Servo Motor Coupling Selection

Five selection factors

① Torque: rated ≥ 1.3× motor peak torque; ② Bore: match both motor and load shaft diameters; ③ Speed: stay under max rpm; ④ Stiffness: servo positioning needs high torsional stiffness; ⑤ Inertia: low inertia reduces motor load.

Torque formula

Rated torque T ≈ 9550 × power(kW) ÷ speed(rpm), in N·m.

Recommended types

For high-precision servo, choose a diaphragm coupling (zero backlash, high rigidity); for damping, a jaw coupling; for the most compact precision, a bellows coupling. SAILINK diaphragm series: bore 3–78 mm, torque to 1040 N·m.