Definition and family positioning
GBX1200320841D is a planetary gearbox in the Schneider Electric GBX series, with a straight-tooth gear set, a 120 mm gearbox external diameter, and a C 45 steel output shaft — a precision reducer sized for direct mounting to a servo or stepper drive in a positioning axis. The reducer is lubricated for life and can be mounted in any position, which matters for panel builders routing the gearbox around existing machine geometry without preserving a specific oil-sump orientation.
Sizing the torque envelope and service life
Continuous output torque is 260 N·m and maximum output torque is 416 N·m; the listed service life is 30000 h at 100 rpm and 30 °C, so the published maximum axial and radial loads (2100 N Fa, 1500 N Fr at the same reference point) are the figures that actually bound a real axis, not the torque numbers alone. Torsional rigidity is 13 N·m/arcmin and maximum torsional backlash is 12 arc.min — backlash dominates the choice for backlash-critical applications like rack-and-pinion or lead-screw drives, while rigidity is the limiting figure when the driven load is sensitive to wind-up under shock.
Precision performance figures on record
Efficiency is 94 % and noise level is 65 dB at 1 m on no-load — the efficiency figure is useful for thermal budgeting of the gearbox under continuous duty, and the noise figure tells a controls integrator that a quiet axis in a laboratory or medical machine is feasible without acoustic enclosure. Moment of inertia is 1.3 g·cm², which keeps the reflected load back to the motor low and lets the drive size the acceleration profile from the driven inertia rather than from gearbox wind-up losses.
Mounting and environmental envelope
The shaft output carries an IP54 seal and the housing is black anodized aluminium — IP54 on the shaft is sufficient for general industrial enclosures but not washdown or outdoor exposure, so the unit sits inside a cabinet or covered machine frame rather than directly on a wet line.