A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development

An attempt was made to design a hydraulic power transmission and a mounting frame with hydraulic lifting mechanism to provide adjustable cutting height for a front mounted pineapple plant dressing machine previously developed. The machine had four blades of 0460 cm, with a spacing of 70-60-70 cm. The tractor used was a Massey Fergusson tractor MF 185. Power was taken from tractor pto through a chain-sprocket step-up transmission. Hydraulic motor used was a low speed and a step-up transmission was used to obtain high blade speed. The developed hydraulic transmission and lifting mechanism could perform well although still some improvements are needed. Field tests were conducted in pineapple plantation. Because of unsatisfactory performance using four blades, only two blades were used. Short time field testing revealed that the field capacity was 0.22 ha/h and field efficiency was 72.3%. Cutting effectiveness was 93%, plant damaged was 0.3%, and height of cut was 35.5 cm. Net torque to drive one blade at normal conditions was estimated to be 5.4 N.m. Maximum torque at motor shaft was 342 N.m. However, when blade shafts were wrapped and clogged by weeds and cut leaves, the machine was likely to stall. A long term testing is necessary to estimate the accurate field performance of the developed machine.

Thesis (M.Eng.) - Asian Institute of Technology, 1998