Used chopper rotor

Role of the rotor in the chopper's cutting system

At the rear of the combine harvester, straw exiting the straw walkers or threshing rotor falls into the chopper. The rotor, a shaft fitted with articulated hammers or knives, spins at high speed within the housing. Alongside fixed counter-knives, it forms the cutting system: each hammer throws the straw against the blades, chopping it into short pieces, then deflectors spread the chopped straw evenly across the cutting width. A worn rotor degrades the entire chopper cutting system: straw is poorly chopped, forms uneven windrows, and hinders the following soil work.

Hammer or knife chopper rotor: two configurations

• Oscillating hammer rotor: steel hammers articulated on axes that retract when hitting foreign objects.
• Knife rotor: thin blades mounted in pairs for finer chopping of cereal straw.
• Number of hammer, knife, and counter-knife rows varies according to cutting width.
• Hammers and knives are wear parts: used rotors are often refitted with a new set.
• Rotor speed is adjusted via the pulley or variator depending on the crop, cereals or maize.

Rotor balancing: vibrations, unbalance and wear

The chopper rotor spins at several thousand revolutions per minute: even slight unbalance causes vibrations that wear bearings, crack the housing, and strain the drive. A lost hammer, broken knife, or warped shaft caused by a stone are enough to unbalance the rotor. When replacing hammers, swap them in opposing pairs of equal weight to maintain rotor balance and cutting system efficiency. Before sale, our technicians verify shaft straightness, hammer pins, and bearing seats: warped rotors are not resold.

TMC Bejenne: chopper rotors for Claas, New Holland, John Deere, Case IH

• Claas: chopper rotors for Lexion 600 and 760 models, and older Dominators.
• New Holland: rotors for TF, TX, CX and CR series, for both walkers and rotor harvesters.
• John Deere: rotors for 9580 WTS, 9780 CTS, S660, and older series.
• Case IH: chopper rotors for Axial-Flow 1660, 2166 and 6088.
• Since 1945, TMC Bejenne dismantles agricultural machinery over a 11-hectare site and offers 25,000 references of used parts.

Rotor alone or complete chopper?

If only the rotor is faulty, a checked used rotor is sufficient: it mounts into the existing housing with its bearings. If the housing is deformed, the chopper clutch slips, or the mounts are damaged, consider a used complete chopper already assembled. The chopper housing is also available separately. In all cases, plan for wear spare parts—hammers, knives, and counter-knives—when acquiring the rotor: dismantling is done only once.

Chopper rotor, brush cutter rotor, or threshing rotor: do not confuse

• Brush cutter and flail mower rotors: tractor-attached tools driven by the PTO, used for hedge and roadside maintenance.
• Gyro mower: horizontal blades driven by the PTO, unrelated to straw choppers.
• Threshing rotor: main rotor in rotor-type combine harvesters like Axial-Flow, which threshes and separates grain.
• Combine chopper rotor: rear-mounted, belt-driven from the machine, not by PTO; the subject of this page.

Compatibility, pickup and delivery options

To find the right rotor, note the brand, model and serial number of the combine, chopper width, number of hammer or knife rows, and shaft diameter at the bearings. A photo of the pulley-side end aids in verifying the drive. On a Laverda as on a Claas, two versions of the same series may have different rotors. Pickup is onsite in Naintré; delivery anywhere in France is available on request, priced according to rotor length.