Numerical Analysis On Rock Breaking Effect With Different Inserted Tooth Rolling Cutters

The construction method of raise boring machine has been widely used in the construction of coal mine,hydropower,transportation and other industries since 1970 s.As a key and easy-wear part of raise boring machine,the rock breaking effect of inserted tooth rolling cutters directly affects the drilling efficiency and excavation cost.So as to research its performance and reasonable arrangement are particularly important.In this paper,using finite element software to simulate the processes of 4(spherical tooth,conical tooth,picking tooth 1and 2)single teeth pressing into the rock and inserted tooth rolling cutters breaking the rock.The main research contents and conclusions are as follows:1.The process of single tooth pressing into the rock was simulated.The rock stress and the influence of different mesh size on the simulation results were analyzed.And the influences of different teeth at different pressures on rock breaking effect were studied.The numerical simulation results showed that(1)The penetration depth and the volume of rock breaking increases nonlinearly with the increase of pressure.(2)The rock breaking effect of picking tooth is best,conical tooth follows by picking tooth,and spherical tooth's is worst.2.The process of inserted tooth rolling cutters breaking the rock was simulated.The cutter forces,rock stress and the influence of rock model size on the simulation results were analyzed.And the influences of rock compressive strength,cutting depth,tooth profile of the cone,cutter tooth clearance,and cutting tooth row clearance on rock breaking effect were studied.The results showed that(1)The higher compressive strength of the rock is,the higher specific energy and the more difficulties to break the rock become.(2)With the increase of cutting depth,the specific energy decreases first and then increases.There is a critical cut depth,at this time the specific energy is smallest.(3)In same cutting depth,the rock breaking effect of the conical inserted rolling cutters is better than the spherical inserted rolling cutters'.(4)The increase of the radius of conical top(R)will result in an increase of the cutting forces and a reduction of the specific energy of rock breaking.And the angle of conical top(?)increases will lead to increase of cutting forces.(5)When the cutter tooth clearance is large,the specific energy variation of the rock breaking is small.Generally the specific energy of the rock breaking is decreased with the cutter tooth clearance reduced.(6)The specific energy of rock breaking decrease at first and then increased with the cutter tooth row clearance increased.