This paper presents a method for realizing a gear-spring balancer (GSB) that can handle variable payloads. The GSB is constructed with a three-gear train articulating a nonzero-free-length spring to a rotating mass. In the proposed method, the parameters of the GSB are derived from solving the identity problem of perfect static balancing. The significance of this method is that it enables the GSB to handle variable payloads via energy-free adjustment and allows the selection of spring stiffness. The effectiveness of the proposed method was demonstrated through a numerical example and experimental tests. The analytical results showed that the GSB theoretically achieved perfect static balancing even when the payload varied. The peak actuator torque of the GSB was practically reduced by more than 90% with different payloads. This paper also describes an application of the GSB to serial robots for pick-and-place operations. A theoretical model illustrated that the peak actuator torques of a serial robot were reduced by an average of 93.4% during operation.

This content is only available via PDF.
You do not currently have access to this content.