Inverse Design of Axis Fan for Permanent Magnet Drive Motor for Special Vehicles

Abstract

The control of mechanical energy loss is especially key in the design of permanent magnet drive motors for special vehicles. This paper takes a 300 kW high-efficiency motor as an example, and under the operating condition of 9000 rev/min, in order to control the size of the mechanical loss Pmech, improve the efficiency of the motor, as well as enhance the ventilation and heat dissipation performance of the motor, the structural parameters of the motor’s Axis fan are identified by using the Reverse Engineering (RE), and the fan performance is simulated and analysed by using the standard k-ε turbulence model of Computational Fluid Dynamics. The mechanical loss calculation model is investigated, and the effects of different blade numbers, wrap angles, and mounting angle parameters of the fan on the mechanical loss Pmech are derived. And finally, the scheme is calculated to show that when the blade number Z is 13, the wrap angle Δφ is 60°, the front mounting angle Φ1 is 45°, and the rear mounting angle Φ2 is 30°, the mechanical loss Pmech decreases from 8.0 kW to 2.54 kW, and the motor efficiency η0 is greatly improved, increasing from 94.2% to 96.1%. Meanwhile, based on finite element simulation experiments, the effects of the motor Axis fan on the steady-state temperature field of the pre-optimised and post-optimised fans are compared, and the optimised axis fan makes the motor ventilation and heat dissipation more reasonable. The maximum temperature of the motor under the same working condition decreased by 16.7 K, the efficiency η0 of this motor was greatly improved, and the efficiency η0 increased from 94.2% to 96.1%.