GB2209806A - Blade pitch change mechanism - Google Patents
Blade pitch change mechanism Download PDFInfo
- Publication number
- GB2209806A GB2209806A GB8720375A GB8720375A GB2209806A GB 2209806 A GB2209806 A GB 2209806A GB 8720375 A GB8720375 A GB 8720375A GB 8720375 A GB8720375 A GB 8720375A GB 2209806 A GB2209806 A GB 2209806A
- Authority
- GB
- United Kingdom
- Prior art keywords
- blade pitch
- actuating member
- axis
- pitch control
- arm
- 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.)
- Withdrawn
Links
- 241000239290 Araneae Species 0.000 abstract description 15
- 230000004075 alteration Effects 0.000 abstract 1
- 238000010348 incorporation Methods 0.000 abstract 1
- 239000011295 pitch Substances 0.000 description 27
- 238000010276 construction Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000001419 dependent effect Effects 0.000 description 2
- 239000006096 absorbing agent Substances 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 230000035939 shock Effects 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
- F03D7/00—Controlling wind motors
- F03D7/02—Controlling wind motors the wind motors having rotation axis substantially parallel to the air flow entering the rotor
- F03D7/022—Adjusting aerodynamic properties of the blades
- F03D7/0224—Adjusting blade pitch
-
- 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
- F05B2260/00—Function
- F05B2260/70—Adjusting of angle of incidence or attack of rotating blades
- F05B2260/74—Adjusting of angle of incidence or attack of rotating blades by turning around an axis perpendicular the rotor centre line
-
- 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
- F05B2260/00—Function
- F05B2260/70—Adjusting of angle of incidence or attack of rotating blades
- F05B2260/76—Adjusting of angle of incidence or attack of rotating blades the adjusting mechanism using auxiliary power sources
-
- 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
- F05B2260/00—Function
- F05B2260/70—Adjusting of angle of incidence or attack of rotating blades
- F05B2260/77—Adjusting of angle of incidence or attack of rotating blades the adjusting mechanism driven or triggered by centrifugal forces
-
- 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
- F05B2260/00—Function
- F05B2260/70—Adjusting of angle of incidence or attack of rotating blades
- F05B2260/79—Bearing, support or actuation arrangements therefor
-
- 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)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Sustainable Development (AREA)
- Sustainable Energy (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Wind Motors (AREA)
Abstract
A blade pitch control mechanism comprises a spider 2 (Figure 1) with arms 3a to 3c to which are respectively hinged triangular plates 4. Each triangular plate 4 is secured at a universal joint to the inner race 7 of a bearing by means of which the blade pitch is altered. Axial movement of an actuating member 1 which is also free to rotate about its axis, causes rotation of the race 7 and hence an alteration in pitch. In an alternative arrangement (Figure 2) member 2'b is axially and rotatably fast with the actuating member while the member 2'a is axially fast bit rotatable relative to the actuating member. The triangular plates may be hinged at their bases by means of respective pairs of bearings (Figs. 3B and 4). The incorporation of the pitch control mechanism in a wind driven rotor is disclosed in detail (Figs 4 to 6) together with details of a mechanism for controlling angular movement ("teeter") of the rotor hub in response to centrifugal force. <IMAGE>
Description
PITCH CHANGE ECHANISM This invention relates to a pitch change mechanism, suitable for changing the pitch of a blade on any bladed rotor.
At present, bladed rotors are used in a wide variety of different applications, from domestic fans through to power generation turbines. In many applications it is desirable to be able to alter the pitch of the blades of the rotor so as to accommodate different operating conditions of the bladed rotor.
Several different types of blade pitch control are known, including electrical and hydraulic arrangements.
These are however complex, and are prone to failure due to their complexity. They are also often bulky, necessitating considerable space in the rotor hub or even external elements.
An improved pitch change control arrangement is described in UK Patent Application Publication No.
2,159,584A wherein a wind power turbine is disclosed in which an axially movable rod is coupled to the rotor hub to effect automatically a change in pitch of the blades.
The arrangement is such that the rod moves axially in dependence upon the speed of a rotor, which is itself controlled according to the power output. The apparatus of the present invention was particularly developed for use with this arrangement but is also applicable to any construction wherein axial movement of a linear actuator is to give rise to a change in blade pitch.
International Application Publication No. wo 83/00195 discloses a blade pitch change mechanism responsive to axial movement of an actuating rod. In this case the pitch change mechanism relies on the use of elongate linkage members pivotally mounted to a spider secured to the rotor shaft. In this mechanism, it is necessary to provide a means for preventing rotation of the actuating rod, and the overall structure of the mechanism is bulky, utilising unwarranted space in the rotor hub.
According to one aspect of the present invention there is provided a blade pitch control mechanism for controlling the pitch of blades of a bladed .rotor, which blades are secured to respective rotatable elements the position of each of which controls the blade pitch, in which mechanism a blade pitch control member is so mounted with respect to an axially movable actuating member that it can undergo only angular motion about a straight line along which it is mounted, which control member has, spaced from said straight line, a further mounting location and means at that location to enable it to be mounted to one of the rotatable elements so that it is free to pivot, relative to the element, about two orthogonal axes through said mounting location, whereby axial movement of the actuating member causes that rotatable element to rotate thereby altering the pitch of its associated blade.
Preferably the blade pitch control member is a planar member or plate of triangular form having a base at which it is mounted- to the actuating member and an apex region at which the further mounting location is provided. Such a plate has sufficient rigidity to resist moments applied about axes other than said straight line.
In the described embodiment a force transfer component is fixedly secured to the axially movable actuating member, the force transfer component having a portion extending with a radial component from the member and to which the blade pitch control plate is so mounted.
The invention also provides a rotor hub including a blade pit-ch control mechanism according to said one aspect of the invention and in which the axes of rotation of the rotatable elements intersect the axis of the axially movable actuating member, preferably orthogonally.
This arrangement has several advantages over the known arrangement. Of particular note are its increased compactness and its reduced tendency to errors due to torsion of elongate linkage members. Other advantages arising from particular embodiments are set out below.
It is noted here that these advantages could not have been foreseen by studying the known arrangements.
Indeed, linear-to-angular motion converters conventionally employ cams and/or elongate linkaye members, pivotably connected one to the other to achieve the desired effect. It has always been thought that a rigid plate would not have the kinematic flexibility effective to accomplish the same aim. The present inventor has perceived that it is possible, rather than reducing undesired degrees of freedom of existing elements and replacing these with the desired configuration of linkage members, to utilise these degrees of freedom to overcome the inherent kinematic inflexibility of a rigid plate.
In one embodiment, there are two force transfer components, with the second of the two components being mounted on the actuating member in such a way as to be fixed against axial movement but free to rotate. There are then two such plates secured respectively to the components, for pivotably mounting respectively to two such rotatable elements. This arrangement (with independently movable force transfer components) enables a two-bladed rotor not only to change the pitch of its blades but also to provide the necessary teeter when the rotor hub is mounted to a shaft on a teeter bearing.
Such a teeter bearing is used to permit the hub to teeter about an axis which is perpendicular to the axis of the rotor shaft and which extends at an angle z to the pitch axis of the blades, where the angle G is 900 plus or minus the delta three angle, which is fixed between 0 and 350. With such a teeter bearing it is advantageous to provide a means for preventing significant teeter motion during start-up and shut-down, but permitting free teeter motion when the rotor is running at normal speed.
According to another aspect of the invention there is provided a teeter control device for use in a rotor hub mounted for limited angular motion about an axis perpendicular to the axis of rotation of the hub, the control device comprising: means for preventing such limited angular motion in a first position thereof and for permitting such motion in a second position thereof; means coupled to said motion preventing means and including a first arm connected to said motion preventing means and mounted for rotation about an axis; a second arm mounted for rotation with the first arm about said axis and connected to a weight which is arranged to exert a force on the second arm in dependence on rotational speed of the hub; and biassing means acting between the first and second arms to exert a moment about said axis tending to oppose the moment arising from the force exerted by the weight and being substantially constant.
By arranging the biasing means to apply a more or less constant moment about said axis, the difference between that moment and the moment arising from the force exerted by the weight increases quickly until at a predetermined speed, it is sufficient to move the motion preventing means suddenly from the first to the second position.
In another embodiment, the force transfer component has three such radially extending portions, with three plates secured respectively thereto for pivotably mounting to three such rotatable elements.
This arrangement has the particular advantage that the actuating member and hence the rotor hub to which it is secured via the rotatable elements are self-supporting.
That is, no bearings etc are required, hence obviating the problems which can arise with the sliding bearings conventionally required to support the rotor shaft. This is a big advantage from a practical point of view since maintenance requirements for the pitch control mechanism are considerably reduced.
The rigidity of the plates, and the forces acting thereon, ensure that the actuating member runs "true".
For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made by way of example to the accompanying drawings in which:
Figures 1 and 2 are diagrams illustrating respectively the principles of the present invention for three bladed and two bladed rotors;
Figure 3A and 3B are an end view and section respectively of a three bladed rotor, Figure 3A being a section on line YY of Figure 3B;
Figure 4 is a partially cut away perspective view of a two bladed rotor;
Figure 5 is a cross-section through the hub of a two bladed rotor; and
Figure 6 is a side view of the rotor, partially cut away in section to show a damping arrangement for the teeter bearing.
Referring to Figure 1, an actuating member 1 is shown. This actuating member may be the axially displaceable rod referred to in the above-referenced UK
Patent Application. A component in the form of a three-armed spider 2 is fixed to the actuating member 1 so as to be fast with the actuating member 1 against both relative axial and angular motion. The spider 2 has three arms 3a, 3b, 3c extending radially and spaced 1200 apart. In Figure 1, the blade pitch control components are shown only in relation to arm 3a. It will be apparent that a similar arrangement applies to each of the arms 3b and-3c.
A triangular plate 4 is mounted to the arm 3a in such a way that it can undergo angular movement about its mounting line A-A. That is, it is hinged to the arm 3b along its base. The apex 5 of the triangular plate 4 is mounted to a support plate 6 fixedly secured to a rotatable element 7 in the form of the inner race of a supporting bearing for the blade shaft (not shown). The triangular plate is mounted at its apex 5 through a universal joint to enable it to rotate about any axis through the mounting location at that joint, In fact, only rotation about two axes (one of which is parallel to the axis of rotation of the rotatable element 7 and the other of which is orthogonal to this and lies in a plane parallel to the plane of the axis of the actuating member) is required, but a universal bearing is a simple practical implementation.The rotatable element is mounted for angular motion about an axis orthogonal to the axis of the actuating member 1. As the member 1 moves axially, for example to the left in Figure 1, the spider 2 and plate 4 also move to the left. It is important to appreciate that, in contrast to the arrangement known from WO 83/00195,the actuating member 1 is free to undergo angular motion about its axis. Were the plate 4 rigidly fixed to the spider arm 3a, its locus of movement would be a straight line parallel to the axis of the actuating member 1. However, it cannot adopt this locus because of its connection to the rotatable element 7; instead it is constrained to move in an arc.The hinge along A-A and the universal bearing at apex 5 accommodate this by permitting the angle and between the spider arm 31 and the plate 4 to alter, thereby enabling the distance in a plane through the rotatable element 7 between the apex 5 and the hinge along A-A to be altered.
As a result of this, the rotatable element is caused to rotate through an angle dependent on the amount of axial movement of the actuating member 1.
It will be appreciated that the principle of
Figure 1 could be implemented without the spider 2; the spider serves to provide however, location points for the plate and to minimize the arc through which the plate 4 swings.
Figure 2 operates on a similar principle embodying a triangular plate 4 similarly connected to an arm 3a' and rotatable element 7: (The support plate 6 is not shown). However, in this case, applicable for a two bladed rotor, there are two independent spiders 2a', 2b'.
The first spider 2b' is axially and rotatabLy fast with the actuating member 1', whereas the second spider 2a' is axially located on the actuating member 1' but is free to rotate relative to the first spider 2b'. This independence ensures that, when the rotor hub is mounted on a teeter bearing, the necessary play is allowed.
However, despite this independence, the connection of the plates 4a', 4b' ensures that the apexes (only one 5a' of which is shown) of the plates 4a', 4b' are aligned on a common line viewed from above in Figure 2. This ensures that the pitches of the two blades are altered simultaneously.
The construction of Figure 1 will now be described in greater constructional detail with reference to
Figures 3A and 3B. The actuating member is designated by reference numeral 10. The spider 12 has three arms 13a, 13b, 13c. The mechanism for controlling the pitch of the blade attached to a rotatable element 17a associated with arm 13a will now be described. The arrangements for the other arms 13b, 13c, are the same. A triangular plate 14 is hinged along its base 18 by two bearings 20a, 20b to the arm 13a. The apex 15 of the plate 14 is mounted to a support plate 16 by a universal bearing 19.
Specifically, this permits movement about any axis through the bearing 19. As described above, axial movement of the actuating member 10 causes the plate 14 to move so as to cause rotational movement of the element 17a, thereby altering-the pitch of the blades.
It is noted that the three bladed rotor shown in
Figures 3A and 3B is self supporting. That is, there is no need to provide a supporting bearing for the rotor shaft to which the actuating member 10 is secured.
Clearly, this has considerable advantages from a practical point of view.
The construction of Figure 2 will now be described in greater constructional detail with reference to
Figures 4-7. Figure 4 is a partially cut away perspective view showing the actuating member 21 and one of each of a pair of plates 24a, 24b, support plates 29a, 29b and rotatable elements 27a, 27b. A teeter device -30 is also illustrated (one of two) to be described in more detail hereinafter.
Figure 5 shows more clearly the pitch control mechanism. In Figure 5, reference numerals 22a, 22b denote the spiders; 24a, b the triangular plates; 29a, b the support plates; 27a, b the bearing elements; 32a, b the universal bearings; and 34a, b the hinge bearings.
Operation of the pitch control mechanism is as described above with reference to Figure 2.
A teeter bearing for the rotor hub is also shown at 36. This enables the rotor hub to tilt into and out of the wind to provide a further control in addition to the blade pitch control. Such teeter bearings are known for this purpose and so will not be further described herein. Two devices for controlling the teeter are provided designated generally at 30a, 30b. These devices serve to prevent significant teeter motion during start-up and shut-up, but allow free teeter motion when the rotor is running at its normal speed.
The devices 30a, 30b are shown in more detail in
Figure 6, which illustrates them in side view. Reference is also made to Figure 4. A first lever arm 40 is connected at one end to a rod 42. The first lever arm is mounted at its other end to an axle 41 (Figure 4) which is rotatably mounted in a fixed bracket 46. Mounted to the other end of the axle 41 is a second lever arm 44, which lies in a plane parallel to but spaced from that of the first lever arm 40. A stop plate 47 is also mounted to the fixed bracket 46. A coil spring 48 is connected between the first lever arm and the fixed plate 46. The coil spring 48 is so arranged relative to the lever arm and fixed plate that it applies a constant moment (to within + 5%) about the axle 41 during the allowed arc of rotation of the first lever arm 40.This can be seen by considering the triangle formed by the points A (axle 41), B (attachment of spring to bracket 46) and C (attachment of spring 48 to lever arm 40). AB and AC are fixed lengths, but BC varies as C moves in an arc centered at A. Thus, the moment arm about A reduces as the spring force increases during such rotation to achieve a constant moment through an arc of 450. The second lever arm 44 is also connected to a wedge 50 via a linkage 52. The wedge 50 acts on an elastomeric shock absorber 54 comprising a piston 56 movable against fluid within a cylinder 58. A weight (not shown) is attached to the rod 42 so as to exert a force on the rod dependent on the rotational speed of the rotor hub. As the speed of the rotor increases from zero, the moment about the axle 41 exerted by the rod 42 on the first lever arm 40 increases but movement of the wedge is prevented by the spring 48 until a predetermined speed is reached at which the moment applied by the weight and rod 42 exceeds the moment applied by the springs 48 and the levers 40 and 44 start to move. The arrangement of a constant moment instead of a progressively increasing moment in the illustrated lever arrangement ensures that a rapidly increasing net force is applied to the wedge as the rotor speed increases. This ensures immediate (within + 1 rpm of the predetermined speed) extraction or insertion of the wedge when the rotor hub has accelerated or decelerated to a predetermined speed, wC rpn
Claims (8)
1. A blade pitch control mechanism for controlling the pitch of blades of a bladed rotor, which blades are secured to respective rotatable elements the position of each of which controls the blade pitch, in which mechanism a blade pitch control member is so mounted with respect to an axially movable actuating member that it can undergo only angular motion about a straight line along which it is mounted, which control member has, spaced from said straight line, a further mounting location and means at that location to enable it to be mounted to one of the rotatable elements so that it is free to pivot, relative to the element, about two orthogonal axes through said mounting location, whereby axial movement of the actuating member causes that rotatable element to rotate thereby altering the pitch of its associated blade.
2. A mechanism as claimed in claim 1 in which the blade pitch control member is a rigid planar member of triangular form having a base at which it is mounted to the actuating member and an apex region at which the further mounting location is provided.
3. A mechanism as claimed in claim 1 or 2 wherein a force transfer component is fixedly secured to the axially movable actuating member, the force transfer component having a portion extending with a radial component from the member and to which the blade pitch control plate is so mounted.
4. A mechanism as claimed in claim 3 which has two force transfer components, with the second of the two components being mounted to the actuating member in such a way as to be fixed against axial movement but free to rotate, two such blade pitch control members being secured respectively to the components, for pivotably mounting respectively to two such rotatable elements.
5. A mechanism as claimed in claim 3 in which the force transfer component has three such radially extending portions, with three such blade pitch control members secured respectively thereto for pivotably mounting to three such rotatable elements.
6. A blade pitch control mechanism substantially as hereinbefore described with reference to, or as shown in, the accompanying drawings.
7. A rotor hub including a blade pitch control mechanism according to any preceding claim in which the axes of rotation of the rotatable elements intersect the axis of the axially movable actuating member.
8. A teeter control device for use in a rotor hub mounted for limited angular motion about an axis perpendicular to the axis of rotation of the hub, the control device comprising: means for preventing such limited angular motion in a first position thereof and for permitting such motion in a second position thereof; means coupled to said motion preventing means and including a first arm connected to said motion preventing means and mounted for rotation about an axis, a second arm mounted for rotation with the first arm about said axis and connected to a weight which is arranged to exert a force on the second arm in dependence on rotational speed of the hub; and biasSing means acting between the first and second arms to exert a moment about said axis tending to oppose the moment arising from the force exerted by the weight and being substantially constant.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8720375A GB2209806A (en) | 1987-08-28 | 1987-08-28 | Blade pitch change mechanism |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8720375A GB2209806A (en) | 1987-08-28 | 1987-08-28 | Blade pitch change mechanism |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB8720375D0 GB8720375D0 (en) | 1987-10-07 |
| GB2209806A true GB2209806A (en) | 1989-05-24 |
Family
ID=10622995
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8720375A Withdrawn GB2209806A (en) | 1987-08-28 | 1987-08-28 | Blade pitch change mechanism |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2209806A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2817298A1 (en) * | 2000-11-30 | 2002-05-31 | A F Electrification | Wind turbine with mechanical regulator, uses weights attached to the blades to alter their angle under centrifugal force on the weights, with a return spring opposing the effect of the weights |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB469124A (en) * | 1936-01-27 | 1937-07-20 | Edward William Trotman | Improvements in or relating to screw propellors |
| GB1069627A (en) * | 1963-03-11 | 1967-05-24 | English Electric Co Ltd | Improvements in or relating to hydraulic turbines,pumps,and reversible pump turbines |
| GB1279101A (en) * | 1969-07-08 | 1972-06-28 | Dowty Technical Dev Ltd | Bladed rotors |
| GB1414278A (en) * | 1973-05-08 | 1975-11-19 | Thielenhaus Maschf | Grinding machine |
| EP0114800A2 (en) * | 1983-01-21 | 1984-08-01 | Svenska Varv Vindenenergi AB | A horizontal shaft wind turbine with few blades |
-
1987
- 1987-08-28 GB GB8720375A patent/GB2209806A/en not_active Withdrawn
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB469124A (en) * | 1936-01-27 | 1937-07-20 | Edward William Trotman | Improvements in or relating to screw propellors |
| GB1069627A (en) * | 1963-03-11 | 1967-05-24 | English Electric Co Ltd | Improvements in or relating to hydraulic turbines,pumps,and reversible pump turbines |
| GB1279101A (en) * | 1969-07-08 | 1972-06-28 | Dowty Technical Dev Ltd | Bladed rotors |
| GB1414278A (en) * | 1973-05-08 | 1975-11-19 | Thielenhaus Maschf | Grinding machine |
| EP0114800A2 (en) * | 1983-01-21 | 1984-08-01 | Svenska Varv Vindenenergi AB | A horizontal shaft wind turbine with few blades |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2817298A1 (en) * | 2000-11-30 | 2002-05-31 | A F Electrification | Wind turbine with mechanical regulator, uses weights attached to the blades to alter their angle under centrifugal force on the weights, with a return spring opposing the effect of the weights |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8720375D0 (en) | 1987-10-07 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |