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KnifeEdge_2K1
06-25-2004, 10:09 AM
how many types of CVTs are there, i only know of one

the engine and output gear are connected through 2 gears which are perpendicular to the previously mentioned 2

Engine]>[output = high gear
Engine]<[output = low gear
Engine]=[output = 1:1

Matra et Alpine
06-25-2004, 11:08 AM
how many types of CVTs are there, i only know of one

the engine and output gear are connected through 2 gears which are perpendicular to the previously mentioned 2

Engine]>[output = high gear
Engine]<[output = low gear
Engine]=[output = 1:1
CVT == Continuously Variable Transmission

It's not about selecting one gear or another.
Original DAF CVT used a rubber band and two pulleys each with a sliding wection to vary the pulley size. So it can be varied from small driving large all the way to large driving small.
Latest CVTs have added 'computer control' so that it does the movement in steps and sounds like a 'real' gearbox.
Driving a real CVT is strange - you put it in gear, push the throttle and the engine revs to steady state and then the car accelerates. No matter how much faster you go as you accelerate the engine note doesn't change.
"Man in the street" doesn't like that so modern CVT's have the computer select power 'bands'.
Modern CVTs still use belts and cone-pulleys as far as I know.
There's been some talk of some Ford/Mazda patent on using fluids between plates, but not seen anything produced.

EDIT: THought I'd posted this already, but stoopid UCP search won't accept DAF asyign it's too short. DUH !!! So I'll post them again. This is a picture of an F3 race car built using DAF CVT transmission technology in the 60s. You can clearly see the band and the 2 pulleys and how the connect - and hopefully how they work :)

henk4
06-25-2004, 01:19 PM
EDIT: THought I'd posted this already, but stoopid UCP search won't accept DAF asyign it's too short. DUH !!! So I'll post them again. This is a picture of an F3 race car built using DAF CVT transmission technology in the 60s. You can clearly see the band and the 2 pulleys and how the connect - and hopefully how they work :)

I think I also posted this earlier but this is certainly the only formula car that can go as fast forwards as backwards (as long as steering geometry allows)

Matra et Alpine
06-25-2004, 04:49 PM
In helping GTR Dreamer I was on-line to the patent office
( it's part of my job. Anyone up for the challenge ... find my patent :) )

Here's the original DAF patent on CVT and it has diagrams and description ( but in legalise patent speak ) taht will explain how it works...

http://patimg1.uspto.gov/.piw?Docid=03052132&homeurl=http%3A%2F%2Fpatft.uspto.gov%2Fnetacgi%2Fn ph-Parser%3FSect2%3DPTO1%2526Sect2%3DHITOFF%2526p%3D1 %2526u%3D%25252Fnetahtml%25252Fsearch-bool.html%2526r%3D1%2526f%3DG%2526l%3D50%2526d%3DP ALL%2526S1%3D3052132.WKU.%2526OS%3DPN%2F3052132%25 26RS%3DPN%2F3052132&PageNum=&Rtype=&SectionNum=&idkey=1E86D45B4AFD