汽車用傳動軸輪端接頭之運動模擬與結構分析

Abstract

本研究係針對汽車用傳動軸輪端接頭次總成（即等速萬向接頭）結合結構有限元素分析的方法，研究目標針對BJ（六顆鋼珠等速萬向接頭）與EBJ（八顆鋼珠等速萬向接頭）之差異進行分析模擬並與實驗比較作為創新的參考，在不影響強度與耐久等機能性試驗條件下，傳動軸輪端接頭亦能輕量化，以達到節省材料成本，並兼具汽車底盤零件在空間擺放時能有限制較小的優點之設計目標。由於現有傳動軸接頭分析輔助系統在軟體方面的不足，致使無法持續往輕量化目標前進，所以本研究使用CAD軟體（Solidworks）結合有限元素分析軟體(COSMOS Works)來研究汽車傳動軸輪端接頭的靜態結構應力變化與分佈，期待突破現有技術之瓶頸，提供未來設計新型接頭與機構零件輕量化之參考依據，不需仰賴國外技術授權之額外成本。 本研究的分析模型包括傳動軸輪端接頭BJ與EBJ型式的機構結構應力的整合分析，首先使用CAD軟體建立機構模擬系統所需的模型以進行分析模擬，評估在運動中的傳動軸輪端接頭結構負荷所造成的應力變化分佈情形。依據應力分析的結果，發現BJ與EBJ型式互有優劣，而EBJ型式的等速萬向接頭比BJ型式的重量少約20%，EBJ鋼珠較BJ鋼珠小，故推論溫升狀況會比較小，與NTN實驗結果比對相互吻合。本研究成果可提供設計輕量化的輪端接頭之參考依據。

This research proposed a practical and useful method which apply Finite Element Analysis to investigate the difference of stress distribution between the constant velocity joint of the BJ type（6 ball CV Joint）and EBJ type（8 ball CV Joint）. One motivation of the research is to confirm the possibility of cost saving in material and production of C.V.Joint, and to get the better superiority in design at the Automobile Chassis space without reducing the strength and durability. This research adopted SolidWorks cooperating with Finite Element Aanalysis system（COSMOS Works）to build the geometric model and solve the stressed distribution of the components of Ball Joint assembly on the driveshaft. The C.V. Joint models in the study are similar models as BJ and EBJ type of NTN product. On behalf of the iterative parameter optimized process, we can conclude that the model of EBJ with less weight could be a more competitive C.V. Joint product than BJ type. As shown in the analysis result, we have investigated the difference of stress distribution between BJ type and EBJ type, and the weight in EBJ type is 20% smaller than BJ type. The Stress at the contact point between EBJ ball and housing is smaller than that of BJ ball, so we can hypothesize that the temperature rise on the housing of the EBJ type will be smaller than that of BJ type, and the conclusion is similar with NTN tested result. The research proposes a model-analysis investigation concurrent design process and the new EBJ type of C. V. Joint has been evaluated and can be concluded that it could be a more competitive product with much more benefit on less weight, smaller size and less temperature rise than that of BJ type.