A New Method to Measure Planet Load Sharing and Sun Gear Radial Orbit of Planetary Gear Sets

Abstract

A new method of measuring planet load sharing of planetary gear sets is proposed in this paper. The method uses strain gauges mounted directly on the planet pins to measure continuously the loads carried by the planets assembled in a fixed carrier. Example 4-planet gear sets of different planet phasing conditions are procured and tested with a family of planet carriers having various levels and combinations of planet pinhole position errors to demonstrate the measurement method. As the radial floating capability of the central members is critical to planet-to-planet load sharing, a companion proximity-probe based measurement system is also implemented to measure the radial motions of the floating sun gear under various planet phasing and carrier pinhole error conditions. It is shown that both measurement methods are effective in characterizing the loads carried by planets.