Machinery giant Case IH is set to introduce a new Quadtrac CVX line-up, bringing its continuously-variable transmission (CVT) to its big tracked, articulated tractors for the first time.
In fact, says Case IH, this is the first time that high-horsepower, articulated, tracked tractors of any brand will be offered with stepless transmissions. While obviously of limited relevance to Ireland (given the size of these machines), this development is indicative of the broader increase in the popularity of CVT technology.
Three new Case IH Quadtrac CVX models will now complement the existing line of five units – the latter having standard powershift transmissions.
The new so-called CVXDrive transmission offers stepless travel from standstill up to 40kph and can be programmed to work at a desired forward speed or a set engine speed. ‘Automatic Productivity Management’ software can then adjust the engine and transmission accordingly.
Hans-Werner Eder, Case IH Quadtrac Product Marketing Manager, explained: “At 613hp [peak], the 540 CVX, which is the flagship in the Quadtrac CVX range, offers the highest available power of any CVT tractor.”
The other models in the range are the Quadtrac 500 CVX and Quadtrac 470 CVX, which have respective maximum power outputs of 558hp and 525hp.
Quadtrac CVX tractors are powered by electronically-controlled 12.9L Cursor 13 6-cylinder engines from sister company FPT Industrial, with a single-stage turbocharger on the two smaller tractors and a two-stage turbocharger in the 540 model. On this tractor, the smaller turbocharger is designed to deliver “low rpm responsiveness”, while the second, larger unit provides “maximum boost at high rpm”.
On the 540 CVX, rated power (ECE R120 2) is 543hp, while Engine Power Management – introduced under load – takes this to 598hp – both measured at 2,100rpm rated engine speed.
Maximum power of 613hp is achieved at 1,900rpm, and maximum torque of 2,607Nm at 1,400rpm. The tractor has a diesel capacity of 1,230L and a DEF (AdBlue) tank that holds 322L.
Inside the transmission
The stepless transmission features four mechanical ranges, with automated changing between each. Four multi-plate wet (hydraulic) clutch-packs, mounted on the four planetary gear-sets, change the ranges; equal clutch speeds are intended to smoothen out ‘shifts’ and reduce wear.
The hydrostatic pump and hydrostatic motor are effectively a single unit, with no high-pressure pipes between the pump and motor. A variable-displacement swash-plate on the pump facilitates different speeds and allows the fixed hydrostatic motor to be operated in both directions.
An example of this is the Active Hold Control feature, where the hydrostatic motor eliminates the input speed from the engine.
Asking price
Depending on model, the CVT option is likely to cost €30,000-40,000 more than a ‘standard’ powershift-equipped Quadtrac.
