Investigation of torque variation under tandem drive during acceleration and deceleration in three-shaft differential planetary gear mechanism

Planetary gear mechanisms are used in numerous machines and are among the most crucial mechanisms in hybrid and electric vehicles. In recent years, planetary gears have been used in automatic transmissions to reduce fuel consumption. The tooth-profile meshing ratio and tooth-surface roughness affect the transmission efficiency. Noncontact magnetic gears increase efficiency by eliminating lubrication, vibration, and noise, as well as enhance slipping to protect the equipment during overload. In this study, torque measurements were performed under two driving conditions during transient acceleration and deceleration in the tandem drive of a 2 K-H-type differential planetary gearbox with two inputs and one output. The torque fluctuation was calculated from the data obtained. A short-time Fourier transform was performed using the calculated torque variation, and a spectrogram was created. Frequency analysis was performed to compare the spectrogram with the torque fluctuation.