O-ring basic knowledge - 1 views
started by kbojezhang44 on 13 Apr 20
started by kbojezhang44 on 13 Apr 20
started by kbojezhang44 on 13 Apr 20
started by kbojezhang44 on 13 Apr 20
O-ring is a circular sealing element with small cross section. The Common cross section is circular. The main material is synthetic rubber, which is the most widely used and common seal in hydraulic engineering. It is mainly used for static sealing and sliding sealing. Compared with other seals, it has the following characteristics:
1. Good sealing and long life; A single circle can seal the two directions;
2. Good adaptability to oil, temperature and pressure;
3. The dynamic friction resistance is small; Small size, light weight and low cost;
4. The sealing part has simple structure and convenient dismantlement and gathering;
5. It can be used as a static seal or a dynamic seal;
6. The dimensions and grooves have been standardized, and the selection and outsourcing are convenient. Its disadvantage: when the dynamic seal is started, the friction resistance is large, which is about 3 ~ of the dynamic friction force ~ 4 times, it is easy to be squeezed into the gap under high pressure.
O-ring material selection mainly considers the following points:
1. The working state of the O-ring refers to whether the O-ring is used for static seal, dynamic seal or sliding seal;
2. The working state of the machine refers to whether the machine is working continuously or intermittently, and considering the length of each intermittent time and whether there is impact load acting on the sealed part;
3. The working medium is gas or liquid, and its physical and chemical properties are considered;
4. Working pressure, pressure magnitude, fluctuation amplitude and frequency, and instantaneous maximum pressure, etc;
5. The working temperature includes the instantaneous temperature and the temperature of alternating hot and cold;
6. Price and source. Generally speaking, nitrile rubber for oil resistance, neoprene for ozone resistance, acrylate rubber or Fluororubber for heat resistance, polyurethane rubber for High Pressure resistance and wear resistance, Copolymer chlorohydrin rubber for cold resistance and oil resistance, etc.