Shaft Couplings
A coupling forgives what machining can't: the small misalignments between motor and shaft that would otherwise destroy bearings.
What are shaft couplings?
A shaft coupling connects two shafts to transmit torque while accommodating the inevitable angular, parallel and axial misalignment between them. Disc couplings flex thin metal discs for zero-backlash servo drives; jaw types cushion through an elastomer spider; universal joints handle large angles; rigid couplings join truly aligned shafts.
Types of shaft couplings
Disc couplings
Stainless disc packs — zero backlash, high torsional stiffness, servo standard.
Jaw (spider) couplings
Elastomer insert damps vibration and shock.
Universal joints
Large angular misalignment and remote drives.
Rigid couplings
Solid clamped connection for precisely aligned shafts.
How to select shaft couplings
- Torque (with service factor) and peak/reversing loads.
- Bore sizes both ends, keyed or clamping.
- Misalignment type and amount to be absorbed.
- Backlash requirement — zero for positioning drives.
Not sure? Send what you have — a part number, drawing or photo — and our engineering team will confirm the selection.
Frequently asked questions
- Which coupling should I use with a servo motor?
- A zero-backlash type — typically a disc coupling (or bellows) — so position commands translate exactly to the load. Jaw couplings with spiders suit general motors where slight elasticity and damping are acceptable.
- When is a universal joint the right choice?
- When shafts meet at a significant angle or the drive must reach an offset position — universal joints transmit through angles no flexible coupling can, singly or in pairs for constant velocity.
Related components
Timing Belts & Pulleys
Timing belts transmit torque tooth-by-tooth — no slip, no lubrication — making them the default for positioning drives and clean power transmission.
Chain & Sprockets
Chain drives move serious torque over long centre distances and rough conditions — the muscle of conveyors and heavy machine drives.
Linear Shafts
The shaft is half of every linear bushing system — its hardness, roundness and surface finish set the accuracy and life of the motion.
Need shaft couplings?
Tell us the specification, quantity and application — or just send the drawing.