Agricultural chain rakes and reel pickup chains are widely used in farm machinery to convey, lift, separate and feed crop materials. They usually operate under heavy loads, high dust and frequent impact, so proper design, material selection and maintenance directly affect machine performance.

Basic structure and working principle

A chain rake mainly consists of drive chains, rake bars or tines, chain wheels and guide rails. The chain is typically a sleeve roller chain or flat-top chain. Rake bars are fixed across the chain links. Power enters from the drive sprocket, making the chain circulate along guide rails. The rake bars push or lift materials along a trough. At the discharge end, materials fall away by gravity and centrifugal force.

A reel pickup chain is used on combine headers or pickup platforms. It is usually fitted with fingers, lugs or spring tines. As the chain runs around the reel or pickup shaft, the fingers engage crop stalks and move them into the header auger or feed conveyor.

Common types and characteristics

By arrangement, chain rakes can be single-row, double-row or multi-row. Single-row types suit light conveying. Double-row types provide stronger capacity and are often found on combine cleaning shoes or forage harvester feed decks. Multi-row rakes distribute material more evenly on large cleaning and conveying equipment.

By tine shape, rake bars can have straight, curved or spring tines. Straight tines suit dry and free-flowing materials. Curved tines give stronger gripping ability for thicker crop layers. Spring tines can deflect when hitting hard objects, reducing breakage.

Common chain pitch sizes include 38 mm and 50 mm. Larger pitch usually means higher single-link strength, but also greater weight and impact.

Typical applications

• Combine header conveyors: move cut crop rearward into the feeder housing.
• Forage harvester feed chains: carry chopped material into the trailer or blower.
• Cleaning and separation conveyors: cooperate with sieves to spread material and separate impurities.
• Grain elevators and conveyors: lift and transport grain or corn with good sealing and low spillage.

Daily maintenance and troubleshooting

Key maintenance points include:

• Chain tension: too loose causes skipping or derailment; too tight accelerates wear. Adjust according to the manual.
• Lubrication: regularly lubricate chains and sprockets. In high dust conditions use medium-viscosity lubricant to avoid mud buildup.
• Rake bar or finger inspection: before and after operation, check for bending, cracking or looseness.
• Sprocket wear: replace sprockets and chains together when hook-shaped tooth wear appears.
• Abnormal noise and tracking: check sprocket alignment, chain elongation and guide rail deformation if periodic noise or side running occurs.

Common faults and treatments:

Selection and replacement points

When purchasing or replacing, match the original parameters: chain pitch, chain width, rake bar spacing and mounting holes must be consistent. Choose alloy steel chain plates, pins and tines with good surface hardness and core toughness. Select the correct strength grade according to operating load. In corrosive or dusty environments, choose surface-coated or sealed products. Replace the chain and sprockets together to avoid rapid wear caused by mismatched new and old parts.

Scientific use and regular maintenance are the key to extending the service life of agricultural chain rakes and reel pickup chains. Users should select the right model according to crop type, working environment and load, and carry out daily inspection and adjustment to reduce downtime and improve efficiency.