Composite thrust bearing set for novel screw drill

Abstract

The invention provides a thrust bearing set of a transmission shaft of a screw drill used for drilling of petroleum and natural gas. The thrust bearing set is composed of hollow cylindrical roller thrust bearings and four-point thrust ball bearings, or tapered roller thrust bearings and the four-point thrust ball bearings, or the hollow cylindrical roller thrust bearings, the tapered roller thrust bearings and the four-point thrust ball bearings, wherein the cylindrical rollers and the tapered rollers are all hollow, both ends of the hollow cylindrical rollers and the hollow tapered rollers all employ fillet structures, each thrust bearing further comprises corresponding inner and outer rings of the bearings, and inner and outer spacing sleeves, and transition portions of the inner and outer rings of the bearings all employ fillet structures. The thrust bearing set uses a composite structure to increase effective contacting area of the rolling elements and the inner and outer rings of the bearings, thereby enhancing bearing capability of the screw drill, improving forces on each parts; and employs a hollow structure to improve a heat radiation capability and possess vibration absorption and reduction functions, thereby effectively prolonging service life of the thrust bearings, and increasing life periods of the whole screw drill.

Description

technical field [0001] The invention relates to a thrust bearing group for screw drilling tools used for oil and natural gas drilling or workover operations, in particular to a thrust bearing set consisting of four-point thrust ball bearings, hollow cylindrical roller thrust bearings and hollow tapered roller thrust bearings. Composite thrust bearing sets combined with each other. Background technique [0002] At present, the screw drilling tool has become the most widely used downhole power tool, and has been widely used in oil drilling and workover. It is mainly composed of bypass valve, motor assembly, cardan shaft assembly and transmission shaft assembly. Among them, the transmission shaft assembly is its weakest link, which is mainly composed of housing, transmission shaft, thrust bearing group, radial bearing and other auxiliary parts. The thrust bearing is one of its most vulnerable parts, mainly because when the drilling tool works in the harsh environment at the bo...

AI Technical Summary

Problems solved by technology

The traditional screw drilling tool thrust bearing set adopts four-point contact ball bearings. The contact area between the ball and the inner and outer rings of the bearing is small, the contact pressure is large, and the friction and wear are serious. Moreover, the force on the ball in the working state is relatively complicated, not only bearing the axial thrust , but also bear the excess shear force derived from the axial thrust, which may easily cause premature rupture of the ball

During the drilling process, the jumping of the drill bit causes the WOB to be very unstable throughout the drilling process, always moving up and down, and the instantaneous WOB often reaches a high level, and the resulting impact force will be fully applied to the thrust bearing. If the thrust bearing The bearing capacity is not strong enough, it is easy to produce crack aging

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