Optimizing Tolerance Allocation in the Remanufacturing Process of Used Electromechanical Products

Optimizing tolerance allocation is crucial for balancing cost and performance in the remanufacturing of used electromechanical products. However, the traditional remanufacturing model of “individual part precision restoration + secondary machining trial assembly” lacks an integrated approach to tolerance planning in the design and manufacturing stages, leading to excessive fluctuations in cost and quality. To address this issue, a remanufacturing value-based tolerance allocation method is proposed, integrating remanufacturing value into the tolerance allocation process. First, a remanufacturing value quantification and evaluation indicator system was established at the failure surface layer (i.e., the remanufacturing processing surface) at the design stage and comprehensively considers the used part quality and enterprise processing capabilities. Quantification methods for each indicator were developed, and a comprehensive weighting strategy combining subjective enterprise standards and objective return quality adopted. Then, a multi-objective optimization model for remanufacturing tolerance allocation was established, targeting remanufacturing cost, quality loss, process stability, and corrected by the failure surface value. Finally, the beetle antennae search (BAS) algorithm was employed to determine the optimal solution. A case study on a used gearbox demonstrated that the proposed method significantly improves cost, quality loss, and process stability compared to the traditional remanufacturing approaches.