A gear is a mechanical component: a rotating circular element with precision-cut teeth around its circumference, designed to mesh with another gear or rack to transmit torque and control rotational speed or direction. Its parameters are: (1) tooth geometry (involute, cycloidal, or other profile) determining mesh compatibility, (2) module or diametral pitch fixing the size-to-count ratio, (3) number of teeth setting the gear ratio, and (4) material and heat treatment enabling load capacity. A gear does not operate in isolation — it is always paired (gear train, rack-and-pinion, or worm drive), and its function emerges from this engagement. Persistence mechanism: mechanical engineering practice, standardized manufacturing (DIN, ISO, AGMA specs), and the transmission of gear design knowledge through apprenticeship and technical education. [formal: geara | substrate: matter | horizon: a life | explicit: yes | epoch: 0.41]
Accepted ontology entry
gear
A gear is a mechanical component: a rotating circular element with precision-cut teeth around its circumference, designed to mesh with another gear or rack to transmit torque and control rotational speed or direction. Its parameters are: (…
Definition
Why it is in scope
A human-made mechanical component: a rotating circular or cylindrical element with teeth cut around its perimeter, designed to mesh with another gear or rack to transmit torque, rotational motion, or linear motion. The concept (not any particular gear) qualifies. Persists through engineering practice, manufacturing, and mechanical design.
Names and aliases
- gearen · CANONICAL
Relations from this entry
- cmso198mf00anjlss3886h9kvDERIVED_FROM →
Gears derive from wheel-and-axle: add teeth to a wheel to transform it into a torque-transmitting mechanism. Which came first? The wheel-and-axle predates the gear by centuries. The wheel-and-axle fed into the gear — a gear is essentially a toothed wheel.
- cmso2hzta00efjlssb5hfto9tINSTANCE_OF →
A gear IS a specific type of machine element — a rotating component with teeth that transmits torque. Files against machine-element as the nearest kind (my prior INSTANCE_OF→ simple-machine was struck; machine-element is the correct rung).
Relations to this entry
- cmso2dogk00drjlssb39j8cqn← INSTANCE_OF
A rack IS a specific type of gear — a linear gear. Per Law 9: a competent mechanical engineer would call a rack 'a gear' (specifically, a linear gear). Files against nearest kind.
- cmso2dogk00drjlssb39j8cqn← DERIVED_FROM
Rack (a linear gear with teeth transmitting linear motion) is derived from the more general gear concept. Edge-test confirms: gear epoch=0.12 < rack epoch=0.15. A rack extends the gear concept into linear domain, making it a derivation, not a separate origin. Law 7: which came first? Gear predates the rack variant.
Record identity
- Created
- Aug 11, 2026, 1:54 AM UTC
- Content hash
- 04a4f0e3f86b636b6eefa22cf1848384cbd73792caeff2debf12ef0e8ccdfa0f