The invention relates to the mechanical engineering, namely to the multistage vane type volumetric pumps, which can be used for lifting the liquid out of oil wells.
The vane pump is known having a housing-stator with radial slots in which the separation plates are diametrically placed with possibility of a reciprocating movement, and the cam-rotor, concentrically installed in the housing-stator space with the ability to interact with the plates and form the working chambers, alternately communicated with the suction and discharge ports, at that the pump is equipped with an additional body, covering the housing-stator with the formation of an circular forcing clearance, in which a spring ring with the possibility of interaction with plates is placed [Patent for the utility model No. 11273 RF, F04C2/28, publ. 16 Sep. 1999]. The presence of the spring ring in such pump prevents seizure of the plates when abrasive particles get into the clearance between the stator slots and plates during operation. When working in abrasive environment, uniform wear of the end faces of the plates occurs associated with the fact that the plates make only linear movement.
However, the design of the pump provides no possibility to be executed in stepped version.
The closest to the invention by the technical nature and the achieved effect is a multistage vane pump, including consistently placed on a common shaft stages, containing the rotor installed with the possibility of axial movement on the shaft, the stator, working chambers between the rotor and stator, separation plates, moving in the slots located in the longitudinal central plane, the bottom cover with input apertures and the top cover with output apertures. The internal surface of the stator is formed by two pairs of symmetrically arranged arcs of different radii and smooth transition areas from the arcs of a larger radius to the arcs of a smaller radius. Each stage is equipped with a safety valve to discharge excess pressure and seal. The covers are fixed on the stator with the placement of at least two apertures opposite the smooth transition areas of the internal surface of the stator [Patent No 2395720 RF, F04C2/344, publ. 27 Jul. 2010].
This pump has the following disadvantages when working in abrasive environment:
1. The clearances between the rotor slots and plates can be clogged with abrasive particles, thereby seizer of the plates is possible, especially at small outer diameters of the pump when the centrifugal forces can not be enough to move the plates out of the rotor.
2. Increased wear of the end faces of the plates, associated with the fact that the plates in addition to the linear movement also make radial movement together with the rotor, besides due to contact with the upper or lower cover the plates bend in the slots of the rotor within the clearance of the slot.
3. The high cost of the pump is due to the necessity of the manufacturing of the plates, stator, rotor, and covers from a hard alloy.
The objective of the invention is to increase the reliability of the pump, simplify design and reduce its cost, when pumping liquids with a high content of abrasive particles.
The specified technical result is achieved by the fact that according to the invention in the multistage vane pump, which includes the stages consistently placed on a common shaft, containing the rotor installed with the possibility of axial movement on the shaft, the stator, working chambers between the rotor and stator, separation plates, moving in the slots arranged in the longitudinal central plane, the bottom cover with input apertures and the top cover with the output apertures, the rotor is made in the form of a cam, the stator is formed of two concentric bushes and the base with the formation of the circular clearance, the slots are made in the inner bush and base, separation plates are connected by synchronizing element, and the input and output apertures in the covers of the stage are located in front of its working chambers on different sides of separation plates, wherein the end faces of the covers of adjoining stages are connected with the formation of the circular space which communicates with the circular clearance of the previous stage.
As a synchronizing element a metal or an elastic ring can be used as well as springs can be installed at each of the separation plate.
To compensate radial loads in each subsequent stage the rotor can be rotated 180° around its geometrical axis, and stators are arranged sequentially without turns. For full compensation of radial loads at this arrangement of rotors and stators at least two stages are necessary. Radial loads can be compensated also in the case if the stators of adjoining stages are turned around each other for 90°, while the rotors are placed sequentially on the shaft without turns. With this arrangement of stages the full compensation of radial loads will require a minimum of 4 stages.
To increase wear resistance radial bearings can be installed between stages or between series of stages, thereby radial loads are compensated and a constant clearance between the rotors and stators are ensured.
Increase of wear resistance is also supported by an additional installation the axial bearings between stages or between series of stages, compensating radial loads generated by the stages, and the axial load effecting on the shaft, but herewith axial clearance between the rotors and axial bearing should be absent. Thus there is a constant clearance between the stators and the end covers.
The nature of the invention is illustrated by drawings, where
The multistage vane pump (
To compensate radial loads the rotor (5) of each subsequent stage (1) is installed with turn of 180° around its geometrical axis (
To increase wear resistance the axial bearings (28) without axial clearance relative to the rotor (5) (
Multistage vane pump works as follows.
During the rotation of the shaft (2) of the rotor (5) the separation plates (6) slide on its profiled surface (15) and on both sides of the plate (3) the working chambers (23) and (24) of variable volume are formed, alternately reported with input apertures (21) in the bottom cover (16) and output apertures (22) in the top cover (17). Upon rotation of the rotor (5) according to the arrow indicated on
Further, the working medium enters the next stage (1) and partially returned into the buffer space formed by the circular clearance (12) in the stator (4) and the top cover (17). When interacting with the projection of the rotor (5) the separating plate (6) moves along the slot (14) in the base (11), recess into the slot (13) and presses on to the synchronizing ring (7), which pushes the diametrically located plate (6) to the rotor (5). Thanks to this, moving plates out is made mechanically and ensures a constant contact of plates (6) with rotor (5), and particles got into the clearance between the stator slots (13) and plates (6), are pushed out or worn by plates (6), that prevents them from seizing.
In the buffer place the working medium presses on plates (6), thereby pressing them to the profiled surface (15) of the rotor (5) and discharging synchronizing ring (7). The rotor (4) of the subsequent stage is rotated on 90°, and the process of extrusion of a working medium of the previous stage coincides with the process of absorption in the subsequent stage, thus the radial loads in the stages are partially compensated.
For full compensation of radial loads between stages (1) or series of stages (26) intermediate radial bearings are installed (27).
Thus, the proposed design has high reliability due to the fact that the plates are constantly pressed against the rotor, making only the linear movement, the rotor does not touch the stator and the stages assembly provides hydraulic unloading the pump elements. The synchronizing ring prevents seizing of the plates when mechanical impurities get into the clearance between the stator and the plate. Reliability of the construction work does not depend on external diameter. High production effectiveness, serviceability and low cost are provided due to a small number of parts and ease of their manufacture. In addition, the simplicity of the parts form facilitates strengthening of friction surfaces, for example, by methods of hardening or spraying of hard alloys and allows using hard alloys, ceramics, carbides of silicon or silicified graphite for their manufacture, which eventually increases the wear resistance of the pump when working in abrasive environments.
Number | Date | Country | Kind |
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2012117392 | Apr 2012 | RU | national |
This is a continuation application of U.S. patent application Ser. No. 14/373,213 filed Jul. 18, 2014, which is a 371 application of PCT/RU2013/000390 filed May 8, 2013, which are both incorporated herein by references, and which claims priority on Russian Patent Application No. 2012117392 filed Apr. 26, 2012, which priority claim is repeated here.
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791919 | Leidy | Jun 1905 | A |
2015307 | Hand | Sep 1935 | A |
2475391 | Johnson | Jul 1949 | A |
2492687 | Dall | Dec 1949 | A |
Number | Date | Country |
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1246091 | Sep 1971 | GB |
WO 9408139 | Apr 1994 | WO |
WO 2005010367 | Feb 2005 | WO |
Number | Date | Country | |
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20150167668 A1 | Jun 2015 | US |
Number | Date | Country | |
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Parent | 14373213 | US | |
Child | 14565157 | US |