Note: Descriptions are shown in the official language in which they were submitted.
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WIND POWER SYSTEM
Field of the Invention
.. . .
This invention relates to improved wind
motors, often referred to as windmills.
Background of the Invention
Wind motors have previously been proposed in
which an assembly of several vanes rotates about a
vertically oriented main shaft, with the additional
vanes being disposed around the main shaft. Typical
patents of this type include the following: T. O.
Perry, U. S. Patent 146,458, granted January 20, 1874;
F. McClintock, U. S. Patent 256,234, patented April 11,
188 1882; L. Royak, U. S. Patent 1,844,796, granted
February 9 1932, and G. Leon, U. S. Patent No.
1,973,290, granted September 11, 1934; C. F. Terhune,
U.S. Patent 2,247,929, granted July 1, 1941, and C. F.
Terhune, ~.S. Patent 2,406,268, granted August 20,
1946. These vertical axes, flat vane, wind energy
converters date back to the last century and are so
elaborate and complicated that they are rarely
mentioned in current literature on the subject. One
source of complication is the gearing or chains
employed to rotatet each vane. Much additional
needless complication of the early designs involve the
inclusion of mechanical regulators to limit centrifugal
forces during high winds. This idea was a carry-over
from experience with radial vane systems which tend to
self-destruct from centrifugal force in high winds.
Propeller units, for example, often have tip speeds
five or ten times greater than the wind velocity.
However, speed regulation is not needed to protect flat
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vane vertical axis units because the vanes do not move
faster than the wind. Calculations indicate that wind
motor units of the present type will operate safely in
winds over 100 miles per hour.
Most of the early patents show tail vanes, a
feature which also indicates a misconception of the
actual operation of the units. This is another
carry-over from the inherently balanced radial vane
systems which all used tail vanes to direct them into
the wind. In the case of vertical axis flat vane wind
converters, in the order of 60% of the torque tending
to rotate the entire units about the central axis
occurs on one side of the machine. Accordingly, even
with a moderately large tail, the units will tend to
shift in the order of 45 degrees or more from the
optimum orientation relat:ive to the wind, thereby
decreasing the efficiency by a substantial factor,
often in excess of 50~.
Most of the early arrangements used four, and
some suggested using more than four vanes. However,
the arrangements used by these early inventors for
synchronously rotating the vanes were exceedingly
complex and inefficient.
Accordingly, a principal object of the present
invention is to provide an improved and simplified
vertical axis flat vane type wind energy converter. A
collateral object of the present invention is to
provide a simple wind motor which may be employed to
re-charge the automobile batteries of an electric car
while the car is parked, either at night, or during the
day while the owner is not using the car.
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Summary of the Invention
In accordance with the present invention, there is provided a wind
motor comprising:
a central vertically extending rotatable main shaft;
three generally rectangular vanes;
means for mounting said vanes equidistant around said shaft to
rotate both about separate axes parallel to the axis of said vertical shaft
and also to rotate together about said shaft;
means including cranks secured to rotate with each vane and
linkages rigidly interconnecting said cranks in a triangular configuration,
for rotating said vanes in unison; and
means for orienting each of said vanes to be perpendicular to the
incident wind when the axis of each said vane is at a point on a line extending
through said main shaft and also extending perpendicular to the direction of
the incident wind, said orienting means including means for fully restraining
against the unbalanced forces applied to said system when it is in the optimum
orientation relative to the wind as defined hereinabove.
According to one embodiment of the invention, a vertical axis flat
vane wind energy converter employes only three vanes, and each of these vanes
is provided with a crank, fixedly secured to the vane, and secured by a simple
triangular mechanical linkage to the cranks on the two other vanes. This
simple rigid triangular mechanical linkage serves to rotate the three vanes
together in a manner which avoids much of the complexity and frictional
problems inherent in prior designs.
One of the three vanes may be used as the master control vane,
and its angular position relative to the main shaft is controlled in any
desired manner, for example by a cog belt, or by a sliding rod arrangement as
2a -
1134749
disclosed hereinbelow.
In accordance with a broad aspect of the invention, the angular
position of the vanes of a wind motor of the present type are preferably
controlled in two steps and only two steps.
First all vanes are made to rotate in unison by means of a crank
at each vane with all cranks linked by one solid piece, or by a rigid member
or linkage. Second, any one of the vanes can now be controlled by a cogged
belt, or similar functional setup, and the other vanes will follow it.
A wind powered system for an electrical car include a collapsible
vertical axis flat vane wind energy converter. The central or main
rotatable shaft of the wind motor may be raised from a normal position
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in which it is substantially within the automobile or
other vehicle, to a raised position in which it extends
above the roof of the car. Simultaneouslv with the
raising of the main shaft, the vanes are extended to
the operative position exposed to the wind. An
enclosing housing serves to mount the assembly on the
roof in a compact configuration when the car is being
driven, and serves to mount the orientation control and
the electrical generating equipment for the system.
The output from the generator is connected through
circuitry including a diode to charge the batteries,
and thus only couples to charge the battery when the
wind is blowing at a sufficient velocity.
The wind motor is preferably located in a
location where substantially prevailing winds are to be
expected. Additional wall type structures may be
provided to funnel the wind toward the wind motor, and
alternatively, the wind motors may be mounted in
physical locations where the natural terrain and/or
man-made structures will concentrate the wind.
A very significant advantage of the present
wind motor is its relatively slow speed, which enables
it to operate at very high wind velocities. Since wind
power varies as the cube of wind velocity, when wind
speed is doubled, for example, output p~wer is
increased 8 times.
Another aspect of the invention involves the
elimination of speed governors, and the use only of
automatic load controlsto reduce the speed of the wind
motor for optimum eenergy conversion.
In accordance with another feature of the
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invention, the wind motors are not provided with
conventional tails, which have generally proved to be
ineffective or inoperative, but are oriented in
precisely the optimum direction for the wind, and are
either clamped in position, or are automatically
shifted to point toward a separately sensed wind
direction.
Other objects, features and advantages of the
present invention will become apparent from a
consideration of the following detailed description and
from the accompanying drawings.
Brief Description of the Drawings:
Figure 1 shows an electric powered automobile
equipped with a wind motor generator;
Figure 2 is an enlarged partial
cross-sectional view showing the collapsible wind motor
for automotive use in its operative configuration;
Figure 2A is a diagram showing the mode of
collapsing of the vanes of Figure 2;
Figure 3 is a schematic view showing the
relative position of the three vanes and the cog belt;
Figure 4 is a schematic showing of the cranks
and the triangular linkage which interconnects the
cranks in the arrangements of Figures 2 and 5;
Figure 5 shows a large scale embodiment of the
invention;
Figure 6 shows an alternate arrangement for
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maintaining the proper orientation of the vanes as the
assembly rotates; and
Figure 7 is a diagram indicating the power
output for wind motors of the present invention plotted
against wind velocity.
Detailed Description:
Referring more particularly to the drawing,
Figure 1 shows an electric car 12 which is provided
with a storage battery compartment 14, and an electric
motor 16 mounted to the rear of the seats 18, 20, for
driving the rear wheels 22. On top of the roof of the
automobile 12 is the wind motor 24 in its collapsed or
stored position. With regard to electrical controls,
the driver controls the application of power from the
batteries 14 to the electric motor 16 by a control unit
26 which may be both foot and hand operated, by
controls which may be similar to those employed in
conventional gas power automobiles. The generator 28
associated with the wind motor 24 supplies power to the
set of batteries 14, through suitable control circuitry
30 which includes, for example, rectifying circuitry to
insure transmission of current only from the generator
to the battery set, and to prevent discharge of the
batteries when the generator 28 is not being operated.
Control circuit 30 may include suitable regulation
circuitry to supply increased charging current from
generator 28 under strong operating wind conditions,
and to stop further charging when the battery unit 14
is fully charged. The details of the electric car
configuration are not disclosed, as such cars have been
operated on an experimental basis, and their principles
of operation are well known.
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Figure 2 shows the construction of the wind
motor 24 when it is shifted from the inoperative or
stowed condition shown in Figure 1 to the operative
configuration. In Figure 2 the roof of the car 12 is
shown at 32, and the floor of the car is indicated at
34. A hollow tube 36 normally holds the main shaft 38
of the wind motor when the unit is in the stowed
configuration. However, the small winch 40 is operated
with the handle 42 to pull the main shaft 38 up to its
operative position through the use of a cable 44
extending over a pulley 46 which maybe secured to the
roof of the car or alternatively to the top of the tube
36. The main shaft 38 is held in its raised position
by any suitable arranqements such as the detent 48.
Three foldable wind vanes 52, 54 and 56 are
provided, and these are oriented relative to one
another as indicated more clearly in the schematic
showings of Figures 3 and 4. Referring back to Figures
2, and 2A, the wind vane 52 is formed of several
foldable sections 58, 60, 62 and 64. These sections
are pivoted as indicated by the lines between them and
as shown schematically in Fig. 2A, and fold down flat
when the upper shell member 66 is lowered to mate with
the lower casing section 68 and enclose the wind motor
for storage during driving, for example. Secured to
and rotatable on the main shaft 38 are the upper vane
supporting trimount 70 and the upper housing 66. The
lower tri-mount 72 and the power pulley 74 rotate with
the main shaft 58, and are keyed to the slot 76 which
runs for most of the length of the main shaft 38 so
that the lower tri-mount 72 and the power pulley 74 may
remain within the housings 66 and 68, when the main
shaft 38 is lowered into the tube 36.
A cog belt 82 extends between two cog wheels
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84 and 86, which have a two-to-one ratio. The inner
small cog wheel 86 does not rotate with the main shaft
38, but is merely journaled to rotate on it. The cog
wheel 86 is fixedly secured to the arm 88 which may be
moved to any desired angular orientation by the handle
90 and fixed in its angular position by the detent 92
which can be secured in any one of a large number of
circumferentially positioned openings 94.
The rubber mounting members 96 support the
lower housing 68 on the roof 32 of the car and restrain
the entire unit against undue vibration.
Concerning the control of the orientation of
the vanes 52, 54, and 56, as the shaft 38 and its two
associated tri-mounts 70 and 72 rotate, this vane
action is controlled by the three cranks 102, 104 and
106 together with the three braces 108, 110 and 112
which together form a rigid triangular linkage. The
cog wheel 84 is rigidly connected to the crank 102 and
forces the vane 52 to rotate as the two tri-mounts 70
and 72 rotate along with the main shaft 38. As the
tri-mount 72 rotates, under the force of wind
travelling in the direction indicated by the arrows
114, the next successive vane 54 will be moved to the
position indicated by vane 52 in Figure 4, following
one-third of a rotation of the main shaft. Similarly
the vane 56 will assume the position shown in Figure 4
by the vane 54, and vane 52 will take the place of vane
56. In this way, the vanes will always be oriented so
as to maximize the clockwise torque applied to the
tri-mounts 70 and 72 and to the main shaft 38.
Under normal conditions, the user of the
electric car of Figure 1 would park it in a windy
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g
location such as on the roof of the parking structure,
while he or she is at work. Then, the winch handle 42
would be turned to raise the main shaft to the position
indicated in Figure 2, and the handle 90 would be
oriented to maximize the wind force being applied to
the unit. The generator 28 receives power from the
power pulley 74, and supplies electricity to charge the
batteries 14, thereby providing sufficient energy to
drive the electric car 12, particularly when it is only
used for commuting purposes. Of course, each owner
would have available to him either within the car or in
another convenient location, charging equipment for
restoring the power level of the batteries 14, in the
event the batteries are not maintained at the desired
charge level by the wind power unit. Normally prior to
driving the vehicle, the detent 48 would be released,
and the winch 42 operated to lower the main shaft 38,
and the equipment supported on it. As the tri-mount 70
is lowered, the portions 58, 60, 62 and 64 of the wind
vane fold, accordion fashion, as shown in Fig. 2A (are)
and stored within the casing 66, 68.
Now, referring to Figure 5, a larger size wind
power unit 122 is provided, and it has three vanes 124
which may each be in the order of 30 feet by 30 feet,
by way of specific example. In the arrangement of
Figure 5, the cranks and the rigid triangular linkage
interconnecting the cranks are mounted above the upper
tri-mount 126, which rotates with the central main
shaft 128 of the structure. The cog gear arrangement
130 is substantially the same as that shown in the
smaller scale version of Figure 2. However, the
orientation arm 132 is provided with a clamping
mechanism 134 which may be secured in recesses in outer
periphery of the circular track ~36. The weight of the
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visible portion of the structure is supported by an end
bearing set into the floor of the block house 138. A
second bearing at roof level, provide lateral support
for the shaft. Suitable power generation and power
utilization or power storage equipment is located
within the blockhouse 138.
As schematically indicated in Figure 5, a
cliff 142 may be located on one side of the wind motor
122, and a structure or building 144 on the other side
of it. Particularly in areas where winds that tend to
be funnelled through narrow spaces such as that
indicated in Figure 5, often running from west to east,
steady strong winds may be present. Such locations are
particularly advantageous for wind motors such as those
of the present invention.
In connection with Figure 6, an alternative
arrangement for controlling the orientation of the
master vane, for substitution for the cog wheel
arrangement will be described. By way of preamble,
attention is directed to Figure 4, and the fact that,
as the vanes rotate they always keep pointing to a
single point 152 on the circle 154 (more precisely, to
a single line 152 on the cylinder 154) describing the
locus of the pivoting axes of the vanes. Accordingly,
if one of the vanes, which will be designated the
master vane, could be maintained pointing toward point
152, as the vane rotated, and if the other two vanes
were held by the triangular bracing in their proper
orientation, then the proper orientation of all three
vanes would be maintained at all times.
The master control rod assembly including the
double sliding rod 156 and the bracket 158 rigidly
11~4~9
secured to rotate with the master vane 160, serves to
accomplish the foregoing function, in combination with
the pivot point assembly 162. The pivot point assembly
162 is located at the same radial distance from the
main shaft 164 as the vane axes, essentially
corresponding to point 152 in Figure 4. The double
sliding rod 156 passes through an opening 166 in the
pivotal member 168. With the arrangement as shown, as
the vane 160 rotates about the main shaft 164, the
bracket 158 slides on the lower portion of the double
rod assembly 156, and the upper portion of the assembly
156 slides through the opening 166. The result is to
maintain the orientation of the master vane 160 always
pointing toward a single point, such as 152 as shown in
Figure 4 (axis 152 in Figure 6). Incidentally, the
bracket 158 slides past pivot point assembly 168 at
point 152, and travels to the other end of the double
sliding rod assembly 156, during successive rotations.
It may also be noted that a trimount assembly
172 and a triangular linkage 174 are provided to
perform the same functions as in other embodiments
discussed hereinabove. Also, to re-orient the unit of
Figure 6 for changes in wind direction, the pivot point
168, and axis 152' must be shifted.
Figure 7 is a rough plot of horsepower and
kilowatts versus wind velocity for several different
sizes of wind motors. The plot of Figure 7 was
calculated for wind motors having four vanes, instead
of the three vanes disclosed herein, however, the
figures as shown in Figure 7 can be readily converted
to the three vane models disclosed herein by
multiplying the horsepower and ~ilowatt figures
by a factor of about 80%. The power figures shown in
11;34749
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Figure 7 are gross figures, so that in practice the net
power output must be reduced by frictional and
resistance losses to obtain net electrical output of
figures.
Now that the detailed description has been
completed, a few generalized statements may be made.
Specifically, relative to the number of vanes, a three
vane wind motor would have a power output which is more
than 70% of what a six or more vane unit would have;
accordingly, the three vane units are greatly to be
preferred because of the simplicity of the structure
and the small number of moving parts which are
involved~ Additional power is easily obtained by
increasing the size of the vanes, which is more
economical than increasing the number of vanes.
Rectangular vanes are generally preferred, but the
shape may be either high and narrow, or low and wide,
as departures from the square configuration. High
profile units can be fitted between adjacent buildings,
and low profile units are less obtrusive when aesthetic
considerations become important.
Concerning the orientation of the vanes, it is
important that, for maximum efficiency, the vane be
perpendicular to the direction of the wind when the
axis of the vane is on a line through the center of the
main shaft of the wind motor, and extending
perpendicular to the direction of the wind. As
discussed hereinabove this orientation may be obtained
by moving the handle 90 in the arrangement of Figure 2,
and by moving the arm 132 is the larger arrangement of
Figure 5. As discussed in detail in the introduction
to the present specification, the usual tails which
have been proposed previously for this type of
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arrangement will not accomplish the desired result,
because of the unbalanced torque provided by the vanes
on opposite sides of the main shaft. In fact, when
applicant originally sought to use a unit with a
substantial size tail, the unit pivoted around until it
reached a neutral position where it was not generating
any power, and was not rotating. Instead of the
positive locking arrangements disclosed in the present
application, other sophisticated techniques could be
employed for orienting the wind motors of the present
invention. For example, a servo motor actuated by a
signal from a small reference vane could be used to
automatically correct vane orientation for changes in
wind direction, thus assuring optimum power output at
all times.
With regard to orientation arrangements, those
of C. A. King shown in U. S. Patent No. 2,003,300 are
interesting in the use of two vanes, a big vane
referred to as a "directional" vane, and a small vane
referred to as a "governing" vane. The "directional"
and "governing" vanes are in addition to the normal set
of vanes which receive the force of the wind and
generate power. In operation, when the wind changes,
the position of the governing vane, in the King system,
shifts, de-energizing one electromagnet and energizing
a different one. The big directional vane is then
supposed to swing around under the force of the wind
and then be held in place by the newly energized
electromagnet. Unfortunately, for the reasons
discussed above, once the directional vane is released,
the force of the wind will tend to shift the vanes to a
neutral position, and fifty per cent of the time this
will not be in the direction for engagement ~ith the
newly energized electromagnet, in the case of the
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embodiment of Figures 1 and 2 of King. Again, this
shows a lack of understanding of the unbalanced forces
which tend to rotate wind motors of this type. Instead
of the tail configurations shown in the patents, wind
motors of the present type must be positively oriented
properly with respect to the wind and held there by a
locking device, or by servo-mechanism providing
positive control throughout the 360 degree angular
movement of the control member which orients the vanes.
Incidentally, the theoretical advantages of
the flat vane system described herein are not generally
understood, and this would appear to be true even in
the case of the inventors listed in some of the patents
mentioned hereinabove. This is clearly indicated by
the addition of the damping or centrifugal speed
limiting systems which have complicated many of the
prior proposals of the present type. More
specifically, wind will exert maximum force against a
flat surface that is perpendicular to it. Any curving
of a given surface or positioning the surface at an
angle other than normal to the wind will reduce the
force against that surface. Although a small sailboat
can go faster than the wind when its sail is set at an
angle, maximum speed is not equivalent to maximum
energy. A heavily loaded barge with a small sail will
move fastest in a downwind direction when its sail is
perpendicular ~o the wind. Note that square-rigged
clipper ships were the most efficient wind powered
carriers of heavy ocean cargoes. The present wind
motor design uses the same direct push of the wind.
Other inherent advantages are that the vanes cover most
of the "window area" which results in an efficient
compact machine, and the rectangular profile of the
unit makes it practical to increase the power output
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many times, by using stationary walls to funnel more
wind through the motor, or by locating the motor where
pre-existing natural or previously constructed
buildings have concentrated the wind force.
As mentioned hereinabove, the three vane
embodiment is to be preferred over other embodiments
with more vanes, for simplicity. Incidentally, in the
diagrammatic showing of Fig. 4, only two vanes are
shown, in opposite positions, to keep the showing
simple. The preferred three vane, and other vane
arrangements could be implemented using the sliding rod
arrangements of Fig. 4 to control the orientation of
the master vane.
lS
In closing, it is emphasized that the present
invention is not limited to that precisely as disclosed
herein. Thus, by way of example and not of limitation,
variations in the specific mechanical arrangements for
implementing the various indicated functions may be
employed. Thus, instead of using folding collapsible
vanes, as ~hown in Figure 2, fabric or other flexible
vanes which are stretched when the unit is placed in
operation could be employed; and instead of a cogged
belt, sprockets and a bicycle-type chain could be used.
Other similar or comparable changes in the structure
could be utilized.
What is claimed is:
