Is it possible to have an infinite number of gear ratios?

Planetary gearboxes are incredibly satisfying. This 3d printed planetary gearbox shows how in combination with a standard combustion engine it is possible to create an infinite number of "gear ratios / transmission speeds".

Enjoy!
-Steven

Designs and STL files available for my Patrons supporters:

Electric Motors and Speed Controller:

Thanks!

#3dprinted #gearbox #cvt #planetgears #satisfying

[themeek]

I'm curious to know what the torque loads would be on the ring gear and electric motor during peak power demands!

[AstonishingStudios]

Learning that there can be infinite gear ratios just unlocked human superintelligence for me.

[ohytheawesome]

D-CVT (Direct-Shift Continuously Variable Transmission) has infinite gear ratios too, but uses belts instead for variable transmission and can switch to manual transmission for lower gears.

[matpidrums]

this is actually a really cool way of making a cvt that i hadn't considered. traditional belt driven cvt's have the potential to slip which is not good to say the least, and this gets rid of the problem by using gears and i think it's really cool

[Hogger]

Yes, used in Prius - engine connected to the ring gear, wheels to the planet carrier and motor/generator/starter connected to the sun gear.

[tigerxra]

Yeah, planetary gear is a key to hybrid cars, tractor cvt's (like Fendt Vario). This gear can add two different a speed and torque engines to a single output shaft, without a conflict. I had a class about transmissions and planetary gear blew my mind. It has such a great potential.

[Alxium]

This whole system seems like it is wasting an enormous amount of energy to just stand still. The engine is running at peak performance at thousands of RPMs while the electric motor is spinning the gear to keep the axle stationary. It would make more sense to just drive the wheels with the electric motor and power that with batteries that can be charged by the grid or an onboard ICE. To be 100% honest, taking an ICE out of the equation would increase energy efficiency by a lot as there is so much energy loss in all the moving components vs a direct or close to direct drive electric motor.

[dutchsailor]

Since action is reaction, you would need a lot of energy from the electric motor to get a decent amount of energy on the output shaft. The outer "stationary" (I know its not in this model) gear has to counteract the the forces applied by the planetary gears. The more torque you need on the output shaft, the more power the electric motor has to deliver.

[MrT------]

It seems to me, having an internal combustion engine only keeping batteries charged and having an electric motor driving the vehicle would be simpler and the motor would only need to run when the batteries are discharged and needs recharging. You wouldn't need any transmission at all or an engine big enough to drive the car, just enough to keep the batteries charged.

The system in the video, as you sit at a stop light waiting to go, the engine would be running at its optimal speed (thousands of RPM's potentially) and your not moving. Sitting there burning a lot more gas than traditional engines would be doing at idle.

[equinox]

I have 0 knowledge about engines or gears but the way you explained it actually made sense, thanks you for this video it was very entertaining 💪🏽🗿

[yngndrw.]

I believe a mechanism like this is used in some tanks, although the electric motor is used to control the difference in speed between the left and right treads rather than the overall speed.

[wizrom]

This concept has been around for a long time.
The BIG problem is that at low speeds the electric motor has to ABSORB power, so (for example) if the main engine is making 100 hp and you want a slow RPM 10 hp at the wheels the electric motor needs to absorb 90 hp and dissipate it as heat (or maybe charge a battery).
So yes, you can create a speed differential but it also causes a power differential.
It can still be useful for some specialty super-low RPM tasks like cranes and tractors but it is poor for cars compared to something like a conventional gearbox.

[dancoulson]

The issue is that now we need two engines, and to be able to vary the speed of the second one...
The second engine needs to be equally as strong as the first, or any resistance on the output shaft will simply cause the weaker force to stop or even rotate backwards.
This is just the same as using a differential in reverse...
By spinning both wheels in opposite directions at the same speed you can have a stationary drive shaft.

[ericgolub]

If I’m not mistaken, won’t the torque of the output be reduced when the motor and the engine are rotating against each other?

[kotelypiesely]

Fendt's Vario heavy-duty transmission, used in tractors, ditches the electric motor and substitutes it with a variable angle hydraulic pumps

[daarshg]

I am a huge fan of your videos. Precise and clear, very informative, and still no information overload !!

[dnorby]

The thing is that the electric motor has to be the same power as the internal combustion one because has to hold the double ring gear spinning to keep spining the output and thats hard to make small and compact so it s intresting but does not make that much sense. because its very difficult.

[gunnerpetrea]

If you spin the electric motor in reverse that would cause the output speed to increase correct?

[jespermller]

But how much power do you need for the electric motor compared to the internal combustion engine?
What does the graph look like but this setup?

[QualityDoggo]

very cool stuff. combines the common/dense/simple fuel-powered-engine with electronically controlled motors, without actually driving the car using a motor. Wonder how the efficiency compares to regular and "hybrid" cars.

Of course... these days another option for "no abrupt changes" is a full-electric system... assuming the car has enough battery power onboard.