RU2349730C1 - Drilling bit washing device - Google Patents

Abstract

FIELD: mechanics, mining.

SUBSTANCE: washing device incorporates a hollow casing with a tapered thrust ledge on its inner surface, jet nozzle with a sealing element fitted on the said ledge and a retainer representing a threaded bush in contact with the said nozzle top end face. The device incorporates additionally extra sealing elements fitted above and below the main sealing element. The upper sealing element is arranged in the area where the casing, the nozzle and the threaded bush are in contact. The lower sealing element is fitted between the thrust ledge and nozzle, shifted relative to the main sealing element towards the nozzle axis. The threaded bush lower end face and the casing have, in the contact area, the parallel tapered sections forming the seat for the upper extra sealing element. The apex of tapered sections faces the nozzle. The lower extra sealing element is fitted in circular space between the additional stages on the nozzle lower end face and the casing thrust ledge.

EFFECT: simpler mounting and dismantling, higher reliability and efficiency.

4 cl, 3 dwg

Description

The invention relates to a rock cutting tool of a hydromonitor type, and in particular to their washing units.

A well-known flushing unit of the drill bit, comprising a housing with a supporting ledge, on which a nozzle with a sealing ring is installed, and a latch in contact with the upper end of the nozzle (see US patent No. 3823789, CL 175-340, 1974).

The disadvantage of this flushing unit is the lack of reliability associated with low reliability sealing. In addition, this flushing unit has a complex structure, which increases the cost of the entire bit.

The closest to the proposed technical essence and the achieved result is a drill bit flushing unit containing a hollow body with a supporting ledge on the inner surface, a water monitor nozzle with a sealing element placed on it, and a clamp in the form of a threaded sleeve in contact with the upper end of the nozzle (see patent RF № 2096577, class Е21В 10/18, published in 1997).

This flushing unit has a simpler design than the analogue and, as a consequence, a lower cost. Its disadvantages include the relatively high probability of flushing fluid getting between the body and the nozzle through the gaps between the contacting ends of the retainer and the nozzle, as well as between the supporting ledge and the lower end of the nozzle. These disadvantages are especially pronounced in large-diameter bits, in which nozzles of a large diameter are also used. The ingress of flushing fluid between the nozzle and the casing, especially in the presence of abrasive particles in it, will inevitably lead to erosion of the casing and the sealing ring located in this cavity and, as a result, to a sharp deterioration in the hydrodynamic parameters of the flushing unit.

In connection with the stated technical result of the invention is to increase the efficiency of the washing unit by increasing the reliability of sealing and improving its hydraulic perfection.

To achieve the technical result, the flushing unit of the drill bit, comprising a hollow body with a tapered abutment ledge on the inner surface, a water monitor nozzle with a sealing element placed on it, and a retainer in the form of a threaded sleeve in contact with the upper end of the nozzle, is equipped with additional sealing elements located above and below the main sealing element, while the upper sealing element is placed in the contact zone of the housing, nozzles and threads oic sleeve, and the lower - between the support shoulder and nozzle body offset relative to the main sealing member toward the nozzle axis.

The solution to the problem contributes to the fact that:

- the lower end of the threaded sleeve and the housing in the zone of contact with the nozzle are made with conical sections forming a socket under the upper additional sealing element, with the top of the conical sections facing the nozzle;

- the lower end of the nozzle and the reference ledge of the housing are made with additional steps, while the lower sealing element is installed in the annular cavity between the additional steps of the nozzle and the housing;

- conical sections of the housing, nozzle and threaded sleeve, forming nests for sealing elements, are made with different taper angles, decreasing from sections with a large diameter to areas with a smaller diameter.

In FIG. 1 shows a General view of the washing unit in longitudinal section; in FIG. 2 and 3 are fragments of the housing and nozzle, respectively, on an enlarged scale.

The washing unit contains a hollow body 1 with a tapered abutment ledge 2 on the inner surface, on which a hydraulic monitor nozzle 3 with a sealing element 4 is installed. The nozzle 3 is pressed against the housing 1 by the lower end of the clamp made in the form of a threaded sleeve 5. Housing 1 is made with three conical sections 6, 7 and 8 on the inner surface, and the nozzle 4 with two conical sections 9 and 10 on the outer surface, located opposite to the lower conical sections 7 and 8 of the housing 1. Conical sections 7, 8 of the housing 1 and 9, 10 - nozzles 3 in the working position are offset relative to each other in height and form nests under the main 4 and lower additional sealing element 11. In this case, the socket under the upper sealing element 12 is formed by a conical section 6 of the housing 1 and a conical section 13 of the lower part of the threaded sleeve 5. Conical sections 6-8 of the body and 9-10 nozzles are made in the form of an inverse cone, i.e. when the top of the cone is facing the nozzle 3. In this case, the taper angle of the conical sections 6-8 of the body and the conical sections 9-10 of the nozzle 3 decreases from sections with a larger diameter to areas with a smaller diameter, i.e. the largest angle of taper has a section under the upper additional sealing element 12, and the smallest section under the lower sealing element 11. Thanks to this embodiment of the conical sections, the same operating conditions of all sealing elements 4, 11 and 12 are ensured. This is explained by the fact that the sealing rings have different areas contact with the housing 1, and the preload force acting on them from the threaded sleeve 5 is the same. Due to the change in the angle of inclination of the conical sections, it is possible to provide the same specific load on the sealing elements 4, 11 and 12, and thereby ensure their equal resistance. The upper sealing element 12 is located in the contact zone of the housing 1, the nozzle 3 and the latch in the form of a threaded sleeve 5 in the socket formed by the conical sections 6 and 13, respectively, of the housing 1 and the threaded sleeve 5. The lower sealing element 11 is located in the socket formed by the conical sections 8 and 10, respectively, of the housing 1 and the nozzle 3, and is offset relative to the main sealing element 4 in the direction of the axis of the nozzle 3.

The assembly of the node is as follows. In the housing 1, a nozzle 3 is installed with sealing elements 4, 11 and 12 and is pressed by their threaded sleeve 5.

During the operation of the drill bit, the destroyed rock is carried out by the flushing fluid supplied to the bottom of the well through the flushing units. Moreover, due to the use of additional sealing elements 11 and 12, reliable sealing of the assembly is ensured regardless of the diameter of the nozzles 3. The flushing fluid from the side of the threaded sleeve 5 cannot enter the gap between the housing 1 and the nozzle 4 due to the upper sealing element 12 located in the contact zone of the housing 1, nozzles 4 and bushings 5. And from the side of the lower end of the nozzle 4, the flushing fluid cannot get into the gap between the supporting portion 2 and the lower end of the nozzle 4 due to the lower seal Nome element 11 disposed offset in the direction of the nozzle 4 relative to the main axis of the sealing member 4.

The application of the proposed site ensures the reliability of the sealing of the washing unit, regardless of the diameter of the bit used and the corresponding nozzles, and thereby increases the overall performance of the bit.

Claims (4)

1. A flushing assembly of a drill bit, comprising a hollow body with a tapered abutment shoulder on the inner surface, a water monitor nozzle with a sealing element placed on it, and a latch in the form of a threaded sleeve in contact with the upper end of the nozzle, characterized in that it is equipped with additional sealing elements located above and below the main sealing element, while the upper sealing element is placed in the contact zone of the housing, nozzle and threaded sleeve, and the lower - between the reference ledge to housing and nozzle with an offset relative to the main sealing element in the direction of the axis of the nozzle. 2. The flushing unit of the drill bit according to claim 1, characterized in that the lower end of the threaded sleeve and the housing in the contact zone with the nozzle are made with conical sections forming a socket for the upper additional sealing element, with the top of the conical sections facing the nozzle. 3. The flushing unit of the drill bit according to claim 1, characterized in that the lower end of the nozzle and the bearing ledge of the housing are made with additional steps, while the lower sealing element is installed in the annular cavity between the additional steps of the nozzle and the housing. 4. The flushing unit of the drill bit according to claim 1, characterized in that the conical sections of the body, nozzle and threaded sleeve forming nests for the sealing elements are made with different taper angles, decreasing from sections with a large diameter to areas with a smaller diameter.

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