25:1 planetary — 230 N.m continuous, 368 N.m peak
The GBX1200250702F is a 120 mm-diameter planetary gearbox from Schneider Electric's GBX series, with a 25:1 reduction ratio. It delivers 230 N.m continuous output torque at 100 rpm and 30 °C ambient, and can handle 368 N.m peak at the same speed and temperature — the peak figure is for intermittent duty, not sustained running.
Efficiency, noise, and backlash — the mechanical trade-offs
Straight-cut teeth give 94 % efficiency, which is typical for this gear type, but the noise floor sits at 65 dB measured 1 m away under no-load conditions — about the level of a quiet office printer. The 12 arc.min maximum torsional backlash means the output shaft can lag the input by up to 12 minutes of arc before the teeth re-engage; for positioning applications this sets the repeatability floor. Torsional rigidity is 13 N.m/arcmin, so under a 230 N.m load the shaft wind-up is roughly 17.7 arcmin.
Mounting and environmental constraints
The black anodized aluminium housing is 120 mm in diameter and carries a shaft output IP54 rating — protected against dust ingress and splashing water at the output seal, but not submersible. The C 45 steel shaft handles 2100 N axial force (thrust) and 1500 N radial force (overhung load) for the full 30,000-hour life at 100 rpm; higher loads are possible for shorter durations (2800 N axial, 2000 N radial for 10,000 hours). The gearbox is lubricated for life — no oil-change port or regreasing schedule. Operating ambient spans -25 to 90 °C.