Planetary gearbox, 3:1, 85 N.m — the critical spare angle
The GBX0800030553F is a Schneider Electric planetary gearbox with a 3:1 reduction ratio and 85 N.m continuous output torque at 100 rpm. The 94 % efficiency means the thermal losses are low enough that the black anodised aluminium housing sheds heat without a fan in most duty cycles. Rated for 30,000 hours service life at 100 rpm and 30 °C ambient — a solid MTBF figure for a positioning axis or conveyor drive that runs a single shift. The IP54 shaft output keeps dust and splash out, but the gearbox itself is not sealed for washdown.
Obsolete — sourcing the spare before the line stops
Schneider Electric lists this gearbox as obsolete. The 80 mm frame and 3:1 ratio with 9 arc.min backlash are the parameters to match if you are looking for a functional replacement. Available through independent surplus channels — quantities are lot-specific and confirmed at RFQ. For a legacy install that still has years of service left, buying a spare now avoids the scramble when the gearbox wears and the line goes down.
Torque and load ratings that govern the fit
Continuous output torque is 85 N.m at 100 rpm; the maximum output torque is 136 N.m at the same speed — the 60 % headroom covers transient overloads during acceleration or momentary jams. Maximum radial force on the output shaft is 650 N at mid-span for the 30,000-hour life target, dropping to 950 N if you accept a 10,000-hour service life. Maximum axial force Fa is 1200 N at 100 rpm for the shorter 10,000-hour window, or 900 N for the full 30,000-hour rating. The C 45 shaft material handles these loads without plastic deformation if the application stays within the envelope.