Experimental Study on Leakage and Thermal Features of Herringbone-Grooved Oil-Film-Lubricated Mechanical Face Seals

The herringbone-grooved oil-film-lubricated mechanical face seals were experimentally studied on aspects of the leakage and thermal features. The outer-diameter pressured test assembly was utilized to measure the leakage and the stator temperature of the seals at rotation speeds of 500 -2500 r/min and medium pressures of 0.35 -0.80 MPa. A novel method is proposed to obtain the radial temperature distribution of the stator face by fitting the measured temperatures of three spots inside the stator. Results indicate that the outer-grooved seal and the middle-grooved seal present acceptable leakage suppression effect, but the temperature increment is larger; the inner-grooved seal maintains zero leakage at lower pressure, and the temperature increment is only half of that of the rest; at higher pressure, the leakage of the inner-grooved seal is overly large; the fitted face temperature distributions contribute to explaining the abnormal phenomena (dark and bubbled) of the collected oil leakages. The mechanism of the leakage and thermal features are analyzed and discussed in aspects of the low-pressure, high-pressure, pumping, cavitation blocking effects of the grooves, as well as the convergent-sealing-gap effect due to uneven temperature profile.