Jixie chuandong (Jun 2023)
Research on the Time-varying Meshing Stiffness Algorithm of Spur Gears with Large Tooth Number Cracks
Abstract
For spur gears with more than 41 teeth, based on the geometry of cutting teeth and the principle of gear meshing, the difference between the starting point of the involute profile and the intersection of the involute and the base circle is clarified, and the transition curve parameter equation is introduced to calculate the time-varying meshing stiffness based on the energy method. The formula has been improved, and the faulty gear tooth models with different crack degrees are comprehensively established. On this basis, the oblique line is used as the effective tooth thickness reduction limit line, which makes the crack tooth model stricter and the considerations more comprehensive. With reference to the calculation results of the finite element method, the effects of model correction, crack extent, and the specific form of the effective tooth thickness reduction limit line on the time-varying meshing stiffness are discussed respectively. The calculation results show that the uncorrected gear tooth model will lead to a small calculation result of the time-varying meshing stiffness of gears with large numbers of teeth; the reduction degree of meshing stiffness increases with the increase of the crack level. According to the degree of cracks, the modeling suggestion for the effective tooth thickness reduction limit line is given: when the crack level is low, the effective tooth thickness reduction limit line should be a straight line; when the crack level is high, using a straight line will cause significant errors. Using a diagonal line is not only convenient for calculation, but also can meet the requirements of calculation accuracy and has stronger practicability.
