垂直式滾珠螺桿表面溫度與磨屑特性分析研究

A Study of Surface Temperature and Wear Debris of Vertical Motion Ball-screw

李奇霖(Chi-Lin Li)

指導教授 ： 陳新郁

共同指導教授 ： 洪政豪(Jeng-Haur Horng)

國立虎尾科技大學/工程學院/機械與機電工程研究所/碩士(2014年)

https://doi.org/10.6827/NFU.2014.00142

摘要

滾珠螺桿為精密傳動元件之一，應用需求逐漸朝向高速與高負荷發展，其內部元件摩擦熱與磨耗所造成之傳動性能影響日益重要也更值得探討，尤其是磨屑隨著運轉時間的增加，磨屑顆粒大小與濃度亦會變化，也造成元件界面特性變化，甚至失效而需要更替元件，然而過去卻甚少文獻探討。因此為了確保滾珠螺桿之性能穩定，由表面溫度與磨屑顆粒進行關係研究分析，可以更深入掌握滾珠螺桿的特徵變化。
本研究藉由垂直式滾珠螺桿摩擦熱傳遞分析微觀波峰接觸溫度與巨觀表面平均溫度變化，並藉由大小兩種不同滾珠螺桿之實驗量測表面溫度與磨損顆粒成分驗證上述兩種溫度的正確性。理論與實驗結果顯示垂直式螺桿機台之螺桿表面溫度主要是為螺桿、螺帽與滾珠間的摩擦熱產生，兩種不同型式螺桿之表面平均溫度理論分析與實驗量測值變化趨勢一致，其誤差低於7 %。同時微觀波峰溫度理論預測數值與磨屑成分形成溫度結果吻合。且發現表面溫度之穩定值與不同型式之螺桿磨耗濃度變化比磨屑顆粒大小有更相似的變化關係，可作為預測螺桿溫度變化之先行指標。
在本文之垂直滾珠螺桿實驗條件下，基於三體微接觸理論分析不同加工表面粗糙度對磨屑溫度與波峰溫度結果顯示，軌道接觸表面之粗糙度於0.2 μm ~ 0.3 μm左右是最佳設計範圍，波峰接觸溫度與磨屑溫度相對接近，且兩者最高溫度比其他粗糙度之最高溫度值較低；表面粗糙度過大，則軌道粗度波峰溫度愈高而磨屑溫度愈低；磨屑大小越大，則顆粒溫度愈高而表面波峰溫度愈低。依據擦損溫度失效理論，本文提供包含磨屑大小、磨屑濃度、表面粗糙度、負荷相互關係之安全與不安全之運轉條件建議，依本實驗機台之運作條件，可以推測磨屑顆粒大小在400 nm以上，或顆粒大小不變，濃度上升至1013 /m2即有可能造成擦損溫度失效，此安全運轉條件之設定方法可作為滾珠螺桿異常現象監控之參考。又依據本實驗之磨耗與預壓下降關係，在固定的換油周期下，本文也提出磨耗之預測方程式及預壓下降之預測方程式Pt =C1 -14.949-0.7065ln (1.0799D)，可作為設計之參考。

關鍵字

滾珠螺桿 ； 表面溫度 ； 磨屑顆粒 ； 波峰溫度 ； 磨耗 ； 預壓力

並列摘要

A ball-screw is one of a precision transmission component, whose application needs develop to high speed and high load. The transmission performance impact of friction heat and wear is also important and worthy of discussing, especially size and concentration of wear debris will also change with increase of operation time, which needs to replace components due to change of components’ interfacial characteristics. In order to performance stability of the ball-screw, it can deeply grasp feature change of the ball-screw through researching and analyzing its surface temperature and wear debris.
Through vertical ball-screw friction heat transmission, it analyzes micro wave contact temperature and average temperature change on macroscopic surface, and utilizes two experiments of big and small ball-screws to measure surface temperature and wear particle ingredients to testify correctness of the above two temperatures. The theory and experimental results show that screw surface temperature of a vertical screw machine is mainly produced by friction heat among the screw, nut and ball, while the change trends in theoretical analysis value and experimental measured value of average surface temperatures of two different screws are consistent, whose errors are lower than 7%. At the same time, the theoretical prediction value of micro wave peak temperature is identical to forming temperature of wear debris ingredients. What’s more it finds that stable value of surface temperature and different types of screw wear concentration change have more similar change relationship than that of wear debris particles, which can be regarded as the leading indicator of predicting screw temperature change.
In the condition of a vertical ball-screw experiment, based on analysis of three-body micro contact theory, different surface roughness on wear debris temperature and wave peak temperature shows that the rail contact surface roughness is optimal design range in 0.2 μm ~ 0.3 μm, the wave peak contact temperature is close to wear debris temperature, and the highest temperatures of the two are lower than those of roughness; the bigger surface roughness brings higher rail roughness peak temperature and lower wear debris temperature; bigger wear debris size brings higher particle temperature and lower surface wave peak temperature. According to chafing temperature failure theory, this paper provides suggestions of safe and unsafe operating conditions including wear degree, wear debris concentration, surface roughness, load relationship. Based on operating conditions of the machine in the experiment, it can predict to cause failure of difference loss temperature when the particle diameter is over 400nm or remains and the concentration increases to 1013 /m2, which can be reference for monitoring of abnormal phenomenon of the machine. Also in accordance with the relationship between wear and preloading decline in the experiment, under fixed oil change period, this paper also proposes a prediction formula of wear prediction line and decline, which is Pt =C1 -14.949-0.7065ln (1.0799D), which can be reference for design.

並列關鍵字

Ball Screw ； Temperature of Surface ； Wear Debris ； Wear ； Peak temperature ； Preload

參考文獻

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