GB2413159A

GB2413159A - Wind-driven generator

Info

Publication number: GB2413159A
Application number: GB0408616A
Authority: GB
Inventors: James Wolfe Macconn Kilpatrick
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-04-17
Filing date: 2004-04-17
Publication date: 2005-10-19
Also published as: GB0408616D0

Abstract

Respective parts 3, 4 of an electric generator are rotated in opposite directions by respective sets of wind-driven vanes 1,6, one located in front of the generator and the other behind, or both located in front of the generator. In the latter case, an axle of the leading set of vanes can pass through a hollow axle of the following set. Gearing may be provided to increase speeds within the generator, and a tail-fin arrangement 7 may be fitted to a casing 9, or to an axle of one of the blade sets, to keep the device facing into wind. The tail-fin arrangement may support an axle 5, by means of a bearing 12. A plurality tail fins may be used in a cruciform or asterisk-like configuration.

Description

Page 1 Modifications to Wind Generators This invention relates to the more

efficient use of wind power in wind generators.

Wind generators are increasingly used in many countries. Large units produce electric power which is fed into National grid systems. Small units are used in yachts and smallholdings.

Each unit requires an installation such as a supporting pylon and casings which, together with wind vanes, gearing, and generator parts, and installation, carry a capital cost. It is therefore logical to use these costly units to produce as much electric power per unit as possible. Existing wind generators use a rotating vane system to drive a rotor which rotates within the magnetic

field of a fixed stator.

The present invention provides for the contra-rotation of rotor and stator using a second wind vane system mounted in line with the first, behind it, and so arranged so that this second system turns in the opposite direction to the first. Rotor and stator, linked as they are to their respective vane systems, are thus impelled in opposite directions and therefore move more rapidly relative to one another than in the generators in current use; more electrical power is produced and noise attributed to gearing may be reduced. The provision of a second wind vane system may change the position and design of fins to keep the generator facing into the wind; this invention provides for this.

The accompanying drawings may be summarised thus: Figure I indicates contra-rotation of rotor and stator.

Figure 2 shows leading and rear mounted wind vane systems linked to rotor and stator respectively.

Figure 3 shows two adjacently mounted wind vane systems linked to stator and rotor.

Figure 4 as in Figure 3 but with the rotor-stator drive reversed.

Figure 5 shows an arrangement for directional fin with a rear-mounted wind vane system behind it.

Figure 6 shows a directional fin with the rear-mounted wind vane system in front of it.

Figures 7 & 8 show alternative designs for a rotating fin.

In Figure One the rotor 3 is seen rotating within the field of the contrarotating stator 4.

In Figure Two the wind vanes 1 drive the rotor 3 via the axle 2. The tail mounted vanes 6 drive the stator 4 via the axle 5.

Figures Three and Four illustrate a different arrangement in which the two vane systems are mounted adjacent to one another at the front of the generator casing and each may drive either the rotor or the stator. In this arrangement the axle 2 lies within the hollowed axle 5. In figure Three the axle 2 drives the stator 4 after traversing the rotor 3 in a tunnel which is a continuation of the hollowed axle 5. Gearing may be required to increase rotational speeds within the generator itself. The rearmost vane system may be of a different format from the leading assembly with vanes of an appropriate attack angle, shape and number to reflect a relatively low pressure situation, since it is impelled by " used" wind.

Page 2 Where a tail fin is fitted to keep the unit facing into wind this would be conventionally fitted to the casing 9 if both vane systems were in front on the casing.

The possible arrangements if fitted behind the casing are shown in Figures Five and Six.

In Figure Five the fin 7 is fitted to the casing 9 ahead of the tail mounted vane system 6. In this case, the axle 5 passes through a tunnel in the fin at 8 or through a supporting bearing at 12, thus stabilising the axle.

In Figure Six, the fin is integral with the axle 5 and turns with it. It is symmetrical about a line, the axis AB in order to present the same lateral profile to a changing wind at whatever point in rotation it may be (for example the fin 10 illustrated in Figure Six is a cone.) An alternative to this design, offering less resistance to airflow through the wind vane system immediately in front of the fin, Ida multi-laminar fin consisting of planes radiating from a central axial extension of the axle 5 in Figure Six. Such a structure may have a cruciform or an asterisk-like cross section and is shown in profile and cross section in Figures Seven to Ten, and presents approximately the same lateral profile at all stages of rotation.

The top of a pylon I 1 is shown in Figures Five and Six to indicate the orientation of the generator unit.

Claims

Page 3 Claims ( 1) A system in which the generator stator is driven by

wind power and rotates in the opposite direction to the associated generator rotor also driven by wind power.

(2) Each element of the rotor-stator system as in claim (1) is driven by its own wind vane system comprising the original wind vane system and an additional wind vane system.

(3) The additional wind vane system as in claim (2) is situation behind the original wind vane system and is in line with it.

(4) The additional wind vane system as in claim (3) is mounted immediately behind the existing wind vane system but in front of the generator casing.

(5) The additional wind vane system as in claim (3) is mounted behind the generator casing.

(6) Where the additional wind vane system is mounted behind the generator casing as in claim (5) and a directional fin is fitted to the unit, the fin is in front of the additional wind vane system.

(7) Where the directional fin is in front of the additional wind vane system as in claim (6), the axle of the additional wind vane system is supported by the directional fin.

(8) Where the additional wind vane system is mounted behind the generator casing as in claim (5) and a directional fin is fitted to the unit, the fin is behind the additional wind vane system.

(9) Where the directional fin is behind the additional wind vane system as in claim (8) the fin is integral with the axle and the wind vane system and rotates with it.

(10) Where the directional fin is behind the additional wind vane system and rotates with it as in claim (9), the directional fin, of whatever profile, is so constructed as to present the same lateral profile at all points of rotation, being symmetrical about a line which is a theoretical backward projection of the axis of rotation of the additional wind vane system.

( 1 1) Where the directional fin is integral with the additional wind vane system and its axle as in claim (9), the fin is a multi-laminar structure consisting of planes radiating from a central axial extension of the axle 5 in Figure Six.

(12) The fin as described in claim 11 may have a cruciform or asterisklike cross section as shown in Figures Eight and Ten respectively.

Page 4 (13) The fin as described in claims (11) and (12) rotates about the axis AB as shown in Figures Seven and Nine.

(14) That wind vane system which lies behind the other wind vane system as in claim (3) is modified in such a way as to compensate for the relatively low pressure nature of the air flow which impels the rearmost system.

(15) Where the additional wind vane system is situated immediately behind the existing wind vane system and in front of the generator casing as in claim (4), the axle of the foremost wind vane system passes through the hollow axle of the wind vane system immediately behind it.

(16) The axle ofthe foremost wind vane system as described in claim 15 drives either the generator rotor or the generator stator.

(17) The hollow axle ofthe rearmost wind vane system as described in claim (15) drives either the generator rotor or the generator stator.

( 18) Where the axle of the leading wind vane system drives one element of the rotor-stator assembly as in claim (15), it may pass through the centre ofthe other element is such a way as to permit the independent rotation of the other element.