CN1056217C - Impeller - Google Patents

Abstract

The present invention relates to an impeller which can reduce the stall phenomenon and has a high step-up ratio in a small flow. The impeller comprises a hub 11, a group of airfoil blades 12 are arranged around the hub 11, and adjacent blades are overlapped. A channel 21 is established between a pair of adjacent blades via the overlapping arrangement, and the volume of the channel is gradually reduced between an inlet and an outlet.

Description

Impeller

The present invention is relevant with a kind of impeller, particularly be applicable to that compression supercharging impeller of fluid such as gas is relevant.

Impeller that people know or fan all dispose one group of wing, and the wing is meant a kind of thin slice or blade that is wing substantially.The shape of the typical wing or blade presents a kind of like this relation, and promptly a side of the wing (normally top side) is compared with relative another side apart from longer.

Because the typical wing or this structure of blade, when the wing is driven when travelling forward, the thickest end of forefront is split surrounding fluid (gas or liquid) separately and is made the flow through end face of the wing of wherein a part of fluid, another part fluid then flow through the wing below, the big flank face of crooked camber line, the distance that fluid is flowed through is also longer, and (normally top side), thereby make fluid be tending towards thinning out.

This situation about obviously weakening of fluid can be followed the pressure reduction takes place, form low pressure and will suck near fluid, promptly produce a kind of swabbing effect that makes progress, if the wing or blade can not rise, fluid will flow along aerofoil and fill up so, and usually very big may be that flow through the backward back edge (trailing edge) of the wing is filled up.

To the blade or the wing of this pattern, we as can be seen, each side of the wing or blade exists a kind of direct relation each other.If bending is big (facing upward) too, the pressure of downside can become Tai Gao and go up side pressure and become too low, the wing or blade will stall (air-flow is discontinuous), high-pressure spray cognition below this moment flows slowly around the back edge of the wing and moves forward along top side face, and this can cause that the fluid stream (with aerofoil) on the top side face separates.Pumping action upwards disappears or has reduced greatly, has also promptly eliminated lift.

High-pressure air also can center on the mobile thereby generation eddy current of the wing or blade wingtip, and it can cause lift decline and produce a tension at the close wingtip place of the wing.

A kind of typical universal fan, its blade or winglet are almost always by being circular layout, because identical factor causes the loss of efficient.To a kind of typical general radial fan, blade or winglet are dispersed (expansion) to horizontal side regions from the center, in this case, each blade or the wing rely on the low-pressure air that flows through the wing or blade low voltage side, come down to flow to the back edge and the fluid junction of radially fiercely flowing through the elevated pressures of coming from the high pressure side of the wing of the wing, therefore if this fan is under the situation that generation back pressure or head are pressed, blade has the stall phenomenon and takes place, if the wingtip speed of this fan is driven the degree that reaches too high, each blade all can stall, under some situation, in fact fluid between every group of blade along the low voltage side or the suction side reverse flow of each blade, promptly produces anti-stream between any two blades.

The object of the present invention is to provide a kind of impeller, it can overcome shortcomings more above-mentioned basically, or provides a kind of alternative share or commercial impeller to society.

The objective of the invention is to reach: a kind of impeller by following characteristics, include anterior district and the rear portion discharge zone introduced, wheel hub and one group of blade that extends around wheel hub that comprises the impeller rotating shaft line, have at least partial blade overlapping relation to be arranged between adjacent overlapped blade, to limit a passage, this passage has an inlet and an outlet, described inlet limited by the forward position of adjacent blades and with front portion introducing district raceway groove, outlet by adjacent blades back along the institute limit and link up with the rear discharge zone, the spin axis of blade pitch wheel hub has certain distance, between spin axis and blade, to limit an entity part, it is characterized in that, each blade be lonely shape to limit an outside convex surface and an inside concave surface, when impeller rotates, outside convex surface impacts and compressed fluid, each blade has the wing root of a below and the wingtip of a top, towards the outlet convergence, the forward position of each blade and back are along outwards being diffusion type from spin axis from inlet for adjacent overlapped blades.

A kind of form of the present invention can belong to an a kind of anterior zone and rear portion discharging area introduced that include; And wheel hub and one group of blade that extends around wheel hub that includes the impeller rotating shaft line, have at least partial blade overlapped, between contiguous overlapped blade, limit a passage, this passage has an inlet and the outlet of linking up with the rear discharging area introducing to link up in the zone with the place ahead, inlet area so just defines the fluid displacement that flows through passage and reduces gradually greater than discharge area.The blade that extends around wheel hub can have the wing root that the back edge of the forward position of qualifying part inlet, a qualifying part outlet, outward extending tip or wingtip and an energy are connected with wheel hub.

Blade is connected on the wheel hub and apart from running shaft certain distance, and to limit an entity part between blade and spin axis, this entity part can cover the 10-50% of whole wheel hub area, is typically to account for 30% at least, less than 100%.Wing root is to be connected with wheel hub at discharging area place, contiguous rear portion.

Blade can have the configuration of the wing, be that its ratio back, forward position is along thick, the fluid that enters is whereby split is divided into two strands, part fluid flows through a side of blade, another part fluid flows through the opposite side of blade, since the shape of aerofoil make blade one side of flowing through fluid process distance than the fluid of the opposite side of flowing through the distance of process long, this will make this segment fluid flow weaken, blade ahead of the curve and the back along between shape can be curved surface, thereby the curved surface of two adjacent blades can spatially form overlapping relation.

Wheel hub is done tapered substantially, can be along introducing the district to the discharge zone expansion, and blade can be connected on the cone hub.Wheel hub can be the plane in fact at discharge zone.

At least a portion blade, preferably all blades stretch out at a certain angle from running shaft, thereby limit being connected from the expansion of wheel hub spin axis between particular vane wing root and wingtip.

Though two adjacent interlobate laps can change, lap preferably is at least 50% to form required passage.

For making the passage between import and the outlet can realize reducing gradually on the volume, the adjacent blades that limits this passage can have the relation of convergence (convergence) each other to the edge, back from its forward position.Each adjacent vanes from the forward position to the length on edge, back about equally because the convergence of blade is reduced the volume of passage.Each adjacent blade can be rigid construction and can be fixed on desirable convergence position.

Another method is arranged, and angle of convergence can change before impeller rotation or in the rotation, and for realizing this purpose, blade can be fixed with pivotal mounting at contiguous its position, forward position, makes the blade can be towards the blade rotation of being close to.Also have additive method to achieve the above object (perhaps being additional to said method), some or all blades can make flexible folding or leaf packet contains a flexible portion so that blade changes shape, realize that it has the relation of convergence with respect to adjacent vanes.

Also has a kind of method: can make a pair of adjacent vanes forward position do longlyer than this back edge to blade, to obtain reducing gradually of volume, like this, the wingtip of each blade is extremely back along tapered from the forward position, basically can be parallel to each other and unnecessary convergence between the blade, need make convergence and also can.In fact forward position that relies on blade and the variation of back along length ratio, even blade still can obtain reducing of volume when being diffusion type.

We also wish to introduce the area of district greater than feeder connection, can be combined by the forward position of each blade and wingtip to limit this and introduce the zone.If blade stretches out at a certain angle from spin axis, introducing zone (i.e. inlet or throat area) can be significantly greater than inlet area (being the inswept area of blade).

Impeller can be installed on the running shaft and be installed in a cover or the housing, can keep the matching relationship that seals between the wingtip of each blade and cover or housing, or distance is very little between the two, and cover or housing can be spill and center on impeller to cooperate.

Fig. 1 is the plane view by a kind of impeller of the present invention;

Fig. 2 is the side view of impeller shown in Figure 1;

Fig. 3 shows the schematic representation that fluid flows through situation between the impeller adjacent blades;

Fig. 4 is the sketch by one embodiment of the present of invention, and impeller has two passages;

Fig. 5 illustrates the schematic representation of the radial fan with two blades of prior art;

Fig. 6 is the schematic representation by the rotatable vane of impeller of the present invention;

Fig. 7 and Fig. 8 are by the rear view of the impeller of another embodiment of the present invention and front elevation;

Fig. 9 is a form of listing the various parameters of impeller shown in Figure 1;

Figure 10 is the plotted curve that draws by the data of table 9.

Now at first consult the impeller 10 shown in the accompanying drawing 1, impeller 10 can be made by metal (is metal though also need not limit), it includes a center hub 11 and one group of blade 12, impeller 10 also comprises an introducing district shown in the with dashed lines 13, and it can be combined by the forward position 14 of specific blade 12 and wingtip 15 and limits.Each blade 12 has forward positions (edge) 14 of linking up with introducing district 13; An outward extending wingtip 15; One in order to be connected blade 12 wing root 16 and back edge (edge) 17 (see figure 2)s of linking up with the discharge zone 18 of impeller 10 on the wheel hub 11.Wheel hub 11 has a centre rotational axis line 19, and wheel hub 11 includes a center hole 20 in Fig. 1, and impeller 10 is installed in a last (not shown) by this center hole and by the axle driven rotary.

Blade 12, one of them part of 12a have overlapped (relation) limiting along this adjacent vanes 12, the passage 21 that extends between the 12a, and the area of overlap between adjacent blades is about 30-70% to guarantee the desirable passage 21 of a size.

Blade relative rotation axi line on the wheel hub 11 19 outside deflections are diffusion type as shown in Figure 1, such structure can obtain a big introducing district 13, this can be by wheel hub 11 is done tapered the realization, as shown in Figure 2, wheel hub is from the contiguous anterior position diffusion type that district's narrower region extends to rear portion discharge zone broad of introducing.Blade 12 roughly is vertically to be installed on the conical surface of wheel hub 11 inclinations, and blade ground just is diffusion type as shown in Fig. 1 and Fig. 2.

The wing root of each blade be connected in that position on the wheel hub comes down to and spin axis between have a spacing, so that wheel hub 11 leaves an entity part 22 (seeing figure I) between the root (wing root) of its spin axis 19 or hole 20 and each blade, this entity part can account between long-pending (face area) 20-60% of hub surface, that is to say that blade 12 does not extend to spin axis 19, also do not extend to 20 places, hole.

With dotted line 23 discharging area or adjacent each outlet 24 to each passage of limiting between the blade are shown among Fig. 2.

Consulting Fig. 3 can find out, each blade all has the structure of aerofoil profile, it includes the forward position 14 of thickening, 14a and back along 17 than what approach, 17a, this airfoil structure of each blade can realize making fluid by each forward position 14 of blade, 14a is split into two-part, part fluid then the flow through downside 26 of blade of upside 25 another part fluids of blade of flowing through, the distance that the shape that downside 26 limits is flowed through fluid is longer, and this fluid that just causes the surface 26 of flowing through has descended with respect to the hydrodynamic pressure on the surface 25.

When impeller 10 rotates, fluid in face of blade is subjected to its upper side 25 extruding and is compressed (see figure 3), meanwhile, fluid on the downside 26 causes decompression because of pressure descends or thins out, when fluid is extruded and when the uper side surface 25 of each blade flows through, if the distance between the back edge of this uper side surface 25 and adjacent blades approximates greatly when flowing through by compression fluid layer thickness of uper side surface 25, the trend decline that fluid is flowed backward along the blade low voltage side.

As shown in Figure 3, the forward position of adjacent blades and back along between present a kind of mutual convergence relation, and a blade back along 17 and adjacent blades uper side surface 25 between distance approximate " thickness " that flows through the high-pressure liquid layer of passage 21 along blade uper side surface 25 greatly.

Because fluid is driven into the zone of high pressure of contiguous discharge zone 18, head in this zone is pressed and is in fact acted on the direction vertical with the fluid mobile phase that flows into the zone of high pressure, this direction marks with item 27 in Fig. 3, high-pressure liquid shown in the figure flows out through exporting 24, the head of discharge zone (for example being a compressed media tank) presses and not exclusively is the directive effect that flows against fluid, and in fact its action direction is perpendicular to the liquid flow path direction.

Have only after the energy that enters gas that is rendered as pressure or speed is adjacent to blade when surpassing along the energy of the gas (for example at inflatable chamber or pressurized container) that is rendered as pressure, in fact the body stream that enters just be disturbed or be prevented from.

Have been found that the blade with fixed pitch, the ability of this pressurized gas of impeller 10 only works in the velocity range that is rather narrow.

Because liquid is in fact incompressible, almost under any rotating speed, the inflow side of impeller 10 is substantially equal to the outflow side, and the degree of convergence of so described blade only need remain in the scope that can play adjusting just passable from the viewpoint of design.

Fig. 6 shows the airfoil fan 12 of Three Represents, 12a and 12b, they all by run-on point 28 being pivotally mounted in (not shown) on the wheel hub, run-on point and forward position 14,14a and 14b are contiguous.When impeller is pressed among Fig. 6 direction shown in the arrow when rotating, these blades can oneself rotate, the back edge of blade automatically deviates from the uper side surface direction displacement of adjacent vanes, make distance between the two be substantially equal to the thickness that flows through this uper side surface high-pressure liquid layer, the generation of this own alignment effect is because at each blade 12, the high-pressure liquid of 12a and 12b uper side surface, be tending towards making blade to rotate, but because the high-pressure liquid on the adjacent blades has limited the degree that can rotate towards the uper side surface of another blades adjacent.This oneself rotate or own effect of regulating also can realize by making blade with flexible material, also can make blade contiguous thereafter along part with the flexible material making, realize self-regulation by its distortion.

Fig. 4 and Fig. 5 have shown the footpath flow fan (Fig. 5) and the mutual significant difference of impeller that adopts two passages (Fig. 4) of pressing example of the present invention in the prior art that only adopts two blades.The fan of prior art shown in Figure 5, the zone between the blade 30 and 31 is inoperative.Among Fig. 4, impeller is by solid material 32,32 expressions, passage 34, entity part between 35 is inoperative, this has shown that impeller acting finishes by any two interlobate effects, and is that the effect of correlation between high pressure side by a blade and adjacent sheet low voltage side is finished.Adopting under the conventional radial fan situation of airfoil fan, the merit of conveyance fluid is actually along finishing on the total length of blade bi-side.Impeller compression and conveyance fluid acting are actually to be finished by the forward position of each blade and the effect between the back edge of blade of being adjacent.

Fig. 7 and Fig. 8 have shown the different embodiment of impeller, in this embodiment, impeller 40 have one to the embodiment who narrated in the past in similar wheel hub 41, wheel hub has impeller is contained in hole 42 on the axle, one group is installed on the wheel hub 41 and is distributed in one group of blade 44a that the impeller outer edge position is spaced apart from each other, 44b.Blade 44a, 44b spatially has the structure of overlapping relation, (be 44d, limit a passage 45 between 44b), passage 45 has the entrance and exit similar to above-mentioned example at adjacent a pair of overlapping blade, also because the forward position 46a of each blade, 46b length greater than blade after along 47a, the length of 47b, and the volume between making inlet and exporting reduces gradually, like this, passage 45 is the decline taper from its inlet to outlet.Rely on the length relation of forward position with respect to the edge, back, adjacent vanes 44a, 44b must not restrain, but can keep a kind of parallel surfaces relation, can spread slightly even, still can obtain reducing of volume.

The impeller of some pattern is from side direction, blade be certain angle and arrange rather than with the perpendicular line parallel of axis, this configuration has advantage under certain conditions, for example, when this impeller that has angle to arrange blade being compared with conventional radial fan, as can be seen, it is bigger than the inlet of conventional radial fan that the fluid of impeller is introduced district's (inlet), can see that also the inswept area of above-mentioned blade of impeller is more much bigger than the inswept area of the blade of conventional radial fan.

The impeller that blade is the angle layout also may be easier to make the fluid diverting axial direction that flows out by impeller, and still maintains the advantage of the centrifugal effect of common diameter flow fan or impeller.Above-mentioned have blade and be the impeller type that angle arranges and also can have the blade convergent characteristics of having narrated.The wingtip 15 of impeller blade is scheduled to and will be skimmed over case with very little matching gap, and for the purpose of each figure represented to know, case was all not shown among the figure.

Fig. 9 and Figure 10 be respectively tabulation and with the advantage of curve shows impeller, indicated impeller from these information and can be operated in the high static pressure of maintenances under the low-down flow situation and can resist the stall generation.Impeller is not followed the conventional fan curve shown in the manual of standards.

A kind of typical centrifugal compressor, its blade or the wing truly have overlapping, yet those blades from the middle part outside edge position be disperse and the blade of impeller can be a convergent.

Centrifugal compressor is to rely on gas velocity to change to realize compression, gas is from very little inlet suction relatively, experienced from the direction change back that axially transfers to radially and outwards dished out with very high speed, the compressor of this pattern is when gas reaches maximum speed when longshore current goes out behind blade.High-speed gas almost immediately reduction of speed and pressure rise, the pressure increase is less relatively in centrifugal compressor.

Notice in centrifugal compressor, gas at first collides each blade of pushing ahead or the high pressure side of the wing is compressed, gas pressure when wingtip is sentenced very high-speed quilt and dished out descends then, raise along with the reduction of its speed can produce pressure again, the quick change of such speed and pressure can make the efficient of compressor reduce.

Have the vane collocation of described characteristics is got the decrement that more close impeller outer edge also can increase the gas that collides with the blade high pressure side of pushing ahead by this way, to reach needed high pressure lift-off value between described blade, and can not produce gas and leave the phenomenon that pressure reduces and pressure raises again that then occurs behind the blade, this phenomenon can produce in centrifugal compressor.

Narrate with another kind of method: between the member (blade) of impeller, say that more specifically obtaining needed pressure between the forward position of a given blade and the back edge at another blade of its front raises, in this way, the impeller that blade is angle configurations type form can make the change of gas flow direction reduce: can provide the inlet of increase or gas to introduce the zone: and can realize gas in fact only along a compressed purpose of direction, rather than the sudden change of three speed and pressure takes place in centrifugal compressor like that.Should be mentioned that typical Axial Flow Compressor is also as centrifugal compressor, the reduction that stand speed could realize gas compression, and the two all can produce the stall phenomenon of the blade or the wing, and this phenomenon reduces when using impeller significantly.Also need propose, blade is big inlet of angle layout pattern rotor or fluid lead-in surface, when ducted fan that is used for replacing conventional forwarding or Axial Flow Compressor, can utilize ram effect.

Impeller can be used for replacing underwater propeller, and the blade of impeller can be any angle with respect to square position formula wheel hub or cone hub, and the tapering of cone hub also can be decided arbitrarily.

Cone hub and described wingtip can occupy a radius, and the blade of impeller is seen all from any angle can be twisted shape.

The blade of impeller can occupy a radius, and this radius changes along its length.

The blade of impeller can have constant thickness or a sharp-pointed forward position and/or a sharp-pointed back edge.

The blade of impeller sees that from the side the angle that its wing root is relative with wingtip can be identical or inequality.

Claims (15)

1. impeller, include anterior district and the rear portion discharge zone introduced, wheel hub and one group of blade that extends around wheel hub that comprises the impeller rotating shaft line, have at least partial blade overlapping relation to be arranged between adjacent overlapped blade, to limit a passage, this passage has an inlet and an outlet, described inlet is limited and is linked up with front portion introducing district by the forward position of adjacent blades, outlet by adjacent blades back along the institute limit and link up with the rear discharge zone, the spin axis of blade pitch wheel hub has certain distance, between spin axis and blade, to limit an entity part, it is characterized in that, each blade be lonely shape to limit an outside convex surface and an inside concave surface, when impeller rotates, outside convex surface impacts and compressed fluid, each blade has the wing root of a below and the wingtip of a top, and towards the outlet convergence, the forward position of each blade and back are along outwards being diffusion type from spin axis from inlet for adjacent overlapped blades.

2. impeller as claimed in claim 1 is characterized in that entity part will account for 30% of hub size at least.

3. according to the described impeller of claim 1, it is characterized in that blade is to be connected with wheel hub at the position that is adjacent to discharge zone.

4. according to the described impeller of claim 1, it is characterized in that the shape on blade extremely back edge from its forward position is lonely shape.

5. according to the described impeller of claim 4, it is characterized in that the degree of overlapping between the adjacent blades is at least 30%, less than 100%.

6. according to the described impeller of claim 1, it is characterized in that blade is fixed.

7. according to the described impeller of claim 1, it is characterized in that blade is movable, to realize the adjusting of degree of convergence.

8. according to the described impeller of claim 7, it is characterized in that blade is a rigidity, it is installed on the wheel hub near the place, forward position by pivot.

9. according to the described impeller of claim 7, it is characterized in that it is flexible that blade has part at least, so that realize the adjusting of degree of convergence when impeller rotates.

10. according to the described impeller of claim 1, it is characterized in that the forward position length between adjacent blades is equal to each other, back between adjacent blades also is equal to each other along length, and reducing of volume only is to be obtained by blade convergence character each other.

11. according to the described impeller of claim 5, it is characterized in that, back along long than this adjacent blades of adjacent blades preceding, the wingtip of each blade have tapering along separately forward position to separately back edge, thus realize inlet area greater than discharge area so that volume progressively reduce.

12., it is characterized in that the introducing district is combined by the forward position of each blade and wingtip to limit according to the described impeller of claim 1.

13., it is characterized in that according to the described impeller of claim 12, introduce the inlet area of district greater than passage, therefore between introducing district and inlet, can obtain reducing of volume.

14., it is characterized in that wheel hub is tapered substantially according to the described impeller of claim 1, expand towards discharge zone along introducing the district.

15., it is characterized in that blade has the configuration of aerofoil from its forward position to the edge, back according to the described impeller of claim 1.

Images