16:1 planetary reduction, 260 N.m continuous — the load-sizing anchor
The GBX1200160551F is a Schneider Electric planetary gearbox with a 16:1 reduction ratio, delivering 260 N.m continuous output torque at 100 rpm and 30 °C ambient. The maximum output torque reaches 416 N.m under the same conditions — this is the peak overload the gearbox can transmit before the straight-tooth mesh or bearings yield. Rated service life is 30000 hours at 100 rpm and 30 °C, with the gearbox lubricated for life — no oil-change interval to schedule. The operating ambient range spans -25 to 90 °C, which covers most indoor machine-tool and conveyor applications but may require derating above 30 °C for the torque figures. Efficiency is listed at 94 %, meaning 6 % of the input power is lost as heat in the gear mesh and bearings. For a motor driving a 260 N.m load at 100 rpm output (about 2.7 kW input), the heat rejection is roughly 160 W — enough to warm the black anodized aluminium housing but within the rated ambient if airflow is not blocked.
Backlash, rigidity, and overhung load limits — the positioning constraints
Maximum torsional backlash is 12 arc.min — this is the angular play between input and output when the direction reverses. For a positioning axis that indexes and holds, 12 arc.min at the output translates to about 0.35 mm of linear error on a 100 mm lever arm; if your application needs tighter repeatability, a gearbox with lower backlash (e.g., 3–5 arc.min) would be required. Torsional rigidity is 13 N.m/arcmin — the stiffness of the gear train under load. At the continuous torque of 260 N.m, the elastic wind-up is about 20 arc.min (260 ÷ 13), which adds to the backlash when the load is applied. This combined positioning error matters for servo-driven indexing tables or pick-and-place gantries. Maximum radial force (Fr) on the output shaft is 1500 N at 100 rpm for the 30000-hour life, rising to 2000 N for a 10000-hour life. Axial force (Fa) limits are 2100 N and 2800 N respectively. These forces must be applied at mid-distance from the output shaft — a belt drive or pinion mounted further out creates a bending moment that reduces the allowable radial load. The shaft material is C 45 medium-carbon steel, which is standard for this torque class.
Obsolete — sourcing through independent channels
Schneider Electric lists the GBX1200160551F as obsolete. The part is available through independent surplus and broker channels — quantities are lot-specific and confirmed at RFQ. For a machine-tool rebuild or MRO replacement, the 120 mm housing diameter, 16:1 ratio, and 260 N.m continuous torque define the form-fit-function envelope. Any substitute must match the output shaft dimensions, mounting flange pattern, and input bore to avoid a mechanical rework. The IP54 shaft output seal means the gearbox is splash-resistant but not washdown-rated — suitable for dry indoor environments with occasional coolant mist.