Planetary gearbox, 120 mm frame, 3:1 ratio
The GBX1200030844D is a straight-tooth planetary gearbox from Schneider Electric's GBX series, with a 120 mm outer diameter housing in black anodized aluminium and a C 45 steel output shaft. It delivers a 3:1 reduction ratio, rated for 115 N.m continuous output torque and 184 N.m maximum, with 96% efficiency — the 3:1 ratio keeps the gear train simple and the losses low for a single-stage planetary.
Torque, life, and mounting constraints
Continuous torque is 115 N.m; maximum output torque hits 184 N.m — the margin above continuous covers brief acceleration peaks or stall events, but sustained operation above 115 N.m shortens the 30,000-hour service life at 100 rpm and 30 °C ambient. Maximum radial force on the shaft is 1500 N at 100 rpm for the full 30,000-hour life (2000 N for 10,000 hours); axial force limits are 2100 N and 2800 N respectively — both measured at mid-span on the output shaft, so an overhung load or a belt drive closer to the bearing face changes the effective rating. Mounts in any position — no oil-level orientation restriction — and the shaft output seal carries IP54, meaning it keeps out dust and splashing water but not pressurized washdown.
Obsolete — sourcing through independent channels
Available through independent surplus and broker channels; quantities are lot-specific and confirmed at RFQ. No pin-compatible or direct drop-in replacement is documented by Schneider, so a BOM review and possibly a frame-size change are needed if substituting.
Backlash, rigidity, and noise floor
Maximum torsional backlash is 8 arc-minutes — typical for a straight-tooth planetary at this price point; if the application needs less than 5 arc-min for servo positioning, a helical or low-backlash variant is required. Torsional rigidity is 12 N.m/arcmin, meaning the gearbox twists 1 arc-minute for every 12 N.m of applied torque — this stiffness is adequate for indexing and simple positioning but not for high-gain servo loops that need sub-arc-minute repeatability. Noise level is 65 dB at 1 m, no-load — audible but not loud for a 120 mm frame; under load the straight-tooth mesh will be slightly louder than a helical, but the 3:1 ratio keeps the tooth contact frequency moderate.
Lubrication and temperature range
Lubricated for life — no oil-change interval, no breather, no level plug. The grease fill is sealed at the factory and rated for the full 30,000-hour service life at 30 °C. Ambient operating temperature spans -25 to 90 °C — the grease stays fluid down to -25 °C and the anodised aluminium housing dissipates heat well at the upper end, though continuous torque should be derated above 30 °C per standard grease behaviour.