Roller bit with roller pull-off prevention alarm apparatus

Abstract

The present invention relates to roller cutter bit and features an early warning device set on the toothed claw shaft neck for prevent pineapple from falling off. The device consists of circumferential rollaway nest, roller inside the nest and locking wedge. After the bearing pair is abrased to preset dangerous limit, the pineapple is clamped in the shaft neck, the working torque and speed of the roller cutter bit will change abruptly, so that the bit to be failed may be replaced timely. The present invention can prevent pineapple from falling off and lower well drilling cost, and the locking wedge in the device has great bearing capacity so that the present invention can meet the requirement of different work conditions, especially great drilling pressure.

Description

Technical field: [0001] The invention relates to a roller cone bit and a roller bit used in various drilling projects (oil and gas drilling, mining engineering, foundation engineering construction, etc.). Background technique: [0002] The roller cone bit used in drilling engineering is usually made up of a drill bit body and a cone, and the cone is installed on the claw journal of the drill body. When the drill bit is working, the roller not only revolves around the axis of the drill bit together with the claw journal, but also rotates around the claw journal. Under this kind of compound motion, the teeth on the cones will impact, press in and scrape the rocks at the bottom of the well. In order to accurately install the cone on the claw journal and prevent the cone from falling off the claw journal, a set of steel balls or circlips are usually used as the positioning and anti-off device for the cone on the claw journal (Also known as locking device). The steel ball lock...

AI Technical Summary

Problems solved by technology

The disadvantage is that when the wear amount of the gear tooth claw bearing pair is too large, the steel ball will come out from the gap between the inner hole of the cone tooth and the tooth claw journal, which has been worn out, which will cause the tooth tooth to fall off.

The circlip locking method is a technology used by Baker Hughes Company of the United States (US Patent No. 4491428). The problem with this technology is that when the thrust surface of the claw bearing is excessively worn, the bearing capacity of the bearing will decrease, and the circlip groove may undergo plastic deformation. Deformation, bite the circlip to death, making it lose its elasticity, resulting in the failure of the anti-off function

The problem with this technology is that because the contact between the locking steel ball and the chute and the inner hole of the cone is point contact, the steel ball may not be able to completely lock the cone when working under the condition of large WOB, resulting in The early warning function cannot be reliably implemented

Practice has proved that the above-mentioned device has good self-starting performance, and can generally play an effective early warning role. However, since the contact between the rolling elements and the raceway and the inner hole of the cone is line contact or point contact, the bearing capacity of the rolling elements Low, cannot fully meet the requirements of stuck cones under the condition of large WOB

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