谐波减速器黏着磨损失效加速寿命模型研究

针对空间润滑谐波减速器黏着磨损失效的加速寿命试验方法问题,首先基于Johnson-Williamson的粗糙表面接触模型建立了混合润滑状态下的黏着磨损模型,模型表明磨损速率主要由粗糙表面微凸体接触承担的载荷比例决定.然后,对磨损部位进行考虑粗糙表面真实形貌与润滑剂流变特性的混合润滑数值分析表明,转速与载荷对微观界面接触与润滑分布状态的影响显著,温度的影响有限,因此传统提高转速并升高温度以保持油膜厚度一致的加速寿命试验方法已不适用.最后以增大转速、载荷并保持或增大混合润滑状态下微凸体接触承担的载荷为加速寿命试验准则,以微凸体承担载荷为加速应力建立了黏着磨损的加速寿命模型,并以不同工况的加速寿命试验与寿命分布统计对其准确性进行了验证.

Accelerated Life Model for Harmonic Drive under Adhesive Wear

The accelerated life test method for space lubrication harmonic drive under adhesive wear was studied in this paper. Firstly, an adhesive wear model under mixed lubrication was established based on the Johnson-Williamson asperity contact model, which indicates the wear rate mainly depended on the asperity contact load ratio. Then the mixed lubrication performances of wear region considering the topography of rough surfaces and rheological behavior of lubricant were studied. The results suggest that the common accelerated life test method (raising speed and temperature to keep the oil film thickness to be constant) was inapplicable for the mixed lubrication condition, because the input speed and output load had more significant influences on the distribution of contact and lubrication between the rough surfaces than temperature. Therefore, a new accelerated life test method was proposed, which could be conducted by raising speed and output load to maintain or increase the asperity contact load. Finally, the new accelerated life test method was verified by accelerated life experiments and statistics of life distribution under different work conditions.