Development of a Positive Lubrication System for Space Application

Abstract

The success of a spacecraft mission depends to a great extent on the performance of the moving mechanical systems. The most common mode of failure in these systems is tribological. Tribological failures occur mainly due to non availability of lubricant at the working zone of the bearings as a result of degradation, evaporation and creep. The life of these moving mechanical systems could be extended, if lubricant is replenished by some means. This paper describes the development of a positive lubrication system named as command lubrication system (CLS). This is an active lubrication system which when actuated by external commands delivers lubricant to the bearings. It is actuated only when there is a demand for lubricant indicated by increase in frictional torque or bearing temperature. The outstanding feature of this system is that the lubricant is stored under ambient pressure and hence less chance of leakage. The CLS can solve the lubrication problem of spacecraft systems which require very long mission life of more than 20 years. It is also suitable to tribosystems in terrestrial devices.

Keywords

• positive lubrication
• spacecraft
• momentum wheels
• space tribology