Based on the finite element simulation software ANSYS Workbench, this study reports the thermal characteristics of a high-speed motorized spindle. The temperature field distribution and axial thermal deformation of the motorized spindle are then detected on an experimental platform. A comparison between the experimental and simulation results revealed the temperature rise of the motorized spindle during the working process. Under steady-state conditions of the working mo-torized spindle, the temperatures of the front bearing, rear bearing and stator were determined as 20°C, approximately 30°C and 25°C, respectively. The axial thermal elongation of the motorized spindle is approximately 10 μm.

This paper presents the loss-oriented performance analysis of a radial highspeed permanent magnet (PM) machine with concentrated windings for automotive application. The PM synchronous machine was designed for an operating frequency up to 800 Hz. The main aim of this paper is to analyse the selected methods for magnet eddycurrent loss reduction. The first approach to rotor modification regards magnet segmentation in circumferential and axial directions. The second approach is based on changes in tooth-tips shape of the stator. The best variants of tooth-tip shapes are determined for further investigation, and adopted with a rotor having magnet segmentation. It is found that the machine with a segmented magnet leads to magnet loss reduction by 81%. Further loss reduction by 45% can be realized with the proposed tooth-tip shape. Additionally, owing to the stator and rotor modifications, the main machine parameters are investigated, such as back-EMF, electromagnetic torque, torque ripple and cogging torque. The 2-D and 3-D finite element analysis (FEA) is used for electromagnetic analysis. An experimental approach based on a partially wound stator is employed to verify the 3-D FEA.