120 mm planetary, 3:1, 115 N.m continuous — what the ratings mean on the line
The GBX1200031081D is a 120 mm diameter planetary gearbox with a 3:1 reduction ratio, rated for 115 N.m continuous output torque and 184 N.m maximum. That continuous figure is the one to size against — the drive train sees that torque indefinitely at 100 rpm and 30 °C ambient. Efficiency sits at 96 %, which means about 4 % of the input power dissipates as heat through the black anodized aluminium housing. For a motor in the 0.5–1.5 kW range, that keeps the gearbox cool enough to run without external ventilation in most conveyor and positioning applications. Backlash is held to 8 arcmin maximum — tight enough for indexing and pick-and-place but not zero-backlash. If the application needs bidirectional positioning without lost motion, a preloaded or helical-gear stage is the next step up.
Torque, life, and overhung load — the three numbers that decide fit
Service life is specified at 30,000 hours at 100 rpm and 30 °C. That is a 3.4-year continuous run at that speed; cycling or lower duty extends it. The gearbox is lubricated for life, so no oil-change interval to schedule. Maximum radial force Fr is 1500 N at 100 rpm for the 30,000-hour target, applied mid-span on the output shaft. If the load pulley or sprocket sits further out, derate accordingly — the 2000 N figure at 10,000 hours gives a sense of the trade-off. Axial force Fa is 2100 N at 100 rpm for the full life rating, 2800 N for a 10,000-hour duty. Both limits assume the force is pure axial, no moment. A belt drive with tension that pulls the shaft axially needs to stay under the lower figure for the long haul.
Active production — sourced per RFQ, no obsolescence risk
Lifecycle status is Active per Schneider Electric. No end-of-life notice, no successor part number to track. This is a current-catalog item, not a legacy or phase-out line. The GBX series covers a range of diameters and ratios; this 120 mm, 3:1 variant is a standard offering.