A coupling connects two shafts — typically a motor to a pump or gearbox — and absorbs small misalignment. To replace one, you match the type, the two bore sizes and the flexible element. Often only the rubber element wears out, not the whole coupling.
Identify the type
- Jaw (e.g. Lovejoy L-type): two hubs with a rubber 'spider' between them — very common.
- Gear and grid: high-torque, metal element, need lubrication.
- Disc and beam/bellows: precision, zero-backlash (servos, encoders).
- Tire/elastomeric: large misalignment and damping.
Measure what defines fit
- Bore of each hub (they're often different) and the keyway.
- Overall outside diameter (OD) and hub length.
- For jaw couplings: the element (spider) size and durometer (rubber hardness, e.g. NBR/SOX vs urethane).
Replacing just the element
If the hubs are intact and only the spider/element is cracked, you can replace that alone — cheaper and faster. Match the element to the coupling size and the required hardness.
We'll match it
Couplings and elements from Lovejoy, KTR, Rexnord/Falk and Ruland are widely cross-referenced. Send us the type, both bores and the OD (or the part number), and we'll quote the coupling or just the element.