Grain Bagger

Overview

A grain bagger, also called a grain bag loader, stores harvested grain on the ground inside a long sealed plastic tube instead of in a silo or bin. It is a Grain Bagger towed behind a tractor and driven from the tractor power take-off. Grain is dumped into a wide Receiving Hopper, lifted by a Feed Auger, and forced into the bag by a Packing Rotor. A plastic bag pre-folded over a Tunnel Cage unrolls as the machine inches forward, leaving a packed, sealed tube of grain behind it.

Bagging suits a harvest that arrives faster than permanent storage or trucking can absorb. A single 300 ft (90 m) bag holds on the order of 11,000 to 12,000 bushels, and a farm can lay down several bags in a field corner in a day. The bag excludes air well enough that the stored grain respires down the oxygen and self-limits mould and insect activity, so dry grain keeps for months without aeration. The trade-off is that the bag is single-use and the grain must be unloaded with a separate extractor before the bag is recycled.

Receiving and feeding

Grain is tipped from a chaser bin or truck into the Receiving Hopper. Fold-out Hopper Extension Wing panels widen the catch area so a tipping trailer can unload without spilling, and a Hopper Grate screens out stalks and cobs that would jam the auger. The hopper floor is protected by a bolt-on Hopper Wear Liner of UHMW polyethylene that lets grain slide and resists abrasion. A manual Flow Control Gate meters how much grain reaches the auger so the operator can match feed to the rotor.

From the gate the grain drops into the Feed Auger. A welded Auger Flighting screw, typically 300 to 400 mm in diameter, turns inside the Auger Tube and lifts the grain to the Auger Discharge Spout, which empties it into the rotor housing. The auger runs on a Auger Shaft supported by an Auger Flight Bearing at each end and is turned through the Auger Drive Sprocket.

Packing into the bag

The Packing Rotor is what actually fills and tensions the bag. A Rotor Drum carries a ring of replaceable Packing Tooth that sweep grain from the discharge spout and ram it forward into the bag mouth through the throat formed by the Rotor Housing. The housing is fitted with a Housing Wear Liner against wear, and a Rotor Scraper strips grain that clings to the drum. Rotor speed, set through the Rotor Drive Sprocket, together with brake drag, controls how tightly the grain is compressed.

Tunnel and bag handling

Before filling, an empty bag is sleeved over the Tunnel Cage in an accordion fold and held by the Bag Cradle and a set of Bag Retainer Strap straps. The cage is sized to the bag, commonly 9 to 10 ft (2.7 to 3.0 m) in diameter. As the rotor packs grain in, internal pressure pushes the filled bag off the tunnel; Tunnel Roller idlers on the rim let the plastic pay off without snagging, and a Tunnel Extension Ring ring smooths the release. The bag is a co-extruded three-layer polyethylene film, white outside to reflect heat and black inside to block light.

Brake and tension control

The Brake & Tension System sets fill density and moves the machine. Instead of a drive wheel, the bagger resists itself: a Brake Band grips a Brake Drum on each transport hub, and the grain being packed in pushes the whole machine forward against that drag. The operator tunes drag with a Tension Winch acting through the Brake Cable, watching a Tension Indicator to keep the bag evenly firm. More drag makes a denser bag and a slower advance; less drag lets the machine creep ahead faster and gives a looser fill. A Cable Ground Anchor reacts the load when the machine is set up.

Drive train and chassis

Power comes in through the PTO Driveline, which needs roughly 90 to 130 hp at the PTO. A Slip Clutch and Shear Bolt protect the driveline if the auger or rotor jams. The Main Gearbox, a right-angle bevel unit, splits power to the auger and rotor through Drive Chain drives kept tight by a Chain Tensioner. The whole machine rides on the Chassis, a welded Main Frame on an Axle Beam with two Transport Wheel flotation tires whose hubs also carry the brake drums.

Hydraulics and variants

The Hydraulic System runs the setup and transport functions. A Hydraulic Pump feeds the Hopper Fold Cylinder cylinders that fold the hopper wings to a 3.0 m road width and the Lift Cylinder that raises the machine onto its wheels. Larger commercial units add hydraulic drive on the auger and a powered tunnel; smaller pull-type baggers for 8 ft bags use the same layout at lower throughput. The same machine architecture is used to bag silage, wet maize and fertiliser by changing the rotor speed and bag film.