Novel Tribometer for Coated Self-Lubricating Spherical Plain Bearings in a Vacuum

Coated self-lubricating spherical plain bearings (SSPBs) are a fairly key component of the space-swing mechanism. To examine the operation status and tribological properties of coated SSPBs, a tribometer with a temperature control module in a vacuum condition was developed. The tribometer was mainly composed of a fixture system, reciprocating rotational motion system, environment control system, etc. First, the tribometer was verified with the self-made hydrogenated diamond-like carbon (H-DLC) SSPBs. The sensor signals indicated that the tribometer conformed to the design specifications. Then, the influence of friction heat on the tribological properties of H-DLC SSPBs was analyzed. The results showed that friction torque and temperature increased with the overall test time. Although the temperature had reached 48 °C, the frictional heat had little effect on the H-DLC SSPBs’ lifespans. The damage mechanism of H-DLC SSPBs was dominated by abrasive wear and fatigue wear in vacuum conditions