A Novel Spring Balancing Device on the Basis of a Scotch Yoke Mechanism

10.6567/IFToMM.14TH.WC.OS8.004

Win-Bin Shieh；Ben-Shiou Chou

Spring balancing ； Gravity balancing ； Potential energy ； Scotch Yoke mechanism ； Zero-free-length spring

Proceedings of the 14th IFToMM World Congress

14th-4（2015 / 11 / 04）

206 - 212

英文

A novel spring balancing device for the gravity balance of a rotary system is presented. Although most existing spring balancing designs use zero-free-length springs or their equivalent devices to counterbalance the gravity effect of the system, a spring-to-gravity balanced system with zero-free-length spring usually suffers from the problems such as the availability of springs, small and uncertain balancing errors, complicated construction of the system, and motion interference between links. Hence, this work proposes a new spring balancing device with a simple and reliable structure, for which it composes of a Scotch yoke mechanism, a compression spring and a gear pair. Using this device, the gravitational effect of a rotary system can be fully balanced at all configurations, where balance condition of the system is derived based on the theory of conservation of potential energy. Practical installation of such a device is illustrated and a numerical example is given for the justification of the approach.