Indirect water cooling system improvements for vehicle motor applications

This study introduces indirect water cooling systems and their improvements utilized in proto typing of vehicle machines. Due the vehicle machines require high torque at acceleration they are often equipped with indirect liquid cooling. One common method to implement liquid cooling is a water jacket inside machine frame as well as on the end plates. The flow rate of different cooling systems are studied. The cooling is improved in a radial machine by removing excessive material from rotor, adding copper heat paths in the rotor and by increasing the liquid cooling channel volume in the frame. Axial machine is utilized to study the cooling improvements with copper heat paths in stator and potting material. Measurements and results are presented for a permanent magnet 110 kW radial machine and for a permanent magnet 75 kW axial machine.