RU2592911C1 - Roller cutter drilling tool - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: invention relates to rolling drilling tools for drilling with straight stroke of wells with stepped bottom or for expansion of previously drilled wells. Roller cutter drilling tool comprises body, to which leading rock cutting elements are connected, or it has device for connection of leading drilling tool of smaller diameter and/or drill rod, as well as attached legs with trunnions, on each of which there is rolling cutter on bearings arranged through axial orifice, capable to accommodate radial and multidirectional axial load, wherein inner ring of bearing is capable of perception of rolling cutter reverse axial load, rested against housing. Each of bearings is radial-thrust one. Inner bearing race, capable of perception of rolling cutter reverse axial load is installed on trunnion with possibility of axial movement and rested against housing by means of one or more of disk springs. There are two bearings capable to take up from rolling cutter straight axial load, inner ring of one of them, near to top of rolling cutter is installed on trunnion with possibility of axial movement and rested against collar journal through one or more of disk springs. Journal on side opposite to leg, is installed in hole of housing so that by preliminary axial pre-load is formed in radial thrust bearings as result of compression of Belleville springs.

EFFECT: technical result consists in increase of strength of pins of cutters, increasing service life of bearings and reduced labour intensiveness of manufacturing of rock drilling tool.

1 cl, 2 dwg

Description

The present invention can be used in mining for direct drilling of wells with a stepped bottom shape or to expand a previously drilled well.

Known bearing support of a drill bit containing paws with trunnions, on which the cone is mounted on bearings capable of absorbing radial and multidirectional axial load, one of which is a peripheral radial thrust lock, the outer ring of which is abutted in the locking device mounted on the roller cone from the side trunnion base. There is an angular contact bearing capable of perceiving direct axial load from the roller cone, the inner ring of which is mounted on the trunnion with the possibility of axial movement and rested in its collar through a disk spring (US Pat. No. US2007 / 0034413, IPC Е21В 10/00, publ. February 15, 2007).

The disadvantage of this design is the location of the locking device on the cone, which leads to a weakening of the cone body, reducing the diameter of the installed bearing. This leads to a decrease in the strength and durability of cones and their supports.

Known cone extender, comprising a housing in the form of a Central barrel with paws attached to it in the form of cages, support shafts with bearings that are detachably mounted between the cage and the Central barrel. The bearings are located in the through axial bore of the roller cone, the roller cone is fixed using a ball lock (AS RF No. 1808971, ЕВВ 10/28, publ. 04/15/1993).

The disadvantage of this design is the location of the locking device in the working area of the bearing support, which reduces its durability.

Closest to the claimed technical solution is a collapsible cone drilling tool containing a housing to which leading rock cutting elements are attached or it has a device for attaching a smaller diameter leading drill tool and / or drill rod, as well as paws with trunnions attached to each of which are mounted cone on bearings located in its through axial bore, capable of absorbing radial and multidirectional axial load, while the inner ring a bearing capable of absorbing the axial axial load from the cutter is abutted in the housing or locked at the end of the paw by means of a removable locking threaded element (US Pat. Utility Model No. 141747, IPC Е21В 10/28, publ. 06/10/2014).

The disadvantage of this design is the cantilever mounting of the cones of the cones, the possibility of significantly reducing the preload in the case of angular contact bearings, if the inner ring of one of them is abutted in the housing, or as a result of working out and wear, if it is locked at the end of the paw by means of a removable locking threaded element. This leads to a decrease in the strength of the cones and the durability of the bearings, increasing the requirements for precision manufacturing and installation.

The objective of the invention is to increase the strength of the trunnion trunnions and increase the durability of the bearings by providing two-pivot mounting trunnions and maintaining the preload of the angular contact bearings using springs while reducing the requirements for precision manufacturing and mounting of the cones, and thus reduce the complexity of manufacturing.

To achieve the indicated technical result, in a cone drilling tool containing a housing to which leading rock cutting elements are attached, or it has a device for attaching an advance drilling tool of smaller diameter and / or drill rod, and paws with trunnions are attached, on each of which a cone is mounted on bearings located in its through axial bore, capable of absorbing radial and multidirectional axial load, while the inner ring of the bearing, it is possible to perceive the axial load from the cone, rested against the housing, according to the invention, each bearing is angular contact, the inner ring of the bearing, capable of perceiving the inverse axial load from the cone, is mounted on the axle with the possibility of axial movement and is supported in the housing by means of one or several disk springs, there are two bearings capable of perceiving direct axial load from the cone, the inner ring of one of them closest to the cone top is mounted on the trunnion with the possibility of axial movement and rested against the collar of the trunnion through one or more cup springs, the trunnion from the side opposite the foot is installed in the bore of the housing in such a way that a preliminary axial tension is formed in angular contact bearings as a result of compression of the cup springs.

In FIG. 1 shows a cone drilling tool on the side; in FIG. 2 - local axial section of the bearing assembly of one of the cones.

Roller cone drilling tool consists of a housing 1, to which leading rock cutting elements (not shown) are attached or it has a device for connecting smaller diameter leading tools and / or drill rods (not shown), for example, in the form of a threaded sleeve 2.

Claws 3 with trunnions 4 are attached to the housing 1, on each of which a cone 5 is mounted on bearings located in its through axial bore, capable of absorbing radial and multidirectional axial loads. The bearing 6, capable of perceiving the reverse axial load from the roller cutter 5, is made radially thrust, its inner ring is mounted on the axle 4 with the possibility of axial movement and abutted into the housing 1 by means of, for example, two disk springs 7.

There are two angular contact bearings 8 and 9, capable of absorbing direct axial load from cone 5. The inner ring of the bearing 8, which is closest to the top of the roller cutter 5, is mounted on the axle 4 with the possibility of axial movement and rested against the shoulder of the axle 4 through, for example, one disc spring 10.

The pin 4 from the side opposite to the foot 3 is installed in the hole of the housing 1 in such a way that a preload is formed in the angular contact bearings 6, 8 and 9 as a result of compression of the disk springs 7 and 10.

To seal the bearing assembly, a sealing washer 11 can be used, which can transmit the axial force of the preload from the cup springs 7 to the inner ring of the angular contact bearing 8.

Works cone drilling tool as follows.

Axial force and torque are transmitted to the casing 1 and paws 3, as a result of which the casing 1 and cones 5 rotate, with the help of which the bottom hole is destroyed (not shown).

The leading rock cutting elements (not shown in the drawing) of smaller diameter or the leading boring tool attached to the threaded sleeve 2 (not shown in the drawing) drill the leading ledge of the well, freeing up space for the top of the cone 5, which does not have rock cutting weapons.

The forces from each cone 5 are transferred to angular contact bearings 6, 8 and 9 and to the pin 4, which has two bearings: on the one hand - paw 3; on the other, housing 1. As a result of the two-pivot mounting of the pins 4, their strength increases.

As a result of pre-compression of the disk springs 7 and 10, a preliminary axial preload is formed in the angular contact bearings 6, 8 and 9, which contributes to their better radial load capacity with multidirectional external axial forces from the cones 5. Direct axial force from the cones 5 that occurs during drilling and directed from their vertices is larger than the opposite, and is perceived by two angular contact bearings 8 and 9, capable of perceiving direct axial load from cone 5. Belleville spring 10 compensates for the errors in the base of the rings of angular contact bearings 8 and 9, and also creates a preliminary axial preload. Small deviations in the accuracy of manufacture or assembly do not lead to a complete loss of the preliminary axial preload of the angular contact bearings 6, 8 and 9, which means that the durability of the bearings of the cone 5 increases and the complexity of manufacturing the cone drilling tool is reduced.

Claims (1)

Rolling cone drilling tool containing a housing to which leading rock cutting elements are attached, or it has a device for connecting smaller diameter leading boring tools and / or drill rods, and paws with trunnions are attached, on each of which a roller cutter is mounted on an axial hole located in its through hole bearings capable of absorbing radial and multidirectional axial load, while the inner ring of the bearing, capable of perceiving reverse axial load from the cone , abutted in the housing, characterized in that each of the bearings is angular contact, the inner ring of the bearing, capable of absorbing the inverse axial load from the cone, is mounted on the axle with the possibility of axial movement and abutted in the housing through one or more disk springs, there are two bearings capable of perceiving direct axial load from the cutter, the inner ring of one of them, closest to the top of the cutter, is mounted on the trunnion with the possibility of axial movement and rests against the trunnion collar through one whether multiple disc springs, pivot the side opposite the claw, installed in the opening of the housing so that is formed in Axial preload the angular contact bearings as a result of compression of the Belleville springs.

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