CA2746564A1

CA2746564A1 - Adjustable flywheel

Info

Publication number: CA2746564A1
Application number: CA2746564A
Authority: CA
Inventors: Normand St-Cyr
Original assignee: Normand St-Cyr; St-Cyr, Therese
Current assignee: St-Cyr Therese
Priority date: 2011-07-12
Filing date: 2011-07-12
Publication date: 2013-01-12
Anticipated expiration: 2031-07-12
Also published as: CA2746564C

Abstract

An adjustable flywheel for a windmill includes a body having a central hub. Means are provided for connecting the central hub to a rotating shaft. The positioning of the rotating shaft in the central hub defines a symmetrical rotational axis for the body and the body provides inertial mass to the rotating shaft. The body has a plurality of arms which extend radially outwardly from the central hub. Each of the arms has two or more weight anchoring positions. The inertial capacity of the flywheel is adjustable by securing weights to each of the arms in selected of the weight anchoring positions.

Description

TITLE
[0001] Adjustable Flywheel FIELD

[0002] There is described an adjustable flywheel that was developed for use in a vertical axis windmill.

BACKGROUND

[0003] Most electric generators and mechanical components, which are driven by windmills, have an optimum operating range. If wind conditions were always consistent, it would be a simple matter of sizing components so that the windmill always operated within that optimum operating range. Unfortunately, wind acting upon a windmill is often subject to variations in intensity from day to day. Even from hour to hour and from moment to moment, the wind may experience periods of gusting and periods of relative calm. For this reason, most windmills are equipped with a flywheel, which tends to keep the rotation relatively consistent. What is required is a flywheel that can be adjusted to suit prevailing wind conditions. The present invention was developed for use in a vertical axis windmill. United States Patent 7,866,938 (Kariya) is an example of a relatively recent patent relating to a vertical axis windmill.
SUMMARY

[0004] There is provided an adjustable flywheel which includes a flywheel body having a central hub. Means are provided for connecting the central hub to a rotating shaft. The positioning of the rotating shaft in the central hub defines a symmetrical rotational axis for the body and the body provides inertial mass to the rotating shaft. The body has a plurality of arms which extend radially outwardly from the central hub. Each of the arms has two or more weight anchoring positions. The inertial capacity of the flywheel is adjustable by securing weights to each of the arms in selected of the weight anchoring positions.

[0005] The adjustable flywheel, as described above, was initially developed for use in a windmill. It is now appreciated that it may have uses in any other application that requires an inertial mass. With the adjustable flywheel, as described above, the inertial capacity of the flywheel is adjusted by either moving the weights inward toward the central hub or outward away from the central hub. The farther away from the central hub that the weights are positioned, the greater is the inertial capacity of the flywheel.

[0006] When adapting the flywheel for use with a windmill, the flywheel body is attached to a windmill shaft. A blade support body is secured to the windmill shaft.
Blade support body has an outer circumference to which a plurality of fixed rotor blades are secured. Wind striking the rotor blades imparts a rotational force via the blade support body to the shaft.

[0007] While the structure of the windmill is not directly relevant to the adjustable flywheel, the flywheel was developed with a particular style of windmill and is known to work well in that structure. It is preferred that the support structure is an open frame structure with four sides. It is preferred that the windmill is a vertical axis windmill, with the shaft supported in a vertical orientation with the rotor blades extending radially outwardly from the shaft in a vertical orientation.

[0008] Although beneficial results may be obtained through the use of the windmill described above, even more beneficial results may be obtained through the addition of wind deflectors to deflect wind onto the rotor blades. It is preferred that the wind deflectors project outwardly from only one corner on each of the sides of the open frame structure to capture and deflect wind across the side of the open face structure and onto a selected face of each of the rotor blades. It is undesirable for the wind to be acting equally on returning rotor blades, as this reduces efficiency. By selectively deflecting the wind in this manner, a greater rotational force is exerted on one face to promote the desired rotation.

[0009] Although beneficial results may be obtained through the use of the windmill described above, even more beneficial results may be obtained by selected improvements to the rotor blades. It is preferred that the rotor blades are elongated with a concave face and a convex face. The concave face captures the wind and the convex face tends to merely divert the wind around. The concave face of each of the rotor blades has a top end and a bottom end.
It is preferred that wind retaining dividers be positioned on the concave face between the top end and the bottom end. These dividers improve the capture of wind and result in a greater rotational force, when compared to identical rotor blades without dividers.

[0010] A significant torsional force is exerted upon the rotor blades, especially when wind deflectors are used. Even more beneficial results may be obtained by reinforcing the rotor blades. Each of the rotor blades has an inside edge and an outside edge.
It is preferred that a brace be placed from the outside edge of one rotor blade to the inside edge of a following rotor blade.

[0011) There are always issues of capacity. It is preferred that the frame structure be arranged as modules that can be vertically stacked to increase capacity. A
linkage is then used to connect the shafts of the frame structures, which are stacked.

[0012] There are a number of safety concerns when windmills are operating. It is preferred that a lowermost frame structure rests upon a base, which elevates the frame structure. This raises the operating windmill high enough that a member of the public who wanders in the area will not be harmed. It also allows for storage space to be provided below the windmill.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] These and other features will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to be in any way limiting, wherein:
FIG. 1 is a top plan view of a windmill with an adjustable flywheel.
FIG. 2 is a side elevation view of the windmill shown in FIG. 1.
FIG. 3 is a top plan view of the adjustable flywheel used in the windmill shown in FIG.1.
FIG. 4 is a perspective view of the rotor blade used in the windmill shown in FIG.1.

DETAILED DESCRIPTION

[0014] An adjustable flywheel generally identified by reference numeral 10, will now be described with reference to FIG. 1 through 4. Adjustable flywheel 10 is shown incorporated into the construction of a windmill 100.

Structure and Relationship of Parts:

[0015] Referring to FIG. 1, windmill 100 has an open frame support structure 12 with four sides 15. It should be understood that windmill 100 may be constructed with a different number of sides and a closed frame. Shaft 16 is supported for rotation by support structure 12 in a vertical orientation.

[0016] Referring to FIG. 3, flywheel 10 has a flywheel body 18 with a central hub 20.
Central hub 20 is secured to shaft 16 by welding, fasteners or other means.
The positioning of shaft 16 in central hub 20 serves to define a symmetrical rotational axis for body 18 and body 18 provides inertial mass during rotation of shaft 16. Body 18 has a plurality of arms 22 which extend radially outwardly from central hub 20 with each arm 22 having two or more weight anchoring positions 24. The inertial capacity of flywheel 18 is adjustable by securing weights 26 using screws, pins or other securing devices in one of the weight anchoring positions 24. The farther away from the central hub that the weights are positioned, the greater is the inertial capacity of the flywheel.

[0017] Referring to FIG. 3, in the windmill application, a blade support body 13 is provided that has an outer circumference to which are secured a plurality of fixed rotor blades 14. Body 13 is and secured to shaft 16, such that wind striking rotor blades 14 imparts a rotational force to blade support body 13 causing shaft 16 to rotate.
Referring to FIG. 4, rotor blades 14 are elongated with a concave face 30 and a convex face 32.
Concave face 30 of each rotor blade 14 has a top end 34, a bottom end 36 and a wind retaining divider 38 positioned between top end 34 and bottom end 36. It has been found that wind retaining divider 38 improves the ability of concave face 30 to capture wind. Referring to FIG. 1, rotor blades have an inside edge 40 and an outside edge 42 with a brace 44 extending from outside edge 42 of one rotor blade 14 to inside edge 40 of a following rotor blade 14.
Brace 44 strengthens body 13 to prevent torsional load created by wind gusts from breaking off one of rotor blades 14.

[0018] Referring to FIG. 1, wind deflectors 28 project outwardly from one corner 29 on each of the sides of open frame structure 12 to capture and deflect wind across side of open face structure 12 and onto a selected face, ie concave face 30, of each of rotor blades 14.

5 [0019] Referring to FIG. 2, support structure 12 may be modular, allowing a plurality of windmills 100 each with their own flywheel 10 to be vertically stacked to increase capacity. A
linkage 46 connects shafts 16 of each windmill 100, so that shafts 16 rotate together. The lowermost frame structure 12 rests upon a base 48 which elevates frame structure 12.

[0020] Referring to FIG. 2, a recommended safety feature is the addition of a shaft brake, shown as box 50. It is preferred that one be placed at a top and at a bottom of a shaft structure. Shaft brakes 50 are commercially available; the one for the proto-type was purchased from DEXTER AXLE (Trademark). It is also preferred that a locking pin 52 be provided. Locking pin 52 is extended through aligned openings in one of flywheel body 18 or blade support body 13 of flywheel 10 and support frame 12. Locking pin 52 extends through flywheel body 18 or blade support body 13 into support frame 12 stops rotation of flywheel 10.

Operation:
[0021] Referring to FIG. 1, regardless of the direction of the prevailing wind, wind is deflected by wind deflectors 28 on support structure 12 onto concave face 30 of rotor blades 14. Wind retaining divider 38 improves the ability of concave face 30 to capture wind. When the wind speed exceeds a threshold value, there is sufficient wind captured to set blade support body 13 of flywheel 10 in motion and cause rotation of shaft 16. If the wind is insufficient to set blade support body 13 in motion and rotate shaft 16, the inertial mass represented by flywheel 10, shown in FIG. 3, can be adjusted, by altering the positioning of weights with respect to weight anchoring positions 24 on arms 22. Referring to FIG. 3, once shaft 16 is in motion, it will tend to remain in motion due to the inertia provided by flywheel 10, as long as there are periodic gusts to maintain flywheel 10 in motion.
Referring to FIG. 1, as the wind increases in intensity, brace 44 extending from outside edge 42 of one rotor blade 14 to inside edge 40 of a following rotor blade 14 prevents the strength of the wind from breaking off one of rotor blades 14. Should the strength of the wind be viewed as rendering operation unsafe, shaft brake 50 may be applied to bring shaft 16 to a stop, which in turn retards motion of flywheel 10 and blade support body 13 and then locking pin 52 inserted to lock body 18 to support structure 12.
[0022] In this patent document, the word "comprising" is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article "a" does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.

[0023] The scope of the claims should not be limited by the preferred embodiments set forth as examples, but should be given the broadest interpretation consistent with the description as a whole.

Claims

1. An adjustable flywheel, comprising:
a flywheel body having a central hub;
means for connecting the central hub to a rotating shaft, the positioning of the rotating shaft in the central hub defining a symmetrical rotational axis for the body and the body providing inertial mass to the rotating shaft;
the body comprising:
a plurality of arms which extend radially outwardly from the central hub, each of the arms having two or more weight anchoring positions, the inertial capacity of the flywheel being adjustable by securing weights to each of the arms in selected of the weight anchoring positions.

2. The adjustable flywheel of Claim 1, secured to a rotating shaft of a windmill to form a windmill-flywheel combination.

3. The combination of Claim 2, wherein a blade support body is provided having an outer circumference to which a plurality of fixed rotor blades are secured to the shaft, such that wind striking the rotor blades imparts a rotational force to the blade support body and causes the shaft to rotate.

4. The combination of Claim 2, wherein the windmill has a fixed open frame support structure with four sides.

5. The combination of Claim 2, wherein the shaft is supported in a vertical orientation.

6. The combination of Claim 4, wherein wind deflectors project outwardly from only one corner on each of the sides of the open frame support structure to capture and deflect wind onto a selected face of each of the rotor blades.

7. The combination of Claim 3, wherein the rotor blades are elongated with a concave face and a convex face.

8. The combination of Claim 7, wherein concave face of each of the rotor blades has a top end, a bottom end, and wind retaining dividers are positioned on the concave face between the top end and the bottom end.

9. The combination of Claim 3, wherein each of the rotor blades has an inside edge and an outside edge, with a brace extending from the outside edge of one rotor blade to the inside edge of a following rotor blade.

10. The combination of Claim 4, wherein the frame structure is modular and can be vertically stacked to increase capacity, with a linkage connecting the shafts of the frame structures which are stacked so that the shafts rotate together.

11. The combination of Claim 10, wherein a lowermost frame structure rests upon a base which elevates the frame structure.