【摘 要】
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How to further improve the working performance of rock bit journal bearings (RBJB) and prolong its service life under complicated conditions of low speed, heavy load, high temperature and high pressur
【机 构】
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School of Mechatronic Engineering, Southwest Petroleum University, Chengdu, China
【出 处】
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第十一届全国表面工程大会暨第八届全国青年表面工程学术会议
论文部分内容阅读
How to further improve the working performance of rock bit journal bearings (RBJB) and prolong its service life under complicated conditions of low speed, heavy load, high temperature and high pressure is one of the urgent problems in the field of drilling engineering to improve drilling efficiency and reduce drilling cost. It is known that reasonable surface texture parameters is an effective means to enhance the lubrication and antifriction performance of sliding surface under the harsh lubrication conditions. Combined with the geometric similarity and Sommerfeld similarity, this paper designs a scaling model experiment of RBJB, which can simulate the working conditions of RBJB, then, carries out the experimental study by an improved journal bearings test bench, which can discuss the effects of nanosecond laser surface texture shape, geometric parameters and angle factors on the tribological properties of RBJB. The experimental results show that the designed circular, elliptical and triangular textures with area ratio in the ranges between 5% and 30% can effectively improve the lubrication and antifriction performance of RBJB, when the texture depth is fixed to 40μm. Reasonable texture parameters combination can make the antifriction efficiency of RBJB improve more than 40%. And for the elliptical texture, when the long axis is perpendicular to the moving direction, lubricating property of RBJB is best, and parallel to the moving direction, the lubrication performance is worst. For the designed chevron groove, when the angle of chevron groove is 90°, the lubrication and antifriction performance is excellent, which can make the antifriction performance of RBJB improve more than 41.8%. Therefore, the findings confirmed that reasonable surface texture parameters arranged on journal surface can effectively enhance the working performance of RBJB and prolong its service life. Meanwhile this study also provides experimental support for the optimal design of textured RBJB.
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