Development of a novel reciprocating cryogenic tribometer through deformations of measurement structure.

In this study, a novel reciprocating tribometer, in which the frictional pairs were immersed in liquid nitrogen directly, was developed to simulate the cryogenic fluid lubrication. To eliminate the negative influence of extremely low temperature on force sensors, a transfer structure of force-deformation, consisting of cantilever beams and measurement beams, was designed specially. It can transfer the structural deformations caused by the loading force and the friction force from the cryogenic zone to the room-temperature zone. The corresponding measurement principle was discussed in detail, and the linear relationship between the structural deformation and the applied force was verified theoretically. Through static calibration experiments, the fitting relationship between the deformations and the loading/friction force was acquired for the developed tribometer. In final, a preliminary investigation of graphite materials was conducted on the tribometer to compare the room-temperature and cryogenic tribological behaviors.