RU2133877C1 - Guide-vane pump - Google Patents

Abstract

FIELD: various industries for handling liquids in draining and filling operations. SUBSTANCE: pump has housing (or housing with sleeve secured in it) with upper and lower contactors located between edges of suction and discharge ports and described by radius R from center of rotor; rotor is provided with floating radial vanes. Relief section is provided after lower contactor from edge of discharge port in way of rotation of rotor over arc of radius R; central angle of relief section is determined from the following relationship: L= (1.1-1.5)b/R, where B is width of working portion of vane. EFFECT: enhanced reliability and durability of pump. 4 dwg, 1 tbl

Description

 The invention relates to hydraulic displacement machines with rotating working bodies with blades moving reciprocating relative to the internal element, in particular to rotary vane pumps, and can be used in various industries as a part of mobile and stationary pumping units for pumping liquids when performing discharge bulk operations.

 As shown by the practice of operating vane pumps, the greatest difficulties in ensuring their reliable operation are associated with wear of the plates.

 Known rotary vane pump for pumping various liquids, having a housing with a profiled inner surface, the sections of the contactors of which in cross section are described by circular arcs with centers coinciding with the center of the rotor, and the profiles of the sections between the contactors are described by curve curves. Radial grooves are made in the pump rotor, in which the plates are installed [1].

 In the known pump, the position of the edge of the discharge window coincides with the mating point of the arc of a circle describing the lower contactor, with the curve of the profile of the housing on the pressure side of the pump. For each plate moving along the lower trap, after the edge of the discharge window has passed by the previous plate, pressure from the pressure cavity of the pump acts. Under the influence of this pressure, the plate is subjected to axial loading on the idle end of the plate, which positively enhances the pressure of the plate to the closure of the body, and bending loading, which leads to wear of the "front" side of the plate. However, when moving the plate along the trap, there is no axial movement of the plate, there is practically no wear from the envelope force and axial movement of the plate. The unloading of the plate from the discharge pressure occurs only at the moment of its passage through the edge of the discharge window.

 The closest in technical essence to the present invention and taken as a prototype is a rotary vane pump containing end caps, a housing with suction and discharge windows, the internal cavity of the housing of which is made with an upper and lower contactor, interconnected by sections with a curved profile - curve curves. A rotor with grooves is installed inside the housing, in which the plates are movable in the radial direction. The discharge suction windows are separated by an arc using contactors [2].

 A disadvantage of the known pump is the uneven stepwise wear along the length of the plates and wear and tear on their rear non-working faces of the plates, which is formed when the plate moves from the bottom contactor to the curve curve-edge of the housing blower window and the plate moves simultaneously along the rotor groove. In this case, the plate is subjected to bending forces from the pressure difference in the pressure port of the pump and the “opening” interplate chamber of the pump.

 This position is explained by the fact that the edge of the discharge window coincides with the contact point of the contactor and the curve, and the plate unloading process theoretically occurs instantly at the moment the plate passes this edge, however, due to the relatively high rotation speeds, there is still a time interval estimated in fractions of a second when the plate not yet unloaded completely, but already has a radial movement, i.e. “instantaneous” impact, the result of which is a linear “denting” of the non-working side of the plate.

 In FIG. 1 shows plates made of various materials after 100 hours of work with wear ("a") of the non-working lateral side of the plates (pump PN-30/4).

 The technical result of the invention is to increase the reliability and durability of the pump by ensuring the process of "unloading" the plate before it begins to radially move it into the groove of the rotor.

The specified technical result is achieved by the fact that in the well-known vane pump containing a housing, inside of which a sleeve with suction and discharge windows is rigidly fixed, and in the inner cavity of the sleeve there is a rotor with radial grooves and movable plates placed in them, interacting with the upper and lower contactors, made along an arc of radius R between the edges of the suction and discharge windows and interconnected curved surfaces described by curve curves, according to the proposed invention, behind the lower contactor from the edge of the discharge window in the direction of rotation of the rotor along an arc of radius R, a discharge section is made, the central angle α of which is determined by the following relation:
α = (1,1 ÷ 1,5) b / R,
where α is the central angle of the discharge section behind the lower contactor;
b is the width of the working part of the plate (see Fig. 4);
R is the radius of the arc of the lower contactor.

In FIG. 1 shows photos of plates of various materials after 100 hours of operation of the PN-30/4 pump;
in FIG. 2 shows a vane pump (cross section);
in FIG. 3 shows a sleeve of a casing of a vane pump (cross section);
in FIG. 4 shows the pump plate PN-30/4 (cross section).

The vane pump consists of a housing 1 with a suction 2 and pressure head 3 nozzles. Inside the housing 1 there is a sleeve 4 having an upper and lower contactor 5, 6, respectively, suction and discharge windows 7, 8. A safety bypass valve 9 is installed in the upper part of the housing 1. Inside the sleeve 4, a rotor 10 with radial grooves 11 is installed, in which plates 12 with discharge grooves are placed 13. The lower contactor 6 from the beginning (point A) to the end (point B) is described by an arc AB of a circle from the center of the rotor 10 of radius R with a central angle β.
To explain the pump, the following conventions are introduced:
R is the radius of the lower contactor of the arc AB from the center of the rotor (point O) from the beginning (point A) to the end (point B).

 β = AOB is the central angle corresponding to the length of the arc contactor AB of radius R between the edge of the end of the suction window (point A) and the edge of the beginning of the discharge window (point B).

 α = BOC is the central angle of the discharge section-arc BC of radius R.

 b is the width of the working part of the plate.

 The vane pump operates as follows. When the rotor 10 rotates in the direction of the arrow, the volume of the cavities is limited by the inner surface of the sleeve 4 of the housing 1, two adjacent plates 12 and end caps (not shown) of the pump, as a result of which a vacuum is created in the suction cavity and the fluid moves to the cavity discharge (to pressure pipe 3). The upper contactor 5 and the lower contactor 6, along which the working ends of the plates 12 slide, divide the pump cavity into the suction and discharge cavities. Before the transition of the plate 12 to the end of the lower contactor 6 (point "B"), the differential pressure acts on the plate 12. The plate 12 after point "B" slides along the discharge section BC after the lower contactor 6 of the same radius R as the arc AB of the contactor 6, which for some time delays the radial movement of the plate 12 along the groove 11 of the rotor 10. This time interval is sufficient to so that the pressure of the liquid on the plate 12 is equal to the pressure entering the subsequent interplate chamber through the gap between the working end of the plate 12 and the edge of the discharge window 8 (point B).

 Thus, the technical essence of the inventive vane pump is to create conditions that reduce wear of the plates, i.e. the process of "unloading" of the plate to the beginning of its radial movement in the groove 11 of the rotor 10 is provided due to the presence of the unloading section BC.

 The application of the invention increases the reliability and durability of the vane pump without reducing the operational characteristics of the pump (see table at the end of the description).

 As can be seen from the table, the presence of discharge sections (BC) of the same radius R at the output of the lower contactor 6 (AB) of the same radius R equal to (1.11.5) the width of the working part of the end face of the plate 12, allows to increase the durability and reliability of the pump. An increase in this area by a value of more than 1.5 is accompanied by a change in the acoustic-vibrational characteristics of the pump.

Therefore, new relative to the prototype (pump company "Blackmer" XL (S) 3), is the execution at the output of the lower contactor of radius R of the discharge section, determined by the following ratio:
α = (1.1 ÷ 1.5) b / R.
The introduction of the discharge section on the lower circuit breaker 6 practically does not require any additional technological operations, their implementation is expected during the development of serial production of new vane pumps PN-60/8 and PN-90/8 in 1998-1999.

 Thus, the proposed technical solution meets the criteria of the invention: novelty, inventive step and industrial application.

Sources of information
1. Bulletin of the company "Blackmer" USA, Bulletin 100, October, 1983, p. 14-15;
2. In the same place with. 10-11, pump XL (S) 3 (prototype).

Claims (1)

A vane pump containing a housing, inside of which a sleeve with suction and discharge windows is rigidly fixed, and a rotor with radial grooves and movable plates placed in them, interacting with upper and lower contactors made along an arc of radius R between the edges of the suction and discharge windows and interconnected curved surfaces described by curve curves, characterized in that behind the lower contactor from the edge of the discharge window in the direction of rotation Nia rotor radius R of the arc discharge portion is formed, the central angle α which is determined by the ratio
α = (1.1-1.5) b / R,
where α is the central angle of the discharge section behind the lower contactor;
b is the width of the working part of the plate, mm;
R is the radius of the arc of the lower contactor, mm

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