Hydraulic seal sealing mechanism

Hydraulic seal should have good elasticity, heat resistance, cold resistance, pressure resistance, abrasion resistance and a certain physical and mechanical strength, and long service life; Fifth, is the low price. Hydraulic seal should be easy to manufacture and install, and its respective sealing groove and ease of manufacturing, precision machining sealing surface requirements and low, low and low grid.

The basic requirement is to seal tightness, safety and reliability, long life, and should seek a compact, simple system, easy maintenance of manufacturing and low cost. Most seals are wearing parts, should ensure interchangeability, standardization, serialization.

Sealing can be divided into static seal and dynamic seal two categories. There are static sealing gasket, sealant and direct contact with the seal three categories. Dynamic seal rotating seal and can be divided into two basic types of reciprocating seal.

Press hydraulic seals its effect relative movement of the parts is in contact, it can be divided into contact and non-contact seal seal. In general, the contact seal sealing, but subject to friction and wear limits apply to the lower sealing surface linear velocity of the occasion. Non-contact seal tightness is poor, suitable for high speed applications.

Hydraulic seal sealing mechanism involves two factors, one is the seal of the cavity, the outer edge of the main hydraulic seal (static component) positioned in the cavity; the second is a dynamic seal sealing lip in contact with the surface of the rotating shaft, this is the most important function of the hydraulic seal.

Sealing mechanism sealing lip contact area of ??hydraulic seal having a seal sealing function plays a very important sense, it depends on: the design of the sealing lip; roughness of the shaft surface; the structure of the elastic material. Radial force of the sealing lip, the sealing lip design combined effect of the angle and distance between the lip and the tip of the spring-centered design, resulting in a kind of axial surface contact pressure distribution asymmetry: the maximum pressure in the oil side and the renewed increase; in air-side pressure was small angle attenuation. In the amount of interference (under the lip of the inner diameter in the free state, no load design slightly smaller than the diameter of the shaft) mating, the contact pressure distribution of this asymmetry, the circumference of the ring with the rotation axis generated confining force combined, leading to the structural characteristics of the sealing lip contact area of ??the deformation. This seal elastomeric deformable structure is formed when commissioning seal, sealing performance plays a decisive role. Thus, hydraulic seals require a commissioning period of transition. Plus the impact of the helix axis of rotation, generated by such deformation structure to the oil side of the pumping action.

Hydraulic Seals lip sliding surface friction characteristics by fluid viscosity and sliding speed governed at the sliding surface of the oil film exists. Mutually sliding surface of the seal member with the shaft in this motion state of lubrication oil film separation, thus maintaining low friction, low wear. In the hydraulic seal sliding contact surface of the oil flow from the air side to the oil side of the oil and from side to side of the atmospheric circulation. Sliding surface oiled, prevent wear and tear, thus there are no leaks. Seen on the sealing lip seal lip material, the shape of the lips subtle control of these two factors affecting lubrication properties and hydraulic seal sealing principle, is essential.