RU2334075C2 - Bit grebennikov-malinkin-ushakova's cone cutter - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: invention concerns drilling equipment, particularly rock breaking tool constructions, such as cone cutter bit for drilling wells of various destination in mining, oil production geological surveys and other spheres of industry. The cutter bit includes separate independent parts i.e. pin with conical tool-joint thread and metric and hexagonal wrench flats for assembly/disassembly, case in the form of solid ring with three holes for breakage face cleaning and threaded holes for connection to the pin with assembled units consisting of pivot shaft, cutters, gaskets, solids of revolution, washer, radial-thrust bearing and breakaway flange with fitting screws, serving as tool joint roller bearing, i.e. fixation device offset outside the working pivot shaft and fixed on the cutter end surface. The number of races or roller bearings is reduced to one, while the outer coupling size for the roller bearing is increased due to reduction of pivot shaft diametre d in mounting section of solids of revolution by d/D=0.20, where d is the pivot shaft section diametre at the conjugation point with solids of revolution, and D is the cutter bit diametre, mm.

EFFECT: ruling out patterns for positioning multiserial bearings with different size, work life resource and durability along vertical axis.

3 cl, 3 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 drill bits, where the cones differ by type (B, H, NU, AU) GOST 20692-2003.

The basic model according to GOST 20692-2003 bits consists of three sections, rigidly welded together, forming a nipple, paw and trunnion with a cone. The roller cutter is mounted on a trunnion, on which treadmills are bored (as well as on the inner roller cone), rolling bodies are located between them, which ensure that the roller cutter rotates relative to the trunnion. There are approximately nine schemes for the execution of cones, based on which the vertical axis with sequentially placed bearings on it with different sizes and service life. The number of bearings depends on the size of the bit.

The disadvantage of such designs is:

- failure to comply with the principle of equal durability;

- indistinguishable bits and unsuitability;

- energy-intensive stamping of the sections of the legs, the complexity of manufacturing;

- high probability of failures (jamming of the support and destruction of rolling elements);

- high costs for changing the bit, entailing significant costs for tripping and many other disadvantages.

Structures of the cones supported by patents No. 1229297 A1 dated May 7, 1986 and No. 2067150 С dated September 27, 1996, where the increase in durability is obtained by changing the geometric shape of the rolling elements and rearranging bearings, are similar in technical solution (in terms of support), and the issue is resolved on ensuring the principle of equal durability. The disadvantage of such designs is the inseparability of the bits and their unsuitability, energy-intensive stamping of the foot sections and a specific (narrow) specialization, creating the prerequisites for monopolizing the production of bits and unreasonably overpricing and many other technical flaws.

The closest in technical essence to the claimed technical solution is a collapsible bit (patent No. 2215112 dated August 21, 2001), consisting of separate independent parts (nipple, case and assembly) - a prototype. The disadvantage of this design is the underutilized technical capabilities of the support cones.

The technical task of the claimed invention is to create a collapsible structure from its constituent parts: nipple, housing and assembly assembly; with a support of cones different from the basic standard, more reliable and durable, less labor-intensive, repair-suitable, with an increased coefficient of performance of rolling bearings, convenient for disposal and the possibility of using serial standard metal-working machines; rejection of powerful press equipment; high degree of unification and standardization; the use of a limited composition of equipment with a low production culture that does not require highly qualified specialists; rationing of permissible axial loads and drilling modes; guaranteed service life and reduced failure probability; system reliability of bits in work is guaranteed; the possibility of increasing the drilling speed and lowering costs for tripping and many other advantages.

The collapsible design of the bit with a modified support of the cone will significantly increase the reliability of the thrust bearings and obtain a resistance of the cone of the cone above the resistance of the weapon.

The problem is achieved in that the volume of the cone cavity is modified due to a rational increase in the size of the rolling bodies, reducing the diameter of the axle section in the places of landing of the rolling bodies based on the ratio d / D = 0.20 (application No. 2005129367/03 of September 20, 2005), where d is the diameter of the axle, mm; D is the diameter of the bit, mm, and changes in the geometry of the inner cavity of the cones by reducing the number of treadmills. Instead of many treadmills, one is cut (turned) to accommodate a much larger roller bearing. It is known that the performance and durability of rolling bearings depends more on the size of the rolling bodies.

So for a bit with a diameter of 215.9 mm with a roller-ball-roller roller cone support with roller sizes of 8 · 16 and 10 · 20, the sum of two working factors is less than that of one roller, with dimensions of 18 · 30 mm. Simplification of the cone support allows axial alignment and significantly reduces the likelihood of failures from misalignment, distortions and jamming of rolling elements during installation and operation of bits. At the same time, the strength of the walls of the cones in all sections is ensured by the correct choice and placement of rolling elements and other details inside the cone.

The use of such a support in collapsible chisels, where the locking mechanism of fixation is outside the working area of the journal, allows you to use the assembly as an independent rock cutting tool for reusable and targeted use.

Changing the complete assembly, depending on geological conditions, makes the collapsible bit more versatile.

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

- the roller cone bearing has one roller bearing;

- the number of treadmills on the cone and trunnion is reduced;

- the efficiency coefficient of one roller and its durability is greater than the sum of the same characteristics in two roller;

- the processing of one track is less time-consuming and does not require special technological equipment and sophisticated measuring controls;

- surface hardening of one treadmill does not require complex technology;

- the inner cavity of the walls of the cones along the wall thickness is made taking into account ensuring equal strength in all its sections;

- the trunnion cross-section at the places of installation of the rolling elements is selected according to the ratio d / D = 0.20 with a five-fold margin of safety in bending by the yield strength for steel, grade 20XH3A;

- the connection of the trunnion with the housing is carried out using a threaded connection;

- the abolition of ball lock and two unequal roller bearings and replacing them with one large roller allows you to concentrate the radial load on a large roller bearing, which eliminates the principle of unequal durability of rolling bearings located in one bearing.

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

The proposed technical solution makes it possible:

- reduce labor costs for machining;

- reduce the cost of manufacturing special technological equipment;

- reduce the fleet of measuring instruments by simplifying the design of the support and reducing the measuring base;

- reduce the cost of hardening treadmills, cones and trunnions;

- to ensure alignment and simplify the assembly of the support of cones and bits in general;

- apply standard serial metalworking machines with a limited composition of equipment and a low production culture:

- abandon the energy-intensive, expensive special pressing and stamping equipment;

- carry out assembly and disassembly at manufacturing plants or at operating sites, taking into account specific mining and geological conditions;

- increase durability by increasing the size of the rolling elements in the rolling bearings;

- reduce contact stress due to the larger contact surface of the rollers with the treadmills;

- redistribute the radial load and ensure the principle of equal durability for rolling elements of a large roller bearing;

- reduce the likelihood of jamming of the rolling elements in the process of wear due to the increased size of the rolling elements;

- to widely use unification and standardization in the manufacture of components and components of the bit, using inter-production cooperation;

- replace and repair individual parts and nodes of the bit and reduce the cost of transportation or delivery of bits to remote places;

- explore the wear processes and classify failures during operation:

- significantly reduce the cost of tripping;

- increase the resistance of the cone support compared to the armament of the bit;

- apply various durable and anti-friction materials for the manufacture of rolling elements;

- reduce the likelihood of rolling cones falling into the bottom of the well, increase the operational resource of the bit and improve the cleaning of the bottom due to the correct geometric shape of the collapsible bit and the outgoing and leaving hydrodynamic flows;

- reduce the number of parts in the support of cones in order to increase the system reliability of the design of the cone bit;

- the proposed ratios d / D = 0.20 and l / d = 1.7 can be used to develop methods for the selection and calculation of the main parameters at the design stage of cone bits.

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. Figure 2 shows the components of a three-cone bit: 1 - nipple; 2 - body and 3 - set of cones. Figure 3 shows the complete assembly (roller cone with a trunnion with accessories). The assembly (Fig. 3) contains a trunnion 1, a seal 2 (antifriction gasket), a detachable flange 3, fixing screws 4, rolling elements - cylindrical rollers 5, a roller cutter 6, a washer 7, an angular contact serial bearing 8. Assembly of the bit begins from the nipple 1 (Fig. 1), which is screwed into the housing 2, then the roller cone is placed on the end surface of the nipple 1 on the housing 2 and the assemblies are assembled 3. The assembly of the assembly 3 (Fig. 3) is made in the following sequence . An angular contact bearing 8 is mounted in the roller cone 6, then a washer 7 is mounted, cylindrical rollers 5 are mounted on the washer 7, then a pin is screwed in, two split parts of the flange 3 are inserted and secured with screws 4, which are then fixed by welding. After checking the correct assembly and scrolling of the assembly 3 relative to the trunnion 1, the joints are indicated by arrows A, and the joint contour of the trunnion 1 with the housing 2 (Fig. 1), marked with the letter A, is welded. After cooling, the circuit connecting the nipple 1 with case 2 (figure 1), indicated by arrow A.

When the bit is operating, part of the axial load (permissible in accordance with GOST 20692-75 Table 6) will be perceived by an angular contact bearing 8 (Fig. 3). The rest (large) of the axial permissible load on the bit will be redistributed to the rolling elements along the line of their contact with the inner surface of the cone. The loading zone is about half the diameter (or 180 ° girth arc) of the cutter’s landing diameter, in which at least 1/3 of the rolling elements of the total number of cutters in the support will be simultaneously involved.

This makes it possible to significantly reduce contact stresses by increasing the area of contact between the rolling elements and the inner surface of the roller cone, i.e. linear contacts are significantly increased compared to the small dimensions of the rolling elements embedded in serial designs of roller cones with a large number of racetracks. In the proposed design due to the abolition of a large number of treadmills in the working area of the roller cone support, the rolling bearing has an equal durability, which they usually try to solve due to rearrangement of the rolling bearings (patent No. 2067150 of September 27, 1996).

A continuous ring-body eliminates the possibility of fracture of the paw sections at the joints of the welds, which occur due to the fault of the manufacturer (lack of penetration) and operators when the drilling modes are selected incorrectly (from shock and vibration).

The ring-body of the bit, which is compactly selected in height, makes it possible to reduce the length of the paw sections, reduce the overall height of the bit and increase the rigidity of the bit, and by eliminating the bulges to give the bit a regular cylindrical shape, which significantly improves the hydrodynamics of jet air or liquid flows and contributes to more efficient cleaning bottom hole, or rather provides higher drilling performance.

Claims (3)

1. A cone drill bit consisting of separate independent parts: a nipple with a taper lock thread and metric and hex flats for a turnkey assembly for disassembling, a casing in the form of a continuous ring with three holes for cleaning the bottom of the well and threaded holes for connecting to the nipple with nodes in assembly consisting of trunnion, roller cones, seals, rolling elements, washer, angular contact rolling bearing and split flange with mounting screws, acting as a lock ball bearing - locking mechanism outside the working axle, placed and fixed on the end plane of the roller cone, characterized in that the number of treadmills or rolling bearings is reduced to one, and the landing size for the rolling bearing - outer - is increased by reducing the diameter of the axle d in the mounting section of the rolling bodies on value d / D = 0.20, where d is the diameter of the trunnion section at the interface with the rolling bodies and D is the diameter of the bit, mm. 2. The bit according to claim 1, characterized in that the coefficient of performance, as well as the durability of one roller bearing, is greater than the sum of the same coefficients for two roller bearings with roller-ball-roller bearings at a selected ratio L / d = 30/18 = 1 , 7 instead of the conventional L / d = 2.0. 3. The bit according to claim 1, characterized in that the end plain bearing in the form of a heel is replaced by a serial angular contact rolling bearing.

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