RU2357065C1 - Support of cone bit - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: invention refers to rock destroying tool, particularly to supports of cone bits. The said technical result is achieved like follows: the suggested support consists of a sleeve bearing, exterior surface of which is coated with a layer of a wear resistant material. Also the surface of the wear resistant material is cut with grooves filled with solid lubricant. Depth of grooves is 0.4-0.6 from thickness of the layer of wear resistant material. In addition, the layer of wear resistant material can be applied as on exterior surface of the journal, so on interior surface of the roller cutter; while the grooves for lubrication are cut as screwed or direct line parallel to journal axis.

EFFECT: upgraded wear resistance of support due to reduced accidental ingress of abrasive material into loaded part of support, when interacting surfaces of journal and roller cutter are simultaneously lubricated.

2 cl, 6 dwg

Description

The invention relates to a rock cutting tool, and in particular to bearings of rolling cutter bits.

A support of a cone bit containing a pin is known, on which a roller cone with working elements is installed by means of sliding and rolling bearings, one of which is a lock, (see the manual “Drill bits”, Paliy P.A. and Korneev K.E., Moscow: Nedra, 1971, p. 175, fig. VI.29).

The disadvantages of this support include its quick failure. This is especially true when using bits for drilling hard and hard rocks, the efficiency of which is determined by the value of the axial load.

The closest to the proposed technical essence and the achieved result is the support of the cone bit containing a pin and a cone with a locking element and a sliding bearing, the outer surface of which is covered with a layer of wear-resistant material (see US patent No. 36205480, CL Е21В 10/22, 1971) .

In this support, due to the surfacing of the working surfaces of the sliding bearing with wear-resistant material, the resistance of the support is significantly increased.

The disadvantage of the prototype is the chipping of the reinforced surface of the sliding bearing, especially when drilling with high axial loads. Particularly significant wear of the reinforced surface of the support is observed when abrasive particles enter the support. The latter during rotation of the cone form scratches on the working surface of the sliding support, resulting in a spalling of the reinforced surface and its quick failure. All this reduces the efficiency of the support, and therefore the bit as a whole.

In accordance with the stated technical object of the invention is to increase the stability of the support by lubricating it and reducing the likelihood of abrasive particles getting into the loaded part of the sliding support.

The stated technical problem is solved in that in the support of a cone bit containing a pin and a cone with a locking element and a sliding bearing, the outer surface of which is covered with a layer of wear-resistant material, according to the invention, the working surface of the wear-resistant material is made with grooves filled with solid lubricant and having a depth of 0 , 4-0.6 from the height of the layer of wear-resistant material, and the contacting surfaces of the sliding bearing and wear-resistant material are formed by depressions and response lines PAMI, arranged angularly offset relative to the grooves of the solid lubricant.

The solution of the problem also contributes to the fact that:

- a layer of wear-resistant material is applied on the outer surface of the journal or on the inner surface of the cone;

- the grooves for lubrication are made in the form of a helical line or a straight line parallel to the axis of the journal.

This embodiment of the support provides constant lubrication of the sliding support and virtually eliminates the ingress of abrasive sludge into the loaded area of the sliding bearing of the bit and thereby increases its resistance.

The invention is illustrated in the drawing, in which figure 1 depicts a General view of the support of the bit in section; figure 2 - section aa in figure 1; Fig.3-5 embodiments of the support and Fig.6 is a section bB in Fig.5.

The support of the cone bit includes a pin 1 and a cone 2 with a locking element 3 (Fig. 1) or 4 (Fig. 5), a sliding bearing 5, the contact surface of which between the pin 1 and the cone 2 is coated with a layer of wear-resistant material 6. The working surface of the wear-resistant material 6 is made with grooves 7 with rounded edges filled with solid lubricant 8, for example, based on graphite, molybdenum disulfate, etc. The depth of the grooves 7 is 0.4-0.6 of the height of the layer of wear-resistant material 6, made on a carbide basis with the addition of chromium, tungsten and cobalt. A layer of wear-resistant material 6 can be applied to the outer surface of the journal 1 (see Fig. 4-6) or to the inner surface of the cone 2 (see Fig. 1-3). The contacting surfaces of the sliding bearing 5 and the wear-resistant material 6 are formed by cavities 8 and mating protrusions 9 located with an angular offset relative to the solid lubrication grooves 7. The grooves 7 can be made both in the form of helical lines (see Figs. 1-3), and in the form of straight lines parallel to the axis of the pin 1 (see Figs. 4-6). The length of the grooves 7 is chosen so that it is equal to at least the length of the sliding bearing 5 to ensure lubrication of its entire working surface. When applying a layer of wear-resistant material 6 on the trunnion 1, at least one of the straight grooves 7 should be located above the loaded part of the trunnion 1 (see Fig.5-6). The implementation of the grooves 7 on the inner surface of the cone 2 provides lubrication of the sliding bearing 5 with a minimum number of grooves 7, which is essential primarily for small bits, because in these bits, even a slight weakening of the cutter body 2 or pin 1 can lead to a premature exit of the cutter, and therefore the bit as a whole, out of order. When the bit is operated with the proposed support, if abrasive material enters its cavity when the cutter 2 rotates, the abrasive material collects in the grooves 7, displacing grease 8 from there, which enters the friction surfaces between the pin 1 and the cutter 2, thereby increasing their service life. Particles of wear-resistant material 6 also accumulate in the grooves 7, which also wears out and crashes during operation of the bit at the bottom of the well. Sealing the support is carried out by a sealing element 9 located at the end of the journal 1.

All this allows you to increase the stability of the support by reducing the likelihood of abrasive sludge getting into the loaded part of the support while providing lubrication of the friction surfaces of the journal and cone. Especially effective is the use of the proposed technical solution when working in forced modes.

Claims (2)

1. Support cone bit containing a pin and a cone with a locking element and a sliding bearing, the surface of which is covered with a layer of wear-resistant material, characterized in that the working surface of the wear-resistant material is made with grooves filled with solid lubricant and having a depth of 0.4-0, 6 from the height of the layer of wear-resistant material, and the contacting surfaces of the sliding bearing and wear-resistant material are formed by depressions and mating protrusions located with an angular displacement relative to the channel Wok for solid lubricant. 2. Support roller cone according to claim 1, characterized in that the grooves for lubrication are made in the form of a helical line or a straight line parallel to the axis of the journal.

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