Rubber seals are widely used in industrial and civil products. In a variety of rubber sealing methods, the O ring is most widely used for its cheap production methods and ease of use. Compared with other sealing elements, the O ring has many advantages:
(1) Simple structure, integrated groove design, low cost of processing and design.
(2) The structure is compact and the shape of the part is small.
(3) The installation is convenient and reduces the risk.
(4) It can be applied to various sealing problems, such as static seal, dynamic seal, single acting and double acting seal.
(5) Wide selection of materials, suitable for most fluids.
(6) Convenient for inventory, maintenance and repair.
In different application environments, in order to achieve perfect sealing effect, the performance of the material itself and the design of the sealing structure are very important. By summarizing the experience of sealing design in hydraulic and pneumatic products for many years, the author analyzed the design of material selection and sealing structure of O ring.
The selection of O ring rubber
When choosing the O ring material, we should pay attention to the physical and chemical properties of the selected materials in order to meet the requirements. The requirements for the sealing material have the following points:
(1) The ability to resist the working medium is strong, and the volume and hardness of the work are small in the long term.
(2) Good elasticity and small permanent deformation. It can be pressed against the sliding surface under very small pressure and effectively prevent leakage.
(3) Small friction coefficient and good wear resistance.
(4) The material has good compactness and no leakage.
(5) With certain mechanical strength and hardness, gas, liquid pressure and workpiece movement cannot destroy it.
(6) Good performance of high and low temperature. It does not decompose and soften at high temperature. It does not harden and brittle at low temperature.
(7) Good weathering resistance, not easy to age in sunlight or air.
(8) It has the softness and elasticity that can be attached to the sealing surface, and does not corrode, and does not adhere to the metal surface.
(9) Easy processing and forming.