Grain Cart

Overview

A grain cart is a towed holding tank whose whole purpose is to keep a Combine Harvester cutting. A combine's on-board grain tank fills quickly, and stopping to wait for a road truck wastes the most expensive minutes of harvest. Instead, the combine unloads on the move into a grain cart running alongside; the cart shuttles to the field edge and dumps into a semi-trailer through a high-capacity auger, then returns. It is pulled and powered entirely by a tractor, so it carries no engine.

The cart is sized to swallow several combine tank-loads and to empty into a truck in a minute or two. Because it spends its life loaded and running over soft, in-crop ground, much of its design, large flotation tires, a tandem axle, a balanced frame, is about carrying tens of tonnes of grain without compacting the field.

How it works

Grain pours into the Grain Tank, a tapered steel hopper that funnels the load down to the auger sump; a roll tarp keeps it dry on the road. Unloading is a two-stage auger train in the Unloading Auger: a horizontal cross auger in the hopper sump feeds a steep upper auger that lifts the grain high enough to clear the side of a truck box, with helical flighting inside wear-resistant tubes moving hundreds of bushels a minute.

The augers are driven from the tractor through the PTO Drive. A guarded telescoping PTO shaft turns a slip clutch, which slips on overload so a packed or bridged auger cannot shear the driveline, and a gearbox turns the auger flighting. For road travel the Auger Fold System uses a hydraulic cylinder to pivot the upper auger down alongside the tank, narrowing the machine to legal width.

Knowing exactly how much grain has moved matters for yield records and truck loading, so the Weigh Scale System carries the tank on load cells and shows live and total weights on an in-cab indicator. The loaded cart rides on a Tandem Axle tandem running gear with big flotation tires, all mounted on the Frame & Hitch. Auger fold, spout swing and the tarp run off the Hydraulic System circuit fed by the tractor's remotes.