Posted by rdoctors on April 7, 2008, 12:42 am
> Or add an extra "take up the slack" wild arm.
> >>>I realize it seems inefficient to convert from circular motion at the top
> >>>of the windmill, to "up and down", back to circular motion on the ground,
> >>>but this is what I have to work with. Unless I redesign the entire old
> >>>style windmill, this would be the simplest for me to convert back to
> >>>rotary motion on the ground. Just curious if anyone has done this
> >>>before. The idea of a Crankshaft on the bottom, with a flywheel to
> >>>maintain the momentum of the "up and down" motion was an idea of mine as
> >>>well.
> >>> Thanks everyone for their help.
> >> The problem with using a crank at the bottom to convert back to rotary is
> >> what happens if the wind dies down and the windmill stops with the crank
> >> at either TDC or BDC. When it tried to move again it would either be
> >> pulling straight up or pushing straight down and with no sideways force
> >> to get the bottom crank turning again it would try to hold the windmill
> >> blades still which could break something if the wind got strong enough.
> >> If the rod moves in a circular motion with the top crank instead of
> >> straight up and down you could add a sliding pivot point halfway between
> >> the 2 cranks which would provide the necessary sideways force and would
> >> prevent the stalled condition I described.
> > Or, like the old-fashioned steam locomotives, put another crank at the top
> > and bottom and arrange them so their 90 degrees shifted from the first
> > (obviously both the top and bottom have to be shifted the same amount).
> > So when one is TDC or BDC, the second crank on the same shaft is 90
> > degrees from TDC/BDC.
> > But you have to be careful to quarter the cranks precisely the same or
> > you'll get binding and ruined crank-pin bearings.
> > daestrom
The power available for a given size of generator depends on the RPM,
same for motors..
My suggestion is to use the up down motion and let it move a geared
track and apply a geared wheel to it. The geared wheel can then be
used to drive an alternator. The alternator wont care about rotational
direction, The alternator will need to turn at least a few turns in
each direction to provide any useful power. The output current can
then be fed into a bridge rectifier and you'll have DC. The voltage
will be dependent on the speed of the strokes so to get a constant
voltage you'll need a DC to DC convertor.
Posted by bealiba on April 7, 2008, 1:59 am
> Or add an extra "take up the slack" wild arm.
> >>>I realize it seems inefficient to convert from circular motion at the top
> >>>of the windmill, to "up and down", back to circular motion on the ground,
> >>>but this is what I have to work with. Unless I redesign the entire old
> >>>style windmill, this would be the simplest for me to convert back to
> >>>rotary motion on the ground. Just curious if anyone has done this
> >>>before. The idea of a Crankshaft on the bottom, with a flywheel to
> >>>maintain the momentum of the "up and down" motion was an idea of mine as
> >>>well.
> >>> Thanks everyone for their help.
> >> The problem with using a crank at the bottom to convert back to rotary is
> >> what happens if the wind dies down and the windmill stops with the crank
> >> at either TDC or BDC. When it tried to move again it would either be
> >> pulling straight up or pushing straight down and with no sideways force
> >> to get the bottom crank turning again it would try to hold the windmill
> >> blades still which could break something if the wind got strong enough.
> >> If the rod moves in a circular motion with the top crank instead of
> >> straight up and down you could add a sliding pivot point halfway between
> >> the 2 cranks which would provide the necessary sideways force and would
> >> prevent the stalled condition I described.
> > Or, like the old-fashioned steam locomotives, put another crank at the top
> > and bottom and arrange them so their 90 degrees shifted from the first
> > (obviously both the top and bottom have to be shifted the same amount).
> > So when one is TDC or BDC, the second crank on the same shaft is 90
> > degrees from TDC/BDC.
> > But you have to be careful to quarter the cranks precisely the same or
> > you'll get binding and ruined crank-pin bearings.
> > daestrom
Wonderful, How many loses can you add before it stops turning
altogether.
Posted by Mauried on April 7, 2008, 3:47 am
On Sun, 6 Apr 2008 22:59:48 -0700 (PDT), bealiba@gmail.com wrote:
>> Or add an extra "take up the slack" wild arm.
>>
>>
>>
>>
>>
>>
>> >>>I realize it seems inefficient to convert from circular motion at the top
>> >>>of the windmill, to "up and down", back to circular motion on the ground,
>> >>>but this is what I have to work with. Unless I redesign the entire old
>> >>>style windmill, this would be the simplest for me to convert back to
>> >>>rotary motion on the ground. Just curious if anyone has done this
>> >>>before. The idea of a Crankshaft on the bottom, with a flywheel to
>> >>>maintain the momentum of the "up and down" motion was an idea of mine as
>> >>>well.
>>
>> >>> Thanks everyone for their help.
>>
>> >> The problem with using a crank at the bottom to convert back to rotary is
>> >> what happens if the wind dies down and the windmill stops with the crank
>> >> at either TDC or BDC. When it tried to move again it would either be
>> >> pulling straight up or pushing straight down and with no sideways force
>> >> to get the bottom crank turning again it would try to hold the windmill
>> >> blades still which could break something if the wind got strong enough.
>> >> If the rod moves in a circular motion with the top crank instead of
>> >> straight up and down you could add a sliding pivot point halfway between
>> >> the 2 cranks which would provide the necessary sideways force and would
>> >> prevent the stalled condition I described.
>>
>> > Or, like the old-fashioned steam locomotives, put another crank at the top
>> > and bottom and arrange them so their 90 degrees shifted from the first
>> > (obviously both the top and bottom have to be shifted the same amount).
>> > So when one is TDC or BDC, the second crank on the same shaft is 90
>> > degrees from TDC/BDC.
>>
>> > But you have to be careful to quarter the cranks precisely the same or
>> > you'll get binding and ruined crank-pin bearings.
>>
>> > daestrom
>Wonderful, How many loses can you add before it stops turning
>altogether.
It would be far better to apply some common sense and simply measure
the swept area of the windmill blades, measure the average windspeed
over a few months and then figure out whether its all worth doing.
Posted by adm on April 7, 2008, 11:17 am
>> Or add an extra "take up the slack" wild arm.
>>
>>
>>
>>
>>
>> > in
>>
>> >>>I realize it seems inefficient to convert from circular motion at the
>> >>>top
>> >>>of the windmill, to "up and down", back to circular motion on the
>> >>>ground,
>> >>>but this is what I have to work with. Unless I redesign the entire
>> >>>old
>> >>>style windmill, this would be the simplest for me to convert back to
>> >>>rotary motion on the ground. Just curious if anyone has done this
>> >>>before. The idea of a Crankshaft on the bottom, with a flywheel to
>> >>>maintain the momentum of the "up and down" motion was an idea of mine
>> >>>as
>> >>>well.
>>
>> >>> Thanks everyone for their help.
>>
>> >> The problem with using a crank at the bottom to convert back to rotary
>> >> is
>> >> what happens if the wind dies down and the windmill stops with the
>> >> crank
>> >> at either TDC or BDC. When it tried to move again it would either be
>> >> pulling straight up or pushing straight down and with no sideways
>> >> force
>> >> to get the bottom crank turning again it would try to hold the
>> >> windmill
>> >> blades still which could break something if the wind got strong
>> >> enough.
>> >> If the rod moves in a circular motion with the top crank instead of
>> >> straight up and down you could add a sliding pivot point halfway
>> >> between
>> >> the 2 cranks which would provide the necessary sideways force and
>> >> would
>> >> prevent the stalled condition I described.
>>
>> > Or, like the old-fashioned steam locomotives, put another crank at the
>> > top
>> > and bottom and arrange them so their 90 degrees shifted from the first
>> > (obviously both the top and bottom have to be shifted the same amount).
>> > So when one is TDC or BDC, the second crank on the same shaft is 90
>> > degrees from TDC/BDC.
>>
>> > But you have to be careful to quarter the cranks precisely the same or
>> > you'll get binding and ruined crank-pin bearings.
>>
>> > daestrom
> Wonderful, How many loses can you add before it stops turning
> altogether.
It's probaby easiest just to replace the old farm windmill head with a new
wind turbine and reuse the existing tower. Probably far more efficient to
just output power directly from the turbine itself than worry about the
mechanical side of things
Posted by Mauried on April 7, 2008, 6:12 pm
>>> Or add an extra "take up the slack" wild arm.
>>>
>>>
>>>
>>>
>>>
>>> > in
>>>
>>> >>>I realize it seems inefficient to convert from circular motion at the
>>> >>>top
>>> >>>of the windmill, to "up and down", back to circular motion on the
>>> >>>ground,
>>> >>>but this is what I have to work with. Unless I redesign the entire
>>> >>>old
>>> >>>style windmill, this would be the simplest for me to convert back to
>>> >>>rotary motion on the ground. Just curious if anyone has done this
>>> >>>before. The idea of a Crankshaft on the bottom, with a flywheel to
>>> >>>maintain the momentum of the "up and down" motion was an idea of mine
>>> >>>as
>>> >>>well.
>>>
>>> >>> Thanks everyone for their help.
>>>
>>> >> The problem with using a crank at the bottom to convert back to rotary
>>> >> is
>>> >> what happens if the wind dies down and the windmill stops with the
>>> >> crank
>>> >> at either TDC or BDC. When it tried to move again it would either be
>>> >> pulling straight up or pushing straight down and with no sideways
>>> >> force
>>> >> to get the bottom crank turning again it would try to hold the
>>> >> windmill
>>> >> blades still which could break something if the wind got strong
>>> >> enough.
>>> >> If the rod moves in a circular motion with the top crank instead of
>>> >> straight up and down you could add a sliding pivot point halfway
>>> >> between
>>> >> the 2 cranks which would provide the necessary sideways force and
>>> >> would
>>> >> prevent the stalled condition I described.
>>>
>>> > Or, like the old-fashioned steam locomotives, put another crank at the
>>> > top
>>> > and bottom and arrange them so their 90 degrees shifted from the first
>>> > (obviously both the top and bottom have to be shifted the same amount).
>>> > So when one is TDC or BDC, the second crank on the same shaft is 90
>>> > degrees from TDC/BDC.
>>>
>>> > But you have to be careful to quarter the cranks precisely the same or
>>> > you'll get binding and ruined crank-pin bearings.
>>>
>>> > daestrom
>>
>> Wonderful, How many loses can you add before it stops turning
>> altogether.
>It's probaby easiest just to replace the old farm windmill head with a new
>wind turbine and reuse the existing tower. Probably far more efficient to
>just output power directly from the turbine itself than worry about the
>mechanical side of things
Tbhis is by far the best option.
The aim is to minimise the mass of moving parts so that the windmill
will actually make power at low wind speeds.
Most decent wind turbines minimise the rotational mass by using very
light weight blades directly coupled to the alternator, no gear box
involved.
The alternators are specifically designed to generate useful power at
low rpm.
XML site map
> >>>I realize it seems inefficient to convert from circular motion at the top
> >>>of the windmill, to "up and down", back to circular motion on the ground,
> >>>but this is what I have to work with. Unless I redesign the entire old
> >>>style windmill, this would be the simplest for me to convert back to
> >>>rotary motion on the ground. Just curious if anyone has done this
> >>>before. The idea of a Crankshaft on the bottom, with a flywheel to
> >>>maintain the momentum of the "up and down" motion was an idea of mine as
> >>>well.
> >>> Thanks everyone for their help.
> >> The problem with using a crank at the bottom to convert back to rotary is
> >> what happens if the wind dies down and the windmill stops with the crank
> >> at either TDC or BDC. When it tried to move again it would either be
> >> pulling straight up or pushing straight down and with no sideways force
> >> to get the bottom crank turning again it would try to hold the windmill
> >> blades still which could break something if the wind got strong enough.
> >> If the rod moves in a circular motion with the top crank instead of
> >> straight up and down you could add a sliding pivot point halfway between
> >> the 2 cranks which would provide the necessary sideways force and would
> >> prevent the stalled condition I described.
> > Or, like the old-fashioned steam locomotives, put another crank at the top
> > and bottom and arrange them so their 90 degrees shifted from the first
> > (obviously both the top and bottom have to be shifted the same amount).
> > So when one is TDC or BDC, the second crank on the same shaft is 90
> > degrees from TDC/BDC.
> > But you have to be careful to quarter the cranks precisely the same or
> > you'll get binding and ruined crank-pin bearings.
> > daestrom