The mechanical seal is a mechanical part used to seal the rotary shaft and stop the pump chamber.
The sealed part is a cylindrical area, the shaft in the equipment rotates and runs through the equipment table, the body part stops and the interior is filled with the fluid medium. In the pressure difference, the concentration difference, the temperature difference driven, the equipment table fluid exchange; "seal" means to control the area between the fluid exchange, so that the interface "no leakage" scene.
Bucht in the "industrial seal skills," a book that is explained:
The mechanical seal
is a combination of a series of simple planning elements, the sealing effect by the two mechanical seal with the plane of the main seal ring end to avoid leakage. In which a seal ring is pivoted together with the shaft and the other seal ring is fixed to the housing. In order to seal the centrifugal pump shaft, the static seal ring is mounted on the sealing chamber gland.
During the rolling of the pump shaft, the sealing surface of the sealing ring mounted on the shaft collides with the opposite static ring sealing surface. The touch effects of the two sealed touch surfaces are similar to bearings and are worn. Any side of the pump-type system leaks must pass through the sealed touch surface. The effect of the force in the axial direction causes the seal ring to always remain in the kettle with a mechanical seal in a conflicting touch, the source of which can be considered mechanical or hydraulic, and in many plans, take both sums. This stable touch can avoid leakage from the collision surface or minimize leakage.
Mechanical seal according to the use of the host classification can be divided into pump seal, kettle seal, compressor seal. Pump seal
contains a variety of centrifugal pumps, vortex pumps, screw pumps, internal combustion engine cooling pumps, marine pumps, etc; kettle with a variety of sealed stainless steel kettle, enamel, glass and other mechanical seal.
The kettle seal is the same as the pump seal principle, but the kettle seal has some unique features:
The top of the bottle is sealed with a gas, only when the kettle is liquid; the mixing axis is long, the swing and oscillation of the shaft are relatively large, and the dynamic ring is usually not fit well, usually Bottom bearing or intermediate bearing; large scale, heavy parts, disassembly and replacement difficult to compare, installation and adjustment is also difficult to compare; with the pump seal comparison, low speed, low PV value, dynamic ring material selection easy.
Pump seal is usually high speed, high pressure, high PV value, heat, sealing the difficulty is how to form a stable smooth film mode. Simply said, the pump seal for the fine, kettle with a seal for the skin is anti-external type.