牙嵌式离合器的运动及失效分析

Analysis on movement and failure of tooth clutch

在空间可展开结构中,为了提高展开的可靠性,通常会对展开的核心部件即驱动源进行备份。当互为备份的两个驱动源有一个出现故障时,需要将其从传动链路中脱离出来,此时需要使用离合器来实现这个功能。牙嵌式离合器因为其体积小、结构简单、传递扭矩大,非常适合在空间可展开机构中使用。文章针对某牙嵌式离合器多次使用后离合力矩下降的问题,对牙嵌式离合器的离合力矩与结构尺寸的理论公式进行推导。分析出当离合器结构参数固定后,齿面摩擦和轴孔摩擦是造成牙嵌式离合器离合力矩变化的主要原因。通过齿面粗糙度、轴孔间隙对离合力矩的敏度分析,并结合零件表面观测结果,得出牙嵌式离合器离合力矩下降的主要原因是离合齿面的磨损,而轴孔磨损对离合力矩的影响并不明显。根据此结论,提高该类型牙嵌离合器齿面的表面粗糙度和硬度,可以提高牙嵌式离合器的保性能使用寿命,提高其在航天机构中使用的可靠性。

In a spatially expandable structure,in order to improve the reliability of deployment,the core component of the deployment,that is,the drive source,is usually backed up.When one of the two drive sources that are backup to each other fails,it needs to be disconnected from the transmission link.At this time,a clutch is needed to realize this function.Because of its small size,simple structure,and large transmission torque,the tooth clutch is very suitable for use in a spatially deployable mechanism.Aiming at the problem of the reduction of clutch torque after a certain tooth clutch is used many times,this paper derives the theoretical formula of the clutch torque and structure size.It is analyzed that when the structural parameters of the clutch are fixed,tooth surface friction and shaft hole friction are the main reasons for the change of clutch torque of the tooth clutch.Through the sensitivity analysis of the tooth surface roughness and the shaft hole clearance to the clutch torque,combined with the surface observation results of the parts,it is concluded that the main reason for the reduction of the clutch torque of the tooth clutch is the wear of the clutch tooth surface,and the shaft hole wear has an less effect on the clutch torque.According to this conclusion,improving the surface roughness and hardness of the tooth surface of this type of jaw clutch can increase the performance-guaranteed service life of the jaw clutch,and improve its reliability when used in aerospace institutions.