Evaluation of sealing performance of bearing rings of roller-cone bits based on grid-shaped bionic non-smooth surface

Abstract

Based on the bionic non-smooth surface theory, this article carries out (1) design of the structure of bionic non-smooth sealing rings and toothed bars of the sealing structure and (2) finite element simulation study on the bionic non-smooth surface structure of roller-cone bits. The result shows that (1) when the parameter Y is equal to the rack angles, the maximum pressure of the Type B is smaller than that of the Type A, while the equivalent stress of the Type A is smaller than that of the Type B; when the parameter Y is equal to the tooth distribution, the maximum pressure and the equivalent stress of the rack angle of 30°are smaller than that of the rack angle of 20°; and when the rack angle is equal to the tooth distribution, the maximum contact pressure and the equivalent stress of the tooth decrease with the increase in the parameter Y.(2) Compared with the O-shaped sealing rings, the new tooth bars avoid the problem of over-large contact area. (3) The grid-shaped sealing structure can increase the wear resistance of rubber rings and delay their wear and aging, thus improving their service life.

Finite-element analysis and structure optimization of X-O composite seal of cone bit

“…The stress distribution of the optimized structure is basically the same as that of the original structure. (2) The change in stress value is very small. When the radial arc radii are 10 (original seal), 9, and 11 mm, the maximum stresses are 7.92, 7.93, and 7.87 MPa, respectively.…”

“…Figure 10 shows that (1) in the same way, the change in arc radius has little effect on the pressure distribution. (2) The change in stress value is very small. When the radial arc radii are 10 (original seal), 9, and 11 mm, the maximum pressures are 3.77, 3.78, and 3.83 MPa, respectively.…”

“…Economic losses caused by the seal failure are immeasurable worldwide, and seal failures cause many accidents. Practice shows that conventional bit seals do not meet requirements well, especially when the drilling speed is high and the seal life is very short, [1][2][3][4][5][6] because the working condition of the cone bit seal is very harsh, including high temperature, high abrasive medium, high load, and very small seal cavity. These working conditions and environment aggravate the failure of the seal, and also bring great difficulties and challenges to the research of the seal.…”

“…The root causes for this behavior are (1) the large contact area of the seal ring that leads to the large friction heat and premature seal failure. (2) The stress and pressure are large and uneven, which leads to wear.…”

Research on the mechanism of drag reduction and efficiency improvement of hydraulic retarders with bionic non-smooth surface spoilers

“…Liu, Zhu, Li, & Liang, 2019) and improvement of sealing performance (X. Chen, Zeng, & Chen, 2019;Zeng, Zhou, & Ma, 2018). The bionic structure has a great influence on the near-surface flow characteristics.…”