Research On Self-compensating Sealing Ring For Full Hydraulic Drilling Rig Chuck

Hydraulic chuck is one of the most important parts in hydraulic tunnel drilling rig, it mostly uses the rubber drum type and hydraulic work mode. Hydraulic chuck is connected to the spindle, with which realize high speed, feed and pulling function by clamping drill pipe in work to output the torque and drilling pressure. In order to provide a continuous pressure oil to rotating chuck, it always uses mechanical clearance seal device as chuck oil supply device. With the improvement of hydraulic tunnel drilling rig operational capability, enlargement of drill pipe diameter, oil sleeve sealing clearance increases because of hydraulic oil temperature and pressure after long hours of work, the leakage rate of sealing ring gets bigger and bigger, which decreases the hydraulic transmission efficiency, directly affects the drilling performance. It is necessary to research the sealing ring and make creation design to meet the oil supply device sealing requirements of hydraulic chuck.This article started from the principle of sealing ring, analyzed structure characteristics and failure reason of the sealing ring, found that the main cause of the increase of seal leakage rate is the increase of seal clearance which influenced by hydraulic oil temperature and pressure. By studying the relationships between ordinary seal clearance and structural parameters thickness ratio, length, oil hole diameter, and the working parameters pressure, temperature, proposed the design ideas of a new type sealing device controlling the seal clearance with pressure compensation method under the effect of temperature field and pressure field.Then invented the self-compensating sealing ring of hydraulic chuck, calculated its key structure parameters the thickness of inner sleeve and o-rings location. Through finite element analysis method studied the relationships between seal clearances of both sealing rings with the structure parameters and working parameters, optimized the structure parameters of self-compensating sealing ring.Hydraulic chuck oil supply device performance testing system is developed to studying the sealing performance of the self-compensating sealing ring with orthogonal experiment method. Through significance analysis studied the primary and secondary relation of its working parameters, and compared with ordinary sealing ring performance test results.The results show that the self-compensating sealing ring has the advantages of stabilized leakage under pressure and uncomplicated processing and assembling, reach the design target, which can provide the reference for the design of Full hydraulic drilling rig chuck oil supply device.