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The Case IH Quadtrac and Steiger CVX range are the first high-horsepower articulated tracked tractors available with CVT technology. The flagship 540 CVX is shown in action. (image: Case IH)

Case IH Quadtrac CVX the first articulated tracked tractor to offer a CVT

The most significant upgrade to Case IH’s Quadtrac and Steiger articulated tracked tractors for 2018 is a new CVXDrive transmission supplied by ZF, the first such application of a continuously-variable transmission (CVT) in the segment, the company claims. CVT development for Case IH’s mid-power tractors dates back 17 years; the company decided that now is the right time to bring the technology and its benefits to the top end of the tractor market.

A range of three Case IH Quadtrac CVX models—470, 500 and 540 CVX—will complement the existing line of five models with the standard powershift transmission. The CVT—a ZF ECCOM 6.0 transmission—is also available on five Steiger models: the 370, 420, 470, 500 and 540. The new machines had a prominent spot in Case IH’s booth at the recent Agritechnica event in Hanover, Germany.

“At 613 peak horsepower, the 540 CVX, which is the flagship in the Quadtrac CVX range, offers the highest available power of any CVT tractor,” Vincent Hazenberg, product marketing director for Case IH in Europe, Middle East and Africa, said during a pre-Agritechnica demonstration for media of the tractor’s performance on a farm in Slovakia.

Quadtrac CVX tractors are powered by an electronically-controlled 12.9-L Cursor 13 six-cylinder engine 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 the 540 CVX, the smaller turbocharger delivers low-rpm responsiveness, while the second, larger unit provides maximum boost at high rpm. Each turbocharger has its own cooling system to provide 30% faster response under load.

Maximum power is achieved at 1900 rpm, and maximum torque of 2607 N·m (1923 lb·ft) at 1400 rpm. The tractor has a diesel capacity of 1230 L (325 gal) and a DEF (AdBlue) tank that holds 322 L (85 gal).

The Quadtrac 470 CVX and 500 CVX have respective maximum power outputs of 525 hp and 558 hp.

The FPT engineering team adapts the engine setting to suit the CVT’s attributes, said Diego Rotti, product marketing manager for off-road engines at FPT Industrial. “There is some tailoring in the engine, and it depends on the application,” he explained. “The matching of engine performance with CVT’s gear management is optimized, because torque output needs to be adapted compared to the standard stepped transmission.”

The engines meet Stage IV/Tier 4 Final emissions legislation through the use of the Hi-eSCR system, which is a maintenance-free SCR-only solution. To meet Stage V limits, coming in 2019 or 2020 depending on power range, FPT Industrial decided not to just add a diesel particulate filter (DPF) to its current solution. Instead, its second-generation Hi-eSCR2 will integrate a particulate filter into the SCR unit with no change in layout or volume, according to Rotti. Moreover, the system will still be for life and regeneration-free, as with the current Stage IV/Tier 4 Final technology, he added.

On the Quadtrac and Steiger tractors, there is “basically no difference” between EU and U.S. market products, according to Hans-Werner Eder, Quadtrac product marketing manager. The only differences for Europe are road lights, decals and signs are according to EU law, he said.

CVT details

The CVXDrive transmission in the Quadtrac 470, 500 and 540 CVX models offers a number of benefits that result in increased productivity with faster cycle times and maximum fuel efficiency, according to Hazenberg. Ease-of-use particularly for inexperienced operators is one of those benefits, as is reduced operator fatigue. Performance enhancements include faster acceleration to field or road speed, full power availability at low ground speeds for special applications/implements, and full hydraulic flow availability at low ground speeds, for applications such as drilling/planting.

Providing stepless travel from standstill up to 40 km/h (25 mph), and 0-18 km/h (11 mph) in reverse, CVXDrive allows three target speeds to be stored, adjustable via the thumbwheel and buttons on the armrest-mounted Multicontroller. The transmission incorporates a kick-down feature that ensures maximum acceleration, and 40 km/h is achieved at just 1640 rpm.

The CVT features four mechanical ranges, with automated range-changing under full draft load. The first time 100% mechanical power transfer takes place is below 10 km/h (6 mph), matching heavy draft application requirements. Four multi-plate wet clutch packs, mounted on the four planetary gear sets, change the ranges without power interruption, with equal clutch speeds guaranteeing smooth shifting without clutch wear.

The hydrostatic pump and hydrostatic motor are a single unit, with no high-pressure pipes between pump and motor. A variable swash plate on the pump creates different speeds and allows the fixed hydrostatic motor to be operated in both directions. An example of this is the Active Hold Control (AHC) feature, where the hydrostatic motor eliminates the input speed from the engine. AHC allows the tractor to remain static when stopped on a hill, without the operator applying the foot or hand brake. The park brake is automatically applied after 45 seconds.

In place of the foot throttle found on tractors with the powershift transmission, Quadtrac CVX models are fitted with a drive pedal that controls the tractor’s ground speed when in automatic mode. In manual mode, the foot pedal acts as a conventional foot throttle. The Multicontroller also incorporates a power shuttle switch, which works in parallel with the shuttle lever on the left of the steering column, for direction changes without releasing the steering wheel. The Eco Drive dual-hand throttle allows the setting of minimum and maximum engine speeds to minimize fuel use, and the engine droop function, which determines the engine speed down to which the rpm can drop under load.

“CVX can bring a wide range of engine, fuel and work advantages to Quadtrac owners’ businesses,” said Eder. “They include reduced engine speed to optimize fuel efficiency, and, for those operating PTO-powered equipment, enhanced operation through the achievement of uninterrupted peak power via stepless speed progression.”

Operating systems and in-cab updates

One of the key operating systems for Quadtrac CVX tractors is Automatic Productivity Management (APM), which is designed to ensure the most efficient operation of the machine, whether the operator or owner’s target is minimum fuel use or maximum output.

APM coordinates the engine and transmission with the Multicontroller and drive pedal, automatically reducing engine speed to the minimum required for the tractor’s workload. The tractor can also be operated in manual mode, without APM, with the transmission controlled via the Multicontroller and the engine speed via the foot or hand throttle.

The variable displacement pump that supplies the key hydraulic requirements is a pressure- and flow-compensating type, providing 216 L/min (57 gal/min) of oil flow (with 428 L/min [113 gal/min] an option). The system operates at a pressure of 210 bar (3045 psi), supplying up to eight remote valves. The valves and the 8949-kg-capacity rear linkage are controlled electronically via the Multicontroller armrest.

Introduction of the CVXDrive transmission prompted a few new features to be added to the established Surveyor cab. The slightly-revised Multicontroller armrest incorporates the dual throttle for minimum/maximum speed settings, and a slightly different Multicontroller joystick is better suited to the operation of the CVT.

Information is still displayed in Case IH’s pillar display in the right-hand A-post. This shows engine speed, transmission forward and reverse target speeds, currently-engaged target speed, actual ground speed, a park brake/neutral/forward/reverse indicator, and which speed will be selected if the direction is reversed. Also shown on the display are the fuel and DEF tank levels.

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