4:1 planetary reduction — what the torque ratings mean for your axis
The GBX0800040842D is a straight-tooth planetary gearbox from Schneider Electric's GBX series, sized for a 4:1 reduction ratio in a compact 80 mm diameter housing. The continuous output torque is rated at 115 N.m, with a maximum peak of 184 N.m — the margin between these two figures defines the overload headroom for acceleration and deceleration events in servo or stepper applications. At 100 rpm and 30 °C ambient, the service life is 30000 hours, and the gearbox is lubricated for life — no maintenance schedule for oil changes. The 96 % efficiency means only 4 % of input power is lost as heat, which keeps thermal rise manageable even in continuous-duty cycles.
Sourcing reality — obsolete, sourced through independent channels
Schneider Electric lists this GBX0800040842D as obsolete. No official successor or cross-reference is recorded from the manufacturer. The part is available through independent surplus and broker channels — quantities are lot-specific and confirmed at RFQ. No pin-compatible or direct bolt-in replacement is documented by Schneider, so a substitution would require verifying the mounting interface, shaft dimensions, and torque curve against the application. For a BOM freeze or legacy machine rebuild, the GBX0800040842D can be quoted to order against the required quantity.
Mechanical limits that govern the fit
The gearbox mounts in any position — horizontal, vertical, or angled — which simplifies integration into existing machine frames. The output shaft is C45 steel, and the housing is black anodized aluminium, giving a corrosion-resistant exterior suitable for dry indoor environments. Shaft output protection is IP54, meaning it resists dust ingress and splashing water at the seal — not rated for washdown or submerged service, but adequate for typical machine-tool or conveyor environments. The torsional backlash is 12 arcmin maximum, and torsional rigidity is 6 N.m/arcmin — these numbers matter for positioning accuracy in pick-and-place or indexing axes where lost motion at reversal must be budgeted. Maximum axial force on the output shaft is 1200 N at 100 rpm for a 10000-hour life, derating to 900 N for the full 30000-hour service life. Maximum radial force is 950 N at 100 rpm for 10000 hours, derating to 650 N for 30000 hours — these limits apply with the force applied at mid-distance from the output shaft. The moment of inertia reflected to the input is 0.52 g.cm², which is low enough that it does not dominate the servo tuning for most small to medium motor loads.
Temperature envelope and noise floor
The noise level is 60 dB at 1 m under no-load — this is a moderate figure; in a quiet assembly cell it will be audible but not intrusive, while in a noisy production hall it will be masked by surrounding equipment.