A Track Type Oil Palm Fresh Fruit Bunch In-Field Transporter for Low Bearing Capacity Peat Terrain

Özet

A tracked type vehicle with 1800 mm X 350 mm size metal reinforced rubber tracks and 550 kg capacity rear tipping fruit bin has been successfully designed, developed, and evaluated to solve the problems of in-field transportation of oil palm fresh fruit bunches (FFB) on low bearing capacity peat terrain in Malaysia. This 2-men operation machine system consists of an operator who drives the vehicle and a worker who loads the cut oil palm FBB into the fruit bin of the vehicle at every picking point in the field. The machine is equipped with a 37.7 kW @ 3600 rpm 4TNE84 Yanmar diesel engine coupled in-tandem with two units of 50 cm3/rev @ 350 bar SAMHYDRAULIK variable displacement HCV 50 Series axial piston main pumps where each pump is used to run a 565 cm3/rev @ 250 bar SAi GM2 600 series high torque hydraulic motor to provide the rear sprocket torque for the rubber track. The required engine size was estimated based on the mathematical models for the vehicle straight and turning motions on intermediate condition of peat terrain with bearing capacity of 19.50 kN/m2. Field performances of the vehicle under the engine speed of 1500 to 2500 rpm and total vehicle mass of 1950 to 2650 kg resulted with traveling speed ranging from 8.28 to 11.85 km/hr and 6.43 to 10.42 km/hr on asphalt and tilled soil, respectively. The vehicle average sinkage on low bearing capacity peat terrain at vehicle total mass of 2500 kg was found to be 104.2 mm which is 13.04% lower than the critical sinkage of 120 mm for the low bearing capacity peat terrain. The average sinkages under vehicle total mass from 1950 to 2650 kg ranges from 71.73 to 108.1 mm on tilled soil and 81.13 mm to 130.08 mm on low bearing capacity peat terrain. The average sinkages of the right track is greater than that of left track by 20.52% during left turning while the average sinkages of the left track is greater than that of right track by 15.98% during right turning.