How this bizarre pericyclic transmission works? 

I've seen high torque gearboxes before, and now I've seen a high twerk gearbox.

The issue you noticed on the end is related to a tiny flaw on the design, you should use tapered roller bearings on the ends! There is force being applied axially as well as radially, thus it requires tapered roller bearings instead of just standard radial ball bearings.

I don't know if it's useful, but it is hardly unnecessary. It may lead to a more advanced design. Try it with beveled helical gears and increase the gear contact by increasing the length of the gear teeth. You have a rather large gap between the teeth and shaft. More contact may increase stability.

i think this was genuinly one of the least annoying sponsor presentation ive seen,nice job bro

If you want it to operate smoothly, three things are to take into account : 1) the distance of each nutation gear to the nutation point depends on several factors such as tha nutation ratio and the difference in tooth count in each gear mesh, if not followed, the gears don't mesh perfectly 2) 3d printed gears need to be work smoothed by runing them with an abrasive to eliminate surface artifacts 3) greasing the gears is key in smooth and qiet operation. Back to the first point, all herringbone gears have an average contact point wich describes a circle, the center of the fear being the center of this circle. With a nutation angle α, and an offset of a nutation gear from the nutation point (where the oblique and straigt axes cross) δ, and a meshing gear of radius r1 the nutation gear average radius needs to be r1/cos(α) + δ*tan(α), if you trace the simple meshing on a piece of paper to find the proper dimensions, you will find this formula with simple trigonometry. On a side note, having the same nutation gears and meshing gears will simplify the design as the nutation gears will bea simetrical to the nutation point

Very interesting and bizarre stuff, I think the biggest shortcoming it has, is that the output is basically getting 'twitched' between gear meshes as a means of moving. So your output side isn't able to deliver a consistent level of torque in a direction. Also I think this means that despite the 40:1 ratio or so, the mechanical advantage is actually lower, each time it steps back it is undoing the mechanical advantage, then the forward stroke has to put it back that much further, so that's a sort of continuous movement ineffeciency. So it's mechanical advantage factor would be measured in the forward-wobble and advancement region only, if that makes sense. Basically it will act like a 40:1, but the input torque used to move it, will take the effort of something more like a 30:1.

Looks like a neat variant of the harmonic drive that doesn't involve deformation

6:12 FWIW, the teeth on *BOTH* sides of the center gear are engaged, so the total force is _really_ spread out.

It’s easy to see that for a continuous input you have a pulsing outout. Even In the double gearbox configuration. You can improve the smoothness of the output by offsetting the mirrored gearbox by 90 degree rotation.

I would love to see a really high load on this gearbox. Maybe test its limits with what 3D printing material and precision you have, until a gearbox of a certain size fails. I bet if you optimize it as much as you can, it may be capable of producing much more torque for its size and mass than other more commonly used gearboxes.

as you mentioned, a solid casing made of thick steel plate, machined solid steel parts, some grease and this thing would genuinely be useful in a lot of industrial applications

I’m very impressed by the finish on that clear cover! I used to work with acrylics and polycarbonate many years ago. That looks as good as an injection moulding. The gearbox is an impressive force multiplier! 👍🏻

Certainly a nice gadget but not a solution for real-life problems: the show-stopper is friction. *Properly designed gear trains have friction only in the bearings but never on the teeth* (rolling motion via evolute geometry). Here, there teeth are sliding into position. Big no-no in engineering and the reason why worm gears wear out so quickly.

Similar to a strain wave gearbox, it should have extremely low backlash due to the large number of teeth engaged.

You can make the gearing ratio even slower if you have 1 tooth difference between the two yellow gears, and each orange gear having 1 tooth more than its yellow mate.

If you can imagine it, it's probably already been done. Fascinating stuff, but he mentioned the practical, real world solution at the start of the video: the worm gear drive.

Just a different form of what I know as a harmonic drive, only a lot worse performance. Harmonic drives have high gear reduction, they're relatively compact, have close t0 0 backlash, run smooth/quiet, and are robust. They are commonly used on CNC machine centers to drive automatic tool changers. We have a bunch of Toyoda's that use them, a few machines are over 30 years old, never had to touch the harmonic drive sections.

Sort of like a harmonic drive that doesn't require the fragile circular spline element. Cool!

@7:05 the screws start to loosen. And that, ladies and gentlemen, is how Harley Davidsons are made.

Excellent work! I hope that students pursuing advanced degrees in mechanical engineering will consider focussing on this concept for their research thesis.

Cool, another gearbox that acts like a cycloidal gearbox. I already have a functioning print of a harmonic drive and a cycloidal drive.

This broke my mind a bit but it is awesome

Now we need a competition with 3D Printing Academy

this would've been a great example for my machine design course

Looks useful for high torque applications, such as driving a winch and spool.

You have amazing skills in explaining things clearly. Well done.

Since the input and output are co-axial I think you could make a cool clock design with this, with a 1rpm input that gives you your minute hand with the input shaft going all the way through to the front and then with a design with a 1:60 reduction then the output wraps around the minute hand and gives you the hour hand and the low speed means that the noise and balance is not so much of an issue

With just a pair of metal worm/gears in series like the ones you showed at the start, you'd get 1600:1. Metal, simpler, stronger, quieter, cheaper, so, ...! Great to explore this kind of stuff, though!

They are very interesting and you have great physics and cad skills

Great work. If you use a much finer gear pitch, the distance of nutation can be reduced greatly, reducing imbalance forces. If you casually look at a harmonic drive, the gear pitch more closely resembles a straight knurl rather than gear teeth.

Interesting variation of the harmonic drive. 👍👍

cool idea. maybe the center gear could be balanced by modulating the infill percentage at least a bit.

Neat. It's a shame that RU-vid is working hard to commit hara-kiri because I'm really going to miss channels like this one.

In practical sense, all tork is on one/ two teeth , balance can be mitigated, nice work thanks for knowledge

Keep in mind, mirroring the gear boxes doubles the gear contact area. 2x the strength, or same strength, half the weight neaded in materials

Maybe good for solar panel tracking because of the slow movement required. Could probably have the gearbox sealed and filled with oil for low maintenance since solar arrays are pretty remote sometimes

i don't know why, but I'm getting a constant velocity joint vibe from it.

That reminds me of how hydraulic pumps and motors work. Frankly, I'm thinking of all the times I wish I had known about this in my special project at work.

Very cool! I have never heard of pericyclic transmissions before

I'm sure the angle for the shaft needs to be big enough for the gear teeth to pass by each other as it spins, but reducing this angle as much as possible will reduce the vibrations as well.

Fascinating. I think that, with a different way of meshing the teeth, the engagement could be gentler, like helical gears, though the vibration will remain an issue.

I think even though it looks like there's a lot of teeth engaging it's still only one at a time. The teeth in front of and behind the one in contact are about to touch but aren't touching yet.

3D printing is showing us so many new systems.

I think that this should technically be backdriveable. The fact that it isn't I think implies that there are inneficiencies in the gear tooth designs. Reminds me a lot of cycloidal gears! I think this idea is very cool and potentially practical!

Thank you for sharing your knowledge on the gearing

These would be great to have in the hubs of each wheel on a vehicle with the proper gear ratio

seems like a fun concept but must be one helluva thing to balance properly

seems like a good application for differential gear

It’s an interesting concept. Have you done a comparison with a traditional gear with the same ratio for friction? I have a feeling the friction may be too high for practical purposes. Adding bearings to the shaft to reduce the friction there was a great idea, but as you mentioned in the video, there are multiple teeth meshing simultaneously instead of just one and that means more friction.

What an interesting little gearbox. Im sure theres a few applications for it

Definitely interesting, but I think the Split Ring Compound Planetary gearbox is a much more useful design. Equally compact, practicality unlimited ratio options, and balanced.

I like this. Still not sure about it vs worm drive but either way I will take the extra arrow for my quiver. The one thing I can say is worm drive vs this has a perpendicular input naturally so this might have some advantage for situations.

Ultra-high gear ratios are not difficult. Three worms, labeled A, B, C. Three 100-tooth gears, labeled 1, 2, 3. Worm A drives gear 1, which is coupled to worm B. Worm B drives gear 2, which is coupled to worm C. Worm C drives gear 3. 1,000,000 to 1. Very compact. Nothing wobbles. Off-the-shelf parts.

There should be a counter balance weight installed to keep the center of mass around the center of rotation.

I think this kind of gearbox is used in some of the electric driven parking brakes in cars (usually at the rear wheels)

Something like this would be perfect for a home telescope.

I want to see it in an enclosed case with gear oil to see if it quites down then put it to its limit!

This is great for high ratio needs.

Very inspiring! Ever considered to make a calender clock this way?

here are planetary gears with high ratios: ---- Ratio: 5310.6 ---- sun1: 106, ring1: 158 diff1: 52, sun2: 110, ring2: 164 diff2: 54, max planets = 15 15, coherent planets: 10 halfDegAB = 17.72727 and 18.39416 ---- Ratio: 3554.626 ---- sun1: 107, ring1: 159 diff1: 52, sun2: 111, ring2: 165 diff2: 54, max planets = 16 16, coherent planets: 10 halfDegAB = 17.59398 and 18.26087 ---- Ratio: 5313.742 ---- sun1: 110, ring1: 164 diff1: 54, sun2: 106, ring2: 158 diff2: 52, max planets = 15 15, coherent planets: 10 halfDegAB = 18.39416 and 17.72727 ---- Ratio: 3557.574 ---- sun1: 111, ring1: 165 diff1: 54, sun2: 107, ring2: 159 diff2: 52, max planets = 16 16, coherent planets: 10 halfDegAB = 18.26087 and 17.59398 i have a planet gear generator which materializes them out of thin air i am checking it it today adn uploading it to thingiverse zoon1234micron soon

I saw a generator that operated on gravity. Just like a pendulum clock, the weight is hoisted up in the day. And at night as (the weight) "slowly" descends, A high gear ratio generator makes power from the potential energy of the big (weight). Only trouble was, no gear could hold all that weight on one tooth. It looks like your gear has solved that problem. ur oh, maybe not. I remember you say your gear, jams up if you try to "back drive" it. And that is exactly what that gravity generator project needs. A slow (rpm) into a fast (rpm)

I had a winch that used a planetary drive but it was unusual, It had the motor connected to the planet gears and no sun gear. It drove between 2 ring gears which had a different number of teeth. One was mounted to the housing the other to the drum.

Excellent job on making this video and explanation. Thank you for sharing with us.

Excellent

The main advantage of a pericyclic gearbox is vey high output torque because several gear teeth are in contact at the same time. Because of its inherent design, we have this vibration problem causing the gearbox to self destruct. The only way to cancel out the vibration is by adding a "mirror image" of the gearbox. But then the output is now in the center of the whole gearbox which leaves us no other option but to use a spur or helical gear which is quite counterintuitive.

Pretty damn cool, but I have to imagine that this would be pretty high wear, no matter how refined it gets. But if it's made with easy to change setup, might be a pretty nice alternative

in praxis you can make the wobblator and its shaft out of 1 part, id opt for a much larger shaft thoug, id go so far to increase its diameter to the point where its just a bit smaller than the inner diameter of the ring. stator

Brilliant, thanks for sharing

This may be the smartest comment section I've ever seen on RU-vid. Congrats! Give yourselves a hand. 👏

I've been addicted to videos of all the various gearing and drive mechanisms , and this is the first of this kind that I've seen! I wonder if these are used in any real products? The geometry doesn't even seem too hard to machine with standard lathes and mills. 🤔

you could make it half the size and 3d print it in metal to get strength and precision . great work!

My husband would understand this. It is interesting. 😊😊👋👋❤❤

Superb! I wonder how well this would work in low speed conditions like bicycle gearing? I’m looking forward to see more. Thanks

How to create a rotor for locomotive, thank you the sound remains

what if those gear tooth are rounded , probably would be much smoother and wouldn't skip since many are engaged at the same time

Increadably high gear wear but good potential. Regards from South Africa

Usefull in the circumstances you don't have access to flexible material for an harmonic drive. Harmonic drive don't have the wobbling of middle gear, much greater ratio and tooth engagement.

That is interesting. In a sense , it looks like a mechanical relative of the planetary gear, or even the differential, If the output is the center and you hold one shaft while spinning the other. Perhaps counterweights in the nutating gear would cure the problem of being out of balance.

I have an idea for a clutch mechanism, that would require a lot of pressure but not a lot of parts.

Sürekli kendini geliştiriyorsun dostum tebrik eder başarılı işler dilerim.

Maybe use a counter weight like in car engines crank shaft to balance the gearbox without adding a mirrored gearbox?

I think this is useful. Perhaps we will see this in microscopic form. Nanogearing.

Wait, even crazier. Make this a mobius strip.

Mechanical engineers are insane

Would be interesting to see how this sounds and operates if it was submerged in a heavy oil.

Try swapping the incoming and outgoing rotation. In order not to slow down the final rotation, but rather to accelerate it. Is it possible to create a propeller based on this transmission mechanism ? For example, for "pedal catamarans".

Huh, this is kind of like strain wave gearing but without the strain

I feel like you could mechanically tether a counterweight to be driven by the same motor to oscillate at the same speed.

This looks similar to the vibration motor mechanisms used in optical lenses

I could make that gear/axis ofset blindfolded if I wanted to

Could be great in a clock escapement.

Might have a use in gear reduction socket drivers unless planet gears are still better.

I think you should make a robot that walks like an insect with this gearbox.

i love energy converters, does it gets hot? i like my ECs cool and chill.

Would it be possible to play with the weight distribution of the wobbling gear to make it stable? I guess that might be more dependent on manufacturing quality compared to adding a mirrored gear, but at least it would only be one unit

Интересная штука. К сожалению, технологически сложная, вряд ли получится сделать редутор использующий этот принцип в домашних условиях. Подшипники можно попробовать игольчатые и конические на концах. Впрочем, подъем гантели впечетлил😊

it looks interesting, i would like to see it build like an elektrik high tourq rewnch like the used for automotive for example

Welded instead of screws and build a mining drill from it

I wonder if you can scale that down to be used in something like a model train locomotive? It could give it true scale speed operation smoothly.

Omg this is exactly what I need