Threshing machinery is a type of agricultural equipment used to separate grain from the stalks and husks. It is a crucial step in the process of harvesting cereals such as wheat, barley, oats, and rice. The primary purpose of threshing is to remove the edible part of the grain from the inedible parts, such as the chaff and straw. There are several types of threshing machinery, each with its own unique design and method of operation. Some of the most common types include: 1. **Flail Threshers**: These are the simplest and oldest type of threshing machinery. They consist of a wooden or metal frame with a series of flails attached. The flails are swung back and forth to beat the grain out of the stalks. 2. **Treadle Threshers**: These are similar to flail threshers but are powered by a person walking on a treadle. The treadle is connected to a series of gears and pulleys that drive the flails. 3. **Drum Threshers**: These threshers use a rotating drum with teeth or spikes to separate the grain from the stalks. The grain is fed into the drum, and the teeth or spikes knock the grain out of the stalks. 4. **Spike Tooth Cylinder Threshers**: These threshers use a rotating cylinder with spikes or teeth to separate the grain from the stalks. The grain is fed into the cylinder, and the spikes or teeth knock the grain out of the stalks. 5. **Rotary Threshers**: These threshers use a rotating drum or cylinder with teeth or spikes to separate the grain from the stalks. The grain is fed into the drum, and the teeth or spikes knock the grain out of the stalks. 6. **Combination Threshers**: These threshers combine the functions of threshing and winnowing. They use a rotating drum or cylinder with teeth or spikes to separate the grain from the stalks, and then use a fan to blow away the chaff and straw. 7. **Axial Flow Threshers**: These threshers use a rotating drum with teeth or spikes to separate the grain from the stalks. The grain is fed into the drum, and the teeth or spikes knock the grain out of the stalks. 8. **Centrifugal Threshers**: These threshers use a rotating drum with teeth or spikes to separate the grain from the stalks. The grain is fed into the drum, and the teeth or spikes knock the grain out of the stalks. 9. **Hammer Mill Threshers**: These threshers use a rotating drum with teeth or spikes to separate the grain from the stalks. The grain is fed into the drum, and the teeth or spikes knock the grain out of the stalks. 10. **Pneumatic Threshers**: These threshers use a rotating drum with teeth or spikes to separate the grain from the stalks. The grain is fed into the drum, and the teeth or spikes knock the grain out of the stalks. 11. **Roller Threshers**: These threshers use a rotating drum with teeth or spikes to separate the grain from the stalks. The grain is fed into the drum, and the teeth or spikes knock the grain out of the stalks. 12. **Spike Tooth Cylinder Threshers**: These threshers use a rotating cylinder with spike

1. THRESHING MACHINERY

2. THRESHING:
It is the process of detaching grains from the earheads or from the plants.
PRINCIPLE OF THRESHING:
 SOME IMPACT OR POUNDING IS GIVEN ON CROPS, THE
GRAINS ARE SEPARATED FROM PANICLES, COBS OR PODS.
 THE CROP MASS PASSES THROUGH A GAP BETWEEN DRUM
AND CONCAVE, WEARING OR RUBBING ACTION TAKES
PLACE

3. COMPONENTS OF THRESHING
MACHINES:

4. PERFORMANCE OF THRESHING:
i. Threshing efficiency
ii. Quality of threshing and
iii. Power required per unit mass of crop threshed.
THRESHING PERFORMANCES DEPEND ON,
a. CROP PARAMETERS AND
b. MACHINE PARAMETERS AND
c. OPERATING PARAMETERS

5. TYPES OF THRESHING CYLINDERS / DRUMS
I. PEG / SPIKE TOOTH
II. WIRE LOOP
III. RASP BAR
IV. ANGLE BAR
V. HAMMER MILL

6. 1. Peg tooth / Spike tooth
 The spikes / peg teeth on the concave and cylinder are arranged that the cylinder teeth pass mildway
between the staggered teeth on the concave. The diameter of the cylinder ranges 300 to 450 mm and
length about 450 to 600 mm.
 Eg: Maize, Millets, etc

7. 2.Wire Loop:
CYLINDER IS STUDDED WITH NUMBER OF WIRE LOOPS THROUGHOUT ITS
OUTER PERIPHERY. WIRE MESH TYPE CONCAVE IS PROVIDED AT THE
BOTTOM. THIS TYPE OF THRESHING DRUM IS SUITABLE FOR THRESHING
WHEAT AND PADDY

8. 3.Rasp bar cylinder:
 CYLINDER HAS CORRUGATED BARS ROUND IT. THRESHING IS
ACCOMPLISHED BETWEEN CORRUGATED CYLINDER BARS AND
STATIONARY BARS OF THE CONCAVE PORTION.
 THE DRUM WILL HAVE A DIAMETER OF 300 TO 450 MM AND LENGTH
ABOUT 450 TO 750 MM. THE DRUM ROTATES AT A SPEED OF 550 TO 900
RPM.
 EX: PADDY THRESHER

9. 4.Angle bar:
 CYLINDER IS EQUIPPED WITH ANGLE IRON BARS, HELICALLY FITTED
ON THE CYLINDER. THE BARS HAVE RUBBED PADS ON THEIR FACES.
 THE CLEARANCE BETWEEN CYLINDER AND CONCAVE UNIT AT THE
ENTRANCE IS FROM 13MM TO 19MM AND REDUCES TO 6 TO 9MM.
 THIS ANGLE BAR TYPE THRESHING CYLINDERS / DRUMS ARE
SUITABLE FOR THRESHING MILLETS.

10. 5.Hammer mill type
 BEATERS ARE IN THE SHAPE OF HAMMER MILL. BEATERS ARE
ATTACHED WITH THE BEATER ARM AT THE TIP. BEATER ARMS ARE
RIGIDLY FIXED TO A HUB WHICH IS MOUNTED ON MAIN SHAFT.
 THIS TYPE OF THRESHING DRUM IS SUITABLE FOR MAIZE, SORGHUM,
ETC.,

11. TYPES OF THRESHER:
a) WHEAT THRESHER
b) PADDY THRESHER
c) GROUNDNUT THRESHER
d) MILLET THRESHER
e) SOYABEAN THRESHER
f) MULTICROP THRESHER

12. Wheat thresher:
AN EQUIPMENT USED FOR THRESHING OF WHEAT CROP WITH OR
WITHOUT BHUSA MAKING PROVISION.

13. Paddy thresher:
AN EQUIPMENT USED FOR THRESHING PADDY CROP.

14. Groundnut thresher
 AN EQUIPMENT USED FOR THRESHING OF GROUNDNUT.
 IT IS A SPIKE TOOTH TYPE THRESHER.
 USED TO REMOVE GROUNDNUT PODS FROM THE VINES.

15. Multicrop thresher:
 AN EQUIPMENT USED FOR MORE THAN ONE CROP WITH OR WITHOUT
MINOR ADJUSTMENT.
 IT CAN THRESH CROPS LIKE WHEAT, MOONG, PADDY, GRAIN,
SOYBEAN ETC.,

16. Thresher losses
1. BLOWER LOSS: THE PERCENTAGE OF GRAINS BLOWN BY
BLOWER ALONG WITH BHUSA WITH RESPECT TO TOTAL
GRAIN INPUT IN THE THRESHER BY WEIGHT.
2. SIEVE LOSS: THE PERCENTAGE OF HEALTHY GRAINS,
DROPPED FROM SIEVE WITH RESPECT TO HEALTHY
GRAINS, RECEIVED FROM THE THRESHER BY WEIGHT.
3. CYLINDER LOSS: THE PERCENTAGE OF UNTHRESHED
GRAIN FROM ALL OUTLETS WITH RESPECT TO TOTAL
GRAIN INPUT IN THE THRESHER BY WEIGHT.
4. VISIBLE DAMAGE LOSS: THE PERCENTAGE OF BROKEN
OR CRACKED GRAINS FROM ALL OUTLETS WITH RESPECT
TO TOTAL GRAIN INPUT IN THE THRESHER BY WEIGHT.

17. SAFE USE OF THRESHERS:
 ENSURE PROPER LIGHTING IN CASE THE MACHINE IS TO BE OPERATED
AT NIGHT, OTHERWISE POOR VISIBILITY MAY LEAD TO ACCIDENTS.
 KEEP THE WORK PLACE AND SURROUNDINGS OF THRESHER FREE OF
ALL KINDS OF OBSTRUCTIONS.
 DO NOT SMOKE OR LIGHT A FIRE NEAR A THRESHING YARD.
 DO NOT CROSS OVER THE FLAT BELT OR MOVE NEAR IT.
 KEEP A FIRST AID BOX HANDY FOR USE IN THE EVENT OF NEED.