3:1 reduction, 115 N.m continuous — what the torque ratings mean
The GBX1200031002F is a straight-tooth planetary gearbox with a 3:1 reduction ratio, meaning the input speed is divided by three while output torque is multiplied by the same factor, minus efficiency losses. At 100 rpm output and 30 °C, continuous output torque is 115 N.m (1017.8 lbf.in), with a maximum peak of 184 N.m (1628.5 lbf.in) — the margin between continuous and peak allows for transient overloads during start-up or momentary jams without immediate derating. Efficiency is listed at 94 %, so roughly 6 % of input power is lost as heat in the gear mesh and bearings. For a motor driving 1 kW through this box, about 60 W dissipates inside the housing — the black anodized aluminium body (120 mm diameter) acts as the heat sink, and the -25 to 90 °C ambient operating range accommodates most cabinet or machine-mounted positions.
Lifecycle reality — obsolete, sourced through independent channels
Schneider Electric lists this gearbox as obsolete, though the internal field reads 'current' — the practical sourcing posture is that new-manufacture units are no longer available from the factory. Availability is through independent surplus and broker channels, with quantities confirmed at RFQ. The 30,000-hour service life at 100 rpm and 30 °C (with lubricated-for-life grease) sets the replacement interval for continuous-duty applications. If the gearbox has been in service approaching this threshold on a critical conveyor or indexing axis, a spare should be sourced now while independent stock remains available.
Shaft loading limits and protection rating
Maximum radial force (Fr) at mid-span of the output shaft is 1500 N for the full 30,000-hour life, or 2000 N if a 10,000-hour service life is acceptable. Axial force (Fa) limits are 2100 N at 30,000 hours and 2800 N at 10,000 hours — both at 100 rpm and 30 °C. These are the load limits for the output bearing; exceeding them shortens life or causes premature failure. Shaft output protection is IP54, meaning the output seal resists dust ingress and splashing water but is not rated for pressurized washdown or immersion. The housing itself is sealed, but the shaft seal is the wet-end boundary — in food-grade or wet environments, a gearmotor with IP65+ output sealing would be required.
Acoustic and torsional performance
Noise level is 65 dB at 1 m under no-load — this is the acoustic emission from the straight-tooth mesh and bearing rotation. In a quiet production environment (below 70 dB background), this gearbox is audible but not intrusive; in a noisy machine hall it will be masked. Maximum torsional backlash is 8 arc.min, which governs positioning repeatability in reversing or indexing applications — for a 3:1 reduction, 8 arc.min at the output corresponds to roughly 2.7 arc.min at the input, acceptable for general motion but not for precision servo axes. Torsional rigidity is 12 N.m/arcmin — this is the stiffness of the gear train under load. At the continuous torque of 115 N.m, the wind-up is about 9.6 arc.min (115 ÷ 12), which adds to the backlash for total lost motion. The C 45 steel shaft and black anodized aluminium housing provide the structural loop for this stiffness.