12:1 reduction, 120 N.m continuous — what the torque ratings mean
The GBX0800120702D is a straight-tooth planetary gearbox with an 80 mm outer diameter and a 12:1 reduction ratio. Continuous output torque is rated at 120 N.m, with a maximum intermittent torque of 192 N.m — the higher figure is for acceleration peaks and emergency stops, not sustained duty. Torsional rigidity is 6.5 N.m/arcmin, and maximum backlash is 17 arc.min. For a positioning axis, that backlash figure tells you the lost motion at reversal — if your application needs under 10 arc.min, this gearbox will not hold it without external compensation.
94% efficiency, 30,000-hour service life — the fine print
Efficiency is listed at 94% — that is the power loss through the gear train at rated load. The noise level at 1 m, no-load, is 60 dB, which is about the hum of a quiet office printer; in a cabinet with a VFD and contactors it will be inaudible. Service life is 30,000 hours at 100 rpm and 30 °C ambient. That is about 3.4 years of continuous 24/7 operation at that speed. The gearbox is lubricated for life — no oil changes, no maintenance ports. Mounting position is any orientation, which simplifies layout in a tight panel.