VARIABLE RATIO TRANSMISSIONS

[Luke101]

Do they exist? if so, where can i find info on them? THANX!!

 

[MintJulep]

I will assume that you mean "continuously variable transmission", as opposed to a descretely variable one.

Yes, they exist.

A search on Google for "continuously variable transmission" yeilds a bunch of hits.

 

[okeng]

Do a little checking on the Fendt Vario ag tractor. They use a fairly old idea (which they claim to have thunk up all on their own) that uses a hydrostatic pump/motor system to drive/hold/backdrive the fixed member of a planetary gear. I've also seen it used on the General Dynamics F-16 fighter generator drive gearbox (mfg by sundstrand), the toyota prion hybrid car, and a really neat SAE challenge pulling tractor built by the Okla. State U. ag engineering guys.

I think Fendt's literature or website has a nice, clear explanation of it.

As MintJulep says, there's lots of info out there on the subject.

Jess Davis
davisprecisiondesign.com

 

[stanking]

Try MagnaDrive Corp, How about permanent magnets with an adjustable gap allowing a turn down ratio of 100%!! feedback loop to allow any set point or constantly variable speed you want. Built in soft start capability. It is variable gap between permanent magnets and copper plate. Magnet induces current and thus opposing magnet. I have one installed on 125 hp motor driving knife hog. ABove a cetain torque it is designed to separate plates and belt feed stops, motor is uncoupled and continues to run. No motor trip with plugged hog!

Larger sizes more economical that freq drive and no dirty current added to mill like freq drive does.

It would make a very interesting car transmission.

10n hp to 1000 hp - it is an incredibly fascinating device.