1. The choice of O-ring diameter, Taiwan imported O-ring.
The choice of O-ring diameter and Taiwan's imported O-ring occupies a very important position in the use of O-ring. If the O-ring diameter is not properly chosen, the O-ring sealing effect is not good; if the O-ring is seriously bitten, the O-ring sealing effect can not be achieved at all. Usually, the larger the O-ring diameter, the smaller the long-term deformation under the condition of constant compression ratio, and the stable sealing effect can be obtained by using the O-ring with large diameter. When the special O-ring is used as a dynamic seal, the large diameter of the O-ring can prevent twisting.
Two, how to design the groove size of O-ring properly.
The O-ring in the groove will deform under the pressure of the medium, and the edge of the O-ring will flow into the gap position to achieve the O-ring sealing function. The greater the pressure on the o-ring, the greater the deformation of the o-ring, the better the sealing effect of the o-ring. When the pressure on the O-ring exceeds its endurance limit, the O-ring will be squeezed into the gap, causing the O-ring seal failure. Therefore, the relationship among hardness, working pressure and clearance tolerance of O-ring must be properly matched in the design of O-ring grooves. The groove gap of O-ring should be as small as possible when designing groove of O-ring. In actual operation, the groove gap of O-ring is inevitable to be larger. in order to avoid the O-ring being squeezed into the gap, it should be considered to choose materials with strong extrusion resistance and good dimensional stability to make o-ring, such as polyurethane o-ring.
Three. The sealing form of O-ring.
O-ring seal can be divided into static seal and dynamic seal according to load type; O-ring can be divided into hole seal, shaft seal and rotary shaft seal according to seal purpose; O-ring can be divided into radial installation and axial installation according to its installation form. When the O-ring is installed radially, the deviation between the inner diameter of the O-ring and the sealed diameter should be as small as possible for the shaft seal, and for the hole seal, the inner diameter should be equal to or slightly smaller than the groove diameter. When the O-ring is installed axially, the pressure direction should be considered. The outer diameter of O-ring should be about 1-2% larger than that of groove under internal pressure, and the inner diameter of O-ring should be about 1-3% smaller than that of groove under external pressure.