At present, there are more and more types of dust-proof seals, and they can be divided into many types according to their functions, characteristics, structural types, and sealing mechanisms.

1. According to the structure: rectangular dust-proof sealing ring; chamfered dust-proof sealing ring; foot-shaped dust-proof sealing ring; 　J-shaped dust-proof sealing ring; triangular dust-proof sealing ring.

2. Divided by function: single-acting dust-proof sealing ring; double-acting dust-proof sealing ring.

3. According to whether there is a framework: no framework dust-proof seal ring; framework-type dust-proof seal ring.

4. According to whether it is combined or not, it is divided into: single type dustproof sealing ring; combined type dustproof sealing ring.

An oil film adheres to the surface of the cylinder piston rod. The place where the oil cylinder is used is usually dust or sand particles, etc. 　 These dust, sand particles and the oil film on the surface of the piston rod will be brought into the oil cylinder, scratching the lip of the lip seal ring on the piston rod, or Scratches on the surface of the piston rod will cause medium leakage. Therefore, it is necessary to install a dust ring on the outside of the piston rod sealing ring, near the end surface of the cylinder. The dust ring is installed in the groove. Because there is a certain amount of interference between the lip of the dust ring and the piston rod, the lip of the dust ring is close to the surface of the piston rod