Yanmar Tractors

[ptsg]

This is where I get lost understanding it the concept of this.


Well said, it seems like this design would be superior to straight hydrostat but if so why is Yanmar is the only manufacturer using it?

If there is anyone who has a YT347 or YT359 I would like to know what your experience has been with this transmission.

Search about Vario transmissions and you'll get some nice animations and explanations of it working, mostly from Fendt. Haven't found any good explanations from Yanmar yet.

As far as why it's not used more on smaller tractors is mainly because this transmission is crazy expensive, super complex and again, crazy expensive to repair as well. Compare the cost of an Yanmar with the iMHT to one with either a shuttle transmission or the HST.

However, I suspect in the future we might see more of these style of transmission on smaller tractors.

 

[Cahaba Valley Farm]

As far as why it's not used more on smaller tractors is mainly because this transmission is crazy expensive, super complex and again, crazy expensive to repair as well. Compare the cost of an Yanmar with the iMHT to one with either a shuttle transmission or the HST.

That's what I suspected. The verdict is also out as to how reliable this design will be in the long run.

 

[airbiscuit]

The 250,000th Fendt Vario transmission unit rolled off the production line at the company’s German factory on Sunday, November 27.

Now every tractor that is manufactured at the factory in Marktoberdorf, in the south of Germany, is fitted with the Vario transmission.

Fendt first began using the Vario transmission 20 years ago, when the manufacturer first began production of the Fendt 926 Vario in 1996.

The stepless Vario transmission remains the only transmission solution for Fendt, according to CEO of AGCO/Fendt Peter-Josef Paffen.

At the time we consciously opted for this innovative technology and started implementing it almost right away in every range and power level.

“We now offer the solution for every power band, from 50 to 500 horsepower. Whatever the operation, the customer can always carry out their work at the right speed,” he said.

 

[ptsg]

That's what I suspected. The verdict is also out as to how reliable this design will be in the long run.

The Fendt Vario ones are fairly reliable. One thing that does kill those transmissions quite fast is when the operator uses the transmission to slow down the tractor, instead of the brakes. That's very hard on the transmission, specially pulling loaded tanker trailers when all that load tries to shift forward.

 

[Cahaba Valley Farm]

The Fendt Vario ones are fairly reliable. One thing that does kill those transmissions quite fast is when the operator uses the transmission to slow down the tractor, instead of the brakes. That's very hard on the transmission, specially pulling loaded tanker trailers when all that load tries to shift forward.

So you're saying that type of transmission is no good for engine braking.

 

[ptsg]

So you're saying that type of transmission is no good for engine braking.

It is good for engine braking, just have to be used properly. The way that transmission works, you can actually force the tractor. Compared to just slowing down by engine braking like on a shuttle transmission or a manual on a car or truck.

Using the transmission entirely as a brake, is what hurts it over time.

 

[rScotty]

So you're saying that type of transmission is no good for engine braking.

I think that it would be a mistake to over generalize. What ptsg appears to be saying is that the variable ratio type transmission he is familiar with - the Vario used by Fendt - requires special care when used for engine braking.

That may or may not have anything to do with Yanmar's design for a variable ratio transmission. Yanmar is known for high quality and for coming up with innovations that work. It's a huge company with a lot of in-house resources.

rScotty

 

[ptsg]

I think that it would be a mistake to over generalize. What ptsg appears to be saying is that the transmission he is familiar with - the Vario used by Fendt - requires special care when used for engine braking.

That may or may not have anything to do with Yanmar's design for a variable ratio transmission. Yanmar is known for high quality and for coming up with innovations that work well. It's a huge company with a lot of in-house resources.

rScotty

What I said applies to any Vario transmission and mainly applies when pulling heavily loaded trailers. That's a lot of mass for that HST inside the transmission to handle. Just engine braking is perfectly fine as long as you're not forcing the transmission to stop the entire load, which you can do with one of those transmissions.

I suspect this won't be a problem at all on Yanmar tractors in the US, since pulling loads with smaller tractors doesn't really happen all that much.

Yanmar's transmission is nothing innovative and it's been used for a long time on Fendt tractors as shown in post #54. Yanmar simply scaled it down to fit their small tractors. On Yanmar Europe website, they even call it Vario transmission to make it clearer.

 

[rScotty]

What I said applies to any Vario transmission and mainly applies when pulling heavily loaded trailers. That's a lot of mass for that HST inside the transmission to handle. Just engine braking is perfectly fine as long as you're not forcing the transmission to stop the entire load, which you can do with one of those transmissions.

I suspect this won't be a problem at all on Yanmar tractors in the US, since pulling loads with smaller tractors doesn't really happen all that much.

Yanmar's transmission is nothing innovative and it's been used for a long time on Fendt tractors as shown in post #54. Yanmar simply scaled it down to fit their small tractors. On Yanmar Europe website, they even call it Vario transmission to make it clearer.

Yes, the variable ratio transmission has been around a long time. in simpler form, it was used on on old single speed motor scooters from the 1950s.

 

[Cahaba Valley Farm]

Guys you blow me away some times with what you know. I couldn't find a dealer that knew anything about them.