What this 3:1 planetary gearbox delivers
The GBX0400030703F is a Schneider Electric GBX series planetary gearbox with a 3:1 reduction ratio and straight teeth. At 94% efficiency, it loses only 6% of input power to friction and windage — a solid figure for a single-stage planetary of this size. Maximum torsional backlash is 24 arcmin, which places it in the standard-precision class — adequate for positioning axes where the load doesn't reverse frequently, but not for high-accuracy indexing or servo applications that need sub-arcmin repeatability. Torsional rigidity is 1 N·m/arcmin, meaning the output shaft twists 1 arcmin for every 1 N·m of applied torque. This stiffness, combined with the 3:1 ratio, suits it for constant-speed conveyor drives or rotary indexing tables where the load is steady and the cycle time is moderate.
Load limits and service life — what the numbers mean
Rated service life is 30,000 hours at 100 rpm and 30 °C ambient. The gearbox is lubricated for life, so no maintenance oil changes — but the 30,000-hour figure assumes the load stays within the published axial and radial force limits. Maximum axial force (Fa) is 200 N at 100 rpm for a 10,000-hour life, dropping to 160 N for the full 30,000-hour target. Radial force (Fr) follows the same derating: 200 N for 10,000 hours, 160 N for 30,000 hours, measured at mid-span on the output shaft. Exceed these and the bearing life shortens faster than the gear teeth. The housing is black anodized aluminium (40 mm external diameter), and the shaft is C45 steel.
Obsolete — sourcing reality for the GBX0400030703F
Schneider Electric lists this gearbox as obsolete. No official successor part number is recorded — the GBX series has been superseded by newer planetary families with different mounting dimensions and backlash classes. Available through independent surplus and broker channels.