CA1164420A - Fan blade with trailing edge tab - Google Patents
Fan blade with trailing edge tabInfo
- Publication number
- CA1164420A CA1164420A CA000370062A CA370062A CA1164420A CA 1164420 A CA1164420 A CA 1164420A CA 000370062 A CA000370062 A CA 000370062A CA 370062 A CA370062 A CA 370062A CA 1164420 A CA1164420 A CA 1164420A
- Authority
- CA
- Canada
- Prior art keywords
- blade
- tab
- trailing edge
- width
- fan blade
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000006073 displacement reaction Methods 0.000 abstract description 8
- 230000003247 decreasing effect Effects 0.000 abstract 1
- 238000000034 method Methods 0.000 description 6
- 238000002474 experimental method Methods 0.000 description 4
- 238000001125 extrusion Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000004026 adhesive bonding Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 229910001234 light alloy Inorganic materials 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03D—WIND MOTORS
- F03D1/00—Wind motors with rotation axis substantially parallel to the air flow entering the rotor
- F03D1/06—Rotors
- F03D1/0608—Rotors characterised by their aerodynamic shape
- F03D1/0633—Rotors characterised by their aerodynamic shape of the blades
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C11/00—Propellers, e.g. of ducted type; Features common to propellers and rotors for rotorcraft
- B64C11/16—Blades
- B64C11/18—Aerodynamic features
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/26—Rotors specially for elastic fluids
- F04D29/32—Rotors specially for elastic fluids for axial flow pumps
- F04D29/34—Blade mountings
- F04D29/36—Blade mountings adjustable
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/26—Rotors specially for elastic fluids
- F04D29/32—Rotors specially for elastic fluids for axial flow pumps
- F04D29/38—Blades
- F04D29/384—Blades characterised by form
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
- F05B2240/00—Components
- F05B2240/20—Rotors
- F05B2240/30—Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor
- F05B2240/301—Cross-section characteristics
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/70—Wind energy
- Y02E10/72—Wind turbines with rotation axis in wind direction
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Sustainable Development (AREA)
- Sustainable Energy (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Aviation & Aerospace Engineering (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
- Extrusion Moulding Of Plastics Or The Like (AREA)
Abstract
ABSTRACT
A propeller fan blade in which an increase in the effective displacement of air at the proximal blade zones having lower circumferencial speed is obtained by providing the trailing edge of the blade with a rigid tab having width decreasing from the proximal end of the blade to the distal end of the blade, the tab forming an inclination angle with the blade between 10° and 70°.
A propeller fan blade in which an increase in the effective displacement of air at the proximal blade zones having lower circumferencial speed is obtained by providing the trailing edge of the blade with a rigid tab having width decreasing from the proximal end of the blade to the distal end of the blade, the tab forming an inclination angle with the blade between 10° and 70°.
Description
t~
I'his invention rela-teS to propeller fan blades of con-stant inclination angle, such as are used, for example, in cooling fans.
Typically propeller fans are composed of two or more blades rigidly attached to a central hub for rotation. The inclination angle of the blade is the angle between the ro-tational axis of the hub and a tangent to the surface of the blade. Blades of constant inclination angle along their length are,essentially, flat, and are also known as "non-twisted" blades.
It is the object of -this invention to provide an improved blade for a propeller fan which blade has a constant inclina-tion angle along its entire length, and which blade presents tabs along its trailing edge, which tabs have suitable dimen-sions and orientation, particularly in the axially inward blade zones, which zones have, during rotation, a lower circumferential speed. In this way an advantageous increase in the effective displacement of air of a propeller fan having blades of constant inclination can be obtained, in particular at the blade zones with lower circumferential speed.
At present the increase of a fan's effective displacement of air at the blade zones with lower circumferential speed is achieved by means of one of the following methods:
(a) Increase of the blade's chord (width) proceeding from the distal (axially outward) end to the blade's proximal (axially inward) root.
~; ~
~:a~
(b) Blade's twist l=increase of the geometrical incid-ence angle of the bladels sections, proceeding from the distal end to the paddle's root).
(c) Combination of the methods mentioned in (a) and (b).
Such techniques, which are used at present, exhibit the follow-ing difficulties:
(1) The chord change of the blade's profile is not feasible on massive paddles, manufactured by extrusion, and is complex with hollow paddles particularly if reinforced.
I'his invention rela-teS to propeller fan blades of con-stant inclination angle, such as are used, for example, in cooling fans.
Typically propeller fans are composed of two or more blades rigidly attached to a central hub for rotation. The inclination angle of the blade is the angle between the ro-tational axis of the hub and a tangent to the surface of the blade. Blades of constant inclination angle along their length are,essentially, flat, and are also known as "non-twisted" blades.
It is the object of -this invention to provide an improved blade for a propeller fan which blade has a constant inclina-tion angle along its entire length, and which blade presents tabs along its trailing edge, which tabs have suitable dimen-sions and orientation, particularly in the axially inward blade zones, which zones have, during rotation, a lower circumferential speed. In this way an advantageous increase in the effective displacement of air of a propeller fan having blades of constant inclination can be obtained, in particular at the blade zones with lower circumferential speed.
At present the increase of a fan's effective displacement of air at the blade zones with lower circumferential speed is achieved by means of one of the following methods:
(a) Increase of the blade's chord (width) proceeding from the distal (axially outward) end to the blade's proximal (axially inward) root.
~; ~
~:a~
(b) Blade's twist l=increase of the geometrical incid-ence angle of the bladels sections, proceeding from the distal end to the paddle's root).
(c) Combination of the methods mentioned in (a) and (b).
Such techniques, which are used at present, exhibit the follow-ing difficulties:
(1) The chord change of the blade's profile is not feasible on massive paddles, manufactured by extrusion, and is complex with hollow paddles particularly if reinforced.
(2) The twist of blades made of plastic material and obtained by extrusion is not feasible.
(~) The twist of blades made of light alloy and obtained by`extrusion, shows the following inconveniences:
-- necessity to exceed the yield point of the material;
-- practical impossibility to reach suitable twist values (particularly on blades having shell section and low elongation ratio, defined as the ratio of the blade's length to the chord) without causing damage to the paddle itself.
The present invention avoids the above mentioned diffi-culties and provides other advantages, which will be appre-ciated by those skilled in the art, as specified in the following description.
According to the present invention, an increase of the lift coefficient of the blade profile (and consequently an increase of the effective displacement of air~ of a propeller fan, whose blades have a constant inclination angle, can be achieved by means of tabs having suïtable wIdth and inclina-tion, fastened at the trailing edge of the blades themselves.
~ti~
Such increase depends on the width of the tab and on its inclination in relation to the profile chord Cornbining suitably the width of the tab with its inclina-tion, increments of the effective displacement of air by the blades can be achieved at the blade zones with lower circumfer-encial speed, which are equal or higher in comparison with the increments obtained by means of blade twist.
Under the same performance, the overall efficiency of the propeller fan equipped with the proposed devices (tabs) is equal or even slightly higher than known propeller fans with twisted blades.
According to the invention there is provided a propeller fan blade having a trailing edge and a substantially constant inclination angle along its entire length comprising a rigid tab secured to the trailing edge at an incidence angle to the blade of between 10 and 70, said tab having a maximum width at the proximal end of the blade and a minimum width at the distal end of the blade, said maximum width being not greater than 30~ of the width of the blade.
Figure 1 is a graph showing the change of the lift co-efficient CL of a blade profile with and without tab, respectively A and B curves, as a function of the aerodynamic incidence angle of the profile.
Figure 2 is a graph showing the change of the mentioned coefficient CL as a function of the tab's width expressed as percentage of the profile chord.
(~) The twist of blades made of light alloy and obtained by`extrusion, shows the following inconveniences:
-- necessity to exceed the yield point of the material;
-- practical impossibility to reach suitable twist values (particularly on blades having shell section and low elongation ratio, defined as the ratio of the blade's length to the chord) without causing damage to the paddle itself.
The present invention avoids the above mentioned diffi-culties and provides other advantages, which will be appre-ciated by those skilled in the art, as specified in the following description.
According to the present invention, an increase of the lift coefficient of the blade profile (and consequently an increase of the effective displacement of air~ of a propeller fan, whose blades have a constant inclination angle, can be achieved by means of tabs having suïtable wIdth and inclina-tion, fastened at the trailing edge of the blades themselves.
~ti~
Such increase depends on the width of the tab and on its inclination in relation to the profile chord Cornbining suitably the width of the tab with its inclina-tion, increments of the effective displacement of air by the blades can be achieved at the blade zones with lower circumfer-encial speed, which are equal or higher in comparison with the increments obtained by means of blade twist.
Under the same performance, the overall efficiency of the propeller fan equipped with the proposed devices (tabs) is equal or even slightly higher than known propeller fans with twisted blades.
According to the invention there is provided a propeller fan blade having a trailing edge and a substantially constant inclination angle along its entire length comprising a rigid tab secured to the trailing edge at an incidence angle to the blade of between 10 and 70, said tab having a maximum width at the proximal end of the blade and a minimum width at the distal end of the blade, said maximum width being not greater than 30~ of the width of the blade.
Figure 1 is a graph showing the change of the lift co-efficient CL of a blade profile with and without tab, respectively A and B curves, as a function of the aerodynamic incidence angle of the profile.
Figure 2 is a graph showing the change of the mentioned coefficient CL as a function of the tab's width expressed as percentage of the profile chord.
3 --llti~
Figure 3 is a perspective view of one embodiment of blade according to the present invention.
Figures 4a and b are perspective views of further embodi-ments of the present invention.
Figures 5a and b are plan views of two further embodiments of the present invention.
Figure 6 is a representative cross-section of the tabs of the preceding Figures secured to the blade.
Figures 7a, b and c are cross-sectional views showing alternative contours which the tab may take.
Figure 8 shows in cross-section an example of a method of securing the tab to the blade.
Figure 9 is a perspective view of a further embodiment of the present invention.
Figures lOa and b shows a further example of a blade and tab, with figure lOa being a plan view thereof, and Figure lOb being a cross-section taken along line A-A of Figure lOa.
Figure 11 is a graph showing the results of experimental tests conducted on the blade of Figure 10 and two prior art devic~s.
As can be seen in Figures lOa and lOb, blade 20 is secured to hub 22.
Referring to Figures 3 through 9, the blade, generally designated 20, is provided with a leading edge 24 and trailing edge 26, and with proximal end or root 23 and distal end 25.
The leading and trailing edges are joined by an upper surface 28 and a lower convex surface 30. The lower surface 30 has a greater curvature than that of the upper surface 28. Tab 32 is secured to the trailing edge 26, and extends upwardly and outwardly from the trailing edge.
In the following description the alternative structures of the tab will be examined.
The tab can be applied to the trailing edge 26 of the blade 20 along its total length as in Figure 4a or along part of its length as in Figure 4b.
The inclination of the tab 32 in relation to the profile chord can be constant or variable along the blade's length.
The tab's width along the blade length can be variable in a linear relationship (Fig.5a), in a non-linear relation-ship (Fig.5b~ or in a combination thereof.
The tab can be formed simply by a bent plate (Fig.6).
The mean line of the tab can be straight (Fig.7a) or can have negative or positive curvature (Figs.7b-7c), or can be a combination thereof.
The constraint between tab and blade can be constructed in such a way that the following options are possible-(a) the incidence angle between the tab and the bladeis fixed and not adjustable;
(b) the incidence angle between the tab and the blade is adjustable when the fan is not running;
(c) the incidence angle between the tab and the paddle is adjustable when the fan is running.
The tab 32 can be fastened to the blade 20 by means of:
(a) glueing, rïveting, bolting, welding, dovetailing and similar methods (see, for example, Fig. 8);
(b) by a combination of two or more of the above mentioned methods;
(c) the tab 32 can be formed also by removal of part (shown in phantom lines1 of the trailing edge 26 of a blade 20, in which case the tab is an integral part of the blade itself (Fig. 9).
The inclination angle of the tab 32 in relation to the profile chord can vary between 10 and 70; the desired effect is not achieved when the angle is less than lO and more than 70, while optimum results are obtained around 40.
The width of the tab can vary from 0% to 30% ( and above, in particular cases) of the blade's width.
EXPERIMENT
The following description, with reference to Figs. lQ and ll further illustrates a particular embodiment of the invention and describes an experiment carried out with this embodiment.
Figure lO gives a schematic representation of the hub 22 and of one of the four blades 20 of the propeller fan used in the experiment.
The characteristics of the fan are as follows:
r = length l,65 m d = diameter of the hub 0,3 m c = blade chord 0,3 m s = maximum width of the tabs 0,070 m l = length of the tabs l,0 B = connection angle of the tabs 45 n = revolutions per minute 3~2 The results of the experiment are reported in the graph of Fig. 11 with the radius r as abscissa and the effective displacement of air per opening unit (kg/m) as ordinate.
In the graph three curves are illustrated, which curves show the trend of the effective displacement per opening unit along the radius r, in the following conditions:
curve A : blade not twisted, without tab;
curve B : twisted blade, without tab;
curve C : blade not twisted, with tab.
The increase of the effective displacement shown by curve C, which represents the blade of the present invention, is evident.
Figure 3 is a perspective view of one embodiment of blade according to the present invention.
Figures 4a and b are perspective views of further embodi-ments of the present invention.
Figures 5a and b are plan views of two further embodiments of the present invention.
Figure 6 is a representative cross-section of the tabs of the preceding Figures secured to the blade.
Figures 7a, b and c are cross-sectional views showing alternative contours which the tab may take.
Figure 8 shows in cross-section an example of a method of securing the tab to the blade.
Figure 9 is a perspective view of a further embodiment of the present invention.
Figures lOa and b shows a further example of a blade and tab, with figure lOa being a plan view thereof, and Figure lOb being a cross-section taken along line A-A of Figure lOa.
Figure 11 is a graph showing the results of experimental tests conducted on the blade of Figure 10 and two prior art devic~s.
As can be seen in Figures lOa and lOb, blade 20 is secured to hub 22.
Referring to Figures 3 through 9, the blade, generally designated 20, is provided with a leading edge 24 and trailing edge 26, and with proximal end or root 23 and distal end 25.
The leading and trailing edges are joined by an upper surface 28 and a lower convex surface 30. The lower surface 30 has a greater curvature than that of the upper surface 28. Tab 32 is secured to the trailing edge 26, and extends upwardly and outwardly from the trailing edge.
In the following description the alternative structures of the tab will be examined.
The tab can be applied to the trailing edge 26 of the blade 20 along its total length as in Figure 4a or along part of its length as in Figure 4b.
The inclination of the tab 32 in relation to the profile chord can be constant or variable along the blade's length.
The tab's width along the blade length can be variable in a linear relationship (Fig.5a), in a non-linear relation-ship (Fig.5b~ or in a combination thereof.
The tab can be formed simply by a bent plate (Fig.6).
The mean line of the tab can be straight (Fig.7a) or can have negative or positive curvature (Figs.7b-7c), or can be a combination thereof.
The constraint between tab and blade can be constructed in such a way that the following options are possible-(a) the incidence angle between the tab and the bladeis fixed and not adjustable;
(b) the incidence angle between the tab and the blade is adjustable when the fan is not running;
(c) the incidence angle between the tab and the paddle is adjustable when the fan is running.
The tab 32 can be fastened to the blade 20 by means of:
(a) glueing, rïveting, bolting, welding, dovetailing and similar methods (see, for example, Fig. 8);
(b) by a combination of two or more of the above mentioned methods;
(c) the tab 32 can be formed also by removal of part (shown in phantom lines1 of the trailing edge 26 of a blade 20, in which case the tab is an integral part of the blade itself (Fig. 9).
The inclination angle of the tab 32 in relation to the profile chord can vary between 10 and 70; the desired effect is not achieved when the angle is less than lO and more than 70, while optimum results are obtained around 40.
The width of the tab can vary from 0% to 30% ( and above, in particular cases) of the blade's width.
EXPERIMENT
The following description, with reference to Figs. lQ and ll further illustrates a particular embodiment of the invention and describes an experiment carried out with this embodiment.
Figure lO gives a schematic representation of the hub 22 and of one of the four blades 20 of the propeller fan used in the experiment.
The characteristics of the fan are as follows:
r = length l,65 m d = diameter of the hub 0,3 m c = blade chord 0,3 m s = maximum width of the tabs 0,070 m l = length of the tabs l,0 B = connection angle of the tabs 45 n = revolutions per minute 3~2 The results of the experiment are reported in the graph of Fig. 11 with the radius r as abscissa and the effective displacement of air per opening unit (kg/m) as ordinate.
In the graph three curves are illustrated, which curves show the trend of the effective displacement per opening unit along the radius r, in the following conditions:
curve A : blade not twisted, without tab;
curve B : twisted blade, without tab;
curve C : blade not twisted, with tab.
The increase of the effective displacement shown by curve C, which represents the blade of the present invention, is evident.
Claims (5)
- THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
l. A propeller fan blade having a trailing edge and a substantially constant inclination angle along its entire length comprising a rigid tab secured to the trailing edge at an incidence angle to the blade of between 10° and 70°, said tab having a maximum width at the proximal end of the blade and a minimum width at the distal end of the blade, said maximum width being not greater than 30% of the width of the blade. - 2. A fan blade according to claim 1 in which the tab extends along the total length of the blade.
- 3. A fan blade according to claim 1, in which the tab extends along part of the length of the blade.
- 4. A fan blade according to claim 1, in which the tab is shaped as a right angled triangle whose bigger side is secured along the trailing edge of the blade.
- 5. One or more blades according to claims 1-3 when assembled together about a central hub to form a propeller fan.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IT19726A/80 | 1980-02-06 | ||
| IT19726/80A IT1141170B (en) | 1980-02-06 | 1980-02-06 | AXIAL FAN WITH BENDS NOT CROSSED AND WITH INCREASED TRACTION |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1164420A true CA1164420A (en) | 1984-03-27 |
Family
ID=11160690
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000370062A Expired CA1164420A (en) | 1980-02-06 | 1981-02-04 | Fan blade with trailing edge tab |
Country Status (8)
| Country | Link |
|---|---|
| JP (1) | JPS56126698A (en) |
| CA (1) | CA1164420A (en) |
| DE (1) | DE3104203A1 (en) |
| FR (1) | FR2475158B1 (en) |
| GB (1) | GB2068472B (en) |
| IT (1) | IT1141170B (en) |
| NL (1) | NL187057C (en) |
| ZA (1) | ZA81595B (en) |
Families Citing this family (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58178499U (en) * | 1982-05-25 | 1983-11-29 | 株式会社日本空調器技研 | Blade material for impellers for centrifugal blowers |
| JPS5927197U (en) * | 1982-08-12 | 1984-02-20 | 昭和アルミニウム株式会社 | impeller blades |
| JPS5927196U (en) * | 1982-08-12 | 1984-02-20 | 昭和アルミニウム株式会社 | impeller blades |
| SE8206627L (en) * | 1982-11-22 | 1984-05-23 | Sture Astrom | freezing tunnel |
| US4571156A (en) * | 1984-03-05 | 1986-02-18 | D. C. Research, Inc. | Air foil with trailing spoiler |
| GB2246398A (en) * | 1990-07-26 | 1992-01-29 | Howden Wind Turbines Limited | Wind turbine blade and rotor incorporating same |
| DE4413235C2 (en) * | 1994-04-15 | 1999-04-29 | Voest Alpine Tunneltechnik Gmb | Tunnel boring machine or pipe jacking machine |
| US5711653A (en) * | 1994-07-31 | 1998-01-27 | Mccabe; Francis J. | Air lifted airfoil |
| US6010307A (en) * | 1995-07-31 | 2000-01-04 | Mccabe; Francis J. | Propeller, structures and methods |
| US6132181A (en) * | 1995-07-31 | 2000-10-17 | Mccabe; Francis J. | Windmill structures and systems |
| US6030179A (en) * | 1995-07-31 | 2000-02-29 | Mccabe; Francis J. | Airfoil structures and method |
| US6039533A (en) * | 1995-07-31 | 2000-03-21 | Mccabe; Francis J. | Fan blade, structures and methods |
| NL1015558C2 (en) | 2000-06-28 | 2002-01-08 | Stichting En Onderzoek Ct Nede | Blade of a wind turbine. |
| EP1205661A1 (en) | 2000-11-13 | 2002-05-15 | Isidro U. Ursua | Vertical axis wind turbine |
| ITMI20010131A1 (en) * | 2001-01-25 | 2002-07-26 | Giorgio Cipelletti | AXIAL FAN WITH DIFFERENTIATED TORSION BLADES |
| EP2479423B1 (en) | 2011-01-24 | 2018-04-04 | Siemens Aktiengesellschaft | Wind turbine rotor blade element |
| DE102012209935A1 (en) * | 2011-12-08 | 2013-06-13 | Wobben Properties Gmbh | Rear box, rotor blade with rear box and wind turbine with such rotor blade |
| DE102012004617A1 (en) * | 2012-03-06 | 2013-09-12 | Ziehl-Abegg Ag | Axial |
| WO2014185758A1 (en) | 2013-05-17 | 2014-11-20 | Shaikenov Blok | Wind wheel (with two alternatives) |
| DK3686423T3 (en) * | 2019-01-22 | 2023-02-27 | Wepfer Technics Ag | Rotor blade for a wind turbine |
| WO2021028573A1 (en) * | 2019-08-14 | 2021-02-18 | Power Curve Aps | Wind turbine blade with a gurney flap |
Family Cites Families (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB299387A (en) * | 1927-10-25 | 1929-01-31 | Camille Edmond Outurquin | Improvements in air propellers |
| US1873853A (en) * | 1930-09-18 | 1932-08-23 | Murray T Quigg | Rotor, impeller, or the like |
| GB352833A (en) * | 1930-10-04 | 1931-07-16 | Joseph Jeremiah Callahan | Improvements in or relating to screw propellers |
| US2385070A (en) * | 1941-10-08 | 1945-09-18 | Gant Leslie | Fan |
| GB637669A (en) * | 1945-03-27 | 1950-05-24 | Edmond De Lagabbe | Improvements in screw propellers |
| GB848278A (en) * | 1957-04-16 | 1960-09-14 | Enso Gutzeit Oy | Improvements in or relating to impellers |
| CH368892A (en) * | 1957-04-16 | 1963-04-30 | Enso Gutzeit Oy | Axial impeller, especially for fans |
| DE1528887A1 (en) * | 1963-09-26 | 1969-10-30 | Winter Dr Heinrich | Hydrodynamic or aerodynamic guide or conveyor element |
| GB1037940A (en) * | 1964-08-05 | 1966-08-03 | United Aircraft Corp | Marine propeller |
| DE2112261A1 (en) * | 1971-03-13 | 1972-09-14 | Battelle Institut E V | Cooling fan |
| US4142844A (en) * | 1977-05-31 | 1979-03-06 | Allware Agencies Ltd. | Fan blade assemblies for box fans |
| JPS55165994U (en) * | 1979-05-18 | 1980-11-28 | ||
| JPS55165993U (en) * | 1979-05-18 | 1980-11-28 |
-
1980
- 1980-02-06 IT IT19726/80A patent/IT1141170B/en active
-
1981
- 1981-01-28 ZA ZA00810595A patent/ZA81595B/en unknown
- 1981-02-02 GB GB8103137A patent/GB2068472B/en not_active Expired
- 1981-02-04 CA CA000370062A patent/CA1164420A/en not_active Expired
- 1981-02-05 JP JP1509981A patent/JPS56126698A/en active Granted
- 1981-02-05 FR FR8102209A patent/FR2475158B1/en not_active Expired
- 1981-02-06 DE DE19813104203 patent/DE3104203A1/en active Granted
- 1981-02-06 NL NLAANVRAGE8100593,A patent/NL187057C/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| DE3104203A1 (en) | 1982-02-25 |
| FR2475158A1 (en) | 1981-08-07 |
| FR2475158B1 (en) | 1985-12-20 |
| DE3104203C2 (en) | 1988-12-22 |
| ZA81595B (en) | 1982-04-28 |
| IT8019726A0 (en) | 1980-02-06 |
| IT1141170B (en) | 1986-10-01 |
| NL8100593A (en) | 1981-09-01 |
| NL187057C (en) | 1991-05-16 |
| GB2068472B (en) | 1984-05-16 |
| NL187057B (en) | 1990-12-17 |
| JPS639119B2 (en) | 1988-02-25 |
| GB2068472A (en) | 1981-08-12 |
| JPS56126698A (en) | 1981-10-03 |
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