The interaction between power transmission and moving gear teeth is a typical complex system with high load, coexistence of multiple scientific phenomena and interaction and overlap of solid-liquid interface. The degradation of bearing characteristics of helical gear damage accumulation is the evolution process of material fatigue under cyclic alternating load of helical gear meshing contact. The failure mechanism based on helical gear meshing lubrication contact characteristics is the key problem of helical gear anti fatigue design. The fatigue pitting corrosion of helical gears is a random process. The stress / strain variation process of meshing is an effective method to predict the fatigue of helical gears. The main conclusions of this paper are as follows:
- Considering the structural characteristics, dynamic characteristics and lubrication behavior of helical gear, a helical gear pitting life prediction model based on multi axis fatigue criterion is established. The effectiveness and accuracy of the model are verified by comparing the test results of helical gear pitting fatigue life.
- The moving average filtering method is used to simulate the change of the initial surface morphology caused by the running in stage. While maintaining the main characteristics of the original morphology, the maximum value of the original test surface roughness peak is reduced by about 20% ~ 50%, which is in line with the law of the influence of running in on the surface morphology.
- The friction coefficient of each meshing point in the transmission process depends on the contact parameters, morphological characteristics, slip roll ratio, etc. there is a large friction coefficient at the initial meshing and sudden load change. Because the helical gear pair does not slide relatively at the node, the helical gear tooth surface friction does not occur, but pitting corrosion is most likely to occur near the node under the action of cyclic stress / strain.
- The key to the fatigue life prediction of helical gear tooth surface is to determine the minimum life of surface initiation crack. The application of elastic field distribution in conventional coordinate system to the fatigue life evaluation of helical gear has limitations. In this paper, the analytical method of coordinate movement and coordinate transformation is proposed to calculate the stress / strain distribution at any angle in the fixed area and evaluate the fatigue life of crack initiation at any angle in the fatigue area prone to pitting corrosion The contact failure of spline and other transmission parts provides modeling methods and ideas.