is installed on the magnetic transmission mechanism is calculated by using MATLAB software. The structure dimensions of the magnets and the distance sleeve should be calculated on the premise that the magnetic torque should meet the requirements and the volume of magnets should be minimum.Simplifying the model of the magnetic transmission mechanism, and establishing the differential equations of the magnetic flux density and eddy density in distance sleeve, then combining the finite element theory, the magnetic flux density, eddy density in distance sleeve, magnetic force in 2D magnetic field can be analyzed by using ANSYS software; Leakage flux can be concluded from the 3D magnetic field analysis.The model and simulation for varied radial dimensions are built by using ANSYS 2D static magnetic field, then the effects of the average radius of working field, thickness of permanent magnets, thickness of distance sleeve, air gaps on magnetic torque and eddy current can be analyzed by using control variable method; The effect of length of the magnets on magnetic torque can be analyzed by using 3D static magnetic field. The conclusion of this article has great significance for the further study on drilling mud turbine generator.