RU2711220C1 - System for lubrication and compensation of drilling cone bit pressure - Google Patents

Abstract

FIELD: soil or rock drilling.

SUBSTANCE: invention relates to structures of drilling cone bits and can be used in well drilling. Lubrication system and compensation of drilling cone bit pressure includes a cavity made in the leg, the plate springs are installed on the cavity bottom, Belleville springs are pressed by perforated washer to receive rubber-metal diaphragm. Lubrication channel communicating lubrication system with chisel support emerges from cylindrical part of cavity. Channel for relieving lubricant from the bottom of the cavity to the breast of the leg connects the bottom of the cavity with the borehole space, namely – with the leg breast. Tube in the form of a cylinder with a radial hole is put on the diaphragm. Tube with its outer cylindrical surface contacts cylindrical part of cavity. Tube is installed with its radial hole towards lubrication channel. Tube is pressed with a cover; the cover is fixed with a retaining ring. O-rings are installed in the gaps between the leg and the tube, as well as between the leg and the cover. Cover has hole for threaded plug with possibility of pumping through lubricant hole. Lubricant release channel on the side of the leg breast is equipped with a threaded end with the possibility of fixing a threaded plug in it. Parts are assembled directly into chisel blade.

EFFECT: increased useful volume of lubricant and increased manufacturability.

1 cl, 1 dwg

Description

The invention relates to designs of cone drill bits and can be used in the field of well drilling.

Since the beginning of the twentieth century, a large number of different designs of cone bits have been known. Initially, they were equipped with an unsealed support and did not require a lubrication system.

A known design of the cone drill bit, the legs of which are equipped with lubricating reservoirs that are connected to the support of the bit lubricating channel (US No. 3739864, IPC ЕВВ 10/24, op. 08/12/1971).

The disadvantage of this design is the lack of elements that compensate for pressure fluctuations, due to which there is a pressure drop around the o-ring of the support and, as a result, a decrease in the total resource of the bit.

A known design of drill bits, in which the lubricating system of the bit made in the paw is equipped with a soft rubber diaphragm to compensate for pressure fluctuations, and after assembling the bit, a needle is punctured. In the event that the pressure in the well exceeds the pressure in the support, compensation occurs by deforming the diaphragm and reducing the volume of the tank; if the pressure inside the support exceeds the downhole pressure, excess lubricant is dumped through the puncture of the diaphragm (RU No. 2513927, IPC ЕВВ 10/24, op. 04/20/2014).

The disadvantage of this invention is the instability of the puncture in the diaphragm, which is associated with the influence of a large number of random factors when performing a puncture and the great complexity of controlling the quality of the operation. If the puncture diameter is too large, the hole may allow drilling fluid to pass into the lubrication system, or the lubrication may be prematurely discharged. If the puncture diameter is too small, the hole may not release grease when

design differential pressure, which will negatively affect the life of the sealing ring of the support, and, consequently, the entire bit.

Closest to the patented invention is the design of a lubrication and pressure compensation system, selected as a prototype. The prototype includes an assembly of parts of a lubricating reservoir, including a pressure relief mechanism made in the form of a pair of Belleville springs, a cavity filled with grease and connected to the support by means of a lubricating channel, a channel extending to the breast of the paw, in order to provide pressure connection with the downhole . Moreover, the prototype has two positions for assembling the lubricant reservoir: the first is the technological one for injecting lubricant, and the second is the working one for lowering into the well (US No. 9194186, IPC ЕВВ 10/24, op. October 17, 2012).

The disadvantage of this invention is the presence of a large number of parts for assembling a lubricant reservoir, which leads to a decrease in the manufacturability of production and an increase in the cost of the bit. Another disadvantage lies in the housing design of the assembly of the lubricant reservoir, which leads to a non-functional increase in the dimensions of the assembly and, consequently, a decrease in the useful volume of the lubricant. Another disadvantage is the relative complexity of assembling the assembly of the lubricant reservoir in the bit and injecting lubricant, which is associated with the need to change the position of the lubricant reservoir, which leads to an increase in the time for the assembly operation, an increase in the qualification requirements of the collector and, as a result, an increase in the cost of the bit as a whole.

The purpose of the invention is to increase the useful volume of lubricant, increase manufacturability and reduce the cost of producing a cone bit, by changing the design of the lubrication system.

The specified goal is achieved in the lubrication and pressure compensation system of the drill bit, including the assembly of the parts of the lubricating reservoir, the diaphragm, the overpressure relief mechanism with

using Belleville springs, a lubricating channel extending to the breast of the paws and a channel for lubricating the lubricant connecting the lubrication system with the support of the bit, characterized in that the assembly of the lubricant reservoir parts is carried out directly in the paw of the bit, the lubricant discharge channel is equipped with a threaded end that allows sealing the lubricant cavity reservoir technological screw plug while filling the system with lubricant.

The figure 1 shows a method of implementing the invention. In paw 1, a lubricant cavity 2 is made, a pair of Belleville springs 3 is laid in the cavity 2, Belleville springs 3 are pressed with a perforated washer 4, on which the rubber-metal diaphragm 5 sits, in order to limit the diaphragm 5, the tube 6, made in the form of a cylinder, is put on top with a radial hole, while the tube 6 with its outer cylindrical surface is in contact with the cylindrical part of the cavity 2, which is pressed by the cover 7, the whole arrangement is fixed by the locking ring 8. To prevent leaks in the gap O-rings are installed between the foot 1, the tube 6 and the cover 7, the sealing rings 9. The hole 10 in the cover 7 is used for injecting lubricant and is muffled by a screw plug 11. The lubrication channel 12 exits the cylindrical part of the cavity 2 and connects the cavity 2 with the support of the bit, the channel 13 for the release of lubricant leaves the bottom of the cavity 2 in the downhole space on the breast of the paw and from the side of the breast of the paw is equipped with a threaded end. At the time of lubricant injection, the channel 13 is jammed by the technological plug 14 from the side of the breast of the paw.

The assembly of the assembly is carried out as follows: first, the sealing rings 9 are laid in the cavity 2 of the paws 1, the Belleville springs 3, the perforated washer 4 and the rubber-metal diaphragm 5 are inserted into the bottom of the cavity 2, all this is pressed by the tube 6, which is installed by the hole in the direction of the lubricating channel 12 and

a lid 7, which is fixed by the locking ring 8. After that, the lubricant discharge channel 13 is suppressed by the process plug 14, and a lubricant injection device is connected to the hole 10. Next, the cavity 2 is evacuated, followed by lubricant injection through the hole 10, after which the process plug 14 is removed and the lubricant discharge pressure is checked, then the hole 10 is suppressed by the screw plug 11 and the product is ready for operation.

Features of such a system are:

- stable operation of the lubrication relief mechanism at the calculated pressure drop, because it does not depend on difficult to control factors, such as the qualification of the collector and manual adjustment of the unit;

- an increase in the useful volume of the lubricant, a more efficient use of the volume allocated to the lubricant reservoir, in comparison with analogues, by reducing the dimensions of the parts;

- ease of execution of parts, the minimum number of milling operations, which reduces the cost of manufacturing a bit.

Claims (1)

A lubrication and pressure compensation system for a drill bit, including a cavity made in the paw, disk springs are placed on the bottom of the cavity, disk springs are pressed by a perforated washer on which a rubber-metal diaphragm is mounted, a lubricant channel exits from the cylindrical part of the cavity connecting the lubrication system with the bit support, from the bottom of the cavity on the breast of the paw comes out a channel for the release of lubricant connecting the bottom of the cavity with the downhole space, namely, with the breast of the paw, characterized in that the diaphragm is one This is a tube in the form of a cylinder with a radial hole, the tube with its outer cylindrical surface contacts the cylindrical part of the cavity, the tube is installed with its radial hole in the direction of the lubricating channel, the tube is pressed by the cap, the cap is fixed by a locking ring, in the gaps between the foot and the tube, and between O-rings are installed with the paw and the cover, the cover is made with a hole for the screw plug with the possibility of pumping through the lubricant hole, and the channel for discharging lubricant from the breast side of the equipped with a threaded end with the possibility of fixing a technological threaded plug in it, while the assembly of parts is carried out directly in the paw of the bit.

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