Design Method of Spring Balance Mechanism Through Derivation of General Solution

The present study set out to devise a means of designing a spring-balance mechanism (hereinafter, a SBM) based on a general solution. The goal was to apply a general solution as a guideline for identifying the optimum design solution. A SBM is used to reduce the actuator output in the design of a mechanical device. As a result, the effect of gravity can be offset and energy-saving in operation can be realized. To date, however, SBMs have been designed on a trial and error basis, with a reliance on the designer’s knowledge or experience. Thus, in some instances, it may not be possible to identify a design solution that should, in theory, be achievable. To overcome this issue, this study examined the application of a general solution to the design of a SBM. Such a general solution would identify a solution space including viable design solutions. Subsequently, once a design that satisfies the general solution had been identified, a search could be made of all the design solutions within the solution space. First, the sequence whereby the general solution is used to identify a SBM design that satisfies the general solution, thus providing a guideline for the search action, is determined. Herein, the method used to identify this initial SBM design is presented. The devised method is based on the description of an energy-conservation formula that does not involve any trial and error. The proposed method incorporates a conventional method into the design solution, which can be derived when the conventional method cannot identify a design solution. As a result, a design method using a general solution for the design of an SBM is realized.