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Glite Dictionary
planet gear

planet gear

7.7
A small wheel with teeth that turns around a central gear and fits inside an outer ring
  • noun
  • /ˈplænɪt ɡɪr/
  • Specialized
translation icon : engranaje planetario
  • In an epicyclic gear train, the planet gear orbits around the central sun gear while also engaging with the outer ring gear.

Examples

  • It consists of fixed sun gears and circulating planet gears of the same diameter.

    Academic text (2000)

  • The mechanical system uses multiple planet gears to ensure smooth and efficient motion.

  • For variable speed and variable mass rotation with rotational asymmetry, consider the oft-used planetary gear set with a single planet gear and weighted carrier.

    Blog text (5)

  • Understanding how a planet gear operates is essential for designing complex gear systems.

Synonyms

planetary gear
vsplanet gear
  • Specialized
1 7.4

A gear that turns around a central sun gear to change speed in a gearbox

meshes with both sun and outer ring gears as part of the system
epicyclic gear
vsplanet gear
  • Specialized
8.8

A gear that turns around a central gear to change speed or turning force

meshes with both the central and outer ring gears while revolving
planet wheel
vsplanet gear
  • Specialized
8.1

A gear that turns around a central gear in a gearbox

meshes with both central and outer ring gears rather than only revolving

How Complex

differential
  • Specialized
5 7.9
planet gear
  • Specialized
7.7
bevel gear
  • Specialized
6.5
gear
180 2.9

Surface Forms

planet gear singular
planet gears plural

Morphology

planet + gear

The compound is compositionally motivated: a B1 learner who knows 'planet' (a body that orbits) and 'gear' (a toothed wheel) can infer this is a gear that orbits or behaves like a planet. However, the full technical detail (meshing with sun and ring gears in an epicyclic train) is domain-specific and not fully predictable from the constituents, so the expression is only partially transparent to general learners.

Etymology

Planet gear gets its name from the image of a small planet that acts like a gear and turns around a central sun gear. Because each planet gear turns around and works with the middle sun gear and the outer 'ring' gear, the name helps you remember it 'orbits' and fits with other gears.