The Improvement of Motor Cooling Through Stator Profile Optimization using CFD Analysis in Hermetic Scroll Compressors

Hermetic compressor motor design face the challenge today that reducing the motor size for cost reason. This causes a higher motor power density and in turns a higher motor temperature. With the help of CFD computation tool, we investigated two ways to improve the motor cooling and bring the motor temperature down. One way is to put rotor ventilation channels to increase the flow in lower pressure side, so that the total percentage of suction gas to cool the motor increased. The other way is to optimize the stator cuts depending on flow rate in each stator cut. By combining these two improvement together, total motor temperature, particularly in stator end wing and rotor lower end ring, was reduced dramatically. Both motor and compressor prototype were tested and results given.