Prior to the 1950s, mechanical lift mechanisms were the method of choice for controlling farm implements. A tractor driver had to reach back and move a lever that lifted or lowered the trailing implement. Hopefully, he could do it without falling off and being run over. Those old designs would make today’s corporate lawyers break out in a cold sweat at the thought of all the potential injury lawsuits.
Sophisticated hydraulic systems changed all that. But even their glory days may be waning. Engineers are beginning to focus their attention on electricity as a replacement for fluid systems, which can be real power hogs.
In the past couple of years, companies have started showing implements at prominent farm machinery shows set up for electric rather than hydraulic control. While many of the larger implement designs shown have been concept machines, some with lower power demands are now well into production. Small three-point hitch mounted sprayers are one example.
But implements with high electrical power demands are likely to remain just interesting concepts here in Canada — for a while, at least. A 100-amp alternator — the size many tractors are equipped with — just won’t put out the kind of electrical muscle necessary to run them.
In Europe, though, it’s a different story. John Deere’s 7030E Premium series tractors use an entirely new design that addresses that concern. Equipped with what Deere calls Intelligent Power Management (IPM), these tractors have an integrated, high-power electrical distribution system. They’ve been on dealers’ lots in Europe since spring 2009.
An engine-driven generator provides the power for electrical components such as the air conditioning compressor, engine cooling fan and air brake compressor, resulting in increased engine performance and better fuel efficiency. In addition, these tractors can provide external electrical power of up to five kilowatts through two power sockets, rated at 230 and 400 volts.
The tractors also have continuous 12-volt power available at an impressive 300-amp rating. That gives them the ability to feature power sockets allowing for the operation of most handheld tools.
Another benefit of the IPM system is it can provide an additional 10 horsepower on demand, which contributes to better acceleration and an improved load response during PTO work. The tractors are rated at 165 and 180 horsepower with a power boost under load pushing those numbers to 200 and 215.
The 7430E and 7530E, the two tractors in the line, recently won in the tractor category for New Equipment Awards at the 2009 Royal (machinery) Show in England. And that wasn’t their first award. Initially introduced to the public at Agritechnica 2007 in Hannover, Germany, they were awarded a Gold Medal for innovation by DLG, the society that hosts that event.
According to Deere’s spokesman, the tractor is only available in Europe, so far. Officially, no date has been announced for its release here in North America.
ELECTRIC MOTORS POWER ROGATOR CONCEPT
Deere isn’t the only manufacturer pushing the limits of electric power. AGCO recently demonstrated its intention to go a step further and explore electricity as a replacement for mechanical and hydraulic-drive systems. The company presented a concept vehicle based on a 1386 RoGator sprayer at AG Connect Expo in Florida in January. “With this concept vehicle, we’re investigating the feasibility of electric propulsion and the myriad of benefits it may help us provide to our agriculture customers,” says Rich Hale, chief engineer with AGCO.
One of the main systems being evaluated is electric drive as a replacement for hydrostatic wheel motors. “We hope to learn that electric propulsion will be feasible in a wide range of possible agricultural vehicle applications,” adds Hale.
According to AGCO’s press release, initial tests show the electric wheel motors on the RoGator deliver 36 per cent higher torque, smoother acceleration and better braking than
the hydrostatic drive. Electric drive also increased the sprayer’s available horsepower by six per cent, while reducing fuel consumption by 20 per cent. And the overall design of the sprayer requires 70 per cent less hydraulic fluid.
Driven by a 650-volt DC generator, the electric motors are capable of speeds up to 35 m. p. h. (56 km/h) and produce 516 foot-pounds (700 Nm) of torque. The generator, motors, controllers and brake resistor are all water cooled.
“We believe using electrical power can increase the flexibility of the overall vehicle design and increase the efficiency of other systems on the machine, such as engine fan drives, A/C compressors, air compressors and hydraulic pumps which often are electric powered,” says Hale. But so far, the sprayer is just a test bed to evaluate the components. There are no firm plans to put one into production.
In fact, a spokesman for the company says these test components are actually more likely to appear on other AGCO machines before they show up on production RoGators.
You know, with all this talk of machines using monster electrical systems, I just can’t shake the vision of engineers from Deere and AGCO doing research in facilities that look like old castles on secluded mountaintops. Inside, they’re hoisting lightning rods from the roof to shock their monster electrical machines to life on a stormy night, yelling “It’s alive!” I guess I watched too many Frankenstein movies as a kid!
Scott Garvey specializes in writing about tractors and farm machinery technology for publications in Canada and Great Britain. He’s also a former affiliate member of the Society of Automotive Engineers (SAE). He farms near Moosomin, Sask.