CN106050730A - Vane pump and impeller blade for vane pump - Google Patents

Abstract

The invention discloses an impeller blade for a vane pump. The impeller blade is provided with a broken line hole which is formed from the lowest pressure point of the blade back face of the impeller blade and penetrates the impeller blade to the blade work face of the impeller blade; the broken line hole is provided with a step face facing the blade back face side; and the hole diameter of the position, close to the blade back face, in the broken line hole is not smaller than the hole diameter of the position, close to the blade work face, in the broken line hole. The impeller blade can prevent or reduce forming of cavitation of the blade back face; and meanwhile, by calculating and designing a hydraulic loss environment of a sudden expansion pipeline and a break angle, the situation that because the pressure difference between the blade work face and the blade back face is too high, jet flow is generated on the blade back face can be reduced or avoided, it is prevented that the jet flow disturbs the blade back face flow field, it can be easily guaranteed that the cavitation strength reaches the lowest in the running process of the vane pump, and the purposes of reducing the essential cavitation margin of the vane pump and improving the anti-cavitation performance of the vane pump are achieved. The invention further discloses the vane pump comprising the impeller blade.

Description

A kind of vane pump and the impeller blade for vane pump

Technical field

The present invention relates to technical field of engineering machinery, particularly to a kind of impeller blade for vane pump.The present invention is also Relate to a kind of vane pump including above-mentioned impeller blade.

Background technology

Impeller blade is the vitals in the equipment such as vane pump, when vane pump runs, when fluid pressure is less than work At a temperature of pressure for vaporization time, in vane pump, current enter device from entrance edge of blade, flow through vane region, and current are to blade Work surface does work, and the water flow pressure making front side of vane is higher, due to the impact of aerofoil profile, and the pressure at the back side near entrance edge of blade Relatively low, also can form pressure lowest region in vacuum side of blade local, once less than water pressure for vaporization at a temperature of at that time, just produce Cavitation phenomenon.Generally, front side of vane refers to face of blade relative with vacuum side of blade on impeller blade.

But, in current vane pump, produce relatively when the set-up mode of impeller blade all may can cause vane pump to run For serious cavitation phenomenon.When this kind of vane pump is applied to the fields such as fluid machinery, high speed culvert, hydrofoil, rudder, underawater ordnance, The appearance of cavitation phenomenon may cause material denudation, makes the hydraulic performance decline of vane pump, mechanical efficiency reduce, affects in vane pump The proper flow of fluid, produces vibration and noise, and then affects the properly functioning of whole system.

Therefore, how to reduce the generation preventing jet while cavitation phenomenon occurs, be that those skilled in the art are current The technical issues that need to address.

Summary of the invention

In view of this, it is an object of the invention to provide a kind of impeller blade for vane pump, it is possible to reduce cavitation phenomenon Generation.It is a further object of the present invention to provide a kind of vane pump including above-mentioned impeller blade, it is possible to reduce cavitation phenomenon Occur.

For achieving the above object, the present invention provides following technical scheme:

A kind of impeller blade for vane pump, described impeller blade is provided with broken line hole, and described broken line hole is by described leaf The pressure minimum point of the vacuum side of blade of impeller blade has set the front side of vane running through described impeller blade extremely described impeller blade, institute Stating the cascaded surface being provided with described vacuum side of blade side on broken line hole, in described broken line hole aperture at the described vacuum side of blade Not less than the aperture at described front side of vane.

Preferably, the bending place in described broken line hole is one, and a described cascaded surface is located at described bending place.

Preferably, the radial section in described broken line hole is circular.

Preferably, both sides, bending place described in described broken line hole are two sections of straight holes, and every section of described straight hole is along central shaft Radial section everywhere is identical.

Preferably, the intersection point of the central shaft of two sections of described straight holes is positioned at described bending place.

Preferably, the vertical dimension between described bending place and described pressure minimum point is that described pressure minimum point is with described The half of the vertical dimension between front side of vane.

Preferably, described broken line hole aperture d between described bending place and described front side of vane₁Described with being positioned at Aperture d between bending place and described vacuum side of blade₂Relation be:

$P_1-P_2=\mathrm{\α}\frac{\mathrm{\ρ}\[{\left(\frac{d_2}{d_1}\right)}^4-1+\mathrm{\ξ}\]}{2}{V}^2$

Wherein: P₁For the pressure of front side of vane import current, P₂For vacuum side of blade outlet stream pressure, ξ is local resistance Coefficient, according to the difference of θ, ξ can check in from local head loss's table, and θ is the angle of the central shaft of two sections of described straight holes, and α is Kinetic energy correction factor, V is the average speed of fluid.

A kind of vane pump, including impeller blade, described impeller blade be as described in above-mentioned any one for vane pump Impeller blade.

The impeller blade for vane pump that the present invention provides is provided with broken line hole, broken line hole perfoliate-leaf impeller blade and setting At the pressure minimum point of vacuum side of blade, connection vacuum side of blade and front side of vane, broken line hole is provided with vacuum side of blade side Cascaded surface, in broken line hole, the aperture at the vacuum side of blade is not less than the aperture at front side of vane.

Broken line hole connection front side of vane and vacuum side of blade on this kind of impeller blade, Appropriate application front side of vane with Pressure differential between vacuum side of blade, the High-Pressure Water of front side of vane can add to the low-pressure centre of vacuum side of blade, makes blade carry on the back The pressure in face does not reaches environment pressure for vaporization, it is possible to stop or reduce the formation of cavitation；Meanwhile, by Divergent Piping and knuckle This hydraulic loss environment, can adjust the pressure reduction of front side of vane and vacuum side of blade effectively and accurately, weakens blade working The part overpressure of face current, reduces or avoids pressure reduction between front side of vane and vacuum side of blade too high and at vacuum side of blade The situation of the jet produced occurs, and prevents from upsetting vacuum side of blade flow field, advantageously ensures that the vane pump applying this impeller blade exists Running cavitation intensity reaches minimum, reduces the necessary net positive suction head of vane pump, improves the anti-cavitation performance of vane pump.

The vane pump including above-mentioned impeller blade that the present invention provides, it is possible to reduce the generation of cavitation phenomenon.

Accompanying drawing explanation

In order to be illustrated more clearly that the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing In having technology to describe, the required accompanying drawing used is briefly described, it should be apparent that, the accompanying drawing in describing below is only this Inventive embodiment, for those of ordinary skill in the art, on the premise of not paying creative work, it is also possible to according to The accompanying drawing provided obtains other accompanying drawing.

Fig. 1 is the front schematic view of the specific embodiment of impeller blade provided by the present invention；

Fig. 2 is the sectional view of Fig. 1.

In Fig. 1 to Fig. 2,1 is front side of vane, and 2 is vacuum side of blade, and 3 is vane pump blade head, and 4 is broken line hole, and 5 are Cascaded surface, 6 is bending place, and 7 is inlet side, and 8 is vacuum side of blade broken line hole opening, and 9 is front side of vane broken line hole opening, and 10 are Vane pump drive end bearing bracket line, 11 is Exit-edge, and 12 is vane pump wheel hub line.

Detailed description of the invention

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete Describe, it is clear that described embodiment is only a part of embodiment of the present invention rather than whole embodiments wholely.Based on Embodiment in the present invention, it is every other that those of ordinary skill in the art are obtained under not making creative work premise Embodiment, broadly falls into the scope of protection of the invention.

The core of the present invention is to provide a kind of impeller blade for vane pump, it is possible to reduce the generation of cavitation phenomenon.This Another core of invention is to provide a kind of vane pump including above-mentioned impeller blade, it is possible to reduce the generation of cavitation phenomenon.

Refer to the front schematic view of the specific embodiment that Fig. 1 and Fig. 2, Fig. 1 are impeller blade provided by the present invention；Fig. 2 Sectional view for Fig. 1.

In a kind of specific embodiment of the impeller blade for vane pump provided by the present invention, impeller blade is provided with broken line Hole 4, broken line hole 4 has been set by the pressure minimum point of vacuum side of blade 2 and perfoliate-leaf impeller blade is to front side of vane 1, by broken line hole 4 Connection front side of vane 1 and vacuum side of blade 2, front side of vane 1 and two relative walls that vacuum side of blade 2 is on impeller blade Face.Being provided with the cascaded surface 5 of vacuum side of blade 2 side on broken line hole 4, broken line hole 4 can regard Divergent Piping as, and fluid is carried on the back by blade Face 2 is during broken line hole 4 flows to front side of vane 1, and the cross section of fluid channel in broken line hole 4 can be undergone mutation at cascaded surface 5. In broken line hole 4, aperture at the vacuum side of blade 2 is more than the aperture at front side of vane 1, i.e. any in broken line hole 4 Two compared with the vacuum side of blade 2 aperture at different two, the aperture at vacuum side of blade 2 is not less than near blade work Make the aperture at face 1.Wherein, in all directions of the central shaft being perpendicular to broken line hole 4 during aperture refers to broken line hole 4 everywhere Size.

Broken line hole 4 on impeller blade in the present embodiment connects front side of vane 1 and vacuum side of blade 2, Appropriate application Pressure differential between front side of vane 1 and vacuum side of blade 2, the High-Pressure Water of front side of vane 1 can add to the low of vacuum side of blade 2 Pressure center, makes the pressure of vacuum side of blade 2 not reach environment pressure for vaporization, it is possible to stop or reduce the formation of cavitation；Meanwhile, logical Cross Divergent Piping and this hydraulic loss environment of knuckle, can effectively adjust the pressure reduction of front side of vane 1 and vacuum side of blade 2, cut The part overpressure of weak front side of vane 1 current, reduces or avoids pressure reduction mistake between front side of vane 1 and vacuum side of blade 2 The situation of jet that is high and that produce at vacuum side of blade 2 occurs, and prevents from upsetting vacuum side of blade 2 flow field, advantageously ensures that this leaf of application The vane pump of impeller blade reaches minimum in running cavitation intensity, reduces the necessary net positive suction head of vane pump, raising The purpose of the anti-cavitation performance of vane pump.

Generally, the impeller blade in vane pump includes inlet side 7, Exit-edge 11, vane pump wheel hub line 12 and vane pump Drive end bearing bracket line 10, there is vacuum side of blade 2 region near inlet side 7 in the minimum pressure region of vane pump.

In above-described embodiment, the bending place 6 in broken line hole 4 is specifically as follows one, and a cascaded surface 5 is arranged on this bending Place 6.Generally, the thinner thickness of the impeller blade in vane pump, only a cascaded surface 5 once and is arranged on bending place 6 by bending, Advantageously reduce difficulty of processing, it is simple to batch production.It is of course also possible to arrange two or other quantity according to process conditions Bending place 6 or cascaded surface 5.

In each embodiment above-mentioned, it is circular hole that broken line hole 4 is specifically as follows radial section, and radial section herein refers to Be the cross section of the central shaft being perpendicular to broken line hole 4 in broken line hole 4 everywhere, in order to simplify processing further.Certainly, broken line hole The radial section of 4 can also be oval or other shapes.

In each embodiment above-mentioned, in broken line hole 4, both sides, bending place 6 are two sections of straight holes, and every section of straight hole is along central shaft Radial section everywhere is identical, say, that broken line hole 4 only comprises a cascaded surface 5, and every section of straight hole is at its central axis Aperture transition is not had, in order to the processing in broken line hole 4 on bearing of trend.

In above-described embodiment, the intersection point of the central shaft of two sections of straight holes can be arranged on bending place 6, and now, this intersection point is rank The central point of tread 5, and cascaded surface 5 is concentric annular face, advantageously ensures that fluid deceleration supercharging effect when cascaded surface 5 Really.Certainly, the intersection point of the central shaft of two ends straight hole can also be for being arranged between cascaded surface 5 and front side of vane 1 or other Position.

In each embodiment above-mentioned, the vertical dimension between bending place 6 and pressure minimum point can be specifically that pressure is minimum The half of vertical dimension between point and front side of vane 1, by the vertical dimension value between bending place 6 and pressure minimum point with And the value of the angle theta of the central shaft of two sections of straight holes can be accurately positioned the position of front side of vane broken line hole opening 9 in broken line hole 4 Put, it is simple to realize the structure of doubling string holes 4 and the accurate control of position.Certainly, the position of bending place 6 can also be according to processing work Skill carries out other and sets.

In above-described embodiment, the broken line hole 4 aperture d between bending place 6 and front side of vane 1₁Be positioned at bending place 6 And the aperture d between vacuum side of blade 2₂Relation be specifically as follows:

$P_1-P_2=\mathrm{\α}\frac{\mathrm{\ρ}\[{\left(\frac{d_2}{d_1}\right)}^4-1+\mathrm{\ξ}\]}{2}{V}^2$

Wherein: P₁For the pressure of front side of vane import current, P₂For vacuum side of blade outlet stream pressure, ξ is local resistance Coefficient, according to the difference of θ, ξ can check in from local head loss's table, and θ is the angle of the central shaft of two sections of straight holes, and α is kinetic energy Correction factor, V is the average speed of fluid.

According to this formula, the partial pressure of front side of vane 1 fluid that fluid weakens behind broken line hole 4 is Δ P=P₁- P₂.Carrying out d₁With d₂Size design during, can be by constantly changing d₁、d₂And two straight hole section central shaft between press from both sides The size of angle θ, and verify P by this formula₂Size, it can be ensured that in pressure minimum point P₂The slightly above fluid at a temperature of this Pressure for vaporization, thus accurately reduce must net positive suction head, and accurately control P₂Size, alleviate cavitation erosion.With 20 DEG C As a example by water, its pressure for vaporization is 2400Pa, and the method is accurately controlled outlet pressure and reaches P₂The effect of >=2400Pa.Certainly, d₁ With d₂Between magnitude relationship be not limited to this.

In each embodiment above-mentioned, the position in vacuum side of blade 2 minimal pressure force specifically can be carried out really by software modeling Fixed.Below to the location in the broken line hole 4 of impeller blade in vane pump and modeling process as a example by a kind of preferred implementation Illustrate.

In this implementation, first use business to calculate hydromechanics CFD software, use finite volume method to vane pump Corresponding operating mode is simulated calculating, and calculation process is as follows:

1, use business 3D sculpting software that movable guide vane and the runner of vane pump are set up and entirely simulated mathematical model；

2, the business stress and strain model software movable guide vane to setting up and runner mathematical model is used to carry out stress and strain model respectively, Block-structured grid is used during stress and strain model；

3, the pretreatment part using business Computational Fluid Dynamics software imports ready-portioned movable guide vane and runner Grid, the various calculating parameters such as the accounting equation of computational fields, boundary condition are set, software for calculation uses finite volume method to solve Flow equation, obtains solving the flow behavior in territory.

4, governing equation:

1) equation of continuity:

Fluid-mixing phase:

$\frac{\∂\mathrm{\ρ}}{\∂t}+\▿\·\left(\mathrm{\ρ}v\right)=0$

In formula: ρ is the fluid-mixing mass density that cavity phase is formed mutually with current；ν is the velocity of fluid-mixing.

Cavity phase:

$\frac{\∂}{\∂t}\left(\mathrm{\ρ}f\right)+\▿\·\left(\mathrm{\ρ}fv\right)=R_e-R_c$

In formula: f is the mass component of cavity phase；Re is the production rate of steam；Rc is the condensation rate of steam.

2) equation of momentum

$\frac{\∂\left(\mathrm{\ρ}v\right)}{\∂t}+\▿\·\left({\mathrm{\ρv}}^2\right)=-\▿p+\frac{1}{3}\▿\[(\mathrm{\μ}+{\mathrm{\μ}}_t)\▿\·v\]+\▿\·\[(\mathrm{\μ}+{\mathrm{\μ}}_t)\▿v\]+\mathrm{\ρ}g$

In formula: p is static pressure；μ is molecule viscosity coefficient；μ^tFor turbulent flow viscosity coefficient.

The relation of hybrid density ρ and gaseous mass mark f is as follows:

$\frac{1}{\mathrm{\ρ}}=\frac{f}{{\mathrm{\ρ}}_v}+\frac{1-f}{{\mathrm{\ρ}}_1}$

5, boundary condition

1) inlet boundary condition

Giving the absolute velocity of import department, concrete numerical value is obtained by the design conditions of pump, and pressure is set on import cross section It is uniformly distributed.

2) export boundary condition

The speed in exit is derived from by the speed of upstream mesh point, revises in proportion according to mass conservation law, its Its physical quantity is taken as the value of the one layer of mesh point in upstream.

3) wall boundary condition

The upper speed of Gu Bi meets non-slip condition, and pressure is taken as second kind boundary condition, and turbulent flow wall uses Wall-function Boundary condition.

4) bubble phase boundary condition

Cavity phase inlet velocity takes First Boundary Condition, and muzzle velocity takes second kind boundary condition, cavity on wall Speed is zero along normal direction gradient, and cavitation corrosion calculates the void volume component of initial flow-field and is assigned to zero.

6, calculating solves and restrains, and uses the solver of computational fluid dynamics software to solve computational fields, calculates Step-length 0.005, restrains residual value 0.00005.

7, result of calculation analysis, uses the post processing part of computational fluid dynamics software to import result of calculation, to calculating Result carries out pressure distribution analysis: use statement minp can try to achieve the minimum pressure of vacuum side of blade 2 under the command window of software Point position.

Afterwards, the structure in broken line hole 4 is determined.Refer to Fig. 1, in conjunction with CFD analysis result, by vane pump blade head 3 It is positioned at the end points of inlet side 7 and minimum range L of vacuum side of blade broken line hole opening 8 and the hole of calculated vacuum side of blade 2 side Footpath d₂, it may be determined that vacuum side of blade 2 specifically arranges the position in broken line hole 4, then, the overall dimensions in initial setting broken line hole 4, enters Row correlation computations, for example, it is possible to utilize the equation below in above-described embodiment:

$P_1-P_2=\mathrm{\α}\frac{\mathrm{\ρ}\[{\left(\frac{d_2}{d_1}\right)}^4-1+\mathrm{\ξ}\]}{2}{V}^2$

Verify, and utilize computational fluid dynamics software that broken line hole 4 structure determined is simulated, such as CFD Whether numerical simulation, see and produce a desired effect, if it is not, carry out modification of dimension, until producing a desired effect；? After, according to position and the size in the broken line hole 4 finally determined, calculate gained pressure lowest point at vacuum side of blade 2 and drill through folding String holes 4.

Except above-mentioned impeller blade, present invention also offers a kind of blade including impeller blade disclosed in above-described embodiment Pump, this vane pump is owing to have employed the above-mentioned impeller blade for vane pump, it is possible to anti-reducing while cavitation phenomenon occurs The only generation of jet.The structure of other each several parts of this vane pump refer to prior art, repeats no more herein.

In this specification, each embodiment uses the mode gone forward one by one to describe, and what each embodiment stressed is and other The difference of embodiment, between each embodiment, identical similar portion sees mutually.

Impeller blade to vane pump provided by the present invention and for vane pump is described in detail above.Herein Applying specific case to be set forth principle and the embodiment of the present invention, the explanation of above example is only intended to help Understand method and the core concept thereof of the present invention.It should be pointed out that, for those skilled in the art, do not taking off On the premise of the principle of the invention, it is also possible to the present invention is carried out some improvement and modification, these improve and modification also falls into this In invention scope of the claims.

Claims (8)

1. the impeller blade for vane pump, it is characterised in that described impeller blade is provided with broken line hole (4), described folding String holes (4) has been set by the pressure minimum point of the vacuum side of blade (2) of described impeller blade and has run through described impeller blade to described impeller The front side of vane (1) of blade, described broken line hole (4) is provided with the cascaded surface (5) of described vacuum side of blade (2) side, described In broken line hole (4), the aperture near described vacuum side of blade (2) place is not less than the aperture near described front side of vane (1) place.

Impeller blade the most according to claim 1, it is characterised in that the bending place (6) of described broken line hole (4) is one, And a described cascaded surface (5) is located at described bending place (6).

Impeller blade the most according to claim 2, it is characterised in that the radial section of described broken line hole (4) is circular.

Impeller blade the most according to claim 3, it is characterised in that bending place (6) both sides described in described broken line hole (4) It is two sections of straight holes, and every section of described straight hole is identical along central shaft radial section everywhere.

Impeller blade the most according to claim 4, it is characterised in that the intersection point of the central shaft of two sections of described straight holes is positioned at institute State bending place (6).

Impeller blade the most according to claim 5, it is characterised in that described bending place (6) and described pressure minimum point it Between vertical dimension be the half of the vertical dimension between described pressure minimum point and described front side of vane (1).

Impeller blade the most according to claim 6, it is characterised in that described broken line hole (4) be positioned at described bending place (6) with Aperture d between described front side of vane (1)₁And the aperture d being positioned between described bending place (6) and described vacuum side of blade (2)₂ Relation be:

$P_1-P_2=\mathrm{\α}\frac{\mathrm{\ρ}\[{\left(\frac{d_2}{d_1}\right)}^4-1+\mathrm{\ξ}\]}{2}{V}^2$

Wherein: P₁For the pressure of front side of vane import current, P₂For vacuum side of blade outlet stream pressure, ξ is local resistance system Number, according to the difference of θ, ξ can check in from local head loss's table, and θ is the angle of the central shaft of two sections of described straight holes, and α is Energy correction factor, V is the average speed of fluid.

8. a vane pump, including impeller blade, it is characterised in that described impeller blade is claim 1 to 7 any one institute The impeller blade for vane pump stated.