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Basic components and functions of mechanical seal

Date:Aug 04, 2020

(1) Dynamic and static ring


Keep a tight fit to form a sealing surface to prevent medium leakage. The dynamic and static rings are required to have good wear resistance. The dynamic ring can move axially, automatically compensate for the wear of the sealing surface, and make it fit well with the static ring. The static ring has a floating property and acts as a buffer.


(2) Elastic elements (springs, corrugated plates, serpentine sleeves, etc.)


It mainly plays the role of compensation, pre-tightening and buffering. It is also a factor that produces a reasonable specific pressure on the end face of the seal. It is required to always maintain elasticity to overcome the friction of the auxiliary seal and the transmission parts, and start the ring compensation. The material requires corrosion resistance.


(3) Auxiliary seal (0-ring, V-ring, wedge-shaped ring and other special-shaped sealing rings)


Mainly play the role of sealing the static ring and the moving ring, but also play the role of floating and buffering. The auxiliary sealing element of the static ring is required to ensure the sealing performance between the static ring and the gland, so that the static ring has a certain degree of floating; the auxiliary sealing element of the moving ring ensures the sealing between the moving ring and the shaft or sleeve. The material is required to be resistant It is close to the medium in terms of heat and cold resistance.


(4) Transmission parts


The transmission part includes a transmission pin, a transmission ring, a transmission seat, a transmission sleeve, a transmission key, a transmission lug or a jaw coupling, and its function is to transmit the torque of the shaft to the moving ring. The material requires corrosion resistance and wear resistance.


(5) Fastening parts


Fastening parts include: set screws, spring seats, glands, assembly sleeves, and shaft sleeves. It plays the role of positioning and fixing the static and moving rings. It is required to be positioned correctly, to ensure that the sealing surface of the friction pair is in the correct position, and to maintain a well-fitting spring pressure ratio; at the same time, it is required to be easy to disassemble, easy to place, and reusable; pay attention to the inverted installation of the sealing ring in the auxiliary seal. Angle and compression elasticity, pay special attention to the requirement of corrosion resistance and abrasion resistance at the matching part of the movable ring seal ring and the shaft sleeve. If necessary, use hard surface cladding.


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