Design and Analysis of a Triple-Rotor Integrated with a Gearbox for a High Power Density Motor

Raytheon Technologies Research Center (RTRC) is currently developing a high power-density motor (12kW/kg) under the ARPA-E ASCEND program. In this paper, we present innovative and unique aspects of a "triple rotor" tightly coupled with a planetary gearbox (GB). The rotor design is unique and makes full use of the electromagnetic potential of permanent magnets (PM). The high speed of the motor is reduced to the target application speed by a planetary GB embedded within the profile of the "inner rotor". The design is guided by the stress and rotordynamics analysis and the GB modeling. Also presented is the risk reduction hardware built to validate the manufacturing process. The program is continuing and in the next 2 years, the RTRC team, supported by Collins Aerospace, will build and test a full 250kW demo. The test results will be presented in a paper on the demonstration.