Permanent magnet pendulum motor

[Paul-R]

But I am sure one can get a patent for it. At least one could file a patent and sell the patent application (because few people can distinguish between a "patent application" and a "granted patent").

I should not bank on many people being unable to distinguish between the verb
"to apply for" and the verb "to grant".

[TinselKoala]

I like travin's idea of simply rotating a permanent magnet on the pendulum shaft. This can be done with a simple gearing arrangement where the swinging of the pendulum drives the rotation of its shaft, and I think it's OK even to have the sense of this rotation reverse on each swing from "back" to "forth".

Simple and cheap and very good "overrunning clutches" can be had at the RC Helicopter store in your area. Look for "one-way bearings" in 5mm shaft size, and their matched centerless-ground steel shafts, in the "TRex 450" spare parts section. They are remarkably cheap for what they are, and they are designed in support of aerobatic helicopters weighing upwards of a kilogram and with shafts turning at 3000 RPM, so they are durable and precise enough for this application.

You could also eliminate the side PMs altogether, put a single PM as the "bob" and use either a mechanically rotated PM or an electromagnet in the base, to give a "pushpull" (repultraction) impulse to the pendulum as it passes over center. In the original system diagrammed, the PMs and the gravity do not "power" anything... they might as well be fancy springs themselves. The power comes from the electromagnet; it can be stored in small increments in the pendulum's swing and then taken out in a larger increment all at once for more power... for a shorter time.... than the input power. But power is not energy, it is not "conserved" in the same way energy is.

It's a neat toy and I just might build one (starting with the original design as presented, of course) just for fun. But I don't see any place where any excess energy can get in, or come out. A pendulum is just a fancy flywheel, storing energy that you put in, in the height of the swing and the inertia of the moving bob. Unlike a standard flywheel, which keeps all its energy in its angular momentum, the pendulum cycles energy back and forth between angular momentum and potential (gravitational) energy, reversing the sign of the angular momentum with each swing.

You get out what you put in, minus losses. For the system to "keep on rocking me baby", you are going to have to replace the losses somehow.


The issue of "patent" versus "patent application" has come up for me before.... it is amazing to me that some people will apply for a patent, with documents and drawings that don't even support their contentions and claims in the application-- thus almost assuring that a real patent will never be granted -- and then speak about their "patent" and act as if one actually existed.

Cheers, carry on, don't mind me, I hope somebody builds and tests it and proves me wrong by making a selfpowered perpetual pendulum, I really really do.

[TinselKoala]

I should not bank on many people being unable to distinguish between the verb
"to apply for" and the verb "to grant".

Those aren't the confusing words. The one that people get confused over is "to have". For example, a person I know claimed for a long time to "have" a patent on her system, when all she really had was an old, poorly documented and supported WIPO application whose "use by" date had long expired.

[DreamThinkBuild]

Hi All,

The pendulum has to be the simplest machine to make oscillating motion. We only need to move the arm 35+ degrees to make a oscillating system useable. Extracting work from it is where the challenge comes in.

I've tried the rotating diametric magnet attached to a motor off a fixed magnet. It does work but it incurs a lot of lateral shearing to the arm as it switches across the bloch wall(vibration). This translate into more work for the motor.

What worked a little better as TinselKoala mentioned is putting a block magnet on the arm and fixing the motor and diametric magnet external to the pendulum. This way it was easier to move the diametric magnet farther away from the pendulum to reduce the vibration, at the expense of less power in swinging.

I also tried this with shooting a cylinder magnet through a tube and coil. As the diametric magnet spun it would repel and attract the cylinder magnet shooting it back and forth in the tube (aka the Slammernator(c) (LOL) sounded like a jack hammer.). The motor always suffered more losses trying to get the magnet across the bloch wall boundaries than it was worth.

I've also tried a geared shifting weight. Attached picture is a failed design but might give someone else a idea, starting point or a way to improve. The middle bar is fixed the smaller gear revolves around the fixed center gear as the arm swings turning the weight at top.

For any kind of pendulum machine the larger the better. Small models don't seem to have enough mass to really produce any useable power.

I'm just relaying my experience. I'm not discouraging anyone from building. Building will give you the experience to see what happens and how to overcome it, so I suggest building it and narrowing down problem areas and try to find ways to overcome them.

Keep experimenting and building.