RU698336C - Screw face engine - Google Patents

Description

The invention relates to a technique for drilling wells, namely, downhole motors for drilling oil and gas wells.

Known screw engine containing the working bodies in the form of a screw, gerotor mechanism, a two-joint cardan shaft and a support node.

Also known is a downhole screw motor comprising a rotor and a stator having a helical tooth and an axial rolling support assembly including cages fixed in the housing.

A disadvantage of known rotary engines is the complexity of the design and the many-component support assembly, as well as the significant axial dimensions of the engine, the latter complicating the use of the engine in directional drilling of wells where it is necessary to have the shortest possible length.

The aim of the invention is to simplify the design and increase the durability of the downhole motor.

This is achieved by the fact that the engine support assembly is provided with a roller rigidly connected to the rotor and having toroidal surfaces, and the cages are made with conical surfaces to interact with the toroidal surfaces of the roller.

Figure 1 is a longitudinal section of the engine; figure 2 - scheme of action of si in contact with the clip roller

The motor comprises a stator 1 with internal helical teeth made of elastic material, for example rubber, a rotor 2 with external helical teeth, a driveshaft 3, an axial rolling support unit, support unit k includes a roller 5 with toroidal rolling surfaces, rigidly coupled to the rotor 2, the upper 6 and lower 7 cages and intermediate rings 8 and 9, fixed in the housing of the support unit 4, a package mounted from the upper and lower cages and intermediate rings, is installed coaxially with the stator in the housing of the support unit. The upper and lower cages contain conical surfaces that interact with the toroidal surfaces of the roller. The diameters of the circles along which the roller contacts the thrust washers are selected from the condition of minimal slippage. In the lower part of the engine there is a nipple (radial support) 10. The output shaft of the engine 11 is connected to the sub to the bit 12.

Engine. Works as follows.

When the flushing fluid is supplied, the rotor 2 performs a planetary motion, rolling around the stator teeth. In this case, depending on the direction of action of the axial load, the roller 5 is in contact with either the upper support cage 6 or the lower 7, and receives the corresponding axial load.

It can be seen from the diagram (Fig. 2) that by changing the angle And it is possible to adjust the magnitude of the radial component (Rad) of the axial force (P) and thereby partially or completely relieve the stator from the action of radial forces.

This embodiment of the support assembly simplifies the design of the engine, almost halves its length and mass, and unloads the rotor from the action of radial forces, which increases its durability.

Since the average diameters of the roller and cage differ by a small amount equal to two eccentricities, the increased reduced radii of curvature in the contact of the surfaces of the roller and cage create low stresses in the contact of the roller with the cages, which provides the necessary bearing capacity,

The engine can be successfully used in directional drilling, where the length of the downhole motor is especially important to obtain satisfactory borehole curvature parameters.

x

fig ..