Combine Grain Header

Overview

A combine grain header is the front platform that cuts standing cereal and oilseed crops and delivers them into the combine for threshing. It is the widest single part of a combine harvest and sets the work rate of the whole machine, because the combine can only process what the header gathers. A grain header has three jobs: cut every stem cleanly at a low, even height, gather the cut crop from the full width to a central opening, and feed it smoothly into the combine without losing heads on the ground. Each job is handled by one of its main systems, and they all work in time with one another.

The crop is cut by a Sickle Cutterbar running the full width, helped into the knife by the Pickup Reel, then carried inward by the Cross Auger to the feed opening. The Header Frame holds these together, the Driveline powers them, the Combine Hookup latches the header to the combine, and the Height Control keep it at the right height across uneven ground.

The sickle cutterbar

The Sickle Cutterbar cuts the crop with a scissor action. A Knife Bar carrying dozens of triangular Knife Section blades reciprocates rapidly from side to side, and each section shears the stems against a fixed Knife Guard finger, the way scissor blades pass one another. A Wear Plate sets the shear clearance, a Hold-down Clip clip keeps the knife pressed onto the guards, and the whole bar is driven by a sealed Wobble Drive that converts the header's rotary input into the back-and-forth knife stroke. Cutterbar Skid skids under the bar carry it just above the soil so it cuts low without digging in. The serrated sections and the guards are routine wear parts that change in the field, and keeping the knife sharp and the clearance correct is the single biggest factor in a clean cut with low loss.

Reel and gathering

A cutterbar alone would let cut crop fall forward, so the Pickup Reel leans the standing crop back into the knife and then sweeps the cut heads onto the table. It is a bat reel: a Reel Shaft carrying several Reel Bat tubes, each fitted with a row of Pickup Finger fingers. A Finger Cam holds the fingers at the right angle through the sweep so they comb the crop back without dragging, and Reel Arm arms let the operator move the reel up, down, fore, and aft to suit crop height and condition. Once the crop is on the table the Cross Auger gathers it. Its Auger Flighting runs left-hand on one side and right-hand on the other so both ends feed toward the center, where Retract Finger fingers extend to pull the crop into the feederhouse and then retract into the Auger Tube so they do not carry it back around.

Frame and crop dividers

The Header Frame gives the header its rigidity and shape. A Backsheet forms the rear wall the auger packs crop against, End Sheet panels close the ends, and a Table Pan forms the floor the cut crop slides across. At each end a pointed Crop Divider parts the crop being cut from the crop still standing, so the header takes a clean swath and does not knock heads off the next pass. A rigid header like this suits standing cereal on reasonably even ground, where a fixed cutterbar gives the lowest cost and the most reliable cut.

Driveline and combine hookup

Power comes from the combine through the Driveline. A Input Gearbox takes the feed drive and splits it through Drive Belt belts and a Drive Chain to the knife and auger, while the reel runs on its own Reel Motor so its speed can be matched to ground speed independently. A Slip Clutch protects the drive if the auger jams. The Combine Hookup is what makes a header quick to change: a Mount Frame matched to the feederhouse, Header Latch latches that lock it on, and a Multi-coupler and Drive Coupler that join all the hydraulic, drive, and electrical connections in one motion, so the operator can swap from a grain header to a corn head in minutes.

Height control and use

The Height Control keep the cutterbar at the right height as the ground rises and falls. Height Sensor sensors on skid arms read ground clearance, a Header Controller runs the auto height and lateral tilt logic, and Tilt Cylinder cylinders tilt the header to follow side slopes so the cut stays even across the width. In the field the operator sets cut height, reel speed and position, and ground speed, then lets the auto height hold the bar low and steady while the combine threshes. A grain header is matched to its combine by width and feed rate, with wider platforms feeding higher capacity machines. It is the workhorse front for small grains and oilseeds, and its clean low cut and steady feed are what let a combine run at full output with minimal grain left on the ground.