RU2463430C1 - Method of assembling positive displacement motor sectional stator - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: first section with left-and-right threaded ends is clamped in assembly chuck. Adapter with left-and-right threaded ends is screwed in said first section to make gap H equal to 15-20 mm. Second stator section is screwed on adapter second threaded end to make the gap identical to that of first section. Then, mounting appliance made up of core with screw surface fitting with that of sections to be jointed together is inserted through first section into second sections o that their screw surfaces are aligned. Gaps H with allowance of ±0.3 mm is are retained. With said screw surfaces of both sections jointed together, core is driven to second section end. Then, first section is released from aforesaid chuck to clamp core therein and to clamp adapter therein. Now, chuck is switched on so that its rotation is transferred to both sections. Sections are screwed on adapter toward each other unless gaps H are taken up and threads are tightened as required.

EFFECT: faster assembly.

2 cl, 2 dwg

Description

The invention relates to downhole screw motors and can be used in their manufacture.

As a prototype, a description of the invention by A.S. No. 1192432, ЕВВ 4/02, publ. 07.07.89 "Mounting device for the oriented assembly of the working bodies of the downhole motor, the method of its adjustment and the method of oriented assembly of the working bodies of the downhole motor".

In accordance with the above description, the mounting device for assembling the stators includes spaced on the rod movable (rotating) and fixed with profile surfaces of the sleeve. The movable sleeve is equipped with a correction unit consisting of equally spaced apart radial notches deposited on the outer end of the movable sleeve and a disk having the same number of radially notches located in the same way. The number of radial notches in general cases is equal to the lead-in of the profile surface of the stator mounting device.

The stator is assembled from sections and a sub with unidirectional thread at the ends by means of a mounting device. First, the stators are connected to one another by a threaded sub and they are pre-fixed to each other by threads. Then, mounting device is placed on the profile surfaces of one and the other stators so that the profile surface of the movable sleeve is located on the profile surface of one stator, and the profile surface of the fixed sleeve is on the profile surface of the other stator. Next, the final sequential fastening of the threads on each section is performed. When fastening the threads, one of the stators is set to a delay together with the fixed sleeve of the mounting device, and the other stator with the movable sleeve is turned relative to the fixed parts. In this case, the coincidence of the radial notches of the disk and the radial notches of the correction unit is achieved in the range of angular displacements of the connected parts (stators and threaded sub) within the permissible torques for the screwed threads.

Signs of a known technical solution, coinciding with the features of the claimed invention, are the presence of operations of preliminary connection of the sections and the sub between the threads at the ends and combining the profile surfaces of the connected sections with the mounting fixture.

The reason that prevents obtaining a technical result in a well-known technical solution, which is provided by the invention, is to use sections and a sub with unidirectional thread for assembly and to use as a result a complex mounting device that requires a lot of time to configure it during assembly, as well as screwing it one by one stators on the sub.

The problem to which the invention is directed, is to increase the efficiency of assembly of sections of stator screw downhole motors.

The technical result, which provides a solution to the problem, is to increase the assembly speed and reliability of fastening of threaded joints.

The technical result is achieved by the fact that in the method of assembling the sectional stator, including the use of sections and a sub with threads at the ends, preliminary connecting the sections to each other by the sub, combining the profile surfaces of the sections to be connected with the mounting fixture, according to the invention, sections and a sub with opposite directional threads are used for assembly at the ends, with the preliminary connection of the sections with the sub, the same gaps must be left between the ends of the sections and the ends the middle part of the sub, then, when the sub is delayed (fixing), the mounting device is rotated, transmitting rotation from it to the stator sections, which are simultaneously screwed onto the sub to meet each other until the gaps are selected and the thread is tightened between them, and a core with a screw is used as the mounting device surface corresponding to the helical surface of the connected sections. The technical result is also achieved by the fact that glue is applied to the threaded surfaces before assembly.

Use for assembly of the stator sections and sub with opposite threads at the ends, a mounting device in the form of a core with a screw surface corresponding to the screw surface of the connected sections, leaving the same gaps between the ends of the sections and the ends of the middle part of the sub during pre-assembly, rotation of the core when the sub is delayed rotate both sections, which are screwed onto the sub to meet each other until the selection of clearances and tightening the thread, provides cantly reduce assembly time compared with the prior art by eliminating the tuning operation of the mounting device and exclusion screwing one of the stator sections. The application of glue to the threaded surfaces before assembly makes it possible to securely fasten the threaded joints.

New features of the claimed technical solution are to use sections and sub with opposite directional threads for assembly, to leave the same gaps between the ends of the sections and the ends of the middle part of the sub when the sections are pre-connected with the sub, as a core mounting device with a screw surface, the corresponding helical surface of the connected sections, in the rotation of the core during the delay of the sub, transferring the rotation of the sections to them and simultaneously om screwing them onto the sub to meet each other until the selection of the clearances and the corresponding tightening of the threads. A new feature is also the coating of threads with glue before assembly.

The invention is illustrated by drawings, where

figure 1 shows a pre-assembled stator with a core inserted into it;

figure 2 shows the finally assembled stator.

Assembly sectional stator helical downhole motor is as follows. One section 1 having oppositely directed threads at the ends is fixed in the key holder for assembly. The sub 2, which also has oppositely directed threads at the ends, is screwed into section 1 until a clearance H of 15 ÷ 20 mm is obtained. The other stator section 3 is screwed onto the second threaded end of the sub 2, leaving the same gap as in the previous section 1. Then, the mounting device in the form of a core 4 with the screw surface corresponding to the screw surface of the connected sections is introduced into section 3 through section 1, combining their screw surfaces. In this case, the preservation of the gaps H with a tolerance of ± 0.3 mm is controlled. After combining the screw surfaces of both sections, the core is brought to the end of section 3. Then section 1 is released from the cartridge, the core is clamped in it, and the sub 2 is fixed in the key delay (fixed). Further include a cartridge, a rotating core, the rotation of which is transmitted to sections 1.3. Since the threads connecting the sub and the sections are oppositely directed, the sections begin to screw on the sub 2 towards each other until the gaps H are selected and the threads are tightened accordingly. Threads are lubricated with glue before assembly. Therefore, at the end of the assembly, the threads are fastened both by tightening and with glue that strengthens the threaded connections.

Claims (2)

1. A method of assembling a sectional stator of a downhole motor, including the use of sections and an adapter with threads at the ends, preliminary connection of the sections between the adapter, combining the profile surfaces of the connected sections with a mounting device, characterized in that sections and an adapter with opposite directional threads are used for assembly at the ends, with the preliminary connection of the sections with the sub, the same gaps must be left between the ends of the sections and the ends of the middle part of the transponder, then when the sub is delayed (fixing), the mounting device is rotated, transmitting rotation from it to the stator sections, which are simultaneously screwed onto the sub to meet each other until the gaps are selected and the thread is tightened between them, and a core with a screw surface is used as the mounting device, corresponding screw surface of the connected sections. 2. The method according to claim 1, characterized in that before starting the assembly, glue is applied to the threaded surfaces.

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