Study On The Contact Analysis Between Transmission Gear And Pin Rail For Coal Shearers

Mechanism of gear and pin rail is mainly applied in the coal mining machine. With the enhancement for the power of coal mining machine, there appears in a series of problems, such as the crack and fracture of gears, and the wear of pin rails, etc. Fault reasons are analyzed using the finite element analysis method in this paper. The optimization results of gear tooth profiles are obtained after the line-arc and arc optimizations, respectively. In the condition of high-speed and heavy-load, the variation principles of the tooth contact and the different contact zones of engagement process are analyzed for the two optimum designs.In order to analyze the variation situation of contact spot, normal force, and Mises stress during the mechanism operation, a calculation process goes through:(1) a target tooth is selected;(2) the target tooth rotates48°in the process of the contact between the target tooth end and the pin rail. In this process, each angle of6°is used to determine a position. Thus,9positions are obtained. Among them,6key positions are analyzed.Calculation results state that changing the friction coefficient had little influence on analysis results. At the same time, the maximum stress is located at the edge of the gear teeth in each position. Under the repeatedly strong stress, the cracks will be generated at the edge of the gear. The growing cracks result in the teeth fracture. Additionally, the larger Mises stress of rails are produced. The abrasion of pin rail would be accelerated after the long-period effect of this type of stress.The model is simplified with the suitable boundary condition when performing the stress analysis after the gear optimization. The force analysis is performed for the tooth engagement at a certain position. The load condition is obtained for the different gear profiles and the optimum design is created.Loading is an important step in analyzing the contact stress of gear. The magnitude and direction of loading will directly influence the results of finite element analysis. This dissertation chose a suitable loading method according to the actual working conditions of the gear in order to ensure the rationality and accuracy of analysis results. The value of tooth contact normal force and the distribution of Mises stress and its number are obtained. The result provides an effective analysis method for research of optimum design of gear. According to this optimization design, the distribution and values of normal contact force and Mises stress for different tooth profiles are obtained. The comparison among the analysis results are carried out, which provides a new study method for the structure optimization of transmission gears.