Transmission capability of precise cable drive including bending rigidity

• Methods to predict the transmission capability of precise cable drive are developed.
• Bending rigidity of the cable is considered and its effect is investigated.
• Sensitivity of the design parameters to the transmission capability is investigated.
• Results could be used to predict the transmission capability in the design phase.

The precise cable drive has been widely used in all types of industrial, commercial, aerospace, military, medical and research applications as an alternative to gearboxes, belts and pulleys, chains and sprockets and other currently available transmission. Classical capstan equation is usually used to investigate the transmission capability of precise cable drive. However, the classical capstan equation cannot hold for precise cable drive because of the existing bending stiffness and elastic elongation of the steel cable. This paper develops analytical methods for predicting the transmission capability of precise cable drive including bending rigidity. This work illustrates interconnections between the transmission capability and design parameters, including preload force, wrapped angle, capstan radius ratio, bending stiffness and friction coefficient. The result is useful to predict the transmission capability of precise cable drive in practical applications.