Design Of Cutting Structure Of Rotary Cutting PDC Bit

In view of the fact that the existing PDC composite sheets can’t be effectively eaten into the hard formation,and the wear is large in the abrasive formation,and the damage is easy to occur,a cutting structure of a new type of drill is proposed,which is formed by using a rotary cutter with a tapered tooth.The mesh cutting marks at the bottom of the well enhance the rock breaking effect.In this paper,the effects of cutting angle,cutting depth and cutting speed on the cutting force are studied by experiments and finite element simulation.The main results are as follows:(1)at the same cutting depth and cutting speed,when the cutting angle is 20°,the cutting force is the smallest and the cutting specific work is minimum;(2)when the cutting angle and the cutting speed are the same,the cutting force varies with the cutting depth.Gradually become larger,the cutting specific work becomes smaller with the cutting depth;(3)under the same cutting depth and cutting angle,the cutting force increases with the cutting speed,and the cutting specific work changes regularly;(4)cutting force and cutting ratio work The increase of the tooth pitch gradually increases;(5)under the same cutting factor,the rock-breaking effect of the tapered tooth is better.Based on the cutting test,combined with the design idea of Kymera combined drill bit and scraped diamond bit,the overall structure of the rotary cutting PDC bit is proposed.Based on the existing PDC bit design theory and method,the cross-sectional shape of the PDC blade and the teeth of the PDC are calculated.The spatial position parameters of the rotary cutting wheel in the PDC bit and the rule of the cone-shaped tooth of the rotary cutter are calculated.The structure of the integral rotary cut PDC bit is obtained.