RU2316676C2 - Method of manufacture of screw pump stator (versions) - Google Patents

Abstract

FIELD: mechanical engineering; mining equipment.

SUBSTANCE: invention relates to manufacture of stators of screw pumps used in screw pumps and downhole motors. Proposed method of manufacture of screw pump stator comes to making of elastic by successive application of layers of green rubber mix onto forming core to form cylindrical blank with outer diameter corresponding to inner diameter of housing with ends made for connection with other parts of equipment. According to first design version, polymerizing composition material is used in manufacture of housing which is applied to elastic part to form housing, and then curing of elastic part and polymerization of housing are carried out at preset temperature. According to second design version, after assembling of elastic part on forming core, it is cured and then layers of polymerizing composite material are applied to cured elastic part fitted on forming core to form housing which is then polymerized at preset temperature.

EFFECT: improved quality of articles, possibility of manufacture of stators of any required industrial length.

4 cl, 2 dwg

Description

The invention relates primarily to the manufacturing technology of rubber technical products and is intended for the manufacture of stators of screw pumps.

A known method of manufacturing metal-polymer products, in particular a cage of screw pumps, comprising sequentially applying layers of raw polymer material to the forming core to form a cylindrical billet with an outer diameter corresponding to the inner diameter of the casing, with ends made with the possibility of connection with other parts of the equipment, installing the core with the elastic part of the product concentrically into the body with adhesive pre-applied on its inner surface, crimping is elastic part of the product when applying a polymer material from the end face under pressure, vulcanizing it and removing the core from the finished product (see SU 1666343 A1, 07/30/1991, B29C 67/18).

The specified method allows the manufacture of helical teeth with an elastic layer of the same thickness, makes it possible to obtain multilayer long-length stators of a screw pump, which significantly improves the quality of the products.

However, as practice has shown, the disadvantage of the proposed method is that with an increase in the length of the stator, difficulties arise with the introduction of a core with an elastic part into a metal casing, as well as difficulties associated with ensuring reliable crimping of the elastic part to the casing.

The task of the invention is to provide high quality and increase the MTBF of screw pumps, as well as providing reliable technology for their manufacture.

The task according to the first embodiment is achieved in a method of manufacturing a stator of a screw pump, which includes the manufacture of an elastic part by sequentially applying layers of crude rubber to the forming core to form a cylindrical billet with an outer diameter corresponding to the inner diameter of the casing, with ends made with the possibility of connection with other parts of the equipment according to the invention to obtain a housing using a polymerizable composite material, which akladyvayut on the elastic part, forming a casing, then at a given temperature vulcanization provide both the elastic part, and polymerizing the housing.

In addition, in the elastic part, the stator helical tooth ridges are reinforced by layer-by-layer laying in the depressions formed after applying the working layer, rubber-fabric ribbons and metal or plastic reinforcement of various configurations to the forming core.

In addition, when the body is formed from a polymerizable composite material, metal tips of various designs are installed at its ends.

The task of the second embodiment is achieved in a method of manufacturing a stator of a screw pump, which includes the manufacture of an elastic part by sequentially applying layers of crude rubber to the forming core to form a cylindrical billet with an outer diameter corresponding to the inner diameter of the casing, with ends configured to connect to other parts of the equipment according to the invention, after assembling the elastic part on the forming core, it is vulcanized, then on the volcano layers of polymerizable composite material are laid over the molded elastic part, dressed on a forming core, forming a body, then it is polymerized at a given temperature.

The invention is illustrated by drawings.

Figure 1 shows a variant of obtaining the elastic part of the stator of a screw pump by sequentially applying layers of crude polymer material to the forming core 1, which may have different physical and mechanical properties in the elastic layers 2, 3, 8, 9, 10, etc. ., their quantity, chemical resistance, adhesive properties, providing reliable fastening to the housing 11 from composite materials, the introduction of reinforcing layers of rubber tape 6 and reinforcement 7 in the form of shaped metal or plastic whips.

Figure 2 shows an installation option in the housing 11 of the metal heads 12, 13 of various designs directly during its assembly on the elastic part of the product.

According to the first embodiment, the method can be implemented as follows. First, a uniform layer 2 is formed from the raw polymeric material on the core forming part 1 of the product, then an elastic layer 3 is applied to the elastic layer 2 (Fig. 1), then rubber bands 6 and metal or plastic reinforcement 7 are laid along the cavity 4 of the helical tooth 5 The embodiment of the elastic part of the product may differ by the presence or absence of both rubber-fabric tape 6 and reinforcement 7, geometry of the reinforcement, various physical and mechanical parameters in the elastic layers 2, 3, 8, 9, 10, etc., as well as their number ohm resistance, chemical resistance, adhesive properties ensuring reliable fastening to the housing 11 made of composite materials.

The execution of the elastic part of the stator of the screw pump on the forming core 1 with its subsequent lining with layers of composite material to obtain a housing 11 with further placement of the entire product in a thermostat or mold with a given temperature, providing both vulcanization of the rubber mixture and polymerization of the composite material, which allows to produce multilayer reinforced elastic elements of multifunctional products, to ensure the manufacture of products with the same cross-sectional dimensions along its about the axis, without the formation of tapering or barrel-shaped, and lining with layers of composite materials provides a reliable body, eliminates the difficult operations of introducing the core with the elastic part into the finished body and does not require crimping the elastic part, which ensures the manufacture of products of any required length and high quality geometry. The ends of the body of the product are made in such a way that it can be connected to other parts of the equipment.

The manufacturing method, depending on the requirements for the product includes the installation of metal heads 12 and 13 of various designs in the housing when it is directly assembled on the elastic part (figure 2). To do this, after the formation of the elastic part, the washers 14, 15 are put on the ends of the forming core 1 and the power layers of the composite material are laid to the outer diameter of these washers, along which, as on the guides, the metal heads 12, 13 are put on, then the final assembly is carried out until a single monolithic body 11, and the assembly of metal heads on the washers 14, 15 is performed on a sliding fit, ensuring alignment of the thread on the heads and the axis of the product in predetermined tolerances.

According to the second embodiment, the method of manufacturing a stator of a screw pump provides for the application of layers of composite materials on the elastic part after its assembly on the core and vulcanization in a mold or in a thermostat, which provides the desired physical and mechanical parameters of the product. The difference of this method is to provide the necessary parameters of the elastic part and the parameters of the stator housing, which are provided at certain different temperatures due to the separate conduct of vulcanization and polymerization.

Example. A multi-start cage for screw pumps was obtained according to the proposed method by lining a “slippery” rubber mixture with a six-way forming core with an outer diameter of 35.74 mm, 2.8 m long, until a uniform layer with a thickness of 3 ± 0.2 mm was formed. Then, several rubber-tissue tapes 0.5-0.8 mm thick were introduced into each cavity of the helical tooth and a second layer of the rubber mixture with a thickness of 4 mm was re-lined with increased bonding properties until a geometry close to cylindrical with a maximum diameter of ≈51 mm was formed . After that, vulcanization of the elastic part was carried out, lining with composite layers of composite material to an outer diameter of ≈58 mm and implantation of heads with an outer diameter of 74-0.3 mm and an inner diameter of 58 + 0.2 mm, then the final assembly of the power part was carried out until monolithic case with a diameter of 74 mm and its polymerization.

According to this method, several clips were made.

For verification, the clips obtained, in addition to non-destructive testing with measuring plugs according to TU 38 1051097-77, were cut along the center line and measured: pitch in a screw thread, shrinkage of the rubber compound, minimum and maximum diameters.

The measurements showed that the clips made by this method fit well within the tolerance limits. No delamination between the layers of the elastic part and from the casing of the cage was detected. The curvature of the center line of the ferrule and the deviation of the axis of the elastic rubber part from the axis of the body were not observed or were significantly less than the currently established tolerances for manufacturing products using existing methods.

As a result of control measurements, it was found that the proposed method provides high-quality lengthy products, tests of which under operating conditions showed an increase in operating life by 2-3 times compared with products made using other technologies.

Claims (4)

1. A method of manufacturing a stator of a screw pump, including the manufacture of an elastic part by sequentially applying layers of crude rubber to the forming core to form a cylindrical billet with an outer diameter corresponding to the inner diameter of the housing with ends configured to connect to other parts of the equipment, characterized in that to obtain the body using a polymerizable composite material, which is applied to the elastic part, forming a body, then at a given temperature The temperature provides both vulcanization of the elastic part and polymerization of the body. 2. The method according to claim 1, characterized in that in the elastic part, the stator helical tooth ridges are reinforced by layer-by-layer laying in the depressions formed after applying the working layer, rubber-fabric ribbons and metal or plastic reinforcement of various configurations to the forming core. 3. The method according to claim 2, characterized in that when the body is formed from a polymerizable composite material, metal tips of various designs are installed at its ends. 4. A method of manufacturing a stator of a screw pump, including the manufacture of an elastic part by sequentially applying layers of crude rubber to the forming core to form a cylindrical billet with an outer diameter corresponding to the inner diameter of the body with ends made with the possibility of connection with other parts of the equipment, characterized in that after assembling the elastic part on the forming core, it is vulcanized, then on the vulcanized elastic part, dressed on the forming core, overlays m layers of polymerizable composite material, forming the casing, then at a given temperature it is polymerized.

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