- 學位論文
SCM415與50CrMo4軸承鋼表面花紋設計對於磨潤性能影響研究
Tribological Performance Study on the Surface Pattern Design for SCM415 and 50CrMo4 Bearing Steels
摘要
傳動元件中兩運動單元，如滾珠螺桿的滾珠與軌道，在高速運動且承受負載下，必定會產生摩擦、磨損，磨痕的增加將會造成傳動性能有所變化，為了保持元件之精密度與增加使用壽命，熱處理是一種廣泛的使用方法，能使材料特性有所改變，不但可以增加硬度，還可以增加其耐磨性；若搭配材料表面進行花紋的設計，表面花紋設計得當可提高潤滑油以抵抗動態負載的能力，減少摩擦、磨損的產生，使得機台在傳動性能上獲得改善。 本研究旨在探討螺帽材料SCM415與螺桿材料50CrMo4於不同條件熱處理以及表面花紋設計下之，表面的油膜承載力、磨耗特性與表面形貌變遷。為了解其滾珠與螺桿及滾珠與螺帽間之滾滑現象，藉由實驗機台對SUJ2鋼珠與平面試件進行往復式來回運動，模擬滾珠的滾滑動情形，並搭配微小擠壓效應得其滾珠與磨屑的接觸情形，模擬軌道中滾珠真實接觸現象，並了解表面花紋對於振動之影響。根據滾珠滑動與滾滑現象，分析其對材料表面磨耗與摩擦係數之關係，以及表面花紋用於保持潤滑油的油膜不被破壞，並能減少摩擦和磨損的特性。研究結果顯示鋼珠與平面的擠壓效應較純滑動易使油膜增厚，以及鋸齒型與直線溝型表面紋路加工皆可有效降低運動界面摩擦力，加速油膜生成，達到降低磨耗效果。
並列摘要
Two motion units in transmission element such as ball and rail of ball screw will certainly generate friction and abrasion under high-speed motion and load. Increase of grinding crack will cause change of transmission performance. In order to keep precision of element and increase service life, heat treatment is a method widely used, which can change features of material, increase hardness and abrasion performance. If material surface has pattern design, the proper design can improve lubricating oil’s capacity of resisting dynamic load and reduce friction and abrasion, to improve transmission performance of drilling machine. The research aims to discuss oil film bearing capacity, abrasion feature and surface appearance of nut material SCM415 and screw material 50CrMo4 in heat treatment under different conditions and surface pattern design. In order to learn rolling-sliding between ball and screw as well as ball and nut, it conducts reciprocating motion of drilling machine SUJ2 steel ball and plane test piece, to simulate rolling-sliding of ball and match with tiny extrusion effect to get contact between ball and abrasive dust. It simulates real contact phenomenon in rail and learns influence of surface pattern on vibration. According to sliding and rolling-sliding of ball, it analyzes the relationship between abrasion and friction coefficient on material and protects oil film of surface pattern for protecting lubricating oil from damage, as well as can reduce friction and abrasion. The research result shows that extrusion effect of steel ball and plane is easier to thicken oil film than pure sliding, and sawtooth and straight line surface texture processing can effectively reduce frictional force on motion interface to accelerate formation of oil film, so as to reduce abrasion.