CVT TRANSMISSIONS?

[BAGTIC]

Does anyone have an over 50 hp tractor with a CVT transmission? What is your experience with the CVT transmission?

The smallest farm tractors I have seen advertised with CVT are 100 hp which is a little too big for me. I would probably be looking at something in the 50-70 hp class. Does anyone know of a tractor with CVT in that approximate size range?

 

[JerryG]

The Fendt 400 series has a CVT starting at 72 PTO HP.

 

[john_bud]

So, what are the true advantages of CVT over HST? Just more efficient?

 

[Z-Michigan]

Should be more efficient, not overheat, and not require any manual gear ranges separate from the CVT.

I for one would be quite happy if someone would put a HST on a true utility tractor (heavy frame, planetary final drive) in the 50-60hp range with a cab. That's about what I wish I had right now. I guess the JD4720 isn't too far from that, or maybe the Kubota L5940, but I'd rather see it on a utility frame.

 

[jovialjeeper]

The CVT transmissions I've seen in the larger (100+hp) tractors usually send power through a combination of a hydrostatic and a mechanical (through planetarys) transmission. The advantage is that you can split the power so that only a portion is going through the hydro and thus you limit the power loss and heat buildup, but you gain the variable speed. One design had an initial planetary set with the ring gear driven by the engine and the sun driven by the hydro. The difference in their speeds (and hydro direction) resulted in the planetaries and their carrier providing a complete range and direction of resultant speeds. The controls on the system allowed the selection of modes for efficiency or power. In power mode, when you step on the peddle, the engine revs to the high point on its torque curve and maintains that speed and then the hydro takes over to vary the ground speed. In fuel effiecient mode, the engine would follow its fuel map trying to maintain the best operating point while meeting the ground speed desired.

I don't know of any small tractors that would have a CVT. Cost is the biggest factor. Hydro's are the closest thing.

 

[Woodbeef]

Only thing I know of besides the Fendt 300 and 400 series is the Ergos from Claas. But it is a hydro tractor not CVT.

 

[RFB]

The Massey Ferguson MF 7465 (95 pto hp) Dyna-VT transmission with infinite speed selection from 0-31 mph

Agco RT110a (110 pto hp) PowerMaxx CVT (continuously variable transmission) provides maximum efficiency through infinite speed selections between 0 and 32 mph

Challenger MT525B (100 pto hp) TechStar CVT (continuously variable transmission) provides the operator with stepless, infinite control

 

[EFC]

Deutz has the CVT in the 90hp through 265hp machines.

Buck

 

[RFB]

Buck,

Do you have a link for that? I can only find the Deutz Agrotron TTV 1145.

 

[gamble77]

Deere uses much the same setup in their 6030 series and up, they call it IVT.