Torque, ratio, and backlash — the sizing constraints
The GBX1200321003F is a planetary gearbox with a 32:1 reduction ratio, straight teeth, and a 120 mm outer diameter housing. The continuous output torque is 260 N.m at 100 rpm and 30 °C, with a maximum of 416 N.m under the same conditions — the continuous figure governs steady-state duty cycles and drives the motor sizing decision. Maximum torsional backlash is 12 arc.min, and torsional rigidity is 13 N.m/arcmin. For a positioning axis that must hold a repeatable stop under load, the 12 arc.min slack limits the absolute accuracy of the output stage regardless of the motor encoder resolution.
Load limits and service life — what the numbers mean for the application
Rated service life is 30,000 hours at 100 rpm and 30 °C, lubricated for life — no periodic oil changes are required, which simplifies maintenance in a sealed-drive assembly. The shaft output carries an IP54 ingress rating, meaning the output seal resists dust ingress and splashing water but is not intended for washdown or submersion. Maximum axial force (Fa) on the output shaft is 2100 N for the 30,000-hour target, or 2800 N for a reduced 10,000-hour life. Maximum radial force (Fr) applied at mid-distance on the shaft is 1500 N for 30,000 hours, or 2000 N for 10,000 hours. Overhung loads from a belt or chain drive must be checked against these limits at the actual speed and duty cycle. The gearbox is rated for an ambient operating range of -25 to 90 °C, and efficiency is 94 % at rated load — about 6 % of input power is lost as heat through the black anodized aluminium housing. The C45 steel shaft and the straight-tooth profile are standard for moderate-speed, moderate-load positioning and indexing applications.
Obsolete — sourcing through independent channels
Schneider Electric has marked the GBX1200321003F as obsolete. The gearbox is available through independent surplus and broker channels — quantities are lot-specific and confirmed at RFQ. For a BOM that requires this exact ratio and torque class, the only sourcing route is the secondary market. A cross-reference to a current-production planetary gearbox in the same 120 mm frame and 32:1 ratio would require a parametric search of the Schneider or competitor catalogues — no direct pin-compatible replacement is documented.