Planetary gearbox for servo motor systems PL120
A planetary gearbox, also known as an epicyclic gearbox, is a sophisticated mechanical system that transmits torque and controls speed. It’s named for its internal gear arrangement, which resembles planets orbiting a sun
- Sun Gear: The central gear, driven by the input (typically the servo motor shaft).
- Planet Gears: Multiple gears that mesh with the sun gear and orbit around it. They are mounted on a planet carrier.
- Ring Gear: An outer gear with internal teeth that meshes with the planet gears.

PL120 Planetary Gearbox Series:
The PL120 likely refers to a frame size or series designation within a manufacturer’s range of planetary gearboxes. Where is typically indicates a size often related to the output flange diameter or center distance in millimeters.

Specifications for a PL120 Planetary Gearbox:
- Frame Size: 120 mm (output flange size of around Ø115 mm).
- Nominal Output Torque: The number of stages (gear ratios) and specific design, but can be from 255 N.m to 345 N.m for single-stage, and higher for multi-stage.
- Gear Ratios:
- 1-Stage: 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 10:1
- 2-Stage: 12:1, 15:1, 16:1, 20:1, 25:1, 30:1, 35:1, 40:1, 50:1, 64:1
- 3-Stage: Even higher ratios up to 512:1 or more.