4. Animal-drawn engine operated reaper:
• It has a cutter bar of 1.35 m length.
• 4-stroke petrol engine operates the cutter bar.
• field efficiency of about 80%.
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5. Power tiller/Tractor front mounted vertical
conveyer reaper windrower:
• A machine called vertical conveyor reaper–cum-windrower can cut
the crop and lay it in the form of windrow for easy picking.
• It consists of a conventional cutter bar assembly, crop row dividers
with star wheels, covers, pressure springs and vertical conveyor belts
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7. Tractor rear mounted PTO operated self-
raking reaper:
• The machine carries a cutter bar, the drive to which is given from PTO
of a tractor.
• It is a side delivery machine in which crop is collected over a platform
and is delivered on one side in the form of bound bunches of desired
size
• The raking and sweeping of harvested crop is done mechanically.
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8. combine harvester
• used to harvest grain crops such as wheat, corn, soybeans, and rice.
• the combine performs two, and more, basic functions of harvesting:
• first it reaps (cuts) the crop, and
• then it threshes it, separating the kernels of grain from the seed coverings
and other debris
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13. Threshers
• A machine use to separate seeds from ear heads and clean them.
• There are rotating drum and stationary cover called concave.
• harvest go through concave and drum to separate and clean them by
air flow made by fan.
• There are two types of threshers
1. Axial
2. Tangential
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14. Main Components of Thresher
• (i) Drive pulley
• (ii) Fan/blower
• (iii) Feeding chute
• (iv) Spikes
• (v) Cylinder
• (vi) Concave
• (vii) Flywheel
• (viii) Frame
• (ix) Towing hook
• (x) Upper sieve
• (xi) Lower sieve
• (xii) Transport wheel
• (xiii) Suspension lever
• (xiv) Can pulley
• (xv) Shutter plate
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15. Principles of threshing:
• The threshing mechanism, which separates the grain from the stalks,
consists mainly of a revolving cylinder and the concaves.
• Axial Flow Thresher: The crop in this thresher is fed into the cylinder
through a feeding chute located at one end of the threshing drum.
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16. Functional components of threshing unit:
• A power thresher essentially consists of feeding unit, threshing unit,
cleaning unit, power transmission unit, main frame and transport unit
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17. Feeding Hopper:
• In this type of feeding device there is a hopper, placed on the top of
the threshing cylinder.
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18. Threshing Unit:
• The threshing is accomplished by the impact of the rotating pegs
mounted on the cylinder, over to the ear heads, which force out the
grain from the sheath holding it.
• There are different types of threshing cylinders :
• Spike tooth/peg type cylinder
• Rasp bar type cylinder
• Angled bar type cylinder
• Wire loop type cylinder
• Cutter blade or syndicator type cylinder
• Hammer mill type cylinder
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