EBZ160 Boom-type Roadheader Hydraulic Walking Mechanism Characteristics Research

Coal resour is abundant in our country,and a large number of coal mines are underground.Because of the complexity of underground coal seam distribution,the coal mining geographical environment is below average.In addition to the individual areas of coal mining,most coal mining areas have poor mining conditions.Cantilever machine as the mechanized comprehensive mining key equipment often encounteres slope conditions in the process of walking.The skidding even backward phenomenon occur between the crawler and the baseboard due to lack of gravity and bottom adhesion,which makes the machine in the underground roadway be difficult to reach the design requirement of gradeability.The hoisting rope usually is adpoted to assist in drawing in the process of walking on the slopes,which can lead to security problems in production.Aiming at this problem mentioned above and considering the machine liquid integration characteristic of traveling mechanism of cantilever machine,the propel machinery,hydraulic drive and roadway floor were incorporated into a unified system.Based on multibody dynamics theory,the hydraulic simulation technology and the ground vehicle mechanics theory,the integrated system was comprehensively studied.Firstly,based on the multibody dynamics theory,the modeling of the cantilever machine crawler walking mechanism was established by using Recurdyn and Solidworks software According to the working principle of the hydraulic circuit,the simulation model of the hydraulic circuit was built by using AMESim software.By using machine liquid co-simulation interface which is provided by Recurdyn/Hydraulic,the machine liquid integration model of travel mechanism was established.According to the above analysis,the walking and climbing ability of the excavator under different baseboard conditions was studied,and the main factors affecting the machine climing ability were found out,then,the parameters of crawler were optimized.The results showed that the track shoe and baseboard related parameters were key factors which affect walking performance.In this thesis,the adhesion was improved by changing track shoe grounded length,track shoe width,track grouser height and number of track grouser on ground,which improved the climbing performance of walking mechanism.On the basis of the vehicle dynamics theory,the influnce of lean clay and heavy clay on the gradeability of walking mechanisms was analyzied.Based on the soil related parameters,both terrain stiffness(k_c)and terrain stiffness(k_phi)of lean clay are higher than those for heavy clay.The speed fluctuation of cantilever machine is small,but the slippage is larger when it walk on heavy clay.The analysis shows that track shoe conditions have great influence on the gradeability of walking mechanisms,and the better soil properties result in the greater adhesion and the more powerful gradeability.