planetary gear
- noun
- /ˈplænɪtɛri ɡɪr/
- Specialized
- The car's speed is optimized by a planetary gear system that adjusts the power from the engine.
- planetary gear system
Examples
-
This planetary gear model gives some sense of the complexity of the gearing required for turbines to handle the transient forces applied to wind generators.
Academic text (2010) -
This planetary gear, made up of a few thousand atoms, would perform much the same as some of its larger ancestors.
Academic text (2005) -
During the demonstration, the students learned how a planetary gear transfers motion from the sun gear to the outer gears.
-
In this design, the planetary gear arrangement allows for smoother operation of the machinery.
Synonyms
A gear that turns around a central gear in a gearbox
A small wheel with teeth that turns around a central gear and fits inside an outer ring
A gear that turns around a central gear to change speed or turning force
Surface Forms
Morphology
The noun phrase is compositionally interpretable: 'planetary' (relating to planets/orbit) combined with 'gear' (a toothed wheel) leads naturally to the idea of a gear that orbits or revolves around another. Although the term is technical, the imagery is transparent and cross-linguistically analogous, so a B1 learner who knows both words would likely infer the correct basic meaning.
Etymology
The name planetary gear comes from a simple picture: small gears called planet gears turn around a central sun gear just like planets 'orbit' a sun. Because the parts move this way, the system is very compact and lets power move smoothly and change speed, which is why engineers use planetary gear arrangements in machines and cars.