Share Loads in a Star Type Epicyclic Gear Train : New Calculation and Measurement Method

New methods for both calculation and measurement of share loads in a star-type epicyclic gear train are proposed. The gear system is modelled as pulleys and connecting springs, and a new set of equations concerning transmission forces between engaging teeth and gear rotational angles is derived, considering the equilibrium of forces and moments. The equations are theoretically solved for some simple cases, and influences of gear position errors and various spring stiffnesses on the share loads are investigated. Further more, a new method for measuring both magnitude and position of a load acting on a planet shaft is proposed. Here, two strain gauges are used to detect bending strains at two different axial positions in a plane of planet shaft.