Experimental Study on the Influence of Load-Equalizing Devices on Planet Loads in a Planetary Gear Set

The uneven load distribution between the planets in planetary gear trains has found multiple solutions including high manufacturing precision, targeted compliance or kinematic mobility of the components of the gear train. This paper presents an experimental investigation of the influence of three different load-equalizing devices on planetary gears’ pin loads in a planetary gear train with three planets. Two of the equalizing devices are designed to increase the radial resilience of the planets, and the third one increases the radial and tangential resilience of the sun gear. Using fast Fourier transform (FFT), the pins’ bending stresses are presented as a function of time and the gear wheels’ rotational frequency. For the experiments, a mechanical closed-loop test rig, designed at the Technical University of Sofia, was used.