A combine harvester can be broken down into seven major systems from the header to the grain tank. The crop flow after entering the harvester is: divider → reel → cutter bar → feed auger → feeder house chain rake → axial-flow drum → concave → vibrating sieve + fan → grain elevator → grain tank → unloading auger.
For agricultural machinery parts dealers, repair service providers, and procurement personnel, understanding the machine’s internal structure is equivalent to mastering a stocking map. Today, let’s take the Lovol RG50 / RG60 series as an example and break down the key components, wear-part distribution, and wear patterns of a rice harvester across the seven core systems with Maikeyier!
Header System Parts
The combine header is the “first scene” of the harvester. Working quality mainly depends on this area. One header assembly contains about 8 sub-assemblies and 145 part line items, making it the most part-dense section of the entire machine.
Dividers
Located at the very front of the harvester, they separate the rice to be cut from the rice not to be cut. Therefore, if a divider is deformed or installed at the wrong angle, the rice at the edge will be pushed down instead of cut, directly becoming grain loss. It is the part that determines header width utilization.
Reel Assembly
The reel holds and pushes the rice backward at the moment the cutter bar cuts the stalks. Core parts include: reel bat assembly, torsion-spring tines, eccentric five-spoke disc weldment / support five-spoke disc weldment, anti-wrapping pipe, reel shaft seat (U-shaped nylon seat), and bushing (nylon part). Among them, torsion-spring tines are wear parts, and the reel shaft seat (U-shaped nylon seat) and bushing (nylon part) are high-frequency consumables, all of which are regular stocking items.
Cutter Bar Assembly
A reciprocating cutter: the moving knives reciprocate at high speed between the knife guards (thousands of times per minute), cutting stalks like scissors. Core parts include: cutter bar assembly, cutter bar knife strip, cutter bar knife head, half blade (small), half blade (large), knife guard, hold-down clip, shim (hold-down clip friction plate), knife head oil seal, cutter bar rivet, swing arm assembly, swing fork shaft, wobble ring seat, and wobble ring drive shaft.
Stocking list: cutter bar assembly, knife guard, hold-down clip friction plate, knife head oil seal, cutter bar rivet.
Header Auger
Gathers the cut grain from both sides toward the center and pushes it into the feeder house. Core parts: feed finger bar assembly, retractable finger bar, feed finger seat, feed finger guide sleeve, stainless steel left/right spiral flights, and eccentric adjustment shaft. Among them, the feed finger guide sleeve (commonly called the “boat,” a nylon part) wears very quickly.
Feeder House
Located between the header and the threshing chamber, it feeds the crop delivered by the auger evenly and continuously into the drum using chain rakes. Core parts: feed chain assembly, chain rake, feed chain, drive shaft (feed shaft) hex shaft, anti-wrapping tube, feed sprocket, sprocket, tension wheel, tension arm assembly, driven feed roller, end cover, and feeder house leakage prevention plate (canvas). Among them, the feed chain and chain rake are wear parts.
Threshing & Cleaning System Parts
Grain enters the threshing chamber through the header, where the grain is knocked off the ears and then separated from the tailings. Threshing & Cleaning System Parts include 6 sub-assemblies and 119 part line items.
Axial-Flow Drum Assembly
The crop advances spirally along the drum axis. The rasp bars on the drum repeatedly strike and comb the crop; after the grain is stripped off, it falls through the concave. Core parts: threshing drum assembly, threshing tooth bar (dense), threshing tooth bar (sparse), threshing drum head, drum head spiral plate, spline sleeve (6-key), bearing. The choice between dense and sparse tooth bars depends on the difficulty of threshing the grain, and they are also among the regular wear parts.
Concave
A grid-shaped sieve screen wrapped below the drum. Core parts: concave assembly, front concave, rear concave, left/right inlet plates, tail sealing plate, feed inlet sealing plate, and curtain. Among them, the clearance between the drum and the concave is the most important adjustable parameter on the harvester.
Sieve Box Assembly
What falls from the concave is not pure grain, but a mixture of grain, broken ears, shriveled grain, broken leaves, and soil. The sieve box is responsible for separating them. Core parts: upper sieve assembly, fish-tail sieve assembly, sieve plate, middle sieve plate, woven mesh, finger sieve assembly (wave sieve), drive pulley (spun), eccentric bearing assembly, bearing, balance weight, rocker arm, and vibrating sieve drive wheel shaft.
Fan Assembly
The harvester’s sieve box performs “screening,” while the fan performs “air separation.” The airflow generated by the centrifugal fan blows away light impurities while heavy grain falls. Core parts: fan assembly, fan blade, fan shaft, input pulley, output pulley, and bearing housing.
Drum Drive Gearbox Assembly
Responsible for distributing power to the drum. Core parts: reversing box housing, reversing bevel gear, drive bevel gear, driven bevel gear, transmission housing, output shaft, and input shaft.
Belts
The power for the threshing and cleaning section is entirely transmitted by belts. There are five belts in total, including the auger belt, vibrating sieve belt, reversing belt, and threshing belt (fan belt).
Grain Handling System Parts
Grain Handling System Parts are responsible for transporting the clean grain coming out of the threshing and cleaning system upward, storing it, and unloading it. This section includes 4 sub-assemblies and 94 part line items.
Auger
Grain Elevator Assembly
The cleaned grain is first collected by the primary horizontal auger, then lifted to the grain tank by the vertical auger. Core parts: primary elevator auger assembly (including scraper blades), elevator auger tube, grain tank body assembly (large), auger scraper blade, bevel gear, grain drive gearbox, and primary auger pulley.
Tailings Elevator Assembly
This section is responsible for collecting unthreshed heads from the sieve surface, sending them to the re-threshing box for secondary threshing, and then returning them to the sieve surface. Core parts: tailings vertical auger, tailings elevator auger tube, tailings drive gearbox assembly, chain box assembly, chain, sprocket, re-threshing box assembly, re-threshing teeth (small), and re-threshing teeth 2 (large).
Unloading
After the grain tank is full, grain is relayed out by the bottom auger + unloading auger tube and discharged directly into a accompanying grain truck. Core parts: eccentric wheel, unloading drive gearbox, large bevel gear, small bevel gear, grain outlet tube assembly, horizontal unloading tube assembly, and O-ring seal.
Undercarriage & Drive Parts
The harvester chassis system is one of the important sections: 3 sub-assemblies and 143 part line items, determining the harvester’s forward movement, turning, and direction.
Wheel System
Track, spun track roller, track roller shaft, inner spacer, track roller oil seal combination, bearing, spun balance wheel, idler wheel assembly (including bracket), idler wheel oil seal, idler wheel shaft, idler wheel, front guide rail, rear guide rail, tension screw, and nut seat.
Drive Axle System
Power path: engine → travel belt → HST continuously variable transmission → gearbox → half shaft → drive sprocket → track. Core components: gearbox assembly (with/without drive sprocket in two configurations), drive sprocket, gearbox housing, half shaft assembly, half shaft, half shaft gear, gears for each range: first gear drive, second gear drive, third gear drive, first gear driven, second gear driven, third gear driven, three-shaft assembly, four-shaft, two-shaft, steering large shift fork, steering shift block, 1–3 gear shift fork shaft, left/right brake rocker arm, outer friction plate, inner friction plate, HST connection seat assembly, flange, bearing, breather plug, breather assembly, etc.
Chassis Frame Assembly
The welded frame that carries everything. There are not many parts, but they are all structural parts, such as supports.
Control & Hydraulic System Parts
Harvester Control & Hydraulic System Parts include 12 sub-assemblies and 64 part line items.
Mechanical Control Cables
- Includes: rods, ball joints, cables, steel ropes. Core components:
- Speed control: handle ball, rod, self-lubricating ball joint
- Steering and lift control: rod assembly, self-lubricating ball joint, dust cover
- Continuously variable speed control: handle ball, rod assembly
- Parking brake: parking brake cable assembly, pedal return spring
- Throttle / shutdown: throttle cable assembly, shutdown cable
- Threshing clutch: tension arm assembly (tension wheel, engine pulley)
- Unloading clutch: tension wheel assembly, unloading belt
- Header clutch: cable, spring
Hydraulic Lines
- Covers cylinders, valves, pumps, and HST. Core components:
- Header hydraulics: reel lift cylinder, reel hose assembly
- Steering hydraulics: steering cylinder, header cylinder, steering hose assembly
- Multi-way valve: two-way valve assembly (the hydraulic “distribution center”), high-position unloading cylinder, suction oil filter, hydraulic tank breather
- Gear pump: double pump, high-pressure oil filter assembly, pump outlet hose
- Continuously variable hydraulic transmission: HST hydraulic continuously variable transmission device, piston pump + piston motor. Precision parts include input shaft, output shaft, cylinder block, piston, nine-hole plate, and valve plate.
Engine & Electrical System Parts
Engine & Electrical System Parts are also an important harvester system, with 12 sub-assemblies and 50 part line items.
Power Section
- Engine: Quanchai 102 engine assembly
- Three filters: oil filter element, fuel filter element, fuel-water separator filter element
- Radiator: radiator, auxiliary water tank assembly, radiator cap, inlet/outlet water pipes
- Intake: air filter cup assembly, air filter assembly, air filter element (outer), air filter element (inner)
- Fuel: fuel tank assembly, fuel tank cap, filter screen, exhaust and after-treatment
- Dust removal: dust cover weldment, latch
- Engine base: vibration damping pad
Electrical Section (Six Wiring Harnesses)
- Operator console: combination switch, ignition switch, central electrical box assembly, relay, combination instrument, button-pull-wire control handle, multi-function warning light, horn
- Harvester body: LED work light, reverse alarm, unloading motor, unloading motor controller, angle sensor
- Grain tank: grain tank wiring harness, grain-full sensor
- Header: header wiring harness, LED light
- Engine: speed sensor, water temperature sensor
- Battery: main power switch, starter cable
- Sunshade fan: fan, toggle switch
Safety & Cab Parts
The harvester is manually operated. During driving, ergonomics, protection, and operational safety must be ensured, so Safety & Cab Parts are essential. Harvester body system includes 7 sub-assemblies and 22 part line items.
- Sunshade system: sunshade
- Operator console assembly: seat
- Guard system: upper guard assembly (header wobble ring), front guard (reel support), left upper/left lower front guard, left lower rear guard, flip-up guard weldment, gas spring
- Rearview mirrors: left rearview mirror assembly, right rearview mirror assembly
- Rear tail cover: rear tail cover, baffle
- Fire extinguisher, etc.
How to Procure or Stock Parts?
After breaking down the entire harvester, we can choose procurement or stocking lists based on actual conditions. This helps reduce inventory while avoiding stockouts during peak season that affect our business.
Stock by Wear Rate
- High-frequency consumables (volume items): tines, blades, rivets, oil seals, belts, filter elements, track roller oil seals, canvas seals. Replaced multiple times per operating season.
- Medium-frequency replacement (repeat purchases): reel bearings, swing arms, tension wheels, gears, sieve plates. Replaced every one to two years.
- Large consumables (higher unit price): tracks, threshing drums, concaves, gearbox assemblies, HST, radiators. Expensive and not frequently replaced.
Choose Suppliers by Manufacturing Process
If the same batch of parts is reclassified by manufacturing process, it will fall into about 25 categories: sheet metal, stamping, casting, aluminum castings, machined shafts, gears, sprockets, chains, belts, oil seals, bearing housings and bushings, spacers, fasteners, springs, cables, canvas, polymer plastic parts, rubber and plastic parts, glass, filter elements, friction plates, hydraulic parts, and motors/electrical parts. During procurement, you can contact factories by process, or find a supplier that can provide one-stop procurement.
- Sheet metal parts: find factories with laser cutting + bending + welding capabilities; large volume, low unit price, depending on tooling and batch size.
- Cast/forged + machined parts (gears, half shafts, bearing housings): look at heat treatment and precision machining capabilities.
- Rubber and plastic parts (tracks, belts, oil seals, nylon parts): look at formulation and tooling.
- Hydraulic parts and precision parts (HST internal parts): choose original factory or specialized supporting factories.
Why Choose Maikeyier for Harvester Parts?
Maikeyier not only knows how to break down the machine, but also knows how to manufacture parts efficiently and with high quality and deliver them to customers. We have deep experience in the agricultural parts field, own a forging factory, and have a stable list of full-category parts factory partners, enabling us to provide you with one-stop supply chain services.
- In-house manufacturing of high-frequency wear parts: core forgings such as cutter bars, blades, knife guards, gears, and sprockets are produced by our own forging factory with controllable quality.
- Full-category supporting supply: rubber and plastic parts, machined parts, sheet metal parts, hydraulic parts, electrical parts, etc., are produced by partner factories strictly according to Maikeyier standards.
- Ready-stock warehousing: 5,000 square meters of ready-stock warehouse; high-frequency wear parts shipped quickly.
- Compatible with mainstream brands: covers all series of Kubota, Yanmar, Lovol, FMWorld, and other models.
If you have any questions about harvesters, welcome to leave us a message. Similarly, if you are looking for a reliable rice harvester parts supplier, please send us your machine model, OEM part number, or requirement list, and our technical team will provide accurate matching and a quotation within one working day.