RU2369717C2 - Dismountable wheel-type drilling bit with shortened sections of arms - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: invention is related to rock destruction tool, namely to dismountable wheel-type drilling bits, and may be used in drilling of various purpose wells. Dismountable wheel-type drilling bit comprises body with nipple, shortened arm sections and unit that consists of journal with toothed wheel installed on it by means of roller bearings. Toothed wheels are arranged as double-layer, consisting of frame and jacket. Support planes of nipple and body are perpendicular to bit axis. Fit size of journals for bearings are arranged according to ratio d/D=0.20 (where d is diametre of journal section in place of bearing fit; D is bit diametre). In body joint with arm sections there are gaps provided for control of size in axial and radial directions. Shortened arm sections are arranged in the form of L-shaped brackets with inclination angle depending on rock properties and area of bit application.

EFFECT: higher labour effectiveness, provision of repairability and reduction of labour intensity in manufacturing.

8 dwg

Description

The invention relates to drilling equipment, and in particular to structures of a rock cutting tool - a cone bit intended for drilling wells for various purposes in mining, oil, exploration and other industries.

Known designs of cone bits, where the cones differ by type (B, H, NU, AU) according to GOST 20692-2003. Modern chisels (GOST 20692-2003) consist of sections of paws on which cones are mounted (conditionally the assemblies are assembled). Assembled sections of paws form a rigid, non-separable structure. The upper part of the legs in assembled form is then bored, followed by cutting on it a tapered locking thread, forming a nipple. In all known schemes for the execution of the cone bearings, there is a ball bearing and a certain number of treadmills for mounting rolling elements in them. Rolling bodies are freely placed on treadmills formed by roller cones and trunnions, without any fixation, that is, without separators. In technology, such designs are called bulk bearings.

Depending on the design of the body, cone bits, regardless of purpose, are divided into two groups A and B.

Group A (sectional chisels) - the body is welded from separate sections (paws) on which the cones are mounted.

Group B (solid-body) - one-piece, molded body, to which legs are welded with cones mounted on them.

Group A includes bits with a diameter from 76 to 393.7 mm, and group B - from 349.2 to 508 mm.

Common for both groups is the presence of sections of the legs on which the cones with lock ball bearing are mounted.

The disadvantages of such structures (GOST 20692-2003) are energy-intensive stamping of the foot sections, insufficiently reliable welded connection, especially in section bits, inability to disassemble and repair structures, unreliable and short-lived support of roller cones with lock ball bearing, production specificity, labor-intensive disposal, lack of constructive and technological resource for further improvement of bits. A confirmation of these shortcomings is GOST 20692-2003, where roller cones are not endowed with consumer properties, do not have a guaranteed working resource and do not allow the consumer to conduct a comparative analysis with foreign analogues and domestic production bits, that is, choose the right bit for work.

Similar in technical solution (in terms of support) is the design stated in patent No. 2067150 6 ЕВВ 10/22 of 09/27/96, where by increasing permutations of bulk rolling bearings, an increase in durability is obtained and the principle of their equal durability is ensured.

The disadvantage of such structures is the limited scope of their application (only for roller-ball-roller-roller supports); the inability to disassemble and repair, and many others. Moving to the lower position of the lock ball bearing in the specified patent No. 2067150 reduces its service life by reducing the size of its rolling bodies and does not exclude all the disadvantages inherent in a loose rolling bearing (run-in, swirl, jamming of rolling bodies). In the roller-ball-roller bearings, the redistribution of the load and the increase in durability will depend not on the large bearing, but on the rapid wear of the lock ball bearing, which increases the likelihood of the cone falling into the face. No less problematic is the method of mounting the rolling elements in the lower position, where damage to weapons (milling or with carbide teeth) will be required, associated with additional labor costs.

The closest in technical essence to the claimed technical solution is a collapsible bit, patent No. 2215112 from 08.21.2001 - a prototype consisting of separate independent parts (nipple, case and assembly assembly).

The disadvantage of this design is the underutilized technical capabilities of the cone support, the design of the body of the bit and the assembly technology of the bit. The technical task of the claimed invention is to create a collapsible design with a predictable service life, maintainable, less laborious to manufacture, not requiring cumbersome pressing and stamping equipment, less energy-intensive, more reliable and durable and with many other positive factors, and most importantly - lower costs for tripping -Lifting operations when drilling deep wells due to the guaranteed resource of operability of the cone support. The folding design of the cone bit, in addition to solving the stated tasks, will simplify the fleet of machine tools, unify the parts and components of the bit, as well as the manufacturing process itself, thereby solving one of the important issues - to make the bit constructive, technological and promising for further improvement.

The collapsible design of the cone bit with the cone support, made according to the ratio d / D = 0.20 (d is the cross-sectional diameter of the axle of the most loaded bearing, mm; D is the diameter of the bit, mm), allows you to vary in a wide range the dimensions of the rolling elements, their geometric shapes, and also schemes of various bearings (standard, bulk, sliding and their combinations).

In contrast to the prototype (patent No. 2215112 from 08.21.2001), the following changes were made to the proposed design: the nipple with the body are made as a whole; sections of paws are shortened and have a rectangular shape; instead of a sliding bearing, an assembled roller rolling bearing with rollers having a spherical end surface and an inclined roller bearing is installed; the cone is made of two layers and consists of a frame and a casing.

The collapsibility of the bit makes it maintainable, easily recyclable, convenient for research and predictable in terms of service life.

The technical problem of the claimed invention is achieved by the following structural solutions.

The connection of the nipple with the body as a whole allows you to exclude the cut of the welds when reversing the drill string and when the bit is jammed.

The use of shortened paws of rectangular section allows to increase their strength and stiffness, reduce costs and improve manufacturability.

Replacing the sliding bearing with roller bearings allows to increase the drilling speed and to prevent the setting and jamming of the sliding surfaces and thus prevent jamming of the roller cutter.

The two-layer cone design allows you to abandon the laborious work of equipping the cone bits of serial bits with carbide teeth. In particular, there is no need to perform drilling, pressing and soldering of teeth. For example, on a 3-cone bit with a diameter of 244.5 mm, up to 200 teeth are used; eliminate such a drawback of cone production bits, such as the loss of carbide inserts due to the weakening of their fastening during operation.

Therefore, the claimed invention meets the criterion of "Novelty."

The proposed technical solution makes it possible:

- reduce manufacturing costs;

- simplify the technology of assembly and control, reduce the cost of technological equipment;

- increase the dimensions of the rolling elements of the bearings or use standard rolling bearings with cages with the same dimensions of the rolling elements that are used in serial bits;

- abandon the complex shape and a large number of treadmills trunnions and cones;

- abandon traditional locking bearings;

- apply, in addition to the types of supports B, N, NU, AU and others, other than those regulated in GOST 20692-2003, in the form of various modifications, based on the drilling mode of low or high-speed and permissible axial load on the bit and torque;

- to ensure equal reliability of the support elements, their timely replacement, to predict the service life of roller cone bits as a whole and to guarantee the equal strength of the support and weapons;

- apply serial standard metalworking machines;

- reduce or reduce the composition of the equipment due to the rejection of energy-intensive pressing and stamping equipment;

- perform assembly and disassembly at manufacturing plants and at the field of operation;

- apply inter-production cooperation in the manufacture of parts and assemblies;

- compile or develop a standard-sized series of parts and assemblies based on 100% unification and standardization of all parts and assemblies of cone bits of the entire standard-sized series;

- to develop a methodology for calculating and selecting the basic design parameters of the bit, taking into account their equal strength, equal durability and system reliability (drive - drilling rig - rock cutting tool);

- redistribute the radial component from the axial load evenly on an arc of 180 degrees, thereby reducing contact stress on the rolling elements;

- reduce the likelihood of jamming cones relative to the trunnion;

- to increase the service life of the support cones by increasing the size of the rolling elements;

- increase the speed of penetration;

- reduce the likelihood of loss of cones in the bottom of the well;

- to provide better cleaning of the bottom of the well due to the correct geometric shape of the new bit;

- ensure the maintainability of bits;

- reduce the cost of tripping;

- to study the processes of wear and failure and to classify them in accordance with the classification system adopted by manufacturers of chisels around the world, especially according to failures of the cone support;

- to divide bits into simple and complex, low and high speed, deep and surface, expensive and cheap, used for drilling in quarries or deep gas and oil wells;

- organize the production in the entire standard size range (GOST 20692-2003) of simpler cone bits for mining, construction, exploration and other industries that do not require complex bits with sealed supports and oilers;

- solve the problem of drill bits, multifunctionality and reusable use of them - to reduce the consumption of nickel-containing steels;

- reduce the total cost of drilling work.

When analyzing patent and scientific and technical literature, a set of features was identified that determined the new properties of the claimed bit. Therefore, it meets the criterion of "inventive step". The claimed design can be implemented on standard equipment using well-known technological processes and therefore it meets the criterion of "industrial applicability".

Figure 1 shows the cone drill bit assembly, which consists of 1 - body nipple; 4 - node assembly; 3 - sections of paws; 2 - a fixing nut.

On figa) and b) shows the nipple-housing 1 in two projections with cutouts 5.

Figure 3-6 shows the section of the legs, which can be made in two versions, one-piece or detachable.

7 shows a node assembly, which contains:

6 - a pin;

7 - anti-friction gasket;

8 - an outer ring of a precast bearing;

9 - pin;

10 - rollers of a precast bearing;

11 - an inner ring of a precast bearing;

12 - rollers of an angular bearing;

13 - a casing;

14 - frame.

The assembly 4 and the section of the legs 3 as a whole are inserted into a rectangular hole and secured with a nut 2, which is then pinned and scalded along the contour.

The proposed design of the bit has the feature that its parts under axial load (which is decisive) work in compression, in contrast to serial bits, where the axial load creates a force working on the shear and rupture of the weld sections of the legs. Compression work of parts eliminates the possibility of paws falling into the face, which is one of the disadvantages of serial bits.

The choice of the integral design of the nipple with the body eliminates the possibility of cutting off the nipple from the body of the bit, which occurs when the nipple and the body are made as separate parts.

The proposed design simplifies the assembly of the assembly with the foot section. In addition, the unevenness of the paw sections is completely eliminated by installing metal gaskets between the body and the supporting surface of the paw section, which cannot be achieved in 3-section roller cone bits of serial production. The elimination of complex, expensive and time-consuming welding of the longitudinal seams of the foot sections and the design of the nipple with the body as a whole in the proposed design greatly simplifies and reduces the cost of the production of bits.

Instead of a tapered plain bearing, two roller bearings with a significantly larger diameter of the rollers are used in comparison with the rollers used in serial bits that are similar in size. Using a bearing with rolling elements reduces the number of treadmills in the axle and roller cone.

In order to reduce the friction of the rollers, their end surfaces are made spherical. In addition, the end surfaces of the rollers can also be made in the form of curves of the second order. The proposed design of the roller provides a reduction in friction resistance compared to rollers having end surfaces in the form of a plane and used in serial bits.

A distinctive feature of the cone in the design of the proposed bit is that it is made of two layers. Its outer surface is a casing made of hard alloy and having flows in shape and size, imitating carbide teeth used in roller cutters of serial bits.

The casing of this design provides:

- the ability to abandon the time-consuming work of equipping the cone bits of serial bits with carbide teeth. In particular, there is no need to perform operations on drilling, pressing and soldering teeth.

- elimination of such a drawback in the cone of serial bits, as the loss of carbide inserts due to the weakening of their fastening during operation of the bits;

- the possibility of using new high-strength materials used in the defense and space industries.

Claims (1)

A collapsible cone drill bit with shortened sections of the paws, comprising a complete assembly and a nipple combined with a casing, characterized in that the cones are double-layered, consisting of a frame and a casing, the supporting planes of the nipple with a casing are perpendicular to the axis of the bit, roller assembly bearings are installed in the cone support , the landing dimensions of the trunnions for bearings are made according to the ratio
d / D = 0.20,
where d is the diameter of the cross section of the trunnion at the seat of the bearing;
D is the diameter of the bit,
in the connection of the body with the sections of the paws, gaps are provided for adjusting the dimensions in the axial and radial directions, the shortened sections of the paws are made in the form of L-shaped brackets with a certain angle of inclination depending on the properties of the rock and the area of application of the bit.

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