Cluster 02 · 5 articles planned · 5 published
Selection & Sizing
How to specify and size a coupling correctly
Sizing a gear coupling correctly is arithmetic, not guesswork, but the inputs are easy to get wrong: driver rated power and speed, an appropriate service factor for the driven machine, and the bore-and-keyway practice of whichever standard governs the order. Get any one of the three wrong and the coupling either fails under torsional shock or is oversized enough to cost the project money for no reliability benefit.
This cluster covers the sizing methodology end to end: converting rated power and speed into a selection torque, how service factor tables differ by driven-equipment type, how angular, parallel and axial misalignment capacity constrains a selection independently of torque, and the bore-and-keyway practice that determines whether a given shaft can even take the coupling being considered.
Every article in this cluster works through a real numeric example rather than stating a formula and leaving the reader to apply it.
Articles in this cluster
5 min read
How to size a gear coupling
A complete worked example from driver rated power and speed through to a final coupling size, with the arithmetic shown at every step.
4 min read
Service factor guide
What a service factor represents, how it varies by driven equipment type, and why two apparently similar machines can carry different factors.
7 min read
Torque calculation
Selection torque for continuous duty, and how peak events such as motor start-up and compressor surge are checked separately against the peak rating.
7 min read
Misalignment capacity
Why misalignment capacity is three separate ratings — angular, parallel and axial — and how they interact on a real installation.
5 min read
Shaft bore and keyway
Clearance versus interference fits, keyway tolerance stack-up, and the point at which a shrink fit becomes the only option.