What are the common types of harvesters? Understanding their classification in one article

A harvester is a machine that harvests crops in an integrated manner, completing harvesting and threshing in one pass, gathering the grain into a storage bin, and then transporting the grain via a conveyor belt to a transport vehicle. The main types of harvesters include portable harvesters, walk-behind harvesters, horizontal-header harvesters, vertical-header harvesters, and so on. This article provides a detailed introduction to the different types of harvesters.

Types of harvesters

Portable harvester: further divided into side-mounted and backpack types.

① Side-mounted automatic harvester: uses a rigid shaft drive, mainly composed of an engine, transmission system, clutch, working parts, control device, and side-mounted belt. At one end of the drive shaft is a 0.75-2 kW single-cylinder two-stroke air-cooled gasoline engine and a centrifugal friction clutch; at the other end is a working part consisting of a reducer and cutting tools. There are many types of working parts; commonly used ones are circular saw blades, blades, or nylon line. During operation, the hook ring on the aluminum alloy sleeve of the drive shaft is hung on a strap below the operator's shoulder, the handle is gripped, and the rigid shaft is swung laterally to complete operations such as cutting weeds and shrubs. The machine weighs about 6-12 kg, with a speed of about 4500-5000 rpm.

② Backpack automatic harvester: uses a flexible shaft drive; its general structure is similar to the side-mounted brush cutter, except that its engine is carried on the operator's back and the cutting parts are driven by a flexible shaft. Engine power is generally 0.75-1.2 kW. The engine and the backpack frame are connected at two points and fitted with special rubber parts for vibration isolation. The flexible shaft is a steel wire flexible shaft enclosed in a hose, used to transmit torque. The hose is a threaded tube wound from steel strip covered by a metal braided mesh coated with a rubber protective sleeve, to prevent dust from entering the shaft and to maintain the lubricating oil on the shaft surface. The cutting width is generally between 1.5-2 m.

Walk-behind harvester: the weight of the machine is supported by walking wheels, the machine is pushed forward by a person, and the engine drives the working parts to carry out cutting and irrigation operations. Its structure and working principle are similar to the portable brush cutter. The suspended harvester is suspended behind a tractor, and the working parts are driven to rotate by the power take-off shaft, suitable for large-area brush cutting operations. It is mainly composed of a frame, saw blade, transmission device, suspension device, and push plate. During brush cutting operations, the tractor travels in reverse, with a working speed of 5 km/h, and can saw shrubs with a diameter of 10 cm.

Horizontal-header harvester: composed of a reel, one or two front and rear canvas conveyor belts, dividers, a cutter, and a transmission device. During operation, the reciprocating cutter, with the cooperation of the reel's pressure plate, cuts the crop and pushes it backward onto the canvas conveyor belt, and the conveyor belt sends the crop to the left side of the machine. Because the rear conveyor belt of the double-belt system is longer than the front conveyor belt, the ear portion falls to the ground later, so that the discharged stalks are laid on the ground in neat windrows at an angle to the machine's direction of travel, making it easy to pick up and bundle by hand. The horizontal-header harvester has good adaptability to different rice and wheat growth densities, plant heights, lodging degrees, and yields, and has a simple structure; however, its longitudinal dimensions are relatively large, and the unit's flexibility during operation is relatively poor. It is mostly matched with wheeled or walk-behind tractors below 15 kW, with a cutting width of less than 2.0 m, and each meter of cutting width can harvest 4-5 mu of wheat per hour.

Vertical-header harvester: the cut crop stands upright on the plane of the cutter and, close against the conveyor, is output outside the machine and laid into windrows. There are two types: side-laid and rear-laid. The side-laid harvester is composed of dividers, reel star wheels (or reel finger wheels), a cutter, a transverse vertical toothed-belt conveyor, and so on. The cut crop is pushed by the reel star wheels toward the upper and lower toothed belts of the conveyor, and the conveyor transports it laterally to one side of the machine for laying. The rear-laid harvester adds, between every two dividers, a set of reel V-belts with pick-up teeth, star wheels, and crop-holding spring bars every 30 cm, so that the stalks maintain a stable upright state during lateral conveyance; after reaching the right side of the machine, they are conveyed backward by a pair of longitudinal conveyor belts, and the stalks, with the cooperation of the crop-holding plate, are laid into windrows behind the machine. In the case of interplanting with corn, this model will not press the windrows onto the corn seedlings, and its cutting width is equal to the width of the wheat bed between two rows of corn. The vertical-header harvester has a compact structure, small longitudinal dimensions, is lightweight and flexible, and has good handling performance, suitable for harvesting rice and wheat on small plots. It is mostly matched with 7-9 kW walk-behind tractors or wheeled tractors of about 15 kW, with a cutting width of 1.1-1.2 m; there are also small self-propelled harvesters matched with 2-3 kW walk-behind dedicated chassis, with a cutting width of about 1 m.