Rotary Tiller Gearbox
A rotary tiller gearbox (rotavator gearbox) is the central right-angle drive that takes the tractor PTO input and turns the tiller rotor that breaks and prepares soil. It is a bevel-gear unit: the splined input shaft, driven at 540 (or 1000) rpm, meets a spiral- or straight-bevel pinion and crown wheel that redirect power through 90 degrees to a horizontal output, usually with a moderate speed reduction so the rotor turns slower and with much higher torque than the PTO.
Typical units step 540 rpm down to roughly 200-280 rpm at the rotor through ratios around 1:1.8 to 1:2.5, delivering output torque commonly from about 400 Nm up to 850-1000 Nm on wider tillers behind 50-100 HP tractors. Single bevel-stage designs dominate, with the side drive to the rotor completed by chain or gears in the tiller frame. Gears are cut to ISO 1328 / AGMA 2015 quality grades and can be load-rated to ISO 6336 / AGMA 2001 where engineering data is required.
Construction is built for abrasive, shock-loaded field work: case-hardened alloy-steel gears (20MnCr5, 20CrMnTi), gas-carburised, quenched and ground, in a rigid grey-iron or ductile-iron housing with tapered roller bearings, robust oil seals and IP65-class sealing against dust and water. Mineral or PAO ISO VG 220 oil is typical, with splash lubrication.
Units are configured by input spline (1-3/8" Z6 or Z21, 1-3/4" Z20), ratio, output shaft and mounting flange, plus shear-bolt or slip-clutch overload protection. Himalay's MSME partners manufacture rotary tiller gearboxes with gear-rating to AGMA/ISO 6336 where engineering data is required, ISO 9001 quality systems, load and efficiency test reports and material traceability; CE (Machinery Directive) and SABER (Saudi Arabia) coordinated as part of the standard order flow.
