The major components of the developed coconut
dehusking machine shown in Figure 2 are frame,
dehusking unit, conveying unit, barrier plates/clearer,
handle and bearing housing.
Figure 2: Diagram of the developed coconut dehusking machine
The frame is the main supporting structure upon which
other components of this machine were mounted. The
frame is a welded structure constructed from
50x50x5mm angle iron with dimensions of 920mm
length, 480mm width and 400mm height. The dehusking
unit comprises of two rollers, two roller shafts and two
spur gears. Each roller was formed by welding thirty-two
metal spikes (2 x 20 x 5mm) on an 80mm diameter mild
steel pipe mounted on a roller shaft. Each of the roller
shafts is a mild steel rod of 55mm diameter and 920mm
long supported at both ends by ball bearings with a gear
mounted at right ends. Also mounted at the right end of
the driving roller shaft is the driving handle while driven
roller shaft drives the conveying unit of the machine
through a driving pulley mounted on it.
The conveying unit consists of a screw conveyor,
shaft, two clearers, pulley and belt. The screw conveyor
was formed by scrolling and welding a 10mm diameter
mild steel rod on a 75mm diameter mild steel pipe with
a pitch of 92mm. The conveyor shaft is a mild steel rod
of 30mm diameter and 920mm long supported at both
ends with ball bearing. The conveyor shaft is driven by a
v-belt pulley of 100mm diameter which runs at the same
speed with the low speed roller (57 teeth gear). The
clearer was constructed by cutting u-notches on one
edge of a mild steel plate of 2mm thickness. The
clearers were fastened on the frame adjacent to the
rollers. The developed coconut dehusking machine is
very easy to operate and requires one operator. When
the handle is wound, the rollers with spikes rotate in
opposite directions towards the centre causing both the
gripping and tearing of husk of coconut fruit placed in
between the rollers. While the rollers rotate, a screw
conveyor mounted between them 70mm below rotate in
the same direction and speed as the driven roller with
the help of a pulley-belt system to ensure proper
discharging of dehusked nuts.