MODEL OF RELIABILITY OF PLANETARY GEARS

A model of the reliability of planetary gears is described, in which the epicycle of a stationary sun gear is connected to the input shaft and the carrier is connected to the output shaft. The input and output shafts are coaxial, and it is assumed that these shafts are loaded only with torques be3 and bending forces. Axial and lateral forces are not considered. Gears of this type are usually used in helicopter main rotor drive systems, as well as in other cases where it is necessary to provide a large transmission ratio. The reliability model is based on a Weibull distribution of the reliability of individual gear elements. The load-bearing capacity of a gear under dynamic loading conditions is the value of torque on the input shaft that can be used to load the gear with a design life of 106 revolutions of the sun gear. Load and durability are related by a power law. The exponential curve in coordinates load - durability and load-bearing capacity under dynamic loading conditions are determined as a function of the load-bearing abilities of the transmission parts.