Cotton Module Builder

Overview

A cotton module builder is a field machine that presses loose seed cotton into a dense, free-standing block called a module. During harvest a spindle picker or stripper fills its onboard basket and then dumps the cotton into boll buggies, which haul it to the module builder waiting at the end of the field. The builder packs that loose cotton into a rectangular module roughly 9.7 m long, 2.4 m wide and 2.4 m tall, holding nine to eleven tonnes of seed cotton. Once capped with a tarp, the module sits in the field until a truck collects it for the gin.

The point of the module is logistics. Loose cotton is bulky and blows away, and a gin cannot accept it as fast as pickers produce it. A module stores a whole picker's output in a weatherproof, stackable form so harvesting and ginning run on their own schedules. The builder is what makes that block: it receives, spreads and compacts the cotton inside a steel mould.

The machine is built around a Chassis and Walls that forms the mould, a Tramper System that does the compaction, a Receiving Hopper that feeds cotton in, and an onboard Diesel Power Unit that drives everything through the Hydraulic System.

How it works

Boll buggies tip seed cotton into the Receiving Hopper at the top of the machine. Inside, a Spreading Auger turned by a Auger Motor lays the cotton evenly along the full length of the mould rather than letting it pile under the dump point. A Feed Grille breaks up clumps and stops the cotton bridging over the auger. The auger runs in a Hopper Shell supported on a Ball Bearing at each end with an Oil Seal keeping lint out of the bearing.

Compaction is done by the Tramper System. Two Tramper Foot pads hang from Tramper Cylinder rams, each able to press with about 8 t of force. The rams ride on a Traverse Carriage that runs on a Linear Guide Rail across the width of the mould, pulled by a Traverse Chain driven from a Traverse Motor. As the carriage tracks back and forth, the feet stamp the cotton down in overlapping passes so the whole layer is packed evenly. A Pressure Sensor reads the ram pressure so the operator can pack to a consistent density along the module.

The mould itself is the Chassis and Walls. A Base Skid Frame skid forms the floor, two Hinged Side Wall panels form the sides, and a End Gate at each end squares the module off. The walls swing on a Wall Hinge and are held against the packing pressure by a Gate Latch at each gate. When the module is full and packed, the operator releases the latches, the side walls swing open, and the machine rolls forward on its Running Gear to leave the finished module standing on the ground.

Power and hydraulics

The builder carries its own Diesel Power Unit rather than relying on a tractor. A Diesel Engine of about 75 kW drives the hydraulics through a Pump Coupling, fed from a Fuel Tank and cooled by a Engine Radiator. Harvest air is thick with lint and dust, so a Air Pre-Cleaner with a cyclonic pre-cleaner protects the engine.

The Hydraulic System is a load-sensing circuit. A Variable Piston Pump supplies 90 L/min at 250 bar to a Valve Bank that feeds the tramper rams, the traverse and auger motors, and the gate cylinders. Oil is held in a Oil Reservoir with pressure and return filters, passed through a Oil Cooler to hold temperature under 80°C during a long packing run. Hoses are routed in a Hose Loom rated to 350 bar with an O-Ring Set on the fittings.

Running gear and controls

The machine moves on its own Running Gear. A tandem Walking Axle carries four Flotation Wheel flotation tyres on cast Wheel Hub units, each running a Ball Bearing pair behind an Oil Seal. The walking-beam layout spreads the weight so the loaded machine does not sink into soft, freshly harvested ground. A Tow Eye lets a tractor pull the unit between fields.

The operator runs the build from a Control System. A Operator Panel carries the function switches and an emergency stop, and an LCD Panel shows pack pressure so the module is built to an even density end to end. An Microcontroller on a Bare PCB sequences the tramper and traverse moves and drives a Relay for each valve solenoid, wired through a Wire Bundle and sealed Connector plugs.

Covering and materials

A finished module is capped by the Module Cover System. A Module Tarp of UV-stable PVC is pulled over the top, lifted into a peaked crown by several Tarp Bow supports so rain drains off rather than pooling, and anchored down with Tie-Down Strap ratchets. A spring Tarp Roller Tube stows the tarp clear while the module is being packed.

The mould walls and base are heavy sheet and beam steel because they take the full reaction of the tramper force. The Tramper Foot pads are thick plate to spread load without bending, and the Wall Hinge pins are greasable since they carry the wall against every packing stroke. Daily service centres on greasing the hinges and carriage guides, checking the Traverse Chain tension, and clearing packed lint from the engine Air Pre-Cleaner and the Oil Cooler fins.