Research On Key Components And Dynamic Characteristics Of 12000N·m Fully Hydraulic Directional Drilling Rig In Coal Mine

Directional drilling rig is the key equipment for accurate drilling and efficient construction of underground coal mine.Its function and output performances directly affect the drilling efficiency.With the increase of mining depth and the length of working face,the existing directional drilling equipment cannot meet the construction needs of ultra-long drilling boreholes in coal seam and high-level long drilling boreholes in roof.There for,it is urgent to develop a high-power directional drilling rig with more powerful function and wider adaptability.The research is carried out on the bases of national science and technology major project subjected as “high-power directional drilling technology and equipment in medium-hard coal seam” Starting with the key problems to be solved urgently in the design of high-power directional drilling rig,such as high capacity output and compact layout,dynamic output performance of key components,real-time monitoring of directional drilling parameters and so on,the key components and dynamic characteristics of 12000N·m fully hydraulic directional drilling rig are comprehensively studied by using theoretical calculation,static design,dynamic simulation analysis and experimental verification methods.The optimization analysis and design of key components and hydraulic system circuit of drilling rig have been completed,and then the technology level of underground directional drilling is improved.It has a significant theoretical significance and application value for design of drilling equipment in coal mine roadway.The main research results are as follows:(1)Based on the analysis of construction technology requirements for ultra-long directional drilling and high-level roof drilling in medium-hard and complex rock and seam,the key structure and overall layout of drilling rig were studied.Combined with the analysis and design of the key function modules of the drilling rig,the design idea of the high-power directional drilling rig in coal mine was illuminated in detail,the design process and key problems to be solved were clarified,and a compact structure with large capacity was formed.(2)Combining with the need of precise control and safety protection for ultra-long borehole directional drilling,the rotary hydraulic circuit and feed hydraulic circuit of drilling rig were analyzed and designed emphatically.By carrying out the dynamic characteristic analysis and performance test of key circuit,the dynamicresponse characteristics of key circuit and key hydraulic components of hydraulic system were revealed,the scheme of hydraulic system was optimized,and a new hydraulic system of directional drilling rig based on double-speed control and multi-logic function protection was developed.(3)The interaction mechanism and typical load characteristics of external dynamic load of drilling rig gyrator were analyzed.Combined with the typical working conditions with impact and torsion characteristics of the gyrator,based on the influence of axial support stiffness and damping of gear transmission system,the dynamics mathematical modeling of circumferential rotation and axial vibration of the slewing gear transmission system was established.With the method of digital simulation analysis,the dynamic characteristics of rotary gear transmission system under extreme load and external excitation were revealed,which provides an effective solution for material and structure optimization of key parts of the drilling rig.(4)The thermal-fluid coupling characteristics of the friction pairs of hydraulic braking system were studied,and the effective temperature load of the system was extracted as well.Aiming at the contact nonlinearity of friction pair in braking system,a digital simulation analysis model based on the interaction between temperature field and stress field was established.The changing rules of thermal deformation and thermal stress of the braking system as well as the influence mechanism of braking characteristics with oil pressure and contact radius were revealed,which provides a feasible solution for optimizing the structure and material of friction pairs.(5)Based on solving the two key technologies of realizing the principle of drilling parameter monitoring and the integrated design of measurement while drilling system,a drilling parameter monitoring system for high-power directional drilling rig in underground coal mine was developed,which meet the need of real-time monitoring of drilling parameters and precise control of drilling process for ultra-long distance directional drilling in underground coal mine.In addition,the leap-forward development of drilling parameter monitoring of directional drilling rig in coal mine from scratch has been realized.(6)Based on the developed high-power directional drilling rig,the indoor test was carried out.Combining with the conditions of medium-hard rock and coal seam,the field industrial tests were carried out,including two typical construction sites of directional drilling in coal seam and high-level directional drilling in roof.The performances of the drilling rig are verified to meet the design requirements and thecorrectness of the research results of key structure and dynamic characteristics of12000N·m fully hydraulic directional drilling rig in coal mine is verified.