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）正在准确的决定轴的径向标的目的及轴向标的目的的位放的同时，扬止轴的跳动。

(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）提高旋转建筑扣件的刚性。

(2) Improve the rigidity of rotating building fasteners.

（3）防行轴向标的目的振动及因为共振而形成的同音。

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

（4）扬止滚动体的扭转滑动，公转滑动及自转滑动。

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

（5）对取套圈，连结滚动体的准确位放。

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

异物可能通过已严重磨损或失效的密封圈进入转向扣件。转向扣件座和零件初次清洗不干净，或过滤器失效，过滤器维护不当，将导致磨粒积聚。硬质颗粒在旋转建筑扣件内滚动，可引起滚子和滚道的麻点和擦伤。旋转扣件座清洁不当而残留的金属碎片或大颗粒灰尘，将导致过早出现疲劳损伤。

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.

槽痕是由碎片或金属颗粒造成的极度严重的磨损。这些污染物楔入软质保持架材料，造成滚动构件出现刻槽，这将影响滚动接触几何形状，降低旋转扣件使用寿命。

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尘、沙粒和环境颗粒造成的，而内部碎屑污染则一般由齿轮、花键、密封圈、离合器、制动器、接头以及旋转扣件座等清洁不当或部件发生损伤或剥落所致。硬质颗粒随着润滑过程在旋转扣件中游走，zui终导致旋转扣件内表面擦伤（压伤）。压痕形成突起，引起表面应力的集中，造成旋转建筑扣件表面早期损伤，降低旋转建筑扣件的寿命。

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.