RU2347883C2 - Demountable cone bit with supports of roller cutters on roller bearings with separators and with shortened demountable sections of legs by gribennikov-malinkin - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: invention refers to drilling equipment, particularly to designs of cone bits. A drilling cone bit consists of separate independent parts, of a nipple, of a frame with the central aperture for nipple connecting, of a fixing mechanism in form of a sectional flange with fastening bolts set off the boundaries of a journal working zone; the said flange is located in a cavity of each roller cutter of a thrust bearing. Also the frame of the cone bit is made in form of a disk with three shortened legs; the disk has three apertures of a complex shape for assembly of shortened leg sections. The exterior surface of the frame has three recesses for bottom hole cleaning of a well. The legs consist of a journal with seats for bearings with the fixing mechanism, with a leg tail and a threaded pin for nut screwing. In the cavity of a roller cutter two serial ball radial rolling bearings with separators are installed on the journal according to the ratio:

where d is diameter of journal cross section at the point of the rolling bearing seat, mm, D is diameter of the cone bit, mm; the thrust bearing is made in form of a serial radial-stop bearing. Dimensions of the roller cutter facilitate uniform strength of its walls in all cross sections.

EFFECT: reduced costs and simplification of the process of cone bit fabrication, also increased service life of supports of roller cutters and increased efficiency of drilling due to increased rate and length of cone bit driving.

4 cl, 6 dwg

Description

The invention relates to drilling equipment, and in particular to structures of a rock cutting tool - a cone bit designed 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 sections of the legs in assembled form is then bored, followed by cutting on it a taper lock thread, forming a nipple. In all nine 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 a roller cone and a trunnion 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 are GOST 20692-2003 energy-intensive stamping of the sections of the legs, insufficiently reliable welded connection, especially in section bits, inseparability and maintainability of structures, unreliable and short-lived support of roller cones with lock ball bearing, production specificity, labor-intensive disposal, impossible knot and no-part operation 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.

A similar technical solution (in terms of support) is the design stated in Patent No. 2067150 6, ЕВВ 10/22 dated 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); indiscriminability and maintainability and many others. Moving to the lower position of the lock ball bearing in the aforementioned patent No. 2067150 decreases its service life by reducing the size of its rolling bodies and does not exclude all the disadvantages inherent in bulk rolling bearings (running, swirling, jamming of rolling bodies). In the roller-ball-roller bearings, the redistribution of the load and the increase in durability will depend not on a 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, housing 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 structure of components: a nipple, a housing and an assembly assembled with a roller cone, different from the basic model of a serial production bit with a predictable service life, maintainable, less time-consuming to manufacture, not requiring cumbersome pressing and stamping equipment , less energy-consuming, more reliable and durable, and many other positive factors, and most importantly, lower costs for tripping during drilling deep wells, due to the guaranteed resource of operability of the cone support. The collapsible design of the cone bit with cage bearings, in addition to solving the stated tasks, will simplify the machine tool park, 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, technologically advanced and promising for further improvement.

A collapsible design of a cone bit with a 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 chisel, mm) allows you to vary in a wide range the dimensions of the rolling elements, their geometric shapes, and layouts of various bearings (standard, bulk, sliding and their combinations).

The task is achieved by the fact that the lock ball bearing is abolished and a locking mechanism is applied instead, which is removed from the working area of the journal;

- the internal volume of the cone cavity is changed in order to rationally reduce the diameter of the axle section under the most loaded bearing by d / D = 0.20;

- the design of the case in the form of a disk has three through holes and three samples for cleaning the bottom, and there is also a hole for connection with a nipple;

- the construction of the paw section is significantly different from the design of serial paws in its folding.

In shape and size, instead of round grooves for mounting the assembly assembly (foot sections), grooves of complex shape are provided.

Unlike the design, patent No. 2215112 of 08.21.2001 - the prototype paw section of the proposed bit is a shortened paw section, where the pin has the form of stepped cylindrical surfaces, and the paw itself, made in the form of an arm with two machined ends, has a section in the shape of “dovetin tail ”, made at an angle of 50 degrees to the axis of the bit, taking into account the bending moment and the moment of resistance, based on the permissible axial load on the bit with a diameter of 215.9 mm 100 N per section of the leg. To fix the paw section relative to the bit body, a cylindrical threaded pin is provided for fastening with a nut.

Instead of three bearings (bulk) according to the roller-ball-roller scheme, only two radial ball-bearings of mass production (with cages) are mounted in the changed volume of the roller cone support; The lock ball bearing is abolished, and the cone is fixed relative to the pin by the locking mechanism, which is removed outside the working area of the pin in the form of a split flange with fixing screws.

Instead of the heel, which plays the role of a thrust sliding bearing, an angular contact rolling bearing of mass production is installed. The dimensions of the rolling bodies in two serial rolling bearings with cages correspond to the dimensions of the rolling bodies in the supports of the bits (one standard size). This ensures equal strength and serviceability in the compared designs. Due to the separators in serial rolling bearings, the load on the rolling elements is redistributed on the 180 ° arc of the axle diameter, which will allow more rolling elements to simultaneously take on the radial component of the axial load.

As a result, in the three-cone bit, all three bit supports with a large number of rolling bodies will be simultaneously involved. A collapsible bit with cone bearings on serial rolling bearings with milled or carbide teeth makes the bit multifunctional, and parts and its assemblies are multi-turn.

Comparison of the claimed solution with the prototype shows that it differs in the following features:

- the casing is reduced in height and bevels are provided for cleaning the bottom of the well; sections of paws are shortened; U-shaped grooves replaced by dovetail grooves; assembly technology assembly and bits are also changed;

- the roller cone support can have two radial ball bearings with cages of mass production and many other combinations of mounting schemes for bearings of various types;

- instead of the thrust sliding bearing (heel), an angular contact bearing of mass production is installed;

- the diameter of the cross-section of the trunnion at the installation site of the bearings, which absorb the greatest effort, is reduced by d = 0.20D (where d is the diameter of the cross-section of the trunnion at the location of the rolling bearing, mm; D is the bit diameter, mm);

- treadmills under the castle ball bearing in cones and trunnion are abolished;

- the mechanism for fixing the cone relative to the axle is moved outside the working area of the axle;

- combined large and small ball bearings;

- the wall thickness of the cones is made taking into account ensuring equal strength in all sections;

- the section of the paw in a dangerous cross section for shear and bending has a cross-sectional area taking into account the action of axial force and the reaction of the face;

- connection of the paw section to the body is carried out using a dovetail section, threaded connection and welding;

- the radial component from the axial load is redistributed evenly along the 180 ° arc of arc on the rolling elements of the bearings;

- the catalog service life in the applied serial rolling bearings with a cage allows you to establish the actual resistance of the bearings (and bits in general), taking into account the specifics of operation (rotation speed, drilling speed, physical and mechanical properties of the rock, etc.).

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

The proposed technical solution makes it possible:

- reduce manufacturing costs;

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

- reduce the fleet of measuring instruments by reducing the measuring bases;

- reduce the cost of hardening the treadmills (to eliminate the chemical-thermal treatment of treadmills and pins);

- provide radial and axial alignment of the axle relative to the cone;

- apply serial standard metalworking machines;

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

- reduce energy costs for stamping massive sections of paws;

- carry out assembly and disassembly in factories - manufacturers and in 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 roller cone bits;

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

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

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

- increase the service life of the support cones;

- 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 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;

- unload bit factories by organizing the production of new simpler cone bits for mining, construction, exploration and other industries that do not require complex bits with pressurized supports and oilers;

- solve the problem of folding bits, multifunctionality and their reusable use;

- reduce the total cost of drilling work.

When analyzing the patent and scientific and technical literature, the totality of the features that determined the new properties of the claimed bit was not revealed. Therefore, it meets the criterion of "Inventive step". The claimed invention can be implemented on standard equipment using known technological processes, therefore, it meets the criterion of "Industrial applicability".

Figure 1 shows the cone drill bit assembly, which consists of 1 - nipple, 2 - body, 3 - assembly assembly (paw section). 2 shows a nipple.

Figure 3 and figure 4 shows the housing.

The figure 5 shows the assembly, which contains a trunnion 5, a detachable flange 6, fixing screws 7, a seal (antifriction gasket) 8, a roller cone 9, a radial bearing (large) 10, a radial bearing (small) 11, an angular contact bearing) 12.

In Fig.6 is a view A in Fig.5.

The assembly of the bit begins with the assembly of the assembly. First, a seal 8 is installed, then a large bearing 10, followed by a small 11 and an angular contact 12. Then a roller cone 9, a flange 6 is mounted and the flange 6 is fastened with screws 7. After checking the correct assembly (by scrolling by hand in any direction along the rotation axis ) the screws are fixed by welding. Then the flange 6 is welded to the cone 9.

The assembled assembly is inserted into the grooves of the housing and secured with a nut 4 (Fig. 1). If necessary, splinted and welded.

Then, a nipple is screwed into the body of FIG. 3 and is welded along the contour to the body of the bit.

When the bit is operating, the axial load is redistributed (theoretically) into three equal parts. One section of the leg leg or cone support accounts for 0.25 P of the axial permissible load previously regulated by GOST 20692-75 (table 6).

For three-cone bits with a diameter of 215.9 mm with supports of the type B, N, NU, AU, the load was 250, 380, 310, 280 kN, respectively. Therefore, one section will have a load three times less than that indicated for each support.

Based on the indicated allowable loads, sections of the paw sections were selected at the moment of resistance. As a result, in the proposed design of the bit, by reducing the trunnion section of the large bearing (the heaviest), it was possible to redistribute the axial load on two bearings by pairing two rolling bearings of serial production with cages or by increasing the size of the rolling bodies in bulk bearings without a cage when the ball bearing is removed.

Due to changes in the geometric shape and integrity of the paw section, as well as an increase in the cross section of the paw as a whole and the seats in particular, the load from the face reaction is redistributed along the contour of the surface of the bit body, forming a rigid system with the nipple and assembly in place, preventing the oscillation of the journal (paw section) relative to the axis of the bit.

The serial rolling bearings with cages used in the claimed patent guarantee a 180 ° loading zone and uniform distribution of the radial load on the rolling bodies located in this zone. In this case, the large and small bearings installed in series make it possible to ensure the principle of their equal durability and redistribute the bottom-hole reaction, which falls to a large extent on the large bearing (when the bearings are designed according to the roller-ball-roller scheme).

Modern chisels (sectional), which are fixed by welding the upper nipple part of the chisel, have elongated sections of the legs, which during drilling under load vibrate (insufficient rigidity) and oscillate about the axis of the chisel with a certain amplitude.

According to the classification of causes of failures, adopted by the international association of manufacturers of chisels, the type of breakage in the form of a split along the welds has its own code in the specified classifier.

In the proposed design, a solid-cast or solid-stamped ring (body) divides the bit into two equal parts, which eliminates breakage of the paw section, and their massive cross-section and blind jamming of the paw section relative to the body excludes vibration in the cross section of the well.

The proposed scheme of the bit and its assembly, and the design of its individual nodes opens up unlimited possibilities for improving the design of the cone bit.

Claims (4)

1. A cone drill bit, consisting of separate independent parts: a nipple with a taper lock and metric thread and flats for a wrench for assembly and disassembly, a housing with a central hole for attaching a nipple, paws, a locking mechanism in the form of a detachable flange with fixing screws, remote outside the working area of the trunnion placed and fixed on the end plane of the cone flange and antifriction gaskets located in the cavity of each cone of the thrust bearing, characterized in that the casing of the bit It is made in the form of a disk with three shortened paws, which are assemblies and include a pin with seats for bearings with a locking mechanism, a paw shank and a threaded pin for screwing the nut, while two serial ball radial bearings are installed in the cone cavity on the pin rolling with cages, and the landing dimensions for the bearings on the axle are made according to the ratio

,
where d is the diameter of the cross section of the trunnion at the location of the rolling bearing, mm;
D is the diameter of the bit, mm
wherein the thrust bearing is made in the form of a serial angular contact bearing, and the dimensions of the cone cavity provide equal strength of its walls in all sections. 2. The bit according to claim 1, characterized in that the shortened legs are made in the form of brackets with two machined ends. 3. The bit according to claim 1, characterized in that the outer surface of the body has three samples for cleaning the bottom of the well. 4. The bit according to claim 1, characterized in that the body of the bit has three holes of complex shape for assembling truncated sections of the legs with an inclined axis of the pins to form an angle of inclination of the axis of the pin with respect to the axis of the bit.

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