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.