What this planetary gearbox delivers
The GBX1200040553F is a 120 mm-diameter planetary gearbox with a 4:1 reduction ratio, straight-tooth gearing, and a black anodized aluminium housing. It delivers a continuous output torque of 155 N.m at 100 rpm and a maximum output torque of 248 N.m under the same conditions — the continuous figure is the one to size against for steady-state duty cycles. Rated efficiency is 94 %, meaning about 6 % of input power is lost as heat in the gear mesh and bearings. For a servo or stepper motor application, that heat stays inside the housing — the lubricated-for-life grease handles it without a maintenance interval. Torsional rigidity is 12 N.m/arcmin, and maximum torsional backlash is 8 arc.min. In a positioning axis, the 8 arc.min of lost motion at reversal is the figure to budget into the overall system accuracy — the rigidity number governs how much windup you get under load before the output shaft moves.
Load ratings and service life
Service life is 30000 hours at 100 rpm and 30 °C ambient — that is about 3.4 years of continuous running. The axial and radial force limits are given at two life points: 2100 N axial and 1500 N radial for the full 30000-hour life, or 2800 N axial and 2000 N radial if you accept a 10000-hour life. These forces are applied at mid-distance from the output shaft; a longer overhung load reduces the allowable radial force. The shaft output carries an IP54 degree of protection — sealed against dust ingress and splashing water, but not submersion. The housing itself is not separately rated; the IP54 applies to the shaft exit seal. Ambient operating range is -25 to 90 °C, which covers most indoor industrial enclosures and unheated warehouses. Noise level is 65 dB at 1 m, no-load — this is the gear mesh whine under no torque. Under load the noise will rise slightly with the tooth contact stress, but the straight-tooth design is inherently noisier than helical at the same reduction. For a noise-sensitive installation (cleanroom, lab, packaging near operators), factor in an enclosure or acoustic damping.
Sourcing reality — obsolete, quoted to order
Schneider Electric lists the GBX1200040553F as obsolete. The part is available through independent surplus and broker channels — quantities are lot-specific and confirmed at RFQ. The shaft material is C45 steel, and the housing is black anodized aluminium. The gearbox external diameter is 120 mm. These dimensions and the 4:1 reduction ratio are the critical fit parameters for replacing an existing unit in a motion-control axis — confirm the mounting flange pattern and shaft keyway dimensions against the original before committing.