Using an IRRI axial flow thresher

Before operating the thresher

Positioning of the thresher

  • vimage27Position the thresher on a level area close to the crop stack to minimize handling and shattering losses.
  • Spread cloth, canvas, or mat underneath the thresher to collect spilled grain from the grain discharge chute or due to shattering during handling.
  • Install the cylinder, cover, and feed tray if dismantled during field transport.
  • Position the thresher so that the straw is thrown with the direction of the wind.  This will eliminate the blowing of straw, chaff, and dust back toward the operator and the threshed grain.

Check the machine

  • vimage28Check each belt's alignment and tension.  Adjust the idler pulley on the blower/cylinder belt to correct tension. Improper alignment and tension are the major causes of premature belt failure.
  • vimage29Check pulley surfaces.  Rough grooves must be smoothened with a fine file if nicked.  Cracked pulleys should be replaced immediately.
  • vimage30Open the cover and check all pegs on the threshing cylinder for tightness.  Loose pegs will damage the machine and can be dangerous to the operators.
  • vimage31Examine the pegteeth for wear.  Maximum wear occurs at the feed end of the cylinder and is more prominent at the leading side in the direction of rotation.  Worn pegs must be rotated 180 degrees or interchanged with those located near the straw paddles.  Badly worn pegs must be replaced or rebuilt by welding.
  • Rotate the threshing cylinder manually at least five revolutions to ensure that there are no obstructions or interferences.
  • Make sure there are no loose or missing bolts and set screws.  Tighten or replace as necessary.
  • Lubricate all bearings with good quality grease  (see maintenance and service section)  The belt idler and oscillating screen eccentric bearings are lubricated for life, thus require no lubrication.
  • Check engine oil and fuel levels.  Follow the engine manufacturer's recommendations.
  • Start the engine and allow it  to warm up.  Feed the thresher with the crop to be threshed for performance checking. Increase cylinder speed if excessive amounts of unthreshed and unseparated grain are observed with the straw. Optimum threshing and cleaning is obtained with cylinder speeds of 600 to 700 rpm.

Maintenance and service

  1. Lubricate cylinder and fan bearings with a good-quality general purpose grease every 25 hours of operation.  Periodically apply a small amount of oil to all hinge points.
  2. Inspect the machine regularly for loose, worn, or damaged pegteeth, concave bars, cylinder, discharge paddles and other parts, and tighten, repair, or replace them immediately.  Missing bolts or nuts must also be replaced.
  3. Reduce belt tensions by loosening the idler pulley and engine mounting bolts when the machine will not be used for an extended period to minimize deterioration.
  4. Check engine crankcase oil level at least every 4 operating hours and follow the engine manufacturer's recommendations for oil change intervals and oil grade.  Be sure the recommended oil level is maintained.
  5. Service the air cleaner, fuel filter, fuel line, carburetor, and spark plug regularly according to engine manufacturer's instructions.

Storage of a threshing machine

  1. Clean the machine thoroughly.
  2. Remove belts and store in a dry place.
  3. Store the machine in a clean, dry location and cover to reduce damage from dust accumulation.
  4. Paint parts that need repainting.
  5. Clean and apply oil to exposed metal surfaces to prevent rusting.
  6. Follow the manufacturer's recommendations on engine storage