Abstract:
India is an agrarian country and the major occupation is farming which is mechanized
nowadays. Rice is one of the major crops which is cultivated in India. In rice cultivation,
weeding is one of the most important intercultural operations. Weeding is the removal of
unwanted crops from paddy field. Losses due to weeds are high and due to this weeding is an
important agricultural operation. A self-propelled three row vertical axis rotary paddy weeder
was developed. The overall structure of the machine is designed and modelled in
SOLIDWORKS software. The machine is equipped with prime mover of 1.51 kW two stroke
petrol engine to drive two paddle wheels and the blades. In the working process the drive from
the engine is transferred to the reduction gear box through centrifugal clutch. The gear box with
a reduction ratio of 236:1 reduces the speed to desirable level where the human can walk in
clayey soil. The drive for the weeding mechanism is derived from the main shaft and the speed
is stepped up to increase the rotating speed of blades. A drive cut-off gear box is provided in
order to engage and disengage the drive given to the blades. The two floats are provided at the
rear to slide the machine over the mud in the paddy fields during weeding operation. The
machine can reduce the labor and cost of operation. The estimated cost for the fabrication of
the developed prototype is Rs. 36606.
