Lip type seals Hydraulic combined seals commonly used in hydraulic machinery equipment hydraulic cylinders in ceramic factories are mainly composed of ○-shaped sealing rings and square sealing rings, U-shaped sealing rings, Y-shaped sealing rings, YX-shaped sealing rings and other special-shaped hydraulic seals. The superposition of circles is composed using
V-shaped sealing ring V-shaped sealing ring has better sealing performance. The number of sealing rings used can be determined according to the size of the working pressure. Usually, the amount of wear of the sealing ring must be compensated by the adjustment of the gland. Its fatal weakness is the structure. It is complex and usually consists of three parts: a support ring, a sealing ring and a pressure ring. Its frictional resistance is large and increases with the increase of the working pressure and the number of sealing rings. Therefore, the V-shaped sealing ring is only suitable for the hydraulic cylinder with low moving speed and high working pressure.
U-shaped sealing ring U-shaped sealing ring has good sealing performance, but it is easy to roll over when used alone, so it needs to be used together with a tin bronze support ring, and its frictional resistance is large and increases with the increase of working pressure. Therefore, the U-shaped sealing ring is only suitable for hydraulic cylinders with low working pressure or low moving speed.
Y-shaped sealing ring Y-shaped sealing ring relies on its open lip to be close to the sealing surface to maintain sealing, usually can be used alone, its sealing performance is good, friction resistance is small, pressure resistance performance is good, and working stability Good, long lifespan. Therefore, the Y-shaped sealing ring is suitable for hydraulic cylinders with high-speed variable pressure, large cylinder diameter and large stroke.
YX-shaped sealing ring YX-shaped sealing ring is a Y-shaped sealing ring with the ratio of section height to width greater than 2 and the working lip is not equal to the non-working lip. It is divided into YX-shaped sealing ring for holes and YX-shaped sealing ring for shaft. The sealing performance is the same, in addition to all the advantages of the Y-shaped sealing ring, the YX-shaped sealing ring will never roll over when used alone, which further improves its pressure resistance and working stability. Therefore, the YX-shaped sealing ring is especially suitable for high pressure, high-speed variable pressure and fast-moving hydraulic cylinders.
Self-sealing tight hydraulic seals: lip seals, like self-sealing compact hydraulic seals, generate high initial contact stress on the sealing surface according to their own deformation, preventing the leakage of unpressurized liquids. When the hydraulic cylinder is working, the pressure liquid squeezes and spreads its sealing lip, making it close to the sealing surface to generate a higher additional contact stress that increases with the pressure of the pressure liquid, and together with the initial contact stress, the pressure is prevented. Leakage of liquid.
Combined seals Commonly used combined seals for hydraulic cylinders are bud ring, Glyn ring and step seal.
1: Bud ring
The bud ring is usually composed of the superimposed use of a synthetic rubber O-shaped sealing ring and a cloth rubber Y-shaped sealing ring. Like the seal, its deformation produces a high initial contact stress on the sealing surface, preventing the leakage of the unpressurized liquid. When the hydraulic cylinder is working, the pressure liquid always squeezes and spreads the sealing lip of the Y-shaped sealing ring through the elastic deformation of the o-shaped sealing ring, so that it is close to the sealing surface and produces a higher pressure which increases with the pressure of the pressure liquid. The additional contact stress, together with the initial contact stress, prevents the leakage of the pressurized liquid.
2: Gleam circle
The grid ring is usually composed of a synthetic rubber o-shaped sealing ring and a square sealing ring filled with polytetrafluoroethylene. It can be divided into a grid ring for holes and a grid ring for shafts. The effect is the same, according to its own deformation, it produces a higher initial contact stress on the sealing surface, preventing the leakage of pressureless liquid. When the hydraulic cylinder is working, the pressure liquid squeezes the square sealing ring to the maximum extent through the elastic deformation of the o-shaped sealing ring, making it close to the sealing surface to generate a higher additional contact stress that increases with the pressure of the pressure liquid, and Together with the initial contact stress, the leakage of the pressurized liquid is prevented.
3: Stephane
The step seal is usually composed of a synthetic rubber o-shaped sealing ring and a special-shaped rectangular-trapezoidal sealing ring filled with PTFE. Like the Glye ring, it can be divided into a hole seal and a shaft seal. With the step seal, its sealing function and sealing mechanism are the same as the Glyley ring, but it only has a one-way sealing effect.
Self-sealing tight hydraulic sealing ring: lip-shaped sealing ring, the contact area of the lip that closely fits with the sealing surface is small, which can produce greater compression deformation and obtain a better sealing effect. However, it is easy to wear, and its sealing effect is significantly reduced after wear. If an o-shaped sealing ring is used in combination with it, that is, when the seal is combined, even after the lip is worn, because the synthetic rubber o-shaped sealing ring has greater elasticity, it is It will force the lip of the lip seal ring to be close to the sealing surface, generate enough surface contact stress to achieve the sealing effect, and the friction resistance is small, the work is stable, and it is easy to assemble and maintain. Therefore, the hydraulic seals widely used in automatic hydraulic brick presses, daily-use ceramic products, discs, plates, isostatic pressing machines, and medium-pressure grouting and high-pressure grouting sanitary ceramic molding machines are almost all combined seals, such as Glacier circle and Sterling circle, etc.
