Beam Couplings for Robotics Applications

Ruland machines beam couplings from a single piece of aluminum or stainless steel for a zero-backlash design and maintenance-free service life.

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Ruland beam couplings are ideal for surgical, warehouse, and industrial robotics due to their increased torque and torsional stiffness and ability to accommodate all forms of misalignment. Ruland manufactures four-beam couplings for encoders and six-beam couplings for light-duty power transmission, such as connecting a stepper or servo motor to a lead screw. This allows robotic designers to design a standard beam coupling into most systems.

Ruland machines beam couplings from a single piece of aluminum or stainless steel for a zero-backlash design and maintenance-free service life. Multiple sets of spiral cuts enable Ruland beam couplings to handle all forms of misalignment – angular, parallel, axial motion, and complex – through frequent starts and stops. The multiple-beam design also allows for higher torque and torsional stiffness than commodity-style single-beam couplings. Ruland manufactures beam couplings in 7075 aluminum for low inertia and 303 stainless steel for increased torque capacity.

Ruland F-Series six-beam couplings have two sets of three beams allowing them to maintain accuracy, repeatability, and reliability in robotic systems. They have larger body sizes than comparable four-beam couplings for increased torque and torsional stiffness. F-series clamp-style beam couplings are supplied with Ruland’s proprietary Nypatch anti-vibration hardware to prevent screws from loosening during operation

Ruland P- and MW-Series four-beam couplings have two sets of two beams for increased flexibility and reduced bearing loads compared to the six-beam style. They also have shorter lengths, making them suitable for space-restricted applications commonly found in encoders. MW-Series couplings have nominal metric dimensions to better fit with systems with metric components.

Ruland offers beam couplings with a clamp or set screw hub attachment with inch, metric, and inch-to-metric combinations ranging from 1/8 inch to ¾ inch and 3 mm to 20 mm. They are manufactured in Ruland’s Marlborough, Massachusetts factory under strict controls using proprietary processes. Non-standard designs such as anodizing, non-standard bore sizes, and special tolerances are available upon request.

Beam couplings are part of Ruland’s complete zero-backlash coupling line, including rigid, bellows, disc, jaw, oldham, controlflex, and slit couplings. Full product information, 3-D CAD files, and additional technical specifications are available at

Why Ruland beam couplings for robotics?

  • Zero-backlash for precise motion control
  • Six-beam and four-beam couplings available in aluminum or stainless steel
  • Increased torque and torsional stiffness when compared to single beam couplings
  • RoHS3 REACH, and Conflict Minerals compliant
  • Manufactured and inventoried in Ruland’s Marlborough, Massachusetts factory
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