What the GBX-120 9:1 does on the driven shaft
The Schneider Electric GBX1200091082D is a straight-tooth planetary gearbox from the GBX-120 family, built to drop onto a servo or stepper drive and deliver a 9:1 reduction at up to 210 N.m continuous output torque. Maximum output torque is 336 N.m and maximum torsional backlash sits below 12 arc.min, which is the figure that decides whether the gearbox can hold position accuracy on a positioning axis or only general motion. For a buyer matching it to a Lexium or similar servo in the same Schneider ecosystem, the compatibility code is GBX — the gearbox mates only with the GBX-coupling input of the same frame family. Efficiency on this reduction is 94 %, so roughly 6 % of the input power shows up as heat in the housing — fine for continuous duty on a moving axis, but worth checking on a vertical load where holding torque matters more than efficiency. Acoustic signature is 65 dB at 1 m no-load, in line with the GBX series envelope; the straight-tooth geometry is the dominant contributor, and the figure does not include any reducer-specific damping option.
Shaft loads, service life, and what derates the rating
Service life is rated 30,000 h at 100 rpm and 30 °C — the figure every mounting calculation anchors to. Maximum radial force at the output shaft is 1500 N at 100 rpm over that 30,000 h life, and 2000 N if the application only needs 10,000 h; maximum axial force follows the same envelope at 2100 N (30,000 h) and 2800 N (10,000 h). Push the shaft harder, run it hotter, or mount a heavy pulley outboard of the gearbox mid-span and the 30,000 h figure starts to compress. Operating temperature window is −25 °C to 90 °C ambient and the unit is lubricated for life — no grease port, no relube schedule to track on the maintenance roster. Moment of inertia at the input is 2.62 g·cm², low enough that it does not dominate the drive-side inertia budget on a typical servo axis; torsional rigidity is 13 N.m/arcmin, the figure that controls how much twist you see under step load.
Mounting, sealing, and what sits where on the build
The housing is black anodized aluminium with a 120 mm gearbox external diameter, shaft in C 45 carbon steel — the standard GBX build, sized to match the matching 120-frame servo flange. It mounts in any position, so the gearbox can be hung below, beside, or in line with the motor without a derating footnote; the IP54 rating applies at the shaft output only, which is what actually sees splash and dust in most cabinet or machine-base installs.
Lifecycle posture and the critical-spare decision
Independent distribution sources the GBX1200091082D against an RFQ on the standard lead-time ladder — production quantities quoted to the BOM line, no stock or price figure carried on the page. There is no official successor or pin-compatible alternative listed for this code in the source data, so any swap to a different reduction ratio or a different GBX frame has to be qualified against the new numbers on its own merits.