Mechanical seals are also called end face seals and are mainly used to seal the rotating shafts of pumps, compressors, hydraulic drives, and other similar equipment. The mechanical seal is a sealing device composed of a pair and several pairs of moving rings and static rings consisting of a plane friction pair.
The mechanical seal is a device that prevents fluid leakage by keeping at least a pair of end faces perpendicular to the axis of rotation under the action of fluid pressure and the elastic force (or magnetic force) of the compensation mechanism and the cooperation of the auxiliary seal to prevent fluid leakage. If the auxiliary seal of the compensation ring is a metal bellows, it is called a bellows mechanical seal.
Mechanical seal composition
Mechanical seals mainly have the following four types of components:
- Main seals: moving ring and static ring;
- Auxiliary seal: sealing ring;
- Compression parts: spring, push ring;
- Transmission parts: bullet base and key or fixed screw.
Mechanical seal classification
According to the rotation or static of the spring element, it can be divided into: rotating type internal flow unbalanced single end seal, referred to as rotating type; static external internal flow balance type single end seal, referred to as static type.
According to the static ring located inside or outside the sealing end face, it can be divided into: internal type and external type;
According to the leakage direction of the sealing medium, it can be divided into: internal loss and external flow;
According to the unloading situation caused by the medium on the end surface, it can be divided into: balanced and unbalanced;
According to the logarithm of the sealing end face, it can be divided into: single end face and double end face;
According to the number of springs, it can be divided into: single spring type and multiple spring type;
Classified by elastic elements: spring compression type and bellows type;
Classified by non-contact mechanical seal structure: hydrostatic pressure, hydrodynamic pressure, dry gas seal;
Classified by the temperature of the sealed chamber: high, medium, normal, and low temperature sealing;
Separate according to the pressure of the sealed chamber: super high, high, medium and low pressure mechanical seal.