Electromagnetic design and temperature field analysis of a high speed permanent magnet claw motor with outer rotor

High speed permanent magnet motor (HSPMM) has the advantages of connecting with the load directly and getting rid of traditional mechanical increasing gear. Therefore, HSPMM is being more widely used in the industrial application and aerospace aspect recently. Inner rotor structure is generally adopted in traditional HSPMM, and in order to avoid enormous tensile stress of PM, special rotor protecting measure is often needed, which brings with huge PM volume, low air-gap flux density and serious eddy-current loss. While outer rotor HSPMM can avoid these problems. Based on a 3kW, 20000rpm outer rotor HSPMM, a electromagnetic scheme towards the machine is designed and analyzed in this paper, and finite element method (FEM) is used to verify the rationality of magnetic field distribution; aiming at the great loss destiny and difficulty of heat dissipation, a water-loops between claw poles cooling system is designed and a 3D finite element model is established. And fluid-solid coupling method is used to analyze the temperature distribution of the motor in detail. The results verify that the cooling system is efficient to reduce the temperature of claw pole stator and windings.