Development and performance verification in mechanical seals with friction reduction and sealing mechanism - Experimental study

A series of experiments were carried out to verify the sealing and lubricating performance of the surface structure for mechanical seals with the functions of the low-friction, the low-leakage, and also the pumping effect. The thrust bearing structures were formed in the higher pressure side as a lubricating mechanism, and the reversed thrust bearing structures were formed in the lower pressure side as a sealing mechanism in the mechanical seals' surfaces. The fluid film thickness and the friction coefficient were measured and compared with the numerical calculation results of our previous report. Cavitation regions formed in the sliding surface were observed with the direct observation system of mechanical seals. Furthermore, the magnitude of the cavitation pressure was also discussed. The experimental results indicated that the theoretical results discussed in our previous report were proved to be valid. Thus we conclude that the novel sealing and lubricating mechanisms for mechanical seals with the functions of the low-friction, the low-leakage and the pumping effect can be technically feasible.