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01-12
79032998 A Rev.
General Information
HOW A COMBINE WORKS
FIG. 32: Four functions are done in the overall
harvesting operation of a combine. These are:
•
Cutting and Feeding
•
Threshing
•
Separating
•
Cleaning
Cutting and Feeding
The crop is gathered by a header which is supported by a
feeder housing.
The grain header uses a reel to direct the crop into the
header auger after the crop is cut by the knife and the
header auger conveys the crop into the feeder (1).
When a pickup header is used, the crop, already cut and
laying in a swath, is lifted by a pickup and fed to the
header auger where the retractable fingers move the crop
into the feeder.
The feeder elevator transports the crop to the front of the
accelerator beater (2) which moves the crop to the rotor
inlet area and the rotor (3). The feed beater also guides
rocks and other foreign objects into the stone trap (16)
located forward and below the beater.
Threshing and Separating
The rotor does four functions as the crop moves in rotary
motion from front to rear:
•
Intake
•
Threshing
•
Separating
•
Discharge
The auger flighting in the intake area starts the crop on a
spiral route around the rotor and moves the crop to the
threshing area.
Threshing and initial separation are done in the threshing
zone as a result of relationship between the rotating
cylinder bars and the stationary open grate concave (4).
Contact with the helical guide vanes (5) causes the
material to move rearward and in a circular route, letting
the material pass over the concave several times.
Remaining separation occurs in the separating section.
Centrifugal force carries the grain and chaff through the
grate (6) while the straw moves rearward in the rotor
cage. Again, the spiral motion of the crop lets the crop
pass over the separating grates several times.
Cylinder bars on the rotating rotor hold the crop against
the grates until the crop reaches the end. Paddles then
bat the material into a discharge chute where the crop is
moved to a straw spreader, chopper, or discharged
directly to the ground.
FIG. 32
1
9
13
16
12
14
2
3
4
5
6
15
7
10
11
8
D-9839