The sealing element of the single hydraulic prop is the key to check the reliability of the prop. The reliability of the roof support depends on the working performance of the sealing element. The sealing surface of the oil cylinder and the piston is commonly used with the Y-shaped mi fengjuan. When the internal pressure reaches 30MPa and the emulsion lubrication performance is very poor, there is extrusion damage, so that the wear is accelerated. This can be achieved by using the coaxial composite sealing device, and the outer ring uses polytetrafluoroethylene, so as to solve the damage of extrusion when the working chamber is under high pressure. The inner ring makes Rubber material is used to solve the static sealing performance of low pressure.
When the mainstay uses water as the working medium, because of poor lubricity and low viscosity, the water medium puts forward higher requirements for anti-aging, wear resistance, hydrolysis resistance and swelling resistance of seals.
Each sealing point of the plunger suspension water medium pillar adopts the principle of sealing compensation and sealing tension. Under the condition of sealing wear, it can effectively compensate. Under the condition of roof pressure or high-pressure support, it can maintain the state of sealing tension, thus reducing the replacement rate of seals and reducing the maintenance and repair costs.
Polyurethane material is a kind of fast developing polymer synthetic material, which has the characteristics of wear resistance, elasticity, foaming, low temperature resistance, adhesion, biological aging resistance, solvent resistance and so on. Therefore, the pillar seal element also adopts the hard composite seal.
