Speed doubler?

[raj]

Can two wheels on separate axles be connected without gears or pulleys such that one of them rotates exactly twice as fast of the other?

[Fletcher]

Yes, if they touch each other, either in directional alignment or at right angles etc. And one is twice the radius of the other where they touch.

[raj]

Hello Fletcher.

Wheels touching each other is gearing of some sort of rims.

And wheels do not have to be one twice as big as the other.

Can this be done?

[Fletcher]

Hydraulics, pneumatics, speed regulated electric motors, wind, steam, etc etc lol.

If you are thinking about levers only it's problematic because they have to physically connect via some means and that usually means at different radius's and so lever length vary thru the cycle.

You might try looking in Google & YouTube for different types of mechanisms like a Scotch Yoke actuator variant, or some such.

[raj]

This drawing shows my OWN speed doubler concept/design I have already incorporated in my current patent pending Desktop Self-Rotating Toy wheel concept.

This speed doubler has been physically tested and work beautifully.

Four pairs of diametrically opposite arms of a larger wheel at 45 degrees intervals (in black) connected by identical strings (in green) to four arms of a smaller wheel (in red) at 90 degrees intervals.

This speed doubler design will work, ONLY when using special measurements of wheels, and strings.

[silent]

.

[raj]

Silent, happy to oblige.

I think I have found a unique way of constructing this speed doubler mechanism. It has to obey a strict measurement requirement.

Once constructed properly, we will have two wheels, a larger one and a smaller one, vertically below on separate axles.

The two wheels will be connected on their rim by identical strings/cords.

A pair of strings, one connected at 12 o'clock position and the other connected at 6 o'clock position on larger wheel , both strings are connected to 12 o'clock position on the smaller wheel.

There are four pairs of diametrically opposite strings connected to rim of larger wheel at 45 degrees intervals, and each pair of strings are connected to rim of smaller wheel at 90 degrees intervals.

When larger wheel rotates 45 degrees, smaller wheel will rotate 90 degrees in the same direction, being pulled by strings on the ascending side.

I hope this explanation suffice.

Raj

[Fletcher]

hmmm .. it looks from your drawing Raj that the lower wheel is about 1/2 radius of the larger, and mounted on its own axle at about -2/3rd radius vertically below the larger wheel axle.

Then the rope length is determined by the distance between tdc of both wheels.

You could also consider using springs or bungy's instead of ropes.

I would guess that the two wheels inertia interplay so that the speeds (rpm) would not be exactly aligned like geared wheels but probably close enough.

I would guess the lower wheel advances and then retards for the same degrees turned as the upper wheel.

I'm a little confused tho. I don't see the possibility of speed (rpm) doubling to call it a speed doubler ? Only speed matching ?

Sorry if I missed something in your drawing.

[raj]

Hello Fletcher.

I can assure you, that the diameter of the smaller wheel is not half the diameter of the larger wheel, and that the rpm of the smaller wheel is twice the rpm of the larger wheel, through 360 degrees rotation. and the three top strings connected to the three top of the four 90 degrees pivots on the rim of the smaller wheel, stay completely outstretched, when the wheels rotate.

Look at this picture:
The top three strings at 45 degrees intervals on the larger wheel connected to the top three 90 degrees intervals pivots on the smaller wheel, and see how all three strings are completely stretched on 180 degrees half circumference.

I think that the secret of this speed doubler mechanism lies in the construction measurements, and connectedness,

I came up with this speed doubler mechanism, after weeks of trial and error attempts.

I am tempted to give all here, the unique measurements, the diameters of the two wheels and the length of the strings.

All must match for this speed doubling concept can work.

Raj

[Georg Künstler]

Hi Raj,

lots of experimenting is lying ahead of you if you try to make this go.

But it is true, you must have two systems which interact.

The sycronization will be your difficult part of the swinging.

[Fletcher]

Hello Fletcher.

Look at this picture:

The top three strings at 45 degrees intervals on the larger wheel connected to the top three 90 degrees intervals pivots on the smaller wheel, and see how all three strings are completely stretched on 180 degrees half circumference.

I think that the secret of this speed doubler mechanism lies in the construction measurements, and connectedness,

I came up with this speed doubler mechanism, after weeks of trial and error attempts.

I am tempted to give all here, the unique measurements, the diameters of the two wheels and the length of the strings.

All must match for this speed doubling concept can work.

Raj

Morninn Raj .. I 'shoudda gone to Spec Savers'.

Here's pics of your Speed Doubler System. I colour coded items so its easier for us blind folk to follow. It can be scaled.

You found a sweet spot where the numbers & angles work out. That's great for those of us also believing there might be a sweet spot in the Laws of Physics to allow an autogravitywheel.

I include the sim for those that might want to play with it. Note the Lower Wheel is free floating (but can have an axle/pin joint). It's rpm hunts around a bit (advances and retards) sometimes slightly faster than 2 x the Upper Wheel (motor driven) and sometimes slightly slower. This means it acts like a small amplitude pendulum swinging forward and backward from the vertical line below the Upper Wheel.

All the best in your search.

[silent]

.

[raj]

A BIG thank you, my dear Fletcher.

Now, could you kindly try with the following measurements.
I believe the ratios of the measurements can be scaled to required size of mechanism:

1. the diameter of larger wheel=16 units.
2. the diameter of the smaller wheel=3 units.
3. the axle of smaller wheel is 4 units vertically below the axle of the larger wheel
4. The length of the strings = 10.5 units

These measurements should give you a perfect speed doubler mechanism.

Raj

[Fletcher]

No problem raj .. I'll get on to it tomorrow. Bit busy atm.

ETA: here is the analysis diagram. Check it to see that the Inputs are correct ?!

FWIW - from what I can see zooming in on the rope connection points to the LW it is not exact i.e. the rope length is close (too short) but not exactly meeting up like the previous analysis sweet spot. This would cause bouncing around if the LW is free floating. Unless the ropes are flexible.

I'll build the sim and post it when I can.

[raj]

Hello Fletcher.

No need to convert my UNITS to meters.
My calling of my measurements as units, is simply to allow us to use any units of measurements, we choose.
I.E: I can choose my larger wheel diameter unit of length as 16 cms, or 16 in, or 16 ft, or 16 meters or 16 yards, depending on the size of my wheel I want to build.

The remaining measurements should follow the same units of length.


So kindly use my unit of measurement I have given above as :

1. Diameter of larger wheel = 16 centimetres or radius=8 cm
2. Diameter of smaller wheel = 3 centimetres. or radius=1.5 cm

3. axle of smaller wheel 4 centimetres vertically below axle of larger wheel.

4. length of strings/ropes = 10.5 centimetres.



Ratio of my larger wheel radius to my smaller wheel radius = 8:1.5

8/1.5=5.333

Ratio of YOUR larger wheel radius to Your lower wheel radius = 1:0.375

1/0375=2.666

Thanks again.

Raj