FARGO, N.D. – When the single tine separation rotor was introduced five years ago, it was considered a big step in John Deere combine technology. For 2006, the company has announced an improvement to its basic STS
design.
Named the Bullet because of its long, tapered nose, the new rotor is designed to take on tough harvest conditions such as wet straw in small grain, green stem soybeans or any other crop that’s difficult to handle because of moisture.
As evidence that the new rotor works in tough conditions, John Deere points out that the Bullet also handles long-stem rice.
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The company said the new design reduces power requirements by as much as 20 percent in tough small grain. This greater efficiency can also be translated to higher ground speeds in more favourable conditions.
“The nose is noticeably more streamlined than any other rotor on the market,” said company spokesperson Pat Duffy.
“The taper goes back farther over the first concave.
“The threshing elements have rifling grooves on the surface, just like the barrel of rifle. With the bullet shape on the rotor and the rifled elements, it creates an effect that is similar to a bullet spiralling through the air.”
Duffy said tough material is smoothed out early in the process at the tapered end of the rotor so that smooth, uniform product is sent deeper into the machine.
The bullet concept comprises three co-ordinated stages: the bullet nose accepts 35 percent more product at the front; the rifling elements engage the material and get the product spiralling along the concave and the grooves help ensure that crop keeps moving and doesn’t jam up.
“The third part of the design is close to the back of the rotor where we now have different vane angles,” Duffy said.
“The vanes are 30 degrees over the seed grates. We got all that material going, so now we start to slow it down and drop the seeds out. We slow it down some more at the rear separator.”
The bullet rotor is not available yet, but will be standard equipment on all 2006 STS 9660, 9760 and 9860 combines, replacing the STS design that has been standard.
For owners of STS combines, Duffy said the bullet is the same length and diameter as the original STS rotor, which means it is interchangeable with any 50 or 60 series wide-bodied combine. It is expected to be available next summer.
If an STS owner doesn’t want to buy a new rotor immediately, he can still use the new technology by installing some of the rifled threshing elements, which are interchangeable with current threshing elements. This change alone could help move material faster.
