GB2498004A

GB2498004A - Vertical axis wind turbine and electricity generator

Info

Publication number: GB2498004A
Application number: GB1200603.7A
Authority: GB
Inventors: Brian Curtis
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-12-22
Filing date: 2012-01-16
Publication date: 2013-07-03
Anticipated expiration: 2032-01-16
Also published as: GB201200603D0; GB201311832D0; GB201122210D0; GB2498004B; GB2503118A

Abstract

An electricity generator comprises a generator housing 2 connected beneath a bearing hub assembly 4 that is beneath a vertical axis wind turbine 6. A support frame 8 is attached to the bearing hub assembly 4 to secure the generator to a supporting structure such as a wall, chimney or mast. Bearing hub assembly 4 comprises a casing containing plural bearings (fig 3, 58, 62) surrounding a rotatable shaft 26 that is connected to, and driven by rotation of, the turbine. Shaft 26 extends from the bearing hub into the generator housing 2 that contains at least one pair of radial fixed plates (fig 2, 16, 18) having aligned openings through which the rotatable shaft 26 extends and between which are arranged plural coils 28. At least one radial spinner plate (fig 2, 30A, 30B) is fixed to and rotates with the shaft and carries plural magnets (fig 2, 32A) that induce an electrical current in the coils to be conveyed to an external store or electricity consumer by cable 19. The wind turbine can comprise wind vanes 94 mounted on rods (fig 11, 88) that pivot on a pair of axially spaced apart rotor plates 74 mounted on a central column (fig 10, 84) connected to the shaft 26. Pivotal movement of the vanes is limited by pegs (fig 9, 98/100) and biased by spring dampers (fig 9, 102). In light winds the vanes remain closed but in strong winds they can open to provide an escape path for the wind.

Description

ELECTRICITY GENERATING APPARATUS

This invention relates to an electricity generating apparatus and in particular an electrical generator that can be powered by a wind turbine.

Summary of the Invention

In a first aspect, the invention provides apparatus for generating electricity comprising: (a) a vertical axis wind turbine; (b) a bearing hub assembly connected beneath the wind turbine; (c) a generator housing connected beneath the bearing hub assembly; (d) a support frame attached to the bearing hub assembly for securing the apparatus to a supporting structure; and (e) means for conveying electricity generated by the apparatus to an external store or electricity-consuming device; wherein the bearing hub assembly (b) comprises a casing containing a plurality of bearings surrounding a rotatable shaft; the rotatable shaft being operatively connected to the wind turbine (a) and driven by rotation of the wind turbine; wherein the rotatable shaft extends from the bearing hub assembly (b) into the generator housing (c); the generator housing (c) containing (c-i) at least one pair of radially oriented fixed plates between which are arranged a plurality of coils, the coils being linked to the electricity-conveying means (e), the fixed plates having aligned openings through which the rotatable shaft extends; and (c-u) at least one radially oriented spinner plate which is fixed to the rotatable shaft and is rotatable therewith, the spinner plate carrying a plurality of magnets; the arrangement of the magnets and coils being such that, in use, rotation of the spinner plate with the rotatable shaft induces an electrical current in the coils, which current is conveyed to the external store or electricity consuming device by the means (e).

By radially oriented is meant that the fixed plates or spinner plates extend radially outwardly from the central axis of the generator (i.e. the axis along which the rotatable shaft lies). Thus the fixed plates and spinner plates lie in a plane which is approximately perpendicular to the rotatable shaft.

The term "plate" as used herein is used in a broad sense to mean a supporting structure of plate-like structure and relative dimensions which can carry either the coils (in the case of the fixed plates) or the magnets (in the case of the spinner plates). The plates may, for example, be formed of a substantially flat sheet material.

The fixed plates are typically formed from an electrically non-conducting (e.g. insulating) material. For example, the fixed plates may be formed from a glass-reinforced composite material such as a glass-reinforced resin or plastics material.

One such material is the phenolic resin and glass-fibre laminated plastics material sold under the trade name "Tufnol" by Tufnol Composites Ltd of Birmingham, UK.

In one embodiment, the fixed plates are disc-shaped.

The spinner plate may be formed from either an electrically conducting or electrically insulating material but preferably it is formed from a conducting material such as a metal (e.g. steel or aluminium). The spinner plate can be circular (e.g. disc shaped) or it can be non-circular. For example, when it is non-circular, the spinner plate can be provided with a plurality of arms (preferably equidistantly spaced apart). Each arm may carry a magnet or array of magnets.

In one embodiment, the spinner plate is of circular disc form and carries four to eight magnets or arrays of magnets spaced equidistantly around the plate. The magnets are positioned so that when the spinner plate is rotated, the magnets pass over the coils (or beneath the coils, when a spinner plate is positioned beneath the fixed plates).

In another embodiment, the spinner plate is of approximately cruciform shape, each arm of the cross shape having a magnet or array of magnets attached thereto.

The magnets may be of conventional commercially available type. For example, the magnets can be rare earth magnets. They can be attached to the spinner plate by means of an adhesive, for example. The spinner plate may have a plurality of surface recesses for accommodating the magnets.

The magnets may all be positioned at the same radial distance from the axis of the rotatable shaft or the magnets may be grouped so that one group is at a first radial distance whereas a second or subsequent group is at a second or subsequent radial distance from the axis. For example, there may be several concentric circular arrays of magnets.

There may be one spinner plate but preferably there are two (or more) spinner plates. In one embodiment, there are two spinner plates, one above an upper one of the pair of fixed plates and the other below the lower of the pair of fixed plates.

Thus, in one preferred embodiment, the generator contains a pair of fixed plates with a plurality of coils held between the fixed plates, a first spinner plate arranged above the pair of fixed plates and a second spinner plate arranged below the pair of fixed plates.

The coils typically comprise a core around which is wound an electrically conductive material such as a wire, e.g. a copper wire. Typically, each coil will have at least ten windings (i.e. loops of conductor), more preferably at least twenty windings, or at least thirty windings, or at least fifty windings, for example from fifty to five hundred windings, or from fifty to two hundred and fifty windings.

The coil cores are typically aligned in an axial direction (i.e. they have an axis which is substantially parallel to the rotatable shaft). Thus, the majority of the individual loops or windings will lie in a plane approximately perpendicular to the

rotatable shaft.

The coils are preferably linked in series to form a circuit, the termini of which are connected directly or indirectly to the means (e) (e.g. a lead) for conveying electricity generated by the apparatus to the external store or electricity-consuming device.

The magnets and coils may be configured and oriented so as to provide an AC current output or a DC current output. In one embodiment, the magnets and coils are configured and oriented to provide an AC current output.

Electricity generated by the apparatus of the invention can be carried to an electrical storage facility, such as batteries or the national grid, or can be used to power an electricity consuming device.

The bearing hub assembly (b) comprises a casing containing a plurality of bearings surrounding a rotatable shaft; the rotatable shaft being operatively connected to the wind turbine (a) and driven by rotation of the wind turbine.

The bearings may advantageously be tapered roller bearings. In one embodiment, the bearing hub assembly is provided with at least two sets of bearings (e.g. tapered roller bearings), one set at or adjacent either end (e.g. top or bottom) of the hub bearing assembly. A preload tube may advantageously be disposed between the two sets of tapered roller bearings to facilitate the application of the correct preload to the two sets of bearings. The rotatable shaft may have a threaded region upon which is mounted a lock nut, tightening of the lock nut serving to impart the required preload to the tapered roller bearings. When there are two sets of tapered bearings with a preload tube disposed therebetween, the lock nut may be tightened by the application of a predefined torque so that an axial force is transmitted from one set of tapered roller bearings via the preload tube to the other set of tapered roller bearings thereby to impart the correct preload to the bearings.

One or more sealing elements may be disposed within the hub bearing assembly for sealing against the rotatable shaft, for example to prevent oil leakage or water ingress into the assembly.

The apparatus comprises a vertical axis wind turbine. In contrast to wind turbines of the propeller driven variety, where the propeller rotates about a substantially horizontal axis, the wind turbine has blades or vanes that rotate about a substantially vertical axis. The term vertical" as used in the context of the present invention refers to an axis which is in a generally upright orientation. It may be absolutely vertical, or it may deviate, e.g. by up to about ten degrees, from absolute vertical.

The wind turbine may comprise upper and lower rotor plates connected to a central column located at the axis of the turbine. The individual vanes of the wind turbine may be mounted on struts or rods linking the upper and lower rotor plates.

Typically, the wind turbine has at least two vanes and preferably has three vanes.

Each vane may be mounted on a pivot rod linking the upper and lower rotor plates, the pivot rod, and hence the vane mounted on it, being pivotable. Preferably means are provided for limiting the extent of pivotal movement of the pivot rod and vanes. For example, the upper and/or lower rotor plates may be provided with one or more stops (e.g. pegs) defining the limits of pivotal movement of the vane.

The stops may define a "closed" position, in which there is a minimal gap between the radially inner edge of the vane and the central column, and an open" position, where there is a larger gap between the radially inner edge of the vane and the central column of the turbine. The (or each) vane is preferably biassed towards the closed position by biassing means such as a biassing spring or equivalent device.

An advantage of this arrangement is that, in very strong winds which could otherwise cause the turbine to rotate too quickly and possibly damage the turbine, the force exerted by the wind on the vane acts against the restoring force of the biassing means and pivots the vane towards the open position. Air can therefore flow through the gap between the radially inner edge of the vane and the central column of the turbine thereby reducing the force on the vane and slowing down the rate of rotation of the turbine. When the force of the wind decreases in intensity, the restoring force of the biassing means causes the vane to pivot back towards the closed position, thereby reducing airflow between the inner edge of the vane and the central column.

The biassing means can be a spring loaded damper of the type used in door closers. In such dampers, the speed of rotation of the vane is controlled so that the inner edge of the vane does not slam into the central column. The damper therefore reduces or prevents noise associated with the opening and closing of the vanes.

The means for limiting pivotal movement of the vanes is preferably be configured so that the maximum extent of pivotal movement of the vanes is no more than 30°, for example less than 25°, e.g. 10 to 25°.

In a particularly preferred embodiment of the invention, the wind turbine comprises: a central column connected to the rotatable shaft; a pail of axially spaced apart rotor plates extending radially outwardly from the central column; at least two pivot rods extending between the spaced apart rotor plates, the pivot rods each having ends which are pivotably mounted in the rotor plates; a wind vane mounted on each pivot rod; limiting means for limiting the extent of pivotal movement of the pivot rod and hence the wind vane on the pivot rod; and biassing means for biassing the vane against pivotal movement about the pivot rod.

Although the electricity generating apparatus of the invention is intended primarily for use in obtaining electrical energy from wind power, the vertical axis wind turbine may be replaced by another source of mechanical power. For example! the wind turbine could be replaced by a water-driven turbine. Alternatively, the vertical axis wind turbine could also be replaced by a more conventional propeller driven horizontal axis wind turbine.

Accordingly, in a second aspect, the invention provides an apparatus for generating electricity comprising: (a) a turbine powered by water or wind power; (b) a bearing hub assembly connected to the turbine; (c) a generator housing connected to the bearing hub assembly; (d) a support frame attached to the bearing hub assembly or the generator housing (preferably the bearing hub assembly) for securing the apparatus to a supporting structure; and (e) means for conveying electricity generated by the apparatus to an external store or electricity-consuming device; wherein the bearing hub assembly (b) comprises a casing containing a plurality of bearings surrounding a rotatable shaft; the rotatable shaft being operatively connected to the turbine (a) and driven by rotation of the turbine; wherein the rotatable shaft extends from the bearing hub assembly (b) into the generator housing (c); the generator housing (c) containing (c-i) at least one pair of radially oriented fixed plates between which are arranged a plurality of coils, the coils being linked to the electricity-conveying means (e), the fixed plates having aligned openings through which the rotatable shaft extends; and (c-u) at least one radially oriented spinner plate which is fixed to the rotatable shaft and is rotatable therewith, the spinner plate carrying a plurality of magnets; the arrangement of the magnets and coils being such that in use rotation of the spinner plate with the rotatable shaft induces an electrical current in the coils, which current is conveyed to the external store or electricity consuming device by the means (e).

In a third aspect, the invention provides an apparatus for generating electricity comprising: (a) a turbine powered by water or wind power; (b) a bearing hub assembly connected to the turbine; (c) a generator housing connected to the bearing hub assembly; (d) a support frame attached to the bearing hub assembly or the generator housing (preferably the bearing hub assembly) for securing the apparatus to a supporting structure; and (e) means for conveying electricity generated by the apparatus to an external store or electricity-consuming device; wherein the bearing hub assembly (b) comprises a casing containing a plurality of bearings surrounding a rotatable shaft; the rotatable shaft being operatively connected to the turbine (a) and driven by rotation of the turbine; wherein the rotatable shaft extends from the bearing hub assembly (b) into the generator housing (c); the generator housing (c) containing (c-i) at least one radially oriented fixed plate on which are arranged a plurality of coils, the coils being linked to the electricity-conveying means (e), the fixed plate having an opening through which the rotatable shaft extends; and (c-U) at least one radially oriented spinner plate which is fixed to the rotatable shaft and is rotatable therewith, the spinner plate carrying a plurality of magnets; the arrangement of the magnets and coils being such that in use rotation of the spinner plate with the rotatable shaft induces an electrical current in the coils, which current is conveyed to the external store or electricity consuming device by the means (e).

Except where otherwise indicated, the particular and preferred features set out above in relation to the first aspect of the invention also apply to each of the second and third aspects of the invention.

In a fourth aspect, the invention provides a method of generating electricity using an apparatus as hereinbefore defined.

The wind turbines described above may be used together with alternative types of electricity generator. Therefore, in a fifth aspect, the invention provides a wind turbine comprising: a central column; a power output shaft connected to the central column; a pair of axially spaced apart rotor plates extending radially outwardly from the central column; at least two pivot rods extending between the spaced apart rotor plates, the pivot rods each having ends which are pivotably mounted in the rotor plates; a wind vane mounted on each pivot rod; limiting means for limiting the extent of pivotal movement of the pivot rod and hence the wind vane on the pivot rod; and biassing means for biassing the vane against pivotal movement.

Particular examples of the limiting means and the biasing means are as set out above in relation to the first aspect of the invention.

Further aspects and embodiments of the invention will be apparent from the claims appended hereto and the apparatus illustrated in the drawings and described below.

Brief Description of the Drawings

Figure 1 is a schematic side view of a wind turbine and electrical generator apparatus according to one embodiment of the invention.

Figure 2 is a side sectional view of an electrical generator forming part of the apparatus of Figure 1.

Figure 3 is a side sectional view of a bearing hub assembly forming part of the apparatus of Figure 1.

Figure 4 is a view from below of a lower cover plate forming pad of the electrical generator of Figure 2.

Figure 5 is a plan view of a magnet-carrying spinning plate forming part of the electrical generator of Figure 2.

Figure 6 is a plan view of an upper cover plate forming part of the electrical generator of Figure 2.

Figure 7 is a plan view of a fixed coil-bearing plate forming part of the electrical generator of Figure 2.

Figure 8 is an exploded view of a support frame for mounting the wind turbine on a wall or other substrate.

Figure 8A is a partial sectional view along line Il-Il in Figure 8 showing the attachment of the support frame of Figure 8 to a wall.

Figure 9 is a plan view of the lower rotor plate of the wind turbine of Figure 1.

Figure 10 is a side sectional view of part of the wind turbine of Figure 1.

Figure 11 is a side view of a pivot rod and vane forming part of the wind turbine of Figure 1.

Figure 12 is a side view of part of the shaft passing through the generator and hub bearing assembly of Figures 1, 2 and 3.

Figure 13 is a view from above of part of the wind turbine assembly.

Figure 14 is a side view of the outer casing of the electrical generator of Figure 2.

Figure 15 is a view from above of the outer casing.

Figure 16 is a side view ofaweatherproofing sleeve which sits inside the outer casing of Figures 15 and 15.

Detailed Description of the Invention

The invention will now be illustrated but not limited by reference to the specific embodiments shown in the drawings Figures ito 16.

As shown in Figure 1, a wind turbine and electrical generator apparatus according to one embodiment of the invention comprises an electrical generator 2 connected via bearing hub assembly 4 to a wind turbine 6. One end of a side arm 8 is fixed by means of welding to the bearing hub assembly 4. The other end of the side arm 8 has a flange 8a which is bolted to a flange on support post 10 forming part of a frame for mounting the wind turbine on a wall or other supporting structure.

The structure of the electrical generator 2 is shown in more detail in Figure 2.

Thus, the generator 2 comprises upper 12 and lower 14 cover plates and three intermediate fixed disc-shaped plates 16, 18 and 20. Spacers 22 (only some of which are shown) are interposed between each of plates 12 and 16, 16 and 18, 18 and 20, and 20 and 14 at their perimeters thereby connecting the plates together.

A central spacer tube (17) links plates 16 and 18. In Figure 2, the spacers linking plates 16 and 18 and 14 and 20 are not shown.

Intermediate plate 20 is formed from a electrically insulating material or a metal such as aluminium whereas intermediate plates 16 and 18 are both formed from an electrically insulating material such as Tufnol, a phenolic resin and glass fibre laminated plastics material available from Tufnol Composites Ltd of Birmingham, UK. The spacers 22 are typically formed from plastics rod and are held in place by screw fastenings through the plates into the ends of the rod.

The upper plate 12 is formed from steel whereas the lower plate 14 may be formed from a metal material or a non-metallic material.

To the upper surface of the upper cover plate 12 is attached by means of welding an upstanding tubular body 50 which forms the outer casing of the bearing hub assembly 4, the structure of which is shown in more detail in Figure 3.

A steel shaft 26 extends through the centre of the generator, passing through holes in the plates 12, 14, 16, 18 and 20, through the central spacer tube 7 between plates 16 and 18, and up into the bearing hub assembly 4. In the embodiment shown in the drawings, the steel shaft 26 extends out through the bottom plate 14 by a considerable distance and can be connected to an auxiliary mechanical device such as a pump so that it functions as a drive shaft for the auxiliary device.

Coils 28 are mounted in a circular array between the two disc plates 16 and 18. In Figure 7, eight coils 28 are shown but fewer or more coils may be employed instead. Each coil comprises a core (e.g. a core formed from a moulded plastics material) carrying a continuously wound conductor wire (e.g. copper wiie). The coils are connected together in series and then to an electrical connector block (not shown) between the plates 16 and 18. The connector block is in turn connected by means of an electrical cable (19) which passes through the plates 18 and 20 into the space between plates 20 and 14 and out through a hole in the bottom plate 14.

The space between the plates 20 and 14 may contain electronic processing equipment such as an AC/DC converter. One or more bags of a desiccant such as silica gel may also be placed in the space between plates 20 and 14 in order to help keep the interior of the generator dry.

A spinner plate 30A carrying an array of magnets 32A is disposed between the top plate 12 and the fixed plate 16. The spinner plate 30A is attached by means of screws 34 to a flange 36 which is in turn connected to a collar 38 surrounding the shaft. A grub screw 39 passing through the screw collar anchors the collar to the shaft 26 so that the spinner plate will rotate with the shaft 26. A second and identical spinner plate 30B is disposed between the fixed plates 18 and 20 and is likewise secured to the shaft 26 by means of a flanged collar 38B so that it rotates with the shaft.

Although the spinner plates may be circular, in this embodiment they are of substantially cruciform shape. As shown in Figure 5, each spinner plate 30N30B has four arms, each arm carrying a magnet set into a recess in the arm and held in place by means of an adhesive. The spinner plates are typically formed from a metal material such as steel or aluminium. The magnets may be rare earth magnets such as the F3P60 magnets available from E-Magnets of Sheffield, UK.

In the embodiment shown in Figure 5, the spinner plate carries four magnets but more magnets (e.g. six or eight) may be used if required. If six or eight magnets are required, a circular spinner plate may be used in place of the cruciform spinner plate.

The interior workings of the generator are protected from the elements by means of a sleeve 40 (see Figure 15) and an outer casing 42 (see Figures 13 and 14) which is clamped about the sleeve. The sleeve 40 is formed from an elastomeric material (e.g. a neoprene-like material) and fits snugly around the outer edges of the plates 12, 14, 16, 18 and 20, the elasticity of the sleeve material serving to hold the sleeve firmly in place. The outer casing 42 is made from a sheet metal material such as steel or aluminium formed into a near circular shape with the upper and lower edges bent inwardly to form upper and lower circumferential flanges 43. The flanges may be notched to facilitate bending of the casing 42. A flange bracket 44 is attached (e.g. by means of welding) to one longitudinal edge of the casing and another flange bracket 46 is attached in a similar manner near the other longitudinal edge of the casing. The two flange brackets 44, 46 have aligned holes through which fastening bolts 45 are inserted. The casing is placed over the elastomeric sleeve 40 and the nuts 47 on the fastening bolts are tightened to draw the two flange brackets 44, 46 together so as to clamp the casing 42 firmly about the generator. As the flange brackets 44 and 46 are drawn together, the longitudinal edge 49 of the casing 42 slides beneath the other edge to form an overlap. The upper and lower inturned flanges 43 fit over the top plate 12 and bottom plate 14 of the generator. The combination of the elastomeric sleeve 40 and the casing 42 clamped firmly over the sleeve provides a barrier to the ingress of water and atmospheric contaminants such as dust and thereby protects the interior workings of the generator.

The construction of the bearing hub assembly 4 is shown in greater detail in Figure 3. Thus, the hub bearing assembly has an outer sleeve formed by the upstanding tubular body 50 welded at its lower end to the upper surface of the top plate 12 of the generator. Arranged concentrically within the outer sleeve 50 is a steel cylindrical body 52 which is secured to the outer sleeve 50 by means of screws 54.

The upper and lower ends of the cylindrical body 52 are both provided with annular recesses. In the lower recess is mounted an annular sealing element 56 formed from an elastomeric material, a metal 0-ring (slip ring) 57 and a tapered roller bearing 58. The upper recess similarly contains an annular sealing element 60 and a tapered roller bearing 62. A preload tube 53 is positioned between the two tapered roller bearings and there is an annular gap 55 between the outer surface of the preload tube 53 and the inner surface of the cylindrical body 52.

The profile of the shaft 26 is shown in more detail in Figure 12. As can be seen, the shaft has a lower end portion 26A of relatively smaller diameter which in use extends through the generator and out through the bottom plate 14 of the generator. Recesses 26B and 26C in the surface of the shaft in use accommodate the ends of the grub screws 39 holding the collars 38 of the spinner plates 30 in place.

Adjacent one end of the narrower diameter portion 26A of the shaft is a threaded portion 26D which carries a locking nut 27. The locking nut 27 rotates with the shaft 26 and holds the slip ring 57 in place. When the bearing hub assembly is assembled, the locking nut 27 is tightened with a torque wrench so that the correct preload is imparted to the tapered roller bearing 58 and, via the preload tube 53, to the tapered roller bearing 62.

On the other side of the threaded portion 26D are a larger diameter intermediate portion 26E (which in use extends through the inner spacer sleeve 53 of the hub bearing assembly), an enlarged diameter portion 26F and an upper end portion 26G. The upper end portion 26G has a pair of threaded holes 26H (only one of which is shown) for attachment to the central column 84 (see Figures 10 and 11) of the wind turbine.

As shown in Figure 3, the shaft 26 extends from the interior of the generator into and through the hub bearing assembly 4. The enlarged diameter portion 26F of the shaft sits in the upper recess in the tubular body and abuts against the annular sealing element 60 and the taper roller bearing 62.

Attached to the shaft 26 by means of welding to the enlarged diameter portion 26F is a mounting plate 62 (not shown in Figure 12). The mounting plate has holes spaced around its circumference to enable a lower rotor plate 68 of the wind turbine 6 to be attached by means of bolts 70.

Sandwiched between the mounting plate 62 and the lower rotor plate 68 is a spinner disc 69 which, in this embodiment, is formed from a plastics material. The spinner disc 69 serves to throw off water and helps to prevent water from running down into the upper part of the hub bearing assembly 4.

The upper end portion 26G of the shaft 26 fits inside the central column 84 of the wind turbine 6 and is secured in place by means of screws 72 which engage the threaded holes 26H in the shaft.

The construction of the wind turbine is shown in more detail in Figures 9, 10, 11 and 13.

Thus the wind turbine comprises a lower rotor plate 68 and an upper rotor plate 74 linked by a tubular central column 84. The upper and lower rotor plates are typically formed from a metal material such as aluminium although steel or various metal alloys may be used instead. The central column is typically formed from a metal tube, e.g. an aluminium tube or a steel tube.

As indicated above, the central column 84 is secured at its lower end to the shaft portion 26G by means of screws 72. At its upper end, the central column 84 is attached to a spigot 76 by means of screws 77 which engage threaded holes in the spigot. The spigot 76 has an enlarged head portion 78 to which an upper mounting plate 80 is attached by means of a weld 82. The upper mounting plate is secured to the upper rotor plate 74 by means of bolts (not shown) passing through aligned JO holes 86/88 in the mounting plate 80 and rotor plate 74.

The lower rotor plate 68 is shown in more detail in Figure 9. As can be seen, the lower rotor plate has three arms, the longitudinal axes of each of which are offset relative to the central column 84. The upper rotor plate 74 is of similar shape. In the embodiment shown in the drawings, the wind turbine rotates in a clockwise direction and hence the leading edge of the lower rotor plate is the edge 93.

However! the wind turbine may be set up for anti-clockwise rotation by turning the rotor plate and vane assembly upside down; i.e. by assembling the turbine so that the vanes and the leading edges of the rotor plates face in the opposite direction to the direction shown in the drawings.

The upper 74 and lower 68 rotor plates each have three holes (one in each arm) in which are mounted the spigot ends of pivot rods 88. The spigot ends are seated in flanged bronze bushes 90 and 92 which are typically lubricated to facilitate pivotal movement of the pivot rods 88. A turbine blade or vane 94 is attached to each pivot rod 88 by means of fastening screws 96. The vanes 94 each have curved outer edges 94A.

The vanes 94 can pivot on pivot rods 88 but the extent of pivotal movement is limited by pairs of limiter pegs 98/1 00 attached to the upper and lower rotor plates.

The limiter pegs 98/1 00 are preferably cushioned by means of rubber or plastics sleeves fitted over the pegs. Each of the vanes is biased against an inner peg 98 (i.e. the peg in each pair which is closest to the central column 84) by means of spring loaded dampers 102, only one of which is shown in Figure 9.

The wind turbine and generator can be secured to a structure such as a wall, chimney, mast or post by means of the support frame illustrated in Figures 8 and BA.

The support frame comprises an upright support post 10 provided with a flange to which the flanged end Ba of the side arm 8 of the hub bearing assembly is attached. Either or both of the flange Ba and the flange on the support post 10 may be provided with half moon slots to allow for a degree of angular adjustment to ensure that the axis of the wind turbine is as close to vertical as possible. The support post 10 is fastened to a sub-assembly comprising a horizontal wall bracket 104, a vertical wall bracket 106, a lower spacer member 108 and an upper spacer member 110. The horizontal wall bracket 104 and the vertical wall bracket each have a series of holes 104a and 106a enabling the brackets to be screwed or bolted to a wall. At its lower end, the vertical wall bracket 106 has a recessed region 106b which is aligned with a recess 104b in the horizontal wall bracket. The inner end of the lower spacer member 108 fits into the recesses 1 04a and 1 06a.

The brackets 104 and 106 (which are of right angle section) and the lower spacer member 108 are fastened together by welding. The upper spacer member 110 is secured to the vertical wall bracket 106 and the support post 10 by means of bolts or screws. The lower end of the support post 10 is welded to the outer end (i.e. the end remote from the wall bracket 104) of the lower spacer member 108.

Further strength and rigidity is provided to the support frame by the angled struts 112 (see Figure 8A) which are fastened to the support post 10 by means of a bolt and nut combination 114 and to a wall by standard wall fastenings.

The wind turbine and electrical generator apparatus of the invention are typically mounted in an elevated position such as a chimney, or high up on the wall of a house or other building. Alternatively, the apparatus may be mounted at ground level in locations where there is sufficient wind.

In use, wind "captured" by the vanes 94 causes the turbine to rotate thereby rotating the shaft 26. As the shaft 26 rotates inside the generator, the magnets 32 on the spinner plates 30 move along a circumferential path and pass over the coils 28 between thefixed plates 16 and 18. In accordance with the laws of electromagnetic induction, a current is induced in the coils. The electrical current generated in this way is carried to the connector block between the plates 16 and 18 and then along a cable which passes out through the lower wall 14 to a desired location.

In light winds, the vanes 94 remain in a closed" position, i.e. they are held against the inner pegs 98 by the force of the spring in the dampers 102. In this closed" position, there is only a small gap between the inner edge of each vane 94 and the central column 84 of the turbine. As the wind strength increases, so the vanes are forced to pivot on the pivot rods 88, the extent of pivotal movement being limited by the outer pegs 100. As the vanes pivot, the gap between the inner edge of the vane and the central column 84 increases thereby providing an escape path for air to pass through. Thus, the possibility of the turbine being overloaded and possibly damaged by very strong winds is avoided by allowing a proportion of the air to pass through the turbine. As the wind strength drops again, the vanes are pulled back towards the closed position by the springs in the dampers 102. The cushioned surfaces of the pegs reduce to a minimum the noise associated with the vanes opening and closing.

The wind turbine and generator apparatus of the invention is of robust construction and can be used in a wide variety of different environments. The large surface area of the vanes means that it is highly efficient at capturing wind. Moreover, the ability of the vanes to pivot within limits, thereby allowing a proportion of the air flow to be channelled through the centre of the turbine, means that it can be used in high winds without suffering damage. The wind turbine and generator have been found to be very quiet in operation and provide an excellent power output.

The generator itself is of very simple construction and does not require the complex equipment often employed to make electrical generators.

Although the main purpose of the shaft 26 is to convert rotation of the turbine into rotation of the spinner plates thereby generating electricity, the lower end of the shaft can be used as a drive shaft to drive a number of mechanical devices such as a pump.

It will readily be apparent that numerous modifications and alterations could be made to the apparatus shown in the drawings without departing from the scope of the claims appended hereto and all such modifications and alterations are intended to be embraced by this application.

Claims

<claim-text>CLAIMS1. Apparatus for generating electricity comprising: (a) a vertical axis wind turbine; (b) a bearing hub assembly connected beneath the wind turbine; (c) a generator housing connected beneath the bearing hub assembly; (d) a support frame attached to the bearing hub assembly for securing the apparatus to a supporting structure; and (e) means for conveying electricity generated by the apparatus to an external store or electricity-consuming device; wherein the bearing hub assembly (b) comprises a casing containing a plurality of bearings surrounding a rotatable shaft; the rotatable shaft being operatively connected to the wind turbine (a) and driven by rotation of the wind turbine; wherein the rotatable shaft extends from the bearing hub assembly (b) into the generator housing (c); the generator housing (c) containing (c-i) at least one pair of radially oriented fixed plates between which are arranged a plurality of coils, the coils being linked to the electricity-conveying means (e), the fixed plates having aligned openings through which the rotatable shaft extends; and (c-ii) at least one radially oriented spinner plate which is fixed to the rotatable shaft and is rotatable therewith, the spinner plate carrying a plurality of magnets; the arrangement of the magnets and coils being such that in use rotation of the spinner plate with the rotatable shaft induces an electrical current in the coils, which current is conveyed to the external store or electricity consuming device by the means (e).</claim-text> <claim-text>2. Apparatus according to claim 1 wherein the wind turbine comprises: a central column connected to the rotatable shaft; a pair of axially spaced apart rotor plates extending radially outwardly from the central column; at least two pivot rods extending between the spaced apart rotor plates, the pivot rods each having ends which are pivotably mounted in the rotor plates; a wind vane mounted on each pivot rod; limiting means for limiting the extent of pivotal movement of the pivot rod and hence the wind vane on the pivot rod; and biassing means for biassing the vane against pivotal movement.</claim-text> <claim-text>3. Apparatus for generating electricity comprising: (a) a turbine powered by water or wind power; (b) a bearing hub assembly connected to the turbine; (c) a generator housing connected to the bearing hub assembly; (d) a support frame attached to the bearing hub assembly or the generator housing (preferably the bearing hub assembly) for securing the apparatus to a supporting structure; and (e) means for conveying electricity generated by the apparatus to an external store or electricity-consuming device; wherein the bearing hub assembly (b) comprises a casing containing a plurality of bearings surrounding a rotatable shaft; the rotatable shaft being operatively connected to the turbine (a) and driven by rotation of the turbine; wherein the rotatable shaft extends from the bearing hub assembly (b) into the generator housing (c); the generator housing (c) containing (c-i) at least one radially oriented fixed plate on which are arranged a plurality of coils, the coils being linked to the electricity-conveying means (e), the fixed plate having an opening through which the rotatable shaft extends; and (c-u) at least one radially oriented spinner plate which is fixed to the rotatable shaft and is rotatable therewith, the spinner plate carrying a plurality of magnets; the arrangement of the magnets and coils being such that in use rotation of the spinner plate with the rotatable shaft induces an electrical current in the coils, which current is conveyed to the external store or electricity consuming device by the means (e).</claim-text> <claim-text>4. A wind turbine comprising: a central column; a power output shaft connected to the central column; a pair of axially spaced apart rotor plates extending radially outwardly from the central column; at least two pivot rods extending between the spaced apart rotor plates, the pivot rods each having ends which are pivotably mounted in the rotor plates; a wind vane mounted on each pivot rod; limiting means for limiting the extent of pivotal movement of the pivot rod and hence the wind vane on the pivot rod; and biassing means for biassing the vane against pivotal movement.Amendments to the claims have been filed as followsCLAIMS1. Apparatus for generating electricity comprising: (a) a vertical axis wind turbine; (b) a bearing hub assembly connected beneath the wind turbine; S (c) a generator housing connected beneath the bearing hub assembly; (d) a support frame attached to the bearing hub assembly for securing the apparatus to a supporting structure; and (e) means for conveying electricity generated by the apparatus to an external store or electricity-consuming device; wherein the bearing hub assembly (b) comprises a casing containing a plurality of bearings surrounding a rotatable shaft; the rotatable shaft being operatively connected to the wind turbine (a) and driven by rotation of the wind turbine; wherein the rotatable shaft extends from the bearing hub assembly (b) into the generator housing (c); the generator housing (c) containing (c-i) at least one pair of radially oriented fixed plates formed from an electrically insulating material, 0 between which plates are arranged a plurality of coils, the coils being linked to the electricity-conveying means (e), the fixed plates having aligned openings through which the rotatable shaft extends; and (c-u) at least one radially oriented spinner plate which is fixed to the rotatable shaft and is rotatable therewith, the spinner plate carrying a plurality of magnets; whereby one of the said radially oriented fixed plates is interposed between the coils and the spinner plate; the arrangement of the magnets and coils being such that in use rotation of the spinner plate with the rotatable shaft induces an electrical current in the coils, which current is conveyed to the external store or electricity consuming device by the electricity conveying means (e).
2. Apparatus according to claim 1 wherein there are two or more spinner plates.
3. Apparatus according to claim 1 wherein the generator contains a pair of the radially oriented fixed plates with a plurality of coils held between the pair of radially oriented fixed plates, a first spinner plate arranged above the pair of fixed plates and a second spinner plate arranged below the pair of fixed plates.
4. Apparatus according to any one of claims 1 to 3 wherein the coils comprise a core around which is wound an electrically conductive material and wherein the coil cores are aligned in an axial direction (i.e. they have an axis which is substantially parallel to the rotatable shaft).
5. Apparatus according to any one of claims 1 to 4 wherein the spinner plate is of approximately cruciform shape, each arm of the cross shape having a magnet or array of magnets attached thereto.
6. Apparatus according to any one of claims Ito 5 wherein the spinner plate is of circular disc form and carries four to eight magnets or arrays of magnets spaced equidistantly around the plate.("4
7. Apparatus according to any one of claims 1 to 6 wherein the bearings within the casing of the bearing hub assembly are tapered roller bearings.
8. Apparatus according to claim 7 wherein the bearing hub assembly is provided with at least two sets of tapered roller bearings, one set at or adjacent either end of the hub bearing assembly.
9. Apparatus according to claim 8 wherein a preload tube is disposed between the two sets of tapered tIler bearings.
10. Apparatus according to any one of claims ito 9 wherein the wind turbine comprises: a central column connected to the rotatable shaft; a pair of axially spaced apart rotor plates extending radially outwardly from the central column; at least two pivot rods extending between the spaced apart rotor plates, the pivot rods each having ends which are pivotably mounted in the rotor plates; a wind vane mounted on each pivot rod; limiting means for limiting the extent of pivotal movement of the pivot rod and hence the wind vane on the pivot rod; and biassing means for biassing the vane against pivotal movement.
11. Apparatus according to claim 10 wherein the biassing means comprises a spring loaded damper.
12. Apparatus for generating electricity substantially as described herein with reference to the accompanying drawings. (4 r (4</claim-text>