Abstract: A device for testing mechanical seal performance includes a main shaft (4), a working chamber (18) with two end covers (6, 13) respectively located at two ends thereof, and two groups of mechanical seals to be tested (7); wherein a shaft sleeve (5) and the main shaft (4) form a clearance fit and penetrate through the end covers (6, 13) at two ends of the working chamber (18) together; the shaft sleeve (5) extends outside U-shaped openings (23) which are arranged at two ends of the end covers (6, 13) and arranged on the same generatrix; driven pins (15) are arranged on the locations of the main shaft (4) corresponding to the U-shaped openings (23); the middle part of the shaft sleeve (5) is provided with two segments of threads having the same thread pitch and opposite rotating directions.

Abstract: A device for testing mechanical seal performance includes a main shaft (4), a working chamber (18) with two end covers (6, 13) respectively located at two ends thereof, and two groups of mechanical seals to be tested (7); wherein a shaft sleeve (5) and the main shaft (4) form a clearance fit and penetrate through the end covers (6, 13) at two ends of the working chamber (18) together; the shaft sleeve (5) extends outside U-shaped openings (23) which are arranged at two ends of the end covers (6, 13) and arranged on the same generatrix; driven pins (15) are arranged on the locations of the main shaft (4) corresponding to the U-shaped openings (23); the middle part of the shaft sleeve (5) is provided with two segments of threads having the same thread pitch and opposite rotating directions.

Abstract: A self-pumping hydrodynamic mechanical seal includes a rotating ring (3) and a stationary ring (11). More than three sets of backward curved grooves (39) are provided on a seal face of the rotating ring (3), outlets of the backward curved grooves (39) are provided at an external diameter portion of the seal face of the rotating ring (3), and an inlet (31) connects with a seal chamber (1) through a duct (30) of the rotating ring (3) or the stationary ring (11). When the rotating ring (3) rotates, a medium in the backward curved grooves (39) is accelerated into a high-speed fluid; under a centrifugal force, the high-speed fluid moves to an external diameter side of the rotating ring (3), so as to be pumped into the seal chamber (1) and generates a low-pressure area at the inlets (31) of the backward curved grooves (39); the medium in the seal chamber (1) is driven by a pressure difference, so as to flow into the backward curved grooves (39) through the duct (30), for forming circulation of self-pumping.