A research on determining of the working speciality of tractor?s pto (540 and 750 rpm)

The objective of this study was to determine differences between the standard 540 rpm and 750 rpm pto (power take-off) revolution in tractors. Loads were applied to three tractors (Massey Ferguson 3085, New Holland TD85, and John Deere 5625) with similar technical specifications, by means of a pto dynamometer (Eddy-current) under stable conditions. Measurements were made of tractor pto torque, engine fuel consumption, specific fuel consumption and cooling water temperatures on the basis of load steps applied at 540 and 750 pto applications. The torque values measured for 540 and 750 applications at load steps (5-50 kW) were found to be between 88 Nm-888 Nm and 63 Nm-638 Nm, respectively. Data analysis showed the fuel consumption increase rates caused by 750 application instead of 540 application varied between 7.56-12.63%, 7.59-14.64% and 1.00-2.80% respectively, for Massey Ferguson 3085, New Holland TD85 and John Deere 5625 tractors at all load steps (5-50 kW) applied to the pto. Besides, specific fuel consumption decreased with power increase for both pto applications in each tractor. Findings showed that the 750 rpm pto application had lower pto torque, higher fuel consumption and specific fuel consumption values than those of the 540 rpm pto application for the all tested tractors. In conclusion, the 750 rpm pto application for many pto-driven machines can be significant alternative to 540 rpm application up to maximum pto loads of tractors.Keywords: Tractor, 540 rpm, 750 rpm, Pto