Development of High Power-Density Motors for Electric Axles Using Nd-Based Bonded Magnets

In recent years, there has been a growing demand for smaller traction motors with higher power. This study focuses on high-speed rotation to achieve miniaturization and develops a prototype motor using Nd-based bonded magnets. Its target maximum rotational speed is 34,000 rpm, which is twice that of existing 50 kW-class motors. The prototype motor exhibited the desired performance in combination with a reducer, and achieved a 54% reduction in weight and a 2.2-fold increase in power density.