A rack is a linear gear: a straight bar with uniformly spaced, precision-cut teeth along one edge, designed to mesh with a circular gear (pinion) to convert rotational motion into linear motion, or vice versa. Parameters: (1) tooth profile — the shape of individual teeth, typically involute or straight-cut per ISO standards; (2) module or diametral pitch — the ratio of teeth per unit length that determines meshing compatibility; (3) length — the active toothed section, manufactured to tolerance; (4) material — steel, brass, plastic, or composite, selected for load and wear. Persistence mechanism: standardized manufacturing (ISO 53: involute rack profiles, DIN module systems) and engineering apprenticeship transmission. [formal: rostrum | substrate: matter | horizon: generations | explicit: yes | epoch: 0.25]
Accepted ontology entry
rack
A rack is a linear gear: a straight bar with uniformly spaced, precision-cut teeth along one edge, designed to mesh with a circular gear (pinion) to convert rotational motion into linear motion, or vice versa. Parameters: (1) tooth profile…
Definition
Why it is in scope
A rack is a human-made mechanical component: a straight, toothed bar that meshes with a circular gear (pinion) to convert rotational motion into linear motion, or vice versa. Built to persist through standardized manufacturing (ISO tooth profiles, module systems) and engineering apprenticeship.
Names and aliases
- racken · CANONICAL
Relations from this entry
- cmso0bxnm007ojlss7vplu5qfINSTANCE_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.
- cmso0bxnm007ojlss7vplu5qfDERIVED_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.
- cmru173ob00evv7faw8ip5r83INSTANCE_OF →
rack is a specific kind of simple machine: a linear mechanical element that converts rotational motion to linear motion (or vice versa). Law 9: is a specific kind of → INSTANCE_OF. Rack extends the simple-machine concept (lever, wedge, pulley, wheel-and-axle, screw, inclined plane) with the rack-and-pinion variant.
Relations to this entry
No accepted relations in this direction.
Record identity
- Created
- Aug 11, 2026, 2:51 AM UTC
- Content hash
- db6bf7e78b317577d609cce2b87f43f5ffbdc957c69413d82bd35aaef3f272d9