Application Of Spherical Floating Sleeve Bearing In Cone Bit

The cone bit is one of the most important tools for rock breaking in drilling filed, its life influences the efficiency and the cost of drilling directly. It is well known that the failure of the cone bit bearing is one of the key factors to its life, and the main performance is the adhesive wear which the floating sleeve bearing can improve this phenomenon. However, the floating sleeve bearing axis would be deflected in the actual work, which produces the stress concentration on the ends of the floating sleeve and reduces the service life.In this paper, We design the outside surface of the floating sleeve in spherical, which can increase the contact superficial area, prolong the service life, and reduce the contact stress, thus lengthen the floating sleeve life. The main topics of this paper are as follows:1) The present paper designs a spherical floating sleeve bearing. Through the theoretical analysis and the finite element simulation analysis, we can discover that the contacting stress of spherical floating sleeve is less than the cylindrical floating one under the same conditions, which can effectively improve the stress concentration on the floating sleeve.2) The paper selects steel18CrNiMo7-6as the basic material, and then determine the process of thermal treatment and simulate the numerical modeling. After the simulation, we found the process improves the abrasive and impact resistance, which can fit the conditions of the cone bit in the actual work.3) In order to further improve friction performance of the spherical floating sleeve, the present paper applies TiN coating technology on the cone bit bearing system. We test a series of parameters of TiN and find it can reduce friction factors between friction pairs effectively, improve surface hardness and abrasive resistance, which states TiN coating technology can increase the service life of cone bit effectively.