RU2325502C2 - Rock drilling bit by malinkin-gribennikov - Google Patents

Abstract

FIELD: mining, drilling.

SUBSTANCE: said invention relates to drilling equipment, in particular, to rock-destruction tool - rock drilling bit designed for drilling wells of different purpose in oil, gas, exploration, ore mining and other fields. Provides for increase in roller bearing durability and lesser overall clearance in pin axis direction as regards to standard rock drilling bits. The rock drilling bit consists of a connector with taper tool-joint and metric thread and two parallel flats, a body with shortened shoe section and three openings for bottomhole cleaning, and threaded holes for connection and assembly mounting. The assembly consists of a pin, a roller, seals, a snap ring, rolling bearings, a locking mechanism, a taper friction bearing with antifriction liner, a hub, which acts as a plain thrust bearing, and a blocking pin with a dummy plug. The pin diameter interfacing with roller bearings is decreased by d=0.2D, where d is the interfacing diameter, mm; D is the drilling bit diameter, mm, and diameters of rolling elements in bearings are increased by the pin downscale value. The hub acts as a thrust bearing. The locking mechanism is located in the lower fifth of the roller cavity and is a hub screw secured by means of a pin and a dummy plug.

EFFECT: rock drilling bit design with improved performance characteristics and durability.

4 cl, 3 dwg

Description

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

A well-known design cone drill bit, where the locking device is outside the working trunnion in the annular grooves of the upper trunnion and roller cone (Patent No. 2166607 from 08.31.1999).

A bit with a similar cone support has a limited scope in the manufacture of serial sectional and body bits. Such bits are collected in sections, then welded to the body, or sections are welded and bored. Such bits are classified as non-separable, repairable and difficult to recycle.

The closest in technical essence to the claimed technical solution is a collapsible cone bit (Patent No. 2215112 of 08.21.2001), consisting of separate independent parts (nipple, case and assembly) - a prototype. The disadvantage of this design is the unreliable fastening of the node to the sections of the legs in the U-shaped grooves, which hang in the air and require additional fastening. Another disadvantage of this design is the upper location of the locking device, which does not allow the assembly to be fixed to sections of the legs without U-shaped slots.

The technical task of the claimed invention is to create a design that allows to separately produce separate independent parts of the cone bits, simplify the manufacturing and assembly technology, reduce labor costs for the production of bits, eliminate the need for expensive pressing and stamping equipment, reduce energy costs, produce bits in enterprises with limited technical equipment (non-specialized), make the bit maintainable, reliable, durable and predictable rokam guarantees on operating time.

The collapsible design of the bit with a modified housing and a screw locking device makes it possible to assemble the bit even in the field. Having a set of cones with different weapons (for rocks of different hardness), you can use the assembly as a multipurpose rock cutting tool for reusable use.

The task is achieved in that the nipple has a symmetrically arranged tapered locking thread for connection to the drill string and metric for connection to the body of the bit. The body with legs, made by casting or forging, is a one-piece construction. In order to reduce the cost of the bit, the body can be made of cheaper structural steel.

The modified cone support with a new locking device makes it possible to assemble without compromising the strength of the paw mount with a pin. The abolition of the lock ball bearing and the small roller bearing, as well as the reduction of the rolling elements of the large roller bearing, ensure the system reliability of the product. Ensuring the ratio d = 0.2 D (d is the pin diameter at the bearing seat, mm and D is the bit diameter, mm) increases the durability of the cone bearings and reduces the total clearance in the axial direction of the pin compared to serial bits where it is practically impossible to ensure exact match between tracks of trunnions and cones due to the large number of bores.

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

- the nipple has a bilateral symmetrically located tapered lock thread for quick replacement when worn or damaged;

- the case with shortened sections of the legs with holes and a metric thread for connection with the assembly assembly is designed for multipurpose and reusable applications and can be made of structural steel in order to save nickel-containing alloys;

- instead of plain bearings, all types of bearings can be used in roller cone bearings (sliding, rolling - serial and bulk type serial bits);

- the number of bulk rolling bearings is limited to one;

- instead of the lock ball bearing and small roller, one more powerful roller bearing (bulk) was used;

- the inner cone of the cones along the wall thickness remained unchanged, and the cross section of the pin was reduced by using the ratio d = 0.2 D, providing a five-fold safety factor in terms of yield strength for steel 20KhNZA;

- reducing the cross section of the trunnion in the places where the bearings are mated allowed to significantly increase the diameters of the rolling elements, which directly increases the durability of the rolling bearings;

- a locking device having a top location at the prototype, is moved down to the bottom and is structurally connected with the working part of the roller cutter, which plays the role of a hub for grinding rock in the bottom of the well;

- the hub performs the function of a heel and a thrust sliding bearing and is made of high-strength material capable of fulfilling its purpose in time (with one-sided wear before the other parts of the bit wear out);

- the cylindrical shape of the body of the bit without sagging metal and straight channels improve the conditions of mowing the drilled rock to allow, if necessary, to increase the diameters for the hydraulic nozzles, as well as increase the flow rate of flushing fluid without erosion of the walls, cavitation and loss of hydraulic power on the bit;

- fixing the hub relative to the trunnion is carried out using a pin, which is mounted in the drilled holes of the cone and trunnion and is closed with a threaded metal plug, then fixed by welding.

Therefore, the claimed invention meets the criterion of "novelty." The proposed technical solution makes it possible:

- perform final assembly at factories or in the field of operation, taking into account specific mining and geological conditions;

- promptly deliver and replace individual units and parts, since they are much lighter than the chisels by weight (non-separable serial - sectional or body);

to simplify manufacturing and assembly technologies, organize the production of knots and parts of bits at non-specialized enterprises with limited technical equipment and low production culture;

- significantly reduce the labor costs of the entire production of bits by simplifying the configuration of the bit and reduce its weight by evenly distributing the mass of metal over the volume of the workpiece, as well as the rejection of the energy-intensive technology of sectional stamping of combined paws with a pin;

- apply various modifications of the cone bearings according to the type and location of the bearings (rolling, sliding, bulk);

- to predict the stability of the weapons cones due to the actual resistance of the support cones;

- reduce the likelihood of loss of cones in the well; to increase the operational resource of the bit and improve the cleaning of the face, which will reduce the number of time-consuming and costly hoisting operations;

- increase the penetration of the bit and predict its durability over time through the use of standard rolling bearings and more powerful bulk;

- apply more rational plain bearings with modern anti-friction materials;

- make the bit maintainable and easily disassembled for disposal of worn parts.

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, the window meets the criterion of "industrial applicability".

Figure 1 shows the bit assembly. Figure 2 shows the components of a three-cone bit: 1 - nipple, 2 - body, 3 - a set of cones. Figure 3 shows the node assembly (cone with a pin). The assembly contains a pin 4, a seal (rubber-metal) 5, a steel spring ring 6, a rubber seal (ring-shaped) 7, a roller cone 8, a rolling bearing (cylindrical rollers) 9, a hub screw 10, a tapered plain bearing 11, a locking pin 12, an antifriction gasket 13 , hub 14, plug 15.

The assembly of the bit begins with the nipple 1 (Fig. 1), which is screwed into the housing 2. Then, in assembled form, they are placed on the end surface of the nipple 1, and the assemblies are mounted on the housing 2. The assembly is assembled first with the first roller cone with the internal side of the body of the bit. Then, regardless of the cone number, the next assembly is assembled. The assembly of the second and third nodes is as follows. The cone 8 with the parts mounted in it according to the specification is attached to the inner surface of the housing 2, into which the pin 1 is screwed (Fig. 3). Then, with the help of the spring ring 6, the sealing elements are fixed in the annular undercut of the cutter 8. According to this technology, the third assembly is assembled. After the assembly is completed, control measurements are made, the assemblies are fixed relative to the housing 2 (Fig. 1) by welding along the contour of the diameter of the journal from the outside of the housing 2 (Fig. 1).

During operation of the bit, a part of the axial load relative to the pin 4 (Fig. 3) through the lower part of the cone, the hub 14 will be perceived by the end surface of the cut cone 8 and the conical part of the pin 4, which acts as a persistent heel, a persistent plain bearing and a tapered plain bearing. The rest of the axial load from the bottomhole reaction will be perceived by a cylindrical roller bearing, which can be considered as a combination of small and large roller bearings paired to ensure equal durability. However, due to a significant increase in the diameter of the rollers and the same size of the small and large bearings, the reliability and durability of the cone bearings are significantly increased due to the redistribution of the axial force on the bit.

The solid ring of the bit body eliminates the collapse of the sections of the legs due to the loss of strength of the welds (nipple part) during vibrations and various longitudinal and transverse vibrations during drilling. The abolition of the lock ball bearing and the displacement of the locking mechanism relative to the working area of the trunnion provides multivariate execution of the cone support. Reducing the diameter of the journal at the points of installation of the bearings in the ratio d = 0.2 D allows to significantly increase the size of the rolling bodies in bulk rolling bearings and to use standard rolling bearings with cages and with the estimated dimensions of the rolling bodies (as in the serial bearings cone of drill bits). Straight lines of a collapsible bit can significantly improve the hydrodynamics of jet streams of air or liquid, which leads to more efficient cleaning of the bottom of the well, thereby ensuring higher drilling performance.

The materials of the hub, thrust heel, plain bearings, as well as rolling bearings and sealing elements are selected taking into account their physical and mechanical properties and antifriction capabilities. The proposed design of the cone drill bit is more compact and rigid compared to the bit designs known in the patents and commercially available in our country and abroad, in which elongated sections of the paws are susceptible to axial and longitudinal elastic vibrations, which is reflected in the drill string and the formation of shallow wells (with open mining).

Claims (4)

1. Roller cone bit, consisting of a nipple with a taper lock and metric thread and two parallel flats, a body with shortened sections of the paws and three holes for cleaning the bottom and threaded holes for connection with the nipple and the assembly, the assembly, consisting of a journal, roller cones, sealing elements, spring ring, rolling bearings, locking mechanism, tapered plain bearing with antifriction liner and hub, which acts as a thrust sliding bearing, and a locking pin with a stopper Coy, characterized in that the diameter of the spigot at the interface with the rolling bearings is reduced by the value d = 0,2 D, where d - diameter of the coupling, mm; D is the diameter of the bit, mm, and the diameters of the rolling elements in the bearings are increased by the size of the reduced trunnion, the hub acts as a heel, and the locking mechanism is located in the lower fifth of the cone cavity and is a hub screw, which is fixed with a pin and plug - stubs. 2. The bit according to claim 1, characterized in that according to the design and assembly technology, the prefabricated nodes are not the same. 3. The bit according to claim 1, characterized in that the locking mechanism is located in the lower part of the cone cavity and is a screw connection, which is fixed with a pin and a plug. 4. The bit according to claim 1, characterized in that to accommodate the locking mechanism, the fifth part of the cutter in height in the lower part is cut and expanded to the required size due to the hub-screw made of high-strength material.

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