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Mining excavator crawler running gear dynamics

Author: HuYingHua
Tutor: ZhaoKeLi
School: Jilin University
Course: Mechanical Design and Theory
Keywords: Crawler excavators Travel agencies Dynamics Simulation
CLC: TD422.2
Type: Master's thesis
Year: 2011
Downloads: 373
Quote: 4
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Abstract

Mining excavator in open pit mining is mainly used for loading and digging operations, is mined in open pit mining equipment machinery indispensable one. With domestic and expanding the scale of mining open pit mine, with the level of technology and equipment, mining technology level, in order to further improve the company's own labor productivity and economic efficiency, reduce the cost of mining, open-pit mines are used to large excavators development has been the general trend. Large mining excavator traveling a short distance, speed is low, the work produced during the impact load is big and bad workplace, these characteristics determine its walking mechanism should be able to withstand greater impact loads, have high stability by sex and mobility. Crawler excavators due to meet the requirements of mine, and is widely used in mining excavator. Due to cost and other factors, the current domestic crawler for existing large mining excavators load spectrum experiments conducted very limited data to draw on relatively small. Based on the above, the use of virtual prototyping techniques crawler computer simulation studies, walking mechanism for understanding the dynamic performance relatively easy to implement. In this paper, theoretical analysis and computer simulation analysis method of combining, for large mining excavator crawler traveling mechanism analysis research will focus on analyzing the running gear vertical load supporting wheels suffered the dynamic characteristics. First, the classic soil - vehicle system mechanics theory as the basis to establish the mechanical model supporting wheels on roller suffered theoretical analysis of vertical load conditions, and then use dynamic simulation software ADAMS simulation model for the walking mechanism for dynamics simulation analysis, the condition of the four typical vertical load supporting wheels the size of the overall track meet lots of pressure distribution and characteristics of the vertical load supporting wheels frequency domain characteristics were analyzed. Theoretical analysis, according to the supporting wheels of the force in the form, the establishment of rollers and track and soil interaction mechanics model focuses on the supporting wheel vertical load size. Unknowns involved in the model are: supporting wheels of approach and departure angles, as well as supporting wheels approach and departure angles at the track tension. The final application of MATLAB software for solving the various rollers static vertical load theoretical value. The calculated results show that the track ground pressure distribution received lots of features: wheel end to end from the guide wheel, supporting wheels in turn increases the force, showing approximate triangular distribution, where the latter supporting wheels vertical load size before a heavy round of its more than twice. Virtual prototype simulation part, the prototype model is the key. This is one of the most critical is the contact force parameter selection and add the contact force is affecting the accuracy of the simulation results of an important part. This part of the contact between the contact parameters, according to the contact member and the structural characteristics of the material to be finalized. In order to more effectively reflect the dynamic nature of crawler, crawler plate hinge of friction and supporting wheels, steering wheel and the friction wheel journal has also been considered in the model. This paper focused on four typical simulation working condition studied, namely uniform straight forward, uniform linear climbing, steering and unilateral drive situ uniform uniform steering. The simulation analysis, the conditions supporting wheels of each vertical load size, take lots of track characteristics and the overall pressure distribution spectrum. This paper focuses on the conditions of the four selected features rollers vertical load curve analysis, and then gives nine unilateral or bilateral All supporting wheels vertical load supporting wheels the size of the load distribution curve plotted , and finally supporting wheels feature a vertical load curve of frequency domain analysis. Simulation results verify the excavator in the same job conditions and different operating conditions, each supporting wheels to withstand a vertical load size, and then track the overall pressure distribution characteristics are lots of differences. Content of this study for large mining excavators crawler machine performance studies, and structural optimization and improvement has some theoretical reference value.

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CLC: > Industrial Technology > Mining Engineering > Mining machinery > Mining machinery > Open-pit mining machinery > Excavator
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