camshaft

IPA/ˈkæmʃɑːft/
KK[kˈæmʃˌæft]IPA/ˈkæmʃæft/

camshaft — noun

  • camshaftsingular
  • camshaftsplural

1. a long metal shaft in an engine that carries cams and controls when the valves o

1.nounC1
Definition

a long metal shaft in an engine that carries cams and controls when the valves open and shut.

Example

The mechanic replaced the worn camshaft after the engine started losing power.

replace a worn camshaft

Wei checked the camshaft before sliding the rebuilt engine back into the car.

Common collocations
  • worn camshaft
  • cracked camshaft
  • replace a camshaft
  • align the camshaft
  • camshaft timing
  • overhead camshaft
Synonyms
  • cam

    used informally in workshop talk, but it can also mean one lobe rather than the whole shaft

  • overhead cam

    a more specific term for a camshaft mounted above the valves

Grammar Patterns

replace a camshaft

camshaft in an engine

Usage Note

Mostly used in car and machine repair. It often follows verbs such as replace, install, inspect, and align, and it commonly appears in compounds such as overhead camshaft.

Common Mistakes

The camshaft sends power to the wheels.
The camshaft controls the valves, while other parts pass power to the wheels.
a camshaft manages valve timing inside the engine; it does not drive the wheels directly.
The mechanic replaced one cam when the whole camshaft was worn.
The mechanic replaced the camshaft because the lobes were worn down.
a cam is one shaped part on the shaft; the camshaft is the complete engine part.

Synonym discussion

Sense: noun/1

Camshaft, crankshaft, and drive shaft are all machine parts, but they do different jobs. A camshaft controls valve timing: as it turns, its cams push parts that open and close the valves. A crankshaft changes the pistons' up-and-down movement into turning movement. A drive shaft carries that turning force to another part, often toward the wheels in a vehicle. Learners often confuse these words because each contains shaft, but the first part of the compound tells you the function. If a mechanic says a worn camshaft is causing rough idling or poor valve timing, the problem is inside the engine. If power is not reaching the wheels smoothly, the problem is more likely a drive shaft or another transmission part.

crankshaftdrive shaftcam ↗

Common collocations

Nouns

  • camshaft timing
  • camshaft bearing
  • camshaft sensor
  • overhead camshaft

Phrases

  • replace a camshaft
  • inspect the camshaft
  • align the camshaft

Prepositions

  • camshaft in [an engine]
  • camshaft for [a car model]

Etymology

English

Camshaft is a modern mechanical compound formed in English from cam and shaft. Shaft is the older everyday word for a long rod or bar. Cam became a technical word for a shaped part that changes turning movement into lifting or pushing movement. When engineers put several cams onto one turning shaft, the compound camshaft became the name for the part that carries those cams and controls valve timing in an engine.

First known use

1842

1842, in the meaning defined above