Beam Couplings for Motors
Beam couplings from Ruland are manufactured with multiple spiral (helical) cuts allowing for zero-backlash and greater torque, torsional stiffness, and misalignment capabilities when compared to standard single beam couplings. The 4-beam style (P- and MW-Series) have two sets of two beams allowing for greater flexibility and more compact lengths than 6-beam couplings, making them an ideal encoder coupling. The 6-beam style (F-series) has two sets of three beams for increased torque and torsional stiffness capabilities when compared to 4-beam style. They are best suited for light duty power transmission applications such as coupling a motor and lead screw.
Most motor designers start with aluminum beam couplings for their cost effectiveness and low inertia. Stainless steel beam couplings are designed for motor applications with higher torque than an aluminum coupling can accommodate, but designers must be careful when using one, as they have significantly greater inertia than aluminum types. Ruland manufactures beam couplings with a balanced design for smooth operation up to 6,000 RPM. They are available in clamp and set screw styles with bores in sizes from 3/32” to ¾” and 3mm to 20mm.
