Tri-cone bit for high RPM drilling applications
First Claim
1. A tri-cone bit for high RPM drilling applications comprising three head sections and three cones each of which is attached at a lower end of the corresponding head section, wherein upper parts of the three head sections are joined together to form a bit body, on which nozzle sockets are provided, and nozzles are installed in bores of the nozzle sockets, being characterized in that a bearing between the cones and the head sections is a composite roller-journal bearing which is formed by rollers and arc-shaped slides arranged in an alternating way, and a seal means for the bearing is of metal face type, wherein a radial thickness of the slides is larger than a diameter of the rollers by 0.03 to 2.00 mm;
- wherein oil grooves are provided at both internal and external arc surfaces of the slide, said oil grooves extend from one circumferential end side of the slide to the other circumferential end side of the slide, and the oil grooves at the internal arc surface of the slide are parallel with each other, and the oil grooves at the external arc surface of the slide are parallel with each other, andwherein the oil grooves on internal arc surface of the slide are positioned and oriented to form an interlaced pattern with the oil grooves on the external arc surface of the slide;
wherein cutting elements arranged on the cones include primary cutting elements, which are convex crested inserts whose crest is formed by a convex curve surface, and heel row cutting elements, which are wedge or spherical inserts.
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Accused Products
Abstract
This invention relates to a tri-cone bit for high RPM drilling applications, which comprises three head sections and three cones. Cutting elements are arranged on each cone. Upper parts of the three head sections are joined together to form a bit body, on which nozzle sockets are provided, and nozzles are installed in bores of the nozzle sockets. A bearing between the cones and the head sections is a composite roller-journal bearing which is formed by rollers and arc-shaped slides arranged in an alternating way, and a seal means for the bearing is of metal face type. The composite roller-journal bearing of the invention can withstand high RPM and high load, and also has a higher resistance to impact, thereby ensuring longer working life of the bearing under high RPM and medium-high WOB. The six-point gage protection structure enhances stability of the bit and reduces cutting element breakage caused by bit vibration. The above tri-cone bit is suitable for high RPM and medium-high WOB drilling applications and features high drilling efficiency and long service life.
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Citations
11 Claims
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1. A tri-cone bit for high RPM drilling applications comprising three head sections and three cones each of which is attached at a lower end of the corresponding head section, wherein upper parts of the three head sections are joined together to form a bit body, on which nozzle sockets are provided, and nozzles are installed in bores of the nozzle sockets, being characterized in that a bearing between the cones and the head sections is a composite roller-journal bearing which is formed by rollers and arc-shaped slides arranged in an alternating way, and a seal means for the bearing is of metal face type, wherein a radial thickness of the slides is larger than a diameter of the rollers by 0.03 to 2.00 mm;
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wherein oil grooves are provided at both internal and external arc surfaces of the slide, said oil grooves extend from one circumferential end side of the slide to the other circumferential end side of the slide, and the oil grooves at the internal arc surface of the slide are parallel with each other, and the oil grooves at the external arc surface of the slide are parallel with each other, and wherein the oil grooves on internal arc surface of the slide are positioned and oriented to form an interlaced pattern with the oil grooves on the external arc surface of the slide; wherein cutting elements arranged on the cones include primary cutting elements, which are convex crested inserts whose crest is formed by a convex curve surface, and heel row cutting elements, which are wedge or spherical inserts. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification