WIND ROTOR

ROTOR D'EOLIENNE

English Abstract

ABSTRACT OF THE DISCLOSURE

Described herein is a rotor for a wind rotor device.
The rotor comprises a pair of elongated wings having
a curved, e.g., semi-circular, cross-section and
arranged in axial direction about a geometrical axis
in a symmetrical fashion such that the concave sides
of the wings partially overlap each other, defining
an axial passage between the inner edges of the wings,
the wings being twisted in a screw-shaped manner in
relation to one another. A shaft extends in the
direction of the geometrical axis and connects one
end of the rotor to a frame in a rotatable manner.
A plurality of elongated, generally blade-like support
ribs rigidly interconnect,at axially spaced intervals,
the outer edge of each wing with the inner edge of the
other wing. The cross-section of the ribs is convex
in one axial direction of the rotor. This rib
arrangement increases the stability of the rotor and,
at the same time, improves the wind flow conditions
within the rotor.
(Fig. 6)

Claims

The embodiments of the invention in which an exclusive
property or privilege is claimed are defined as follows:

1. A rotor for a wind rotor device with a
frame, comprising:
- a pair of elongated wings having an outer
and an inner edge and a curved, e.g.,
semi-circular, cross-section and arranged in
axial direction about a geometrical axis in a
symmetrical fashion such that the concave
sides of the wings partially overlap each other,
defining an axial passage between the inner
edges of the wings, the wings being twisted
in a screw-shaped manner in relation to one
another;
- a shaft extending in the direction of the
geometrical axis and being connected at one
end to the frame in a rotatable manner; and
- a plurality of elongated, generally blade-like
ribs rigidly interconnecting, at axially
spaced intervals, the outer edge of each wing
with the inner edge of the other wing, said
ribs being arranged in a substantially
perpendicular relationship to the geometrical
axis, and the cross-section of the ribs being
convex in one and same direction of the
geometrical axis.
2. A rotor as claimed in Claim 1, wherein the
cross-section of the ribs is substantially linear in
the opposite direction of the geometrical axis.
3. A rotor as claimed in Claim 1, wherein the
cross-section of the ribs is substantially concave in
the opposite direction of the geometrical axis.
4. A rotor as claimed in Claim 1, wherein the
shaft extends over the whole axial length of the rotor.




5. A rotor as claimed in Claim 1, wherein the
wings are twisted in relation to one another by
substantially 180 degrees.
6. A rotor as claimed in Claim 1, wherein the
length of the rotor is at least 4 times its diameter.
7. A rotor as claimed in Claim 1, wherein each
rib extends from the outer edge of one wing, via the
inner edges of the other wing and said one wing, to the
outer edge of the other wing, thus rigidly interconnecting
both edges of both wings.
8. A rotor as claimed in Claim 1, wherein the
axially spaced intervals are equidistant.
9. A rotor as claimed in Claim 1, wherein the
general planes of the blade-like support ribs
substantially lie in radial planes of the geometrical
axis.

Description

3~


Wind Rotor

The present inventlon concerns a rotor for
a wind ro~or device of a type disclosed in the
PCT Publication wo 81/01~43. Such a prior art
device comprises:
- a base;
- a frame pivotably connected to the base;
- a rotor comprising a pair of elongated wings
having an outer and an inner edge and a
curved, e~g., semicircular, cross-section
and arranged in axial direction about a
geometrical axis in a symmetrical fashion
such that the concave sides of the wings
partially overlap each other, defining
an axial passagè between the inner edges of
the wings, the wings being twisted in a
screw-shaped manner in relation to one
another;
- a shaft extending in the direction on the
geometrical axis and connecting one end of
the rotor to the frame in a pivotable manner;
and
- means for resiliently keeping the rotor in a
first axial direction in relation to the frame
but allowing the rotor to pivot as a function
of the wind strength influencing on the rotor.
The prior art rotor has the drawback of not being
rigid enough to withstand high wind velocities,
particularly if kept in upright position whereby the
wings tend to separate.
It is an object of the present invention to
eliminate the above drawback and, at the same time,
make a wind rotor of the above type m~re efficient.

~L~3~3C~




The invention is based on the idea that by
providing a rotor of the above type with spaced win~-
shaped (or blade-shaped) support ribs rigidly inter-
connecting the edges of the wings, particularly
advantayeous stability and wind flow conditions
within the rotor are achieved.
The rotor according to the invention is
mainly characterized by
a plurality of elongated, generally blade-
like support ribs rigidly interconnecting,
at axially spaced intervals, the outer edge
of each wing with the inner edge of the
other wing, said ribs being arranged in a
substantially prependicular relationship
to the geometrical axis, and the cross-section
of the ribs being convex in one and same
direction of the geometrical axis.
The novel rotor has a number of advantages over the
prior art constructions.
The blade-shaped support ribs guide the wind flow
in the axial direction of the rotor. As no support
plates are necessary at the axial ends of ~he rotor,
the rotor functions equally well in the horizontal
as in the vertical position.
By using a plurality of support ribs, a particularly
rigid and stable construction is achieved.
The blade-like ribs make it possible for the rotor
to pivot without changing the correct flow direction
within the rotor. In the horizontal position, the support
ribs function as the blades of a turbine, increasing the
over all efficiency thereof.
The rotor according to the invention will be
examined in more detail, reference being made to the
attached drawing, in wich:

~3~3~




Fig. 1 is a perspective view of one ambodiment
of the rotor according to the invention.
Fig. 2 is a persepctive view o~ a second
embodiment of the invention.
Fig. 3 is an axial cross section of the
embodiment of Fig. 1.
Fig. 4 shows perspective views of three different
support rib shapes.
Fi~. 5 is a perspective view of a shaft and
~ib arrangement of a third embodiment of the invention.
Fig. 6 is a perspective view on an enlarged
scale of a ~ourth embodiment of the invention.
The rotor according to the invention comprises
a-pair of elongated wings 1, 2 having a curved,
preferebly semi-circular, cross section.
The wings 1, 2 are arranged in axial direction about
a geometrical axis in a symmetrical fashion such that
the concave sides of the wings 1, 2 partially overlap
each other. Thereby an axial passage is defined between
the inner edges of the wings 1, 2. The wings 1, 2 are
twisted in a screw-shaped manner in relation to one
another by substantially 180. The length of the rotor
is preferably at least 4 times its diameter.
A sha~t 3 extends in the direction of the
~eometrical axis and is connected at one end to
a ~rame (not shown) in a rotatable manner. As
discussed above, the connection may also be pivotable~
In that case means are pro~ided for resiliently keeping
the rotor in a first axial direction in relation to
the frame but allowing the rotor to pivot as a function
of the wind strength influencing on the rotor.
A plurality of elongated, generally blade-like
support ribs 4-, 4', 4" rigidly interconnect, at axially
equidistant intervals, the outer edge of each wing 1, 2
with the inner edge of the other wing 2, 1. Said ribs

~236~


4, 4', 4" are arranged in a substantially perpendicular
relationship to the geometrical axis and their cross
section is convex in the upper direction of the rotor.
As seen in Fig. 4, the cross section may consist
of a convex upper side and a linear lower sid~ ~embodiment
A). The cross-section may also have a concave lower side
(embodiments B and C).
The shaft 3 may extend over the whole axial length
of the rotor as is the case in Figures 1 and 6~ or the
rotor may be constructed with only a short shaft portion 3
~Fig. 2).
A particularly strong construction can be achieved
by using ribs extending from the outer edge of one wing 1,
via the inner edges of the other wing 2 and said one wing 1,
to the outer edge of the other wing 2. Such a rib is
indicated in Fig. 6 by the reference numeral 5.
The ribs 4 yuide the inflowing air in the axial
direction of the wings 1, 2. The ribs 4 have a profile
close to that of the wings of an air-craft. Such a
form gives a particularly rigid structure in which
the ribs can be made rather thick without impairing
the flow conditions.
The curved plate-like rib structure 4 ~cf.
Figures 2 and 4) is a preferred embodiment in the
sense that it saves material and has a form similar to
the bla~es of a turbine.
The ribs 4, 4', 4" are preferably made of metal,
whereas the wings 1, 2 can be made of metal or plastic.
The connections between the ribs and the edges of the
wings can be made by welding, riveting or cementing in
a way known per se.