English
中文简体1. What is an O-ring?
An O-ring is a circular ring, usually made of elastic rubber. Its dimensions are determined by the inner diameter d1 and the wire diameter d2.
2. How does the O-ring work?
The sealing effect of the O-ring is obtained by its elastic deformation of the radial diameter d2 in a reasonably designed groove. This means that the circular cross-section is compressed into an ellipse, thereby closing the gap between the sealing or contact surfaces and at the bottom of the groove. The resulting surface compression is key to achieving the desired sealing effect. The degree of deformation of the O-ring wire diameter mainly depends on the groove depth t.
3. How are O-rings produced?
1. Molding
Raw materials are manually added to the mold before the upper and lower molds are combined. Since this process is time-consuming, this process is suitable for small batches and large-scale manufacturing.
2. Injection molding
Raw materials are automatically injected into multi-cavity molds. This process is particularly suitable for high-volume and small-scale manufacturing.
4. The key dimensions of the installation groove of the O-ring
In order to achieve the intended sealing purpose, the O-ring must be placed in the groove especially designed for it. These installation spaces are usually processed by drilling or milling machines, and the cross-section of the groove is generally rectangular. The figure below is a typical groove, and its size is determined according to the recommendation of the national standard.
5. How to determine the size of the groove? (Illustrated with an axial seal subject to internal pressure)
1. First determine the size of the O-ring
The specification of the O-ring selected here is 9.5x1.8
2. Refer to the national standard "GB-T 3452.3-2005 O-shaped rubber seal ring groove size and design calculation criteria for hydraulic and pneumatic" to determine the relevant size of the groove.
According to the national standard, when subjected to internal pressure, the size and tolerance of the O-ring groove are determined in accordance with Table 2, Table 3, and Table 12 in the national standard.
in
Table 2 is the basic dimensions of the details of the axial sealing groove, and the dimensions b, h, r1 and r2 can be determined;
Table 12 is the radial dimension of the axial seal groove, d7 can be determined;
Table 3 is the dimensional tolerance of the axial sealing groove, and the tolerances of all the above-mentioned dimensions can be found in this table.
3. So far, the size of the O-ring groove with a specification of 9.5x1.8 can be determined as follows (tolerance is not listed):
b=2.6mm
h=1.28mm
r1=0.2~0.4mm
r2=0.1~0.3mm
d7=12.9mm
I hope this content is helpful to you. xinqide is a professional supplier of custom special rubber seals. If you want to know more professional information, please continue to follow us.
