40:1 reduction, 230 N.m continuous — the ratings that decide the fit
The GBX1200400704F: This is a Schneider Electric GBX-series planetary gearbox with a 40:1 reduction ratio and a 120 mm external diameter. The continuous output torque is 230 N.m at 100 rpm and 30 °C — that is the sustained load it can carry hour after hour without overheating the lubricant. The maximum output torque peaks at 368 N.m under the same conditions, which covers startup peaks and short overloads but not continuous running. Straight-cut teeth mean higher efficiency than helical — 94 % — but more audible whine at speed. The 65 dB noise level at 1 m is the no-load figure; under load it will be louder, so budget for acoustic enclosures in noise-sensitive areas. The 30000-hour service life at 100 rpm and 30 °C is the design life at rated torque — run it harder and the life shortens. The gearbox is lubricated for life, so no oil-change intervals to schedule, but the sealed-for-life design means a failed seal or bearing is an end-of-life event, not a service item.
Torque, backlash, and the loads that limit the application
Maximum torsional backlash is 12 arc.min — that is the angular play between input and output when the direction reverses. For positioning axes that need less than 0.2° repeatability, this gearbox needs a preloaded or dual-drive arrangement. Torsional rigidity is 13 N.m/arcmin, meaning each 13 N.m of applied torque twists the output shaft by one arc-minute; at 230 N.m continuous that is about 17.7 arcmin of windup under load. Maximum radial force on the output shaft is 1500 N at 100 rpm for the 30000-hour life, or 2000 N if you accept a 10000-hour life. Axial force limits are 2100 N for the long life and 2800 N for the shorter one. Both assume the force is applied at mid-distance from the output shaft — overhung loads reduce these numbers. The shaft is C45 steel, standard medium-carbon grade, adequate for these load levels without case hardening. Shaft output sealing is IP54, which keeps dust and splashing water out of the bearing cavity but does not survive hose-down or submersion.
Obsolete — what that means for sourcing
Schneider Electric lists the GBX1200400704F as obsolete. No stock-holding claim is made here; quantities are lot-specific and quoted per BOM line. For a replacement, the closest functional match would be another GBX-series gearbox with the same 120 mm diameter, 40:1 ratio, and 230 N.m continuous torque rating, but the mounting flange dimensions and shaft keyway must be verified against the existing installation. No direct pin-compatible cross-reference is published by Schneider.