Interesting CVT transmission patent

[greycloud]

Hi

I was online reading about CVT types and stumbled upon attached Patent application for a unique CVT idea from 1983!

it looks feasible but I don't seem to find any actual application for it. This is surprising as it seems to solve common problem with current CVTs especially regarding high torque handling.

anyone has any idea why such idea wasn't adopted in the automotive or heavy equipment industries?

below is link to patent for anyone interested

EP0108577A1 - Power transmission apparatus - Google Patents

Power transmission apparatus for driving an output shaft (3) from an input shaft (2) comprising a fluid cylinder (36) secured to the output shaft (3) and a piston (35) slidably mounted in the cylinder. The piston (35) is driven in reciprocal movement in the cylinder (36) in response to rotation...

patents.google.com

 

[XR250]

Probably way too inefficient for automobile use. Maybe could be used in heavy equipment but I suppose current hydrostatic transmissions are adequate enough.

 

[BrianPetersen]

This sounds suspiciously like a Honda motorcycle CVT transmission from some years ago: https://global.honda/en/newsroom/news/2007/2071004-eng.html

Back when this was introduced to the market, it showed up in a peculiar model called the DN01. Friend of mine worked in a Honda powersports dealer at the time. They joked that those initials (well, close enough ...) stood for "do not order one" ... It was a failure in the marketplace, and Honda has not followed it up in other models.

Honda now builds some models with a dual-clutch-automatic, and others with automated manual layouts, but not that hydraulic CVT.

 

[greycloud]

This sounds suspiciously like a Honda motorcycle CVT transmission from some years ago: https://global.honda/en/newsroom/news/2007/2071004-eng.html

Back when this was introduced to the market, it showed up in a peculiar model called the DN01. Friend of mine worked in a Honda powersports dealer at the time. They joked that those initials (well, close enough ...) stood for "do not order one" ... It was a failure in the marketplace, and Honda has not followed it up in other models.

Honda now builds some models with a dual-clutch-automatic, and others with automated manual layouts, but not that hydraulic CVT.

that indeed looks very similar indeed! any idea what was the problem with such transmission?

 

[greycloud]

Probably way too inefficient for automobile use. Maybe could be used in heavy equipment but I suppose current hydrostatic transmissions are adequate enough.

why do you think it would be inefficient?