Design of a novel oil cooling system for permanent magnet synchronous motor

Oil cooling system is widely used to manage the heat dissipation of the permanent magnet synchronous motors. While some problems are still unresolved, such as increasing the heat transfer efficiency and making the structure more compact et al. Therefore, an oil cooling system that has a new type of oil flowing channel connecting with stator channel, rotor channel and spray channel is suggested. In the stator, a tangential main flowing channel connects the oil inlet and two arrays of symmetrically distributed axial flowing channels. The two arrays of axial flowing channels connect two spraying channels respectively. In the rotor, two oil axial flowing channels between the hollow channel and the two arrays of radial channels direct the cooling oil to radial flowing channel. By the simulation, it is found that this new design can reduce the pressure loss. In the rotor, two oil axial flowing channels ensure the same flowing path of the oil before entering the radial channels. Thus, the oil can be thrown from the radial channels more uniformly. In order to simplify the structure of the motor, the stator channel and the rotor channel share the same oil inlet. Taguchi method is used to optimize the design parameters of the new oil flowing channel in the stator. After optimization, the width of the main flowing channel in the stator is set to be 12 mm, the number of the axial flowing channel in the stator is 96, the cross-sectional area of the axial flowing channel in the stator is 9 mm 2 and the diameter of the oil spraying port is 1.5 mm. By simulation it is found the new oil cooling system with optimized design parameters shows a better performance than traditional oil flowing system and the new oil cooling system without optimized design parameter.