CSBE-SCGAB

Power reqirements of a self-propelled combine

Authors: Dodds, M. E.
Description: Larger farms and improved farming methods have created a need for more capacity in harvest equipment. This demand has encouraged the introduction of larger machines with bigger power units. The availability of more tractor power has renewed the interest in pull-type, pto com bines, though self-propelled models remain in favor. The size of combines has increased from those which were powered by 35 to 40 hp engines a few years ago to units with power plants which develop 80 to 115 hp. The early models of pto combines performed well on level land when operated by a tractor which developed 15 to 20 dbhp. But on hilly land, in loose footing, or in heavy crops, it was necessary to narrow the width of cut to have enough power to thresh the grain (6, 8, 9). The absence of a live pto on the tractors created difficulties when the combine plugged with grain and straw (7). A pto combine with an eight-foot cutter bar and a 24-inch rasp bar cylinder needed 9 to 15 hp at the pto shaft when handling grain and straw at the rate of 200 to 400 pounds per minute, and up to 14 hp to propel the tractor and combine at four mph on level land (5). Eight to 15 hp were required to propel a 16-foot self-propelled combine on level land, but up to 40 hp were necessary when operating in sandy conditions or in hilly areas (3) this same machine used up to 40 hp to operate the cutting and threshing mechanisms. The power required by the cutter bar increased as the rate of cutting increased, while the power demand of the cylinder fluctuated with the feed rate, and represented 50 percent of the total power requirement when operating under normal conditions (2).
Keywords: power reqirements of a self-propelled combine
Citation: Dodds, M. E. 1968. POWER REQIREMENTS OF A SELF-PROPELLED COMBINE. Canadian Agricultural Engineering 10(2):74-76.
Volume: 10
Issue: 2
Start page number: 74
End page number: 76
Date: 1968
Coverage: Canada
Located in: Volume 10 (1968)