SU1740609A1 - Drilling bit - Google Patents

Abstract

The invention relates to drill bits. The goal is to increase the durability of the bit by increasing the stability of the supports by implementing the phenomenon of selective transfer. The chisel contains feet 1 with trunnions / C / 2, the ends of which are made corrugated, the surfaces 4 of the bearings 5 are made with a layer of copper or copper alloy. At C2, the mounts / W / 6 are mounted by means of supports, in the bottom part 7 of which spring-loaded plates / P / 8 are installed. Installed П 8. With the ability to move them along the axes Ш 6 and contact with the ends 3 Ц 2. On the surfaces 9 П 8, contacting with the end 3 Ц 2. Radial grooves are made. P 8 are made of copper or copper alloy, and surfaces 4 are wooded with a layer of copper or copper alloy. The chisel contains a lubricator 11 and a sealing unit 12 located between W 6 and C 2. When the cutting pin P 8 rotates, the grooved end 3 is abraded. The products are worn away with a lubricant through the grooves to the surfaces and the copper layer is constantly supported on them. This makes it possible to reduce the coefficient of friction between the rubbing surfaces and increase the stability of the supports. 2 Il.

Description

The invention relates to a rock drilling tool for drilling wells, namely to bits having roller cones as working members.

The purpose of the invention is to increase the durability of the bit by increasing the stability of the supports due to the implementation of the phenomenon of selective transfer.

FIG. 1 shows a bit section, section; in fig. 2 is a section A-A in FIG. one.

The chisel contains feet 1 with pins 2, the ends of which 3 are made of corrugated, and the surface 4 of the bearings 5 are made with a layer of copper or copper alloy. On the pins 2 by means of the supports are mounted the cones 6, in the bottom part 7 of which spring-loaded plates 8 are installed

the ability to move them along the axes of the cutters 6 and contact with the ends of the 3 axles 2. On the surfaces 9 of the plates 8. contacting the ends of the axles, radial grooves 10 are made. The plates 8 are made of copper or copper alloy, and the surfaces 4 of the bearings 5 are with a copper layer or copper alloy. The chisel contains a lubricator 11 and a sealing unit 12 located between the roller cutter and the trunnion.

During the operation of the bit, fresh lubricant flows between the rubbing surfaces and, under the effect of the overpressure created by the lubricator 10, a metered leakage of lubricant into the annulus occurs. As the lubricant is supplied from bast

О About O

oh che

To the cavity located at the tops of each of the cutters, a fresh lubricant passes through all the rubbing elements of the supports into the radial grooves 9 and the sealing unit 12.

After the descent of the currently used chisels to the bottom, the running-in of the rubbing surfaces of the supports is done. This process consists in gradually increasing the area of contact between the working elements of the supports due to abrasion and removal of point lugs, while also aiming to eliminate or reduce the possibility of scoring and gouging on the rubbing surfaces, as this can lead to an accelerated exit from the pillars of the chisels. The run-in is carried out by gradually increasing the axial load on the rotating bit for 1.5-2 hours or more.

In the proposed bit, due to the effect of selective transfer, the run-in time can be significantly reduced or eliminated altogether, since the soft metal (copper, copper alloy) applied to the abrasive surfaces of the supports smooths out the unevenness on them, eliminates scuffs, reduces the coefficient of friction by a factor of several .

To reduce the time for running-in of the supports, to reduce the coefficient of friction and wear in them, during the operation of the bit before assembling it, a layer of copper or a copper alloy is applied to the rubbing surfaces of the supports (on the axle surface). Since the chisel of the proposed design is designed for very long work (hundreds of hours), to maintain for such a time a deposited layer of copper or copper alloy on the rubbing surfaces it is planned to install plates with grooves 10 made of copper or copper alloy in the bottom of the cones. These plates, being spring-loaded, are constantly pressed against the ends of the trunnions, whose surface is made corrugated, i.e. has sharp recesses and protrusions (like a file). As the cutter rotates, the plates wear out, and the products of its abrasion

the lubricant is carried away to the surfaces, and a layer of copper or copper alloy is constantly supported on them. The phenomenon of selective transfer, which takes place after application during the manufacture of the bit and in the subsequent layer of copper or copper alloy leads to the following:

- in the contact area of the rubbing surfaces a plastic film of soft metal is formed;

- the wear products of this film are held on the rubbing surfaces by electrical forces;

- a system is formed that prevents the oxidation of friction surfaces;

- the protective film reduces contact pressure and adhesive interaction:

All this leads to a decrease in the relative wear of the rubbing surfaces by 10–100 times, and the coefficient of friction between them decreases by a factor of 8–10 compared to the work of the support with boundary lubrication. A positive effect can be obtained if there is an airtight support and when moving a renewable lubricant through all rubbing surfaces.

Claims (1)

Claims Chisel bit containing feet with trunnions, roller cones mounted on trunnions by means of bearings consisting of rolling and sliding bearings, lubricator and sealing unit, in order to increase the durability of bits by increasing the durability of the supports by implementation of the phenomenon of selective transfer, the supports are provided with spring-loaded plates mounted in the bottom part of the cones to move along the axes of the latter and contact with the ends of the trunnions, the plates being made of edi or a copper alloy, and their surfaces contacting the ends of the pins, provided with radial grooves, wherein ends of the pins are made corrugated, and the bearing surface formed with a layer of copper or copper alloy. one ten FIG. 2