Dynamic Characteristics Research On Gear Reducer Of The Hoist Machinery Of Electric Mining Shovel

The gear reducer of the hoist mechanism of electric mining shovel is bulky, thestructure is complex, and the working condition is poor. In order to keep the operationof the excavator safe and reliable, it is necessary to research on the dynamics charac-teristics of the gear reducer. The gearbox is widely used in industrial development asthe essential component to transmitting motion and power in machinery. The gear boxof the excavator gear reducer is highly developed，as the rapid development of mod-ern industrial technology. The power of transferred by transmission system increaseswith the gear speed ’s accelerate. When the external excitation frequency of the re-ducer suffered coincide or close to the natural frequency of the gear box, there will bea resonance phenomenon and that will affect the stability and security of the reducer.It can also lead to damage of other parts of in the reducer. So it is particularly impor-tant to research the dynamics of the gearbox. This paper takes the gearbox of theelectric mining shovel’s hoist mechanism as the research object, and do the dynamicsresearch it. Which provide the basis for system analysis and design of gearbox of theelectric mining shovel’s hoist mechanism. This paper includes the following parts.1. Introduced the driving characteristics of the secondary symmetric straight gear.The three-dimensional modeling of the gear reducer was set up and assembled withthe UGNX7.5software. Finish the calculation of its transmission ratio, meshing vi-bration frequency and rotary vibration frequency. The gear tooth deformation wasobtained the variation of the tooth’s meshing stiffness from calculation is used inIshikawa method with MATLAB. The ISO formula was used to calculate the dynamicload theoretically, and then the gear transmission dynamic load curve was obtained inone cycle, find the maximum contact dynamic of the gear tooth was found, and laidthe basis for the performance of the gear reducer.2. The calculation accuracy and efficiency was take into account, and thethree-dimensional model of the gearbox was reasonable simplified. We takepre-treatment operation on gearbox using the pre-processing software HyperMesh.Do the calculation on the reaction forces of each bearing according to the mechanics, and then make them correctly applied. the gearbox was taken the static analysis basedon the structure statics, from the results we can see that the strength and stiffness ofthe gearbox meet the requirements, and this result lay the foundation for the dynamicsanalysis below.3. On the basis of static analysis, we take the dynamic analysis on gearbox. Wetake the modal analysis on gearbox based on the theory of modal analysis, to get thenatural frequencies and mode shapes. Compared the external excitation frequency ofgearbox suffered with the natural frequency on it, and described each vibration type,to find large deformation trend node on gearbox, then make the prepare for the gear-box’s harmonic response analysis4. The harmonic response analysis was taken on gearbox based on the theory ofharmonic analysis. Applied periodic excitation force produced by the gear meshing tothe actual location on gearbox. Do the analysis on larger node of the deformationtrends elected by the modal analysis to obtain the frequency displacement curves, andto verify if the gearbox will have resonance phenomenon under the effect of periodicexcitation force, and finally to verify the reasonableness of the gearbox’s design.This paper do the research on the dynamic characteristics of gearbox of hoistmechanism of the electric mining shovel, comprehensive using the technology ofmodeling by modeling software, calculating by programming software and simulationby dynamics simulation software were used. Which is reference for the structure de-sign and improvement of gearbox and improving vibration capability.