Bin Sweep Auger Product

Overview

The bin sweep auger is a specialized conveying machine designed to completely empty flat-bottom grain storage bins without manual entry or disturbance. A long rotating auger (screw conveyor) mounted on a single center pivot sweeps across the entire bin floor in a spiral pattern, drawing all remaining grain toward its intake and conveying it toward the discharge outlet.

This design is far superior to manually raking grain or relying on slope to empty bins. It ensures complete product recovery (98%+), eliminates dead zones where grain spoils or bridges, and improves safety by eliminating the need for workers to enter confined spaces. The machine is essential in modern grain handling systems where multiple bins must be cleared quickly and completely.

How it works

The Center Pivot Bearing Assembly is anchored at the exact center of the bin floor. The Radial Support Arm extends from center to the bin wall radius (typically 10–30 m). The Sweep Auger Screw Assembly, a long spiral-flighted shaft, runs along the entire length of this arm, with its inlet near center and outlet at radius.

The Motor and Drive Assembly and Main Drive Gearbox rotate the entire radial-arm assembly around the center pivot at a slow rate (typically 30–80 rpm). As the arm rotates, the spinning Sweep Auger Screw Assembly screw continuously picks up grain from the bin floor and conveys it toward the Discharge Spout at the radius. A stationary Auger Inlet Hopper at the center draws material from the rotating auger's inlet.

The Floor Wheel Assembly rolling on the bin floor support most of the radial arm's weight, reducing friction and allowing smooth rotation. The Center Pivot Ball or Roller Bearing carries the arm weight and the Thrust Bearing prevents vertical lift.

Over many rotations (one complete sweep revolution takes 15–40 minutes depending on speed), the auger covers every part of the bin floor, clearing grain that would otherwise remain inaccessible.

Auger screw design

The Sweep Auger Screw Assembly is a standard spiral auger with Auger Helical Flighting (welded helix) on a Auger Main Shaft. The pitch (distance advanced per revolution) is typically 1–2 turns per meter, balanced to convey grain steadily without excessive slipping or binding.

Unlike stationary augers, this screw must rotate continuously as the arm sweeps, so the bearing placement is critical. Pillow Block Bearing Supports at intervals (typically every 3–5 m) support the shaft and prevent sagging under grain load and its own weight.

Drive transmission

The motor drives a Main Drive Gearbox (typically 6:1 to 20:1) reducing speed to the Center Pivot Bearing Assembly. An Intermediate Drive Gearbox mounted at the radial-arm end then turns the drive 90 degrees using Bevel Gear Set, converting the horizontal arm rotation into vertical (or axial) auger shaft rotation.

This arrangement means the auger screw speed is proportional to arm rotation speed, but they are mechanically independent—the auger will slow if grain becomes dense, but the arm continues rotating, sweeping all areas.

Operational control

Variable-speed operation is common via a Variable-Frequency Drive (variable-frequency drive). Slower sweep speeds (10–20 rpm) give the auger more time to extract grain from dense zones, reducing overload. Faster speeds (50–80 rpm) increase throughput when grain is loose or mostly cleared.

The Control and Safety System includes a Safety Interlock Switch preventing auger operation if any bin access door is open, protecting workers from rotating equipment.

Advantages over alternatives

Manual shoveling or raking is slow, hazardous, and leaves significant grain residue (5–10%). Vibrating hoppers risk damaging grain and require heavy power. The sweep auger is the least damaging method (grain falls directly via gravity), is fully automatic, and recovers nearly all saleable grain.

Maintenance and wear

The critical wear points are the auger shaft Auger Helical Flighting and the Center Pivot Ball or Roller Bearing. Flighting becomes smooth over thousands of tons of throughput, reducing conveying efficiency. Augers typically last 2,000–5,000 tons before being replaced. Pivot bearings should be greased every 200–500 hours.

The Floor Wheel Assembly must be checked for flat spots and alignment; misalignment causes binding and excessive load on the center pivot.

Integration with storage

Large grain elevators often have multiple bins, each with its own sweep auger. Central controls coordinate discharge from sweep augers into a common conveyor line for downstream processing or loading. Sequence logic ensures only one auger operates at a time, preventing backlog.

Some installations include Grain Cleaner Aspirator or other cleaning equipment directly after sweep-auger discharge, removing any dust or fine material that settled in the bin during storage.