Chain Conveyor for Pallets

Chain Pallet Conveyor System

In the foundational architecture of automated warehousing systems, the chain pallet conveyor plays the role of a structural backbone. Compared with roller conveyors, it functions more like a robust “spine” specifically designed to handle heavy-duty, irregular, or poorly supported pallet loads. For applications where unit loads frequently exceed 1.5 tons or pallet undersides are uneven or widely spaced, chain conveyors are generally the more reliable and stable solution.

This article provides a technical breakdown of chain pallet conveyor systems, covering structural design, material selection, and maintenance considerations.

Chain Selection: Roller Chain vs. Plate Chain

The core of a chain conveyor system lies in the load capacity and durability of the chain.

For standard heavy-duty applications (1–2 tons), double-row roller chains (08B or 10A) are commonly used due to their availability and lower replacement cost. However, in extreme heavy-load conditions (above 3 tons) or high-temperature environments, flat-top plate chains offer superior performance. Plate chains provide a larger contact surface, reducing wear on pallet bottoms, and their structure is less prone to accumulation of oil, dust, or metal debris due to the absence of rollers and bushings.

Proper pitch matching with sprockets is critical. Oversized pitch may cause skipping, while undersized pitch can lead to chain jamming or seizure.

Structural Rigidity: Torsional Resistance and Foundation Stability

During startup and operation, chain conveyors generate significant transient tensile forces.

If structural rigidity is insufficient, the frame may twist under load, causing chain misalignment or edge wear. For conveyors longer than 10 meters, the main frame is typically constructed using heavy-duty channel steel (No. 16 or higher), welded back-to-back and reinforced with structural ribs.

Foundation conditions are equally critical. Poor ground rigidity may lead to uneven settlement, affecting chain tension stability. It is recommended to install independent concrete foundations with precision leveling during installation to ensure long-term structural integrity.

Tensioning System: A Key Factor in Chain Lifespan

A chain should never be overly tensioned.

Excessive tension increases bearing load, accelerates motor heating, and shortens chain life. Conversely, insufficient tension leads to skipping and instability. High-quality systems are equipped with automatic gravity-based or spring-loaded tensioning devices at the tail section, allowing real-time compensation for chain elongation.

During maintenance, a mid-span deflection of 20–30 mm is generally considered optimal.

Photoelectric Sensing and Anti-Jamming Design

Pallet transport on chain systems involves high friction, which may generate static buildup or occasional jamming.

Sensor placement is critical. Photoelectric sensors should not be installed directly above the chain path due to potential signal interference. Side-mounted through-beam sensors are recommended for detecting pallet side plates.

At curve sections and transfer points, guide rails or side plates should be installed to correct pallet alignment and prevent corner lifting that may cause mechanical blockage.

Special Operating Environments: Cold Storage and High Temperature

Environmental conditions significantly affect chain performance, particularly lubrication and material behavior.

In ultra-low temperature environments (down to -30°C), standard lithium-based grease may solidify, leading to increased friction and noise. Low-temperature aviation-grade lubricants or stainless-steel chains with dry lubrication systems are recommended.

In high-temperature environments such as forging workshops, heat-resistant alloy chains should be used, along with thermal shielding to protect motors and gearboxes from radiant heat.

Drive Configuration: The Necessity of Multi-Point Drives

For long-distance conveyors (over 15 meters), single-point drive systems are not recommended.

Excessive chain length increases sagging and resistance, leading to uneven load distribution. Multi-point drive configurations (dual-end or mid-drive systems) are preferred. PLC-controlled synchronization ensures balanced torque distribution across motors, reducing mechanical stress and improving system reliability.

Maintenance Considerations: Lubrication and Cleaning

The primary challenges of chain conveyors are noise and contamination.

Modern systems are designed with automatic lubrication ports to ensure consistent and controlled oil supply. In food-grade applications, oil collection trays and sloped drainage structures should be installed to prevent contamination and facilitate cleaning.

Chain pallet conveyors are classic heavy-duty industrial systems where reliability outweighs complexity. Their value lies not in advanced intelligence, but in long-term mechanical durability and operational stability. In system selection, priority should be given to steel yield strength and chain tensile rating, which are fundamental to ensuring uninterrupted production flow.