The Research Of Coreless DC Motors For Traction Robot In Horizontal Well

The control motors in the well traction robot require high temperature resistant, quick response, small volume and large power density. Because Coreless DC motors uses ironless-rotor, the inertia and inductance is very small, mechanical time constant is less than 28 milliseconds, several products can attain in less than 10 milliseconds. Its weight and size are 1/3 - 1/3 less when compared with an iron core motor of same power.Because Coreless DC motors's structure is special, it's difficult to manufacture, the research on the Coreless DC motors is very lack.With the use of rare-earth magnet and the application of finite element method (FEM) in the magnetic field analyse, the tradition design method of electric motor should be modification. A new design and optimization method was generated.According to the performance technical requirement and the key dimension relation, select the key dimension and outer magenet structure. The motor's magnetic field is analyzed with finite element method (FEM) by ANSYS software. The EMF and electro-magnetic torque are calculated with path method base on the air gap magnetic flux density(B).The influence on the electromagnetic parameters, by the change of air ply, permanment magnet length and the magnetic pole arc coefficient, are calculated by the ANSYS software. The optimum parameter of the magnetic pole is obtained by solving the magnetic field.The vibration characteristic of the rotor is calculated by the ANSYS software. The first ten natural frequencies and mode shapes are calculated. The utmost velocity of the rotor can be calculated.