Cummins, Cat work together on Versatile

It’s unusual to see two head-on competitors co-operate on a joint project in the sometimes-hostile world of ag implement manufacturing.

But that’s what happened last year when Cummins mated its latest engine technology to Caterpillar’s latest transmission technology.

Although Cummins and Cat are direct competitors in many machinery markets, they joined forces to provide the new Versatile tractors with the most efficient power and drive train package possible.

Cummins has provided Versatile with engines since 1966. Cat began providing Versatile with its popular TA-22 power shift transmission in 2007.

When Versatile realized three years ago it could not meet the new Tier 4 standards with its existing 4×4 platforms, the company called on Cummins and Cat to work together with Versatile engineers.

Their objective was to make the engine and transmission talk to each other to extract maximum performance from both components.

“This Cummins/Cat partnership is a unique situation, for sure,” said Wayne Goris of Caterpillar’s agricultural applications division.

“But there are no high level corporate problems. We’re both learning a lot working together on this project, and Versatile gets a better tractor out of the deal. The Cummins engines are J1939 protocol and that’s what our ECMs speak. So we’ve gained a lot doing integration development with Cummins.”

Goris said the conversation between a diesel engine and a heavy-duty transmission means the transmission senses the engine’s load, r.p.m. and torque level.

The Powershift ECM reads this data continuously, making instantaneous decisions that go through the electronic control, pressure control (ECPC) valve.

It’s always determining whether it should up shift, down shift or maintain the status quo. It can go one gear up or one gear down seamlessly without a break in torque.

Goris said the ECM can tell immediately when r.p.m. starts to drop and torque output starts to rise. It knows it’s time to shift when it hits that point in the curve.

“It shifts so smoothly because we always have two clutches engaged for every gear,” Goris said.

“When it’s time to shift, we drop one clutch off in a millisecond and put the next clutch on in a millisecond. It works that way shifting up or down. If you’re shifting a manual transmission, you’ve got to clutch, slow those shafts down, make the shift and reengage the clutch. It’s never smooth.”

He said there have been no Cat transmission failures in the five years they have been going into Versatile tractors.

“We like to think these TA-19 and TA-22 transmissions will be good for 10,000 hours or more.”

The TA-19 is optional in the Versatile 350, 375 and 400. The TA-22 is optional in the Versatile 450 and the only transmission available in the 500 and 550.

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There are surprises the first time a new QSX-powered Versatile is started: no diesel odour, smoke or noise.

In fact, one of the new tractors recently sat idling in the main exhibition hall at the Winnipeg Convention Centre for a half hour after security said it must be turned off. Nobody noticed it was still running.

When the tractor was fired up again later that day for the official debut, many of the Versatile dealers and customers in the hall didn’t even notice it Wth no smoke and no smell, and it meets all the Tier 4 interim criteria.

Although industry and diesel customers have complained bitterly about emission standards imposed over the years, the latest QSX engines prove that the standards have tangible benefits for end users.

Not only are the QSX Tier 4i engines quieter and less odorous, but they can burn B20 and make more power per unit of fuel, according to Cummins representative Nick Ciavarro.

“Diesel engine manufacturers are required to meet Tier 4 interim. That forced us to really focus on the upgrade of our technology. Tier 4 interim forced a total re-think. It’s not just an extension of Tier 2 and 3.

“As a result, we have the new high powered 2250 ECM (engine control module), the exhaust gas recirculation (EGR) process, variable geometry turbo (VGT) and the diesel particulate filter (DPF).

“So, the Tier 4 interim has been a very good thing for us at Cummins.”

However, Ciavarro said it’s not easy making all these high-tech systems function at their optimal level when mated to a new transmission installed in a new tractor.

“When we deliver something like a 50 or 60 percent torque rise, our tech guys have to work pretty closely with the Cat transmission guys and the Versatile guys so we know it all works as a package.”

Ciavarro said it took a lot of intense fine-tuning and co-operation, but it wasn’t all dyno work and sitting in front of a computer screen.

“It was long underwear, snowmobile suits and frozen fingers. We spent January, February and March out at the Versatile test site south of Winnipeg.”

Cummins, Cat and Versatile engineers burned the midnight oil, putting as many hours as they could on the tractors, pulling load carts and running tests.

“We were tuning the engine and transmission so they could talk to each other without glitches,” Ciavarro said. “It was basically polishing and perfecting our Tier 4 interim to match the transmission and the tractor.”

QSX 11.9 Tier 4i engines go into the new 350, 375 and 400 tractors, while the larger QSX 15 Tier 4i engines go into the new 450, 500 and 550 tractors.

Ciavarro said DPF is one of the most significant technological breakthroughs prompted by the new emission standards. It requires no urea additives and provides 99 percent passive regeneration in normal work conditions.

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“We use heat from the combustion chamber to break down the particulate material to the point that the exhaust is putting out only carbon dioxide, carbon monoxide, nitrogen and water. No particles and no smoke.”

He said the EGR and DPF must work together. Exhaust is recycled back into the combustion chambers to burn off more nitrous oxide, which reduces the workload on the DPF and uses a continuous catalytic reaction to burn off remaining particles.

“If you do the kind of heavy work these tractors are designed for, you will definitely create enough heat and exhaust flow to regenerate the DPF system automatically.

“But, at idle and low duty cycles, the engine doesn’t generate enough heat for passive regeneration. In that case, you simply press the DPF button and wait 30 or 40 minutes for the system to regenerate itself.”

Maintenance comes at 6,000 hours, at which point the DPF must be dismantled and the centre section brought to a Cummins service centre to have ash blown out.

The DPF will not perform as designed unless the operator changes oil every 500 hours and uses only low ash CJ4 oil. Fuel should be only low sulfur diesel with a maximum of 15 parts per million of sulfur.

Ciavarro said the VGT can change the term ratio of the turbine to match the workload.

“The VGT can act like a smaller turbine than it really is so it spools up quicker. That gives better transient response and load acceptance.”

He said that in automotive language, it’s like turbo lag and throttle response. VGT virtually eliminates turbo lag and provides instant throttle response.

“At the high end, we really open up the VGT to move a huge volume of air through that engine. The 550 engine goes to 590 h.p. on the power bulge. That’s nearly as much useable power as the current 575 Versatile.”

He said the QSX15 in a Tier 4 final agricultural tractor will be 675 h.p.

“It’ll have a bigger VGT turbo and more of a free flow exhaust in the after treatment system. People should remember that these aren’t like the old Cummins engines, when you’d simply turn the screw a little bit for more power. You can’t modify or retune or hot rod these engines, even if you had the right computer access. These engines are carefully dialed in as part of the whole drive train package.”

He also said many users of this equipment aren’t particularly interested about tier standards and emission control systems.

“Most customers in industry, construction, highway transportation and agriculture do not care about what’s coming out of the tailpipe,” he said.

“My boss is head of industrial application engineering. He stresses to us that customers want to get their work done in the least amount of time, burning the least amount of diesel.

“However, I often get some very relevant questions from farmers who are quite informed and up to speed on the emission standards. It tells me they study the subject.”

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For more information, contact Wayne Goris at 309-675-0767 or goris_waynea@cat.co m and Nick Ciavarro at 812-377-1239 or nicholas. j.ciavarro@cummins.com .