Field testing of a PTO powered disk tiller

Abstract

Field testing of a PTO powered disk tiller was conducted in Bangkok clay soil. Tests were conducted at different forward speeds of 1,2,3,4 and 5 km/h and 33, 28 and 23° gang angles. Average PTO speed was 540 rpm and average soil moisture content was 26% during all the tests. The draft requirement was measured by a three point linkage dynamometer. The PTO torque was measured by a slip ring torque transducer. Specific draft, specific torque, power and energy consumption to till a unit volume of soil were calculated for different gang angle settings during passes 1 and 2. Quality of work was assessed in terms of soil cone index. Better tillage performance was observed at 28° gang angle than at 33°. At 23° gang angle the implement did not penetrate well due to the gage wheel remaining on unplowed soil. It was observed that at 28° gang angle setting, the implement consumed less power compared to the 33° gang angle setting at all forward speeds and passes. It consumed as much as 27% more power at 33° gang angle setting than at 28° gang angle setting. The power consumption decreased with higher passes. The energy consumption was higher at 33° gang angle than at 28°. It was also higher at lower forward speed compared to higher forward speed at any given gang angle setting and pass. The work quality in terms of soil cone index at 28° gang angle was better than at 33° gang angle. Disk tiller performance in unpowered mode was also evaluated. It consumed more draft power during unpowered mode compared to powered mode.