Mechanical seals are relying on one or several of the perpendicular to the axis of the end for relative sliding in the fluid pressure and compensation of the elastic body (or magnetic) to keep under seal affixed to the merger with aids to achieve the resistance of the seal leakage device. Commonly used mechanical seal structure From geostationary ring (static ring) 1, rotating ring (actin ring) 2, elastic element 3, Spring Block 4, 5 set screws, rotating auxiliary ring seals 6 and 8 geostationary ring seals and other auxiliary components,

anti-turn pin 7 fixed on the cap 9 on the stationary ring to prevent rotation. Rotating ring and stationary ring often can be the basis of whether they have the ability to compensate axial ring known as the

compensation or compensation also. Mechanical seal leakage of fluid may be ways to have A, B, C, D four channels.C, D leakage channel separately and are stationary ring gland, shell gland and the seal between the two seals are static. B-channel are rotating between the ring and shaft seal, when the end-friction and wear, it just can follow the example of compensation for micro-ring along the axial movement in fact is still a relatively static seal. Therefore, these leaks are relatively easy to channel closure. Static sealing components

have the most commonly used rubber O-ring or PTFE V-ring, and as compensation for the rotation of ring ring ring or auxiliary static seal, and sometimes using both elastic element function in rubber, PTFE

or metal bellows structure. A channel is a rotating ring and stationary ring affixed to the end of cooperation with each other relative sliding dynamic seal, it is the mechanical seal device of the main seal, but also decided to mechanical seal performance and life of the key. Therefore, the sealed end of the processing is demanding, so in order to simultaneously maintain the necessary seal between the end of the lubrication film, must be strictly system-side cavity surface pressure per unit area, the pressure is too large and difficult to form a stable liquid film lubrication will accelerate the end - Wear; pressure is too small, leakage increased. Therefore, it is necessary to obtain a good sealing performance and life enough in the design and installation

of mechanical seals, we must ensure that the pressure per unit area face value at the most appropriate scope.

Mechanical seal with the soft packing seal comparison, has the following advantages:

①reliable sealing cycle in the long run, the sealed state is stable, theleakage is very small, according to rough statistics, its leakagegenerally soft packing seal is only 1 / 100;

② long life in the oil and water type of media in general up to 1 ~ 2 years or more, usually in the chemical medium can reach more than half a year;

③ friction power consumption of small mechanical seal friction power only soft packing seal 10% ~ 50%;

④ shaft or wear sleeve is essentially unregulated;

⑤ repair long face automatic compensation for wear and tear, under normal circumstances, do not need regular maintenance;

⑥good anti-vibration on the rotation axis of vibration, as well as the deflection axis of the deflection of the seal cavity is not sensitive;

⑦applicable to a wide range of mechanical seals can be used for low-temperature, high temperature, vacuum, high pressure, different speed, and a variety of corrosive media and abrasive media, such as

containing the seal.

But its shortcomings are:

① structure more complicated, the manufacturing processing requirements;

② installation and replacement is too much trouble, and requested the installation of the workers have a certain skill level;

③ accidental accident happened when the deal more difficult;

④ high one-time investment.