Under some special operating conditions, the service life of steering fastener can be longer than that calculated by traditional calculation, especially under light load. These special operating conditions are the surface damage that may be caused when the rolling surface (track and rolling parts) is effectively separated and limited by a lubricating oil film. In fact, under ideal conditions, the service life of the so-called * rotating fastener is not impossible

（1）正在準確的決定軸的徑向標的目的及軸向標的目的的位放的同時，揚止軸的跳動。

(1) While accurately determining the positioning of the radial target and axial target of the shaft, lift and stop the runout of the shaft.

（2）提高旋轉建筑扣件的剛性。

(2) Improve the rigidity of rotating building fasteners.

（3）防行軸向標的目的振動及因為共振而形成的同音。

(3) The purpose of preventing the axial mark from vibration and homophony due to resonance.

（4）揚止滾動體的扭轉滑動，公轉滑動及自轉滑動。

(4) Lift and stop the torsional sliding, revolution sliding and rotation sliding of the rolling element.

（5）對取套圈，連結滾動體的準確位放。

(5) Take the ferrule and connect the accurate position of the rolling element.

異物可能通過已嚴重磨損或失效的密封圈進入轉向扣件。轉向扣件座和零件初次清洗不干凈，或過濾器失效，過濾器維護不當，將導致磨粒積聚。硬質顆粒在旋轉建筑扣件內滾動，可引起滾子和滾道的麻點和擦傷。旋轉扣件座清潔不當而殘留的金屬碎片或大顆粒灰塵，將導致過早出現疲勞損傷。

Foreign matters may enter the steering fastener through the severely worn or failed sealing ring. The initial cleaning of the steering fastener seat and parts is not clean, or the filter fails, and the filter is not maintained properly, which will lead to the accumulation of abrasive particles. Hard particles rolling in the rotating building fastener can cause pitting and scratch of the roller and raceway. The residual metal fragments or large particles of dust caused by improper cleaning of the rotating fastener seat will lead to premature fatigue damage.

槽痕是由碎片或金屬顆粒造成的極度嚴重的磨損。這些污染物楔入軟質保持架材料，造成滾動構件出現刻槽，這將影響滾動接觸幾何形狀，降低旋轉扣件使用壽命。

Groove marks are extremely severe wear caused by debris or metal particles. These contaminants wedge into the soft cage material and cause grooves in the rolling members, which will affect the rolling contact geometry and reduce the service life of the rotating fasteners.

外部碎屑污染通常是由灰塵、沙粒和環境顆粒造成的，而內部碎屑污染則一般由齒輪、花鍵、密封圈、離合器、制動器、接頭以及旋轉扣件座等清潔不當或部件發生損傷或剝落所致。硬質顆粒隨著潤滑過程在旋轉扣件中游走，zui終導致旋轉扣件內表面擦傷（壓傷）。壓痕形成突起，引起表面應力的集中，造成旋轉建筑扣件表面早期損傷，降低旋轉建筑扣件的壽命。

External debris contamination is usually caused by dust, sand and environmental particles, while internal debris contamination is generally caused by improper cleaning or damage or peeling of components such as gears, splines, sealing rings, clutches, brakes, joints and rotating fastener seats. Hard particles swim away in the rotating fastener with the lubrication process, Zui eventually leading to scratch (crush) on the inner surface of the rotating fastener. The indentation forms protrusions, causing the concentration of surface stress, causing early damage to the surface of rotating building fasteners and reducing the service life of rotating building fasteners.