CN1882764A

CN1882764A - Variable geometry turbocharger

Info

Publication number: CN1882764A
Application number: CN 200480033927
Authority: CN
Inventors: B·D·措林格尔; D·H·里特迈尔; K·P·斯拉普斯基
Original assignee: Honeywell International Inc
Current assignee: Garrett Power Technology (Shanghai) Co.,Ltd.
Priority date: 2003-09-25
Filing date: 2004-09-24
Publication date: 2006-12-20
Anticipated expiration: 2024-09-24
Also published as: CN100400799C

Abstract

A variable geometry turbocharger includes vanes (50) disposed therein having an inner airfoil surface (68) oriented adjacent a turbine wheel, and an outer airfoil surface (66) oriented opposite and parallel to the inner airfoil surface (68). The vane (50) includes first and second axial surfaces (70, 72) that are each positioned perpendicular to and interposed between the inner and outer airfoil surfaces (66, 68). A vane leading edge (74) is positioned along a first inner and outer airfoil surface junction, and a trailing edge (76) is positioned along a second inner and outer airfoil surface junction. One or more of the first and second axial surfaces (70, 72) have a composite construction comprising a solid section that extends a distance from the leading edge towards the trailing edge, and a cored-out section that extends a distance from the trailing edge towards the leading edge.

Description

The turbosupercharger of variable geometry

Invention field

The present invention relates generally to the field of turbochargers of variable geometry, relate to the traditional light aerodynamics guide vane of solid vane of weight ratio that movably is arranged at wherein, compare with known non-solid vane, show low gas leakage, the blade that the blade working that improves prolongs/turbosupercharger working life is provided thus.

Background of invention

The turbosupercharger that is used for gasoline and purple oily internal-combustion engine is this technology known devices, and they are used to utilize the heat of the waste gas that flows out from motor and volume flow is pressurizeed or the suction air stream of supercharging inflow engine firing chamber.Particularly, the waste gas that flows out from motor is with a kind of turbine shroud that can make the mode that rotated in housing by exhaust-driven turbine flow into turbosupercharger.This is installed on the end of an axle by exhaust-driven turbine, and this is shared for the radial air compressor that is placed in the compressor housing that is installed on this other end.Therefore, the rotation of turbine also makes this air compressor rotate in the compressor housing of the turbosupercharger of separating with turbine shroud.The rotation of air compressor makes and enters air and enter compressor housing, and in itself and fuel mix and before the engine combustion Indoor Combustion pressurized or amount that supercharging one needs.

In a turbosupercharger, usually wish to control efficient or the operational range that the exhaust flow that leads to turbine improves turbosupercharger.The configuration of the turbosupercharger of variable geometry has been made into and has satisfied this requirement.One type of the turbosupercharger of this kind variable geometry is a kind of turbosupercharger that an exhaust nozzle that can change is arranged, and is called the turbosupercharger of variable-nozzle.In the turbosupercharger of variable-nozzle, utilized the not isomorphism type of variable-nozzle to control exhaust flow.In the turbosupercharger of this kind variable-nozzle, be used for obtaining a kind of of exhaust flow control and center on the turbine inlet blade of a plurality of pivot type rotation of arrangement circlewise by way of relating to using.The blade of these pivot type rotation is controlled jointly and is changed the bottle-neck section of passage between blade, plays the effect that control enters the exhaust flow of turbine thus.

For the running suitably and reliably of the turbosupercharger that guarantees this kind variable-nozzle, importantly that these are single blade configuration and being assembled into according to desirable exhaust flow controlling and driving in turbine shroud freely moves or pivot type rotation.A kind of prior art blade 10 that is used for this kind turbosupercharger purposes of Fig. 1 illustration comprises outer aerofoil 12 and inner airfoil surface 14 and opposed axial surface 16 and 18.The blade of the type is a kind of blade with " solid " structure, because the axial surface of blade 16 and 18 is to be defined by a kind of continuous plane structure.

Though the traditional solid vane 10 of this kind can be used for the turbosupercharger of variable geometry, but the solid design of known these blades makes blade be difficult to move in turbosupercharger, and producing relevant frictional influence in known blade and the relevant blade mobile mechanism in turbosupercharger, this influence can be shortened the running working life of turbosupercharger.In addition, it is quite expensive adopting the cost of solid vane.

Fig. 2 A and 2B illustration another kind respectively make the prior art blade 20 with non-solid construction.Exactly, the configuration of this kind prior art blade 20 is made has axial surface 22 and 24, and different with above-mentioned solid vane, they have the axial surface that hollows out basically.

As shown in Fig. 2 A, blade axial surface 22 is limited by two area of knockouts 26 and 28, and they occupy the major part of this axial surface area together.Blade axial surface 22 comprises a solid section 30 that is arranged between two cored-out sections 26 and 28, and it occupies the fraction of this axial surface area.As shown in Fig. 2 B, blade axial surface 24 is limited by two cored-

out sections

32 and 34, and they occupy the major part of this axial surface area together.Blade axial surface 24 comprises that is arranged on two holes 36 between the cored-out sections, and the position in this hole is mutually opposed with the solid section 30 of opposed blade axial surface 22.

The cored-out vane of the prior art can be used to provide the blade structure of weight saving, has reduced thus to plant the relevant active force and the wearing and tearing of motion blade of structure in the turbosupercharger therewith, and has reduced cost.But the hollow structure of this kind blade can produce undesirable air flow effects in turbosupercharger.For example, the axial surface of these cored-out vane may work and form leakage paths to being directed into the lip-deep air of blade airfoil.For example, be directed into blade inlet edge and aerofoil surfaces rather than the air that is directed along this aerofoil surfaces may be because this hollows out that configuration reduces the resistance of air stream leaks between blade axial surface and adjacent turbosupercharger surface.Vane leakage in this kind turbosupercharger is undesirable, because its serious running efficiency that reduces turbosupercharger.

Therefore, wish to make a kind of so interior blade of turbosupercharger that is used for variable geometry, when with traditional solid vane relatively the time, this leaf weight alleviates, and this blade reduces as far as possible or eliminated the unwanted air flow effects relevant with the air leakage of crossing blade in the turbosupercharger, improved the operating reliability and the turbocharger efficiency of blade thus.

Brief summary of the invention

Blade of the present invention is arranged in a kind of turbo charger unit of variable geometry, and this device comprises turbine shroud, a spiral case and near the nozzle wall this spiral case that is connected on this inlet that an exhaust gas entrance and an outlet are arranged.A turbine is supported in this turbine shroud and is attached on the axle.A plurality of this kind blades are arranged in the turbine shroud and between exhaust gas entrance and turbine.

Blade of the present invention has the inner airfoil surface of this turbine of vicinity and one and the opposed and substantially parallel outer airfoil surface of inner airfoil surface.First and second axial surfaces are separately perpendicular to interior outer airfoil surface and in being arranged between the outer airfoil surface.A blade inlet edge is provided with along outer airfoil surface connecting part in first.A trailing edge is provided with along outer airfoil surface connecting part in second.Blade of the present invention also comprises a hole that is arranged at least one axial surface in first and second axial surfaces, and a bar is used for packing in the hole.

A key features of blade of the present invention is that at least one in first and second axial surfaces comprises the composite construction of a kind of solid section and cored-out sections.In the embodiment of a demonstration, this solid section from leading edge backward edge extend a segment distance, and this cored-out sections is extended a segment distance from trailing edge to leading edge.Position of this solid and cored-out sections and configuration are made and are reduced or eliminated gas as far as possible along the passing through of blade axial surface, and work thus and improve the running efficiency of turbosupercharger.

The accompanying drawing summary

To more be expressly understood the present invention with reference to following accompanying drawing, in the accompanying drawing:

Fig. 1 is a kind of perspective view of prior art solid vane;

Fig. 2 A and 2B are a kind of perspective views of prior art cored-out vane;

Fig. 3 is the isometric map of decomposition of turbine shroud that is used for a kind of turbosupercharger of the variable geometry that utilizes traditional blades;

Fig. 4 A and 4B are a kind of side views of blade made in accordance with the present invention; And

Fig. 5 is the horizontal sectional view of the blade of Fig. 4 A and 4B.

Detailed Description Of The Invention

The blade of making for the turbosupercharger that is used for variable geometry of the present invention is made the axial surface in hollowing out of settling of key position and solid surface of being characterized as with each.More particularly, blade of the present invention has one to be that solid first axial surface and one are second axial surface that hollows out along big surface area along big surface area.Each first and second axial surface comprises that also of the axial surface that occupies separately is than the corresponding solid of small surface area with hollow out the cross section.Blade of the present invention is made such configuration, makes can shorten as far as possible between the turbosupercharger on-stream period or eliminate the possible leakage paths that passes the blade axial surface.

Blade of the present invention is arranged in the turbosupercharger a kind of variable geometry or variable-nozzle.The turbosupercharger of this kind variable geometry is total comprises an attached center housing that a turbine shroud is arranged and a compressor housing that is attached at the other end at one end.An axle is arranged in the bearing means that is comprised in this center housing rotationally.Turbine or turbine are attached at an end of axle and are supported in this turbine shroud, and compressor impeller is attached at the other end of axle and be bearing in this compressor housing.Turbine shroud and compressor housing utilization (for example) extend in the bolt between the adjacent housings and are attached on this center housing.

The part of the turbosupercharger 38 of a kind of known variable-nozzle of Fig. 3 illustration, this turbosupercharger 38 comprises a turbine shroud 40, the latter has a standard inlet 42 and that is used to accept exhaust flow to be used for waste gas is guided into the outlet 44 of the releasing system of motor.A spiral case is connected on this exhaust entrance, and comprises an outer nozzle wall in the turbine shroud foundry goods of contiguous this spiral case.Turbine of this turbine shroud internal support and shaft device 46.Supply the waste gas of this turbosupercharger or other high energy gas and enter turbine by this inlet and be distributed in this turbine shroud, be used for radially entering basically this turbine by the nozzle inlet 48 of periphery by spiral case.

A plurality of blades 50 are installed on the nozzle wall 52 by the axle 54 that vertically stretches out betwixt.These are arranged in the corresponding hole 56 in this nozzle wall.Each comprises that they are engaged in the corresponding groove 60 of associative ring 62 from the driving plate 58 that stretches out with the opposed side of axle these blades, and associative ring 62 plays second nozzle wall.

Drive assembly is connected with this associative ring and makes as required and rotate this ring along a direction or other direction, so that with respect to the rotatingshaft of this turbine radially outwards or move inward these blades, thus correspondingly increase or reduce to lead to the exhaust flow of turbine.When associative ring rotates, driving plate 58 end to end from groove in its corresponding groove 60 of blade is moved.Because the orientation of these grooves has a radial component along associative ring, so the driving plate of blade mobile in its corresponding groove make blade pass cross sharf in its corresponding hole rotation and make pivot type rotation, thereby open or close this mentioned nozzle area according to the associative ring sense of rotation.U.S. Patent No. 6,269 discloses an example of the turbosupercharger of the known variable-nozzle that comprises this kind parts in 642 and No.6,419,464, and they are incorporated herein by reference.

Described in top background, the configuration of suitable these blades of running requirements of the configuration that comprises the above-mentioned a plurality of blades shown in Fig. 3 of the turbosupercharger of variable geometry is made and is both helped carrying out desirable blade in the mode that does not produce excessive wearing and tearing and move design as a kind of light weight, helps the high efficiency flow of gas in turbine shroud again as not encouraging flow leakage.

The blade 64 of Fig. 4 A and 4B illustration a kind of example embodiment of the present invention, this blade are designed for the turbosupercharger above-mentioned turbosupercharger as shown in Figure 3 of variable geometry especially, so that satisfy all these requirements.Fig. 5 also represents the horizontal section of this blade, so that provide further reference to those blade parts of discussing below.With reference to Fig. 4 A and 5, blade 64 comprises a low pressure or outer aerofoil 66, opposed high pressure or an inner airfoil surface 68 and an axial surface 70 and 72 (being shown among Fig. 4 B).These blade surfaces define with respect to the leaf position in the turbine shroud.Blade 64 is included in the leading edge 74 and the trailing edge 76 at the opposed common end place of low pressure aerofoil 66 and high pressure aerofoil 68.This blade comprises that one is positioned near the leading edge 74 and from axial surface 79 outwardly directed thin slices 78.The configuration of thin slice 78 make in the above described manner with the groove of an associative ring with close so that the driving of blade.

Blade of the present invention can comprise except above-mentioned aerofoil configuration disclosed.In a preferred embodiment, blade of the present invention can have one can be greater than about 0.16 times of about 0.16～0.50 times aerofoil that promptly is positioned at length of blade of length of blade or radial thickness (thickness records between opposed inside and outside aerofoil, and length records with the straight line between the blade front and rear edge).In addition, this outer aerofoil can be the about 0.8 times convex surface of its radius of curvature less than length of blade.Secondly, the feature of blade inlet edge is to have sizable radius of curvature, makes that the neighbouring part of this outer aerofoil is quite far away from driving thin slice, produces the thickness of an increase thus near leading edge.

In addition, inner airfoil surface can be provided with a continuous convex (promptly being defined by an independent radius of curvature), and a compound shape that is defined by at least two difform sections can be arranged.Move from leading edge, this inner airfoil surface has one by a convex part that radius of curvature defined greater than the radius of curvature of leading edge, so that be mixed in this internal surface to this leading edge outline or with leading edge.Edge 74 extends to by chance through thin slice 78 before this convex part.Partly move from this convex, this internal surface has a concave portions that extends to trailing edge.

The axial surface 70 of blade comprises a combining surface that is formed by solid surface section and hollowed-out surface section, and these two surface segment are specifically settled the location, to avoid the unwanted flow leakage on surface vertically.As use herein, the surface portion that term " solid " is used in reference to appointment is flat or the plane, is not recessed with respect to the interface edge of inside and outside aerofoil.In the embodiment of this demonstration, blade axial surface 70 comprises a solid section 80 that extends to axis hole 82 between inside and outside aerofoil 68 and 66 from blade inlet edge 74.Thin slice 78 stretches out from this solid section 80, and this solid section to occupy the most surfaces of this axial surface 70 long-pending.In the embodiment of this demonstration, the axial surface area that this solid section occupies is greater than about 25%, and is preferably greater than about 50%, preferred greater than 55%.

For the blade that in the turbosupercharger of the above-mentioned variable geometry shown in Fig. 3, turns round, the part that is exposed to turbosupercharger inner high voltage difference of blade axial surface and blade can gas leakage part be the superimposed part corresponding to this associative ring of blade, or rather, be the superimposed part of combined circular groove.Can reasoning, the high pressure air physical efficiency is guided on the axial surface of blade through these grooves by associative ring.For this reason, the configuration of axial surface 70 is made the position of the solid area 80 that has corresponding to combined circular groove, so that shorten leakage paths as far as possible for any high pressure air physical efficiency by this groove.

The configuration in hole 82 is made and wherein can be packed one into, makes pivotal movement to allow blade in turbosupercharger.In the embodiment of a demonstration, stretch out by blade fully in hole 82, and comprise a concave part 84 of settling with one heart around it.This concave part 84 helps flattening running as embossing.The tolerance of flatness closely on the axial surface 70 of blade is important for shortening leakage paths with satisfied relevant loss in efficiency.

The axial surface 70 of blade comprises a cored-out sections 86, and this section 86 extends a segment distance from the wall 88 of the part that defines axis hole 82 to trailing edge 76.Area of knockout 86 is defined by the opposed inwall of inside and outside aerofoil.Cored-out sections 86 occupies the fraction surface area of axial surface 70.In the embodiment of a demonstration, the axial surface area that area of knockout 86 occupies is less than about 40%, preferably less than 35%.

For the blade that the turbosupercharger with the above-mentioned variable geometry shown in Fig. 3 turns round, the part that is exposed to quite low pressure reduction of blade axial surface 70 be blade extend to the part of trailing edge from axis hole 82.For this reason, the possibility of gas leakage has diminished, and this section is built into has the configuration that hollows out and will help reducing cost and reducing rotating mass.

Fig. 4 B illustrates the view of the blade of watching from another axial surface 72 64.Axial surface 72 comprises a kind of by solid and hollow out the composite construction that two surface segment are formed, as axial surface 70, is that specific location arrangement is not passed through therebetween to avoid flow leakage with needing.The characteristics of this blade axial surface also are shown among Fig. 5.In the embodiment of this demonstration, blade axial surface 72 comprises a cored-out sections 92 that extends to axis hole 82 between inside and outside aerofoil 68 and 66 from blade inlet edge 74.

Or rather, cored-out sections 90 is defined by the inwall and the wall section 92 of opposed inside and outside aerofoil, and wall section 92 limits the border of the axis hole 82 that extends through this blade.As being clearly shown that among Fig. 5, in the embodiment of a demonstration, the degree of depth of cored-out sections 90 is determined by the inner wall section 94 of the solid section 80 that is provided with along opposed axial surface 70.The part of the axial surface 72 that cored-out sections 90 is occupied is similar to substantially or equals part by the occupied axial surface 70 of solid section 80.In the embodiment of this demonstration, it is long-pending that cored-out sections 90 occupies the most surfaces of axial surface 72, for example occupies greater than about 50% more preferably greater than 55% axial surface area.

As axial surface 70, axial surface 72 comprises a concave surface part 96 of settling with one heart around axis hole 82.This concave surface part 96 is convenient to flatten running as embossing.In order to shorten leakage paths and to reduce relevant loss in efficiency, the charcoal lattice flatness tolerance on the axial surface 72 of blade is important.

Blade axial surface 72 also comprises a solid section 98 of extending a segment distance to trailing edge 76 from axis hole 82.Solid section 98 is defined by inside and outside aerofoil, and occupies the fraction surface area of axial surface 72.A part of axial surface 72 that solid section 98 occupies is substantially similar to or equals a part of axial surface 70 that cored-out sections 86 occupies.In the embodiment of a demonstration, the axial surface area that solid section 98 occupies is less than 40%, preferably less than 35%.

The blade that turns round in the turbosupercharger for the above-mentioned variable geometry shown in the load map 3, the part that is exposed to the High Pressure Difference in the turbosupercharger of blade axial surface 72 and the part that is vulnerable to gas leakage most of blade are the parts of the contiguous trailing edge of blade.Found through experiments, this part of blade can be measured ground impulse turbine efficient.For this reason, the configuration of axial surface 72 is made the solid section 98 that has between this hole and trailing edge, to shorten the leakage paths to any pressurized gas as far as possible.In addition, the part that is exposed to quite low pressure reduction of blade axial surface 72 be blade extend to the part of axis hole 82 from leading edge.This part of blade axial surface is slided along a uncrossed smooth flat surface of nozzle, and there is not the high-pressure air source that produces remarkable leakage current in this place.For this reason, reduced the possibility of gas leakage, helped building one and reduce cost when hollowing out this section of configuration and reduce rotating mass.

The configuration of blade of the present invention is made consciously with axial surface has the section of being made up of the combination of solid section and cored-out sections.In a preferred embodiment, this solid and cored-out sections be arranged on one with another sharf to lip-deep hollow out accordingly with the opposed blade axial surface of solid section on.In the preferred embodiment, this solid and cored-out sections is positioned near the leading edge or trailing edge of blade.Blade of the present invention with the mode configuration of above-mentioned illustration and description, in the time of in being used for the turbo charger unit shown in Fig. 3, by shortening as far as possible along the leakage paths of the solid and cut-out of each axial surface and reduce the blade axial surface as far as possible and adjacent turbosupercharger surface between gas leakage.

But, be appreciated that blade of the present invention can comprise that its configuration is different from above-mentioned illustration and description and depends on the composite construction of the solid and cored-out sections of specific turbocharger configuration and turbosupercharger purposes.For example, blade of the present invention can have surperficial vertically solid and cored-out sections of differently settling, so that tackle the High Pressure Difference of diverse location in the turbosupercharger.A key features of the present invention is that at least one blade axial surface comprises the combination that hollows out with solid section.

Blade of the present invention can be made with the material of the same kind that is used to make traditional prior art blade.Blade of the present invention can be made by machining or mould pressing process.In a preferred embodiment, blade of the present invention is made with the metal injection moulding technology.Blade of the present invention provides a kind of desirable cost benefit and light weight that is different from solid vane, and the while reduces as far as possible or eliminate the interior undesirable gas leakage effect of turbosupercharger.Therefore, the running of blade of the present invention can improve the mobility of blade, reduces wear effects, improves the running efficiency of turbosupercharger, and prolongs the running working life of turbosupercharger.

Described the present invention in detail according to the requirement of patent statute now, the Technology professional is appreciated that and can makes amendment and replace specific embodiment disclosed herein.These modifications are included within scope of the present invention and the intention.

Claims

1. the turbo charger unit of a variable geometry comprises:

The turbine shroud (40) that one exhaust gas entrance (42) and an outlet (44) are arranged, one is connected the spiral case on the inlet (42) and the nozzle wall of this spiral case of vicinity;

One is supported in the turbine shroud (40) and is attached at turbine on the axle (46);

A plurality of be set in the turbine shroud (40) and the blade (50) between exhaust gas entrance (42) and turbine, each blade (50) comprising:

A near inner airfoil surface (68) that is positioned at this turbine;

Location and inner airfoil surface (68) outer aerofoil (66) opposed and in parallel;

First and second axial surfaces (70,72) are positioned to separately perpendicular to interior outer airfoil surface (68,66) and between the side outer airfoil surface;

The leading edge (74) of outer airfoil surface connecting part configuration in one along first;

The trailing edge (76) of outer airfoil surface connecting part configuration in one along second;

First and second axial surfaces (70 wherein, 72) at least one in comprises the composite structure of a solid section and a cored-out sections, this solid section occupies at least 25% of this axial surface area, and extend to trailing edge (76) from leading edge (74), and this cored-out sections is extended a segment distance from trailing edge (76) to leading edge (74).

2. the device described in claim 1 is characterized in that, first and second axial surfaces (70,72) comprise this composite structure separately, and wherein the cored-out sections of the position of the solid section of first axial surface (70) and second axial surface (72) is opposed.

3. the device described in claim 1, it is characterized in that, each blade (50) also comprises one at first and second axial surfaces (70,72) hole of a bar is used at least one to pack into, wherein this solid section is extended to this hole from leading edge (74), and this cored-out sections is extended to the position of contiguous this trailing edge (76) from this hole (36).

4. the device described in claim 1 is characterized in that, this solid section occupy first axial surface (70) surface area greater than 50%.

5. the device described in claim 1 is characterized in that, comprises that also one outwards protrudes and is positioned near the leading edge (74) thin slice (58) from this solid section.

6. the device described in claim 3, it is characterized in that, blade (50) is passed to second axial surface (72) from first axial surface (70) in this hole, wherein this first axial surface (70) comprises from leading edge (74) and extends to the solid section in this hole and extend to the cored-out sections of the position of a contiguous trailing edge (76) from this hole, and wherein second axial surface (72) comprises from leading edge (74) and extends to the cored-out sections in this hole and extend to the solid section of trailing edge (76) from this hole.

7. the device described in claim 6, it is characterized in that, it is long-pending that the solid section of first axial surface (70) occupies the most surfaces of first axial surface (70), and that the cored-out sections of second axial surface (72) occupies the most surfaces of second axial surface (72) is long-pending.

8. the device described in claim 6 is characterized in that, comprises that also one outwards protrudes from first axial surface (70) and is positioned near the leading edge (74) thin slice (58).

9. the turbosupercharger of a variable geometry also comprises:

A near inner airfoil surface (68) that is positioned at this turbine;

Location and inner airfoil surface (68) outer airfoil surface (66) opposed and in parallel;

Perpendicular to interior outer airfoil surface (68,660 and be configured in first and second axial surfaces (70,72) between the inside and outside aerofoil, wherein this second axial surface (72) is positioned near this nozzle wall,

The trailing edge (76) of outer airfoil surface connecting part configuration in one along one second;

One is passed the hole that second axial surface (72) is provided with, and the velamen that is used for packing into therein is configured in the bar between blade (50) and this nozzle wall; And

Be set at the driving mechanism on first axial surface (70);

One is set near the blade (50) ring-type associative ring (62) along first axial surface (70), and this ring (62) comprises the mechanism that so that mesh these a plurality of blades (50) blade (50) is rotated in order to cooperate with this driving mechanism in this turbosupercharger;

First and second axial surfaces (70 wherein, 72) at least one in comprises the composite structure of a solid section and a cored-out sections, wherein this solid section occupy the blade axial surface that extends to trailing edge (76) from leading edge (74) surface area at least 25%, wherein this cored-out sections is extended a segment distance from trailing edge (76) to leading edge (74).

10. the device described in claim 9, it is characterized in that, this solid section extends to the position in the hole vicinity second axial surface (72) along first axial surface (70) from leading edge (74), and this solid section extends to trailing edge (76) along second axial surface (72) from this hole.

11. the device described in claim 10, it is characterized in that, the position of this cored-out sections along first axial surface (70) from a contiguous trailing edge (76) extends to the position of vicinity second axial surface (a 72) mesopore, and this cored-out sections extends to the position in contiguous this hole along second axial surface (72) from leading edge (74).

12. the device described in claim 10 is characterized in that, the solid section of first axial surface (70) occupy blade (50) first axial surface (70) that between front and rear edge (74,76), records surface area at least 50%.

13. the device described in claim 9 is characterized in that, this driving mechanism is a thin slice (58) that outwards protrudes from blade (50), and this matching mechanism is a groove (60).