CVT TRANSMISSIONS?

BAGTIC · Jul 14, 2007

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 · Jul 14, 2007

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

john_bud · Jul 17, 2007

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

Z-Michigan · Jul 17, 2007

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 · Jul 17, 2007

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 · Jul 17, 2007

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 · Jul 18, 2007

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 · Jul 18, 2007

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

Buck

RFB · Jul 18, 2007

Buck,

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

gamble77 · Jul 19, 2007

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

EFC · Jul 19, 2007

They call it the ZF transmission. It is available on all Agrotron models. Profiline is also an option for that transmission which will automatically vary output speed for load matching. Your right that the TTV is the only true step less model ZF but I have not been able to feel the steps on the regular ZF especially with load matching turned on.

Buck

Grrrr · Jul 19, 2007

I dont know of any tractors that have a CVT under 100hp but one of our neighbours has just taken delivery of a JD 6430 with AutoPower and it sure is a nice tractor

Woodbeef · Jul 21, 2007

EFC said:
They call it the ZF transmission. It is available on all Agrotron models. Profiline is also an option for that transmission which will automatically vary output speed for load matching. Your right that the TTV is the only true step less model ZF but I have not been able to feel the steps on the regular ZF especially with load matching turned on.

Buck

Hey Buck,got any pics of these shiftless Agrotrons by anychance? I'd like to see them.

The ones using the ZF EECOM II are the only cvt equipped tractors. The Agrotrons use a ZF/STEYR tranny/rearend......emphasis on the STEYR part.

EFC · Jul 27, 2007

shiftless?

Grrrr · Jul 27, 2007

EFC said:
shiftless?

They are like hydrostatics but don't work like hydros. They use gears or belts or a combination of things to provide variable speed from 0 upwards. You never have to change gear, the transmission does it for you. The transmission also never disengages power to the wheels.

This is Deeres system

John Deere : Infinitely Variable Transmission (IVT&#8482)

Woodbeef · Jul 29, 2007

EFC said:
shiftless?

= same as being CVT equipped

EFC · Jul 31, 2007

I understand what shiftless means I was just wondering where I said "shiftless" since you asked to see a "shiftless" Deutz.

Buck

BAGTIC · Aug 10, 2007

I found the Fendt site.

I wish I had a rich German uncle about to croak.

Those CVT Fendt Varios are the most impressive tractors I have ever seen.

Front AND rear quick attack connections.

Front AND rear PTO, 3 and 4 speed PTOs including ground contact rate regulated PTO.

Two stage serial hydraulic pumps.

Hydraulic controls for front AND rear mounted equipment.

Engine AND cab maintenance access with the loaders still attached.

Cruise control.

Speed range from 100 feet per hour to 32 miles per hour without shifting.