Definition
A precision mechanical coupling used to join two rotating components, formed by matching curved, radial teeth machined into the mating faces of each part. When the two faces are bolted together, the interlocking teeth self-center the components and transmit torque without slipping. Curvic couplings are commonly used to join the compressor and turbine wheels of gas turbine engines.
Plain English
A way of joining two spinning engine parts so that their flat faces lock together using matching curved teeth, like two gears pressed face-to-face. The teeth keep the parts perfectly centered and stop them from twisting against each other when the engine runs.
Context Anchor
Seen mainly in aircraft engine maintenance, especially in turbine or compressor rotor assemblies where rotating parts must be joined very accurately.
Derivation
The name comes from 'curvic,' a contraction of 'curved' used by the Gleason Works, the company that developed the coupling. The curved (rather than straight) teeth are what give the coupling its self-centering ability.
Why Pilots Care
It maintains continuous power transmission in high-stress engine sections where minor shaft movement occurs during operation.
Analogy
Think of two matching toothed rings pressed face to face. When the teeth mesh, the rings can only fit together in the correct alignment and will turn together.
Intuition Check
A Curvic coupling is not a loose or flexible connector. It is a rigid, precision-machined joint meant to hold rotating parts in exact alignment.
Example Sentence 1
The turbine wheel is joined to the compressor shaft with a curvic coupling, which keeps the two perfectly aligned at high rpm.
Example Sentence 2
Proper alignment of the curvic coupling ensures smooth torque delivery from the turbine to the propeller.