Hydraulic seal DesignHydraulic seal Design Tips

 

Chamfer seal is sealing a connector at the surface, with an O-ring to be fitted into a groove by chamfering generated, then squeezed through the housing to create a seal. The main consideration when designing the product must be slightly stretched, appropriate to reduce the amount of compression, appropriate to increase the fill rate. Chamfering is generally 15 ° ~ 30 °, according to the working pressure selected, under pressure, to an angle close to a small value. On the contrary, whichever is greater.

 

Couplings Hydraulic seals are static seal ring is mounted without considering the hydraulic pressure to the O-ring groove ring assembly deformation and other effects of simple calculations joint diameter (d ') unilateral interference amount to 10 to 20 wire, or 0.1 ~ 0.2mm.

 

Of course, taking into account the dimensional tolerances of the parts (O-ring cross-section diameter, O-ring diameter, inner diameter of the sealing surface, O-ring groove and the ring groove dimensions shore size), coaxial and eccentric position of equipment, assembly may further calculate a single occurrence when the edge closer to the limit, to ensure that this time the loose side interference is not negative. In order to further define the sealing surface, O-rings groove, groove dimensions and tolerances shore. Then calculate D 'value (O-ring groove outer diameter) D' = d2 2H where: d2 = d1 / 1.03-1.07D1 - O-ring seal in accordance with the actual inner diameter of the gap and to select the appropriate operating pressure hydraulic seal hardness, hardness of the rubber ring should be level with the working pressure varies with the size of the gap, the pressure is high, the gap is large hardness should be slightly larger, otherwise smaller.

 

One important reason for the hydraulic seal damage is at operating pressure is extruded inside the gap C, the gap allowed values ??and working pressure, hydraulic seals rubber hardness and size of cross-sectional diameter d0, see Table 4.

 

Hydraulic compression ring size can directly affect the sealing performance and service life, the amount of compression is too small, the sealing effect is not good; the amount of compression is too large for O-ring assembly adverse, increasing frictional resistance movement, life will be shortened. Therefore, seal design process, to control the amount of compression reasonable O-ring, generally 7% to 30% compression rate prevail. Diameter compression section of a hydraulic mounting ring 5% to 3.5%, for the fixed value is too large to obtain seal, for sealing activities taking small value.

 

To ensure a reasonable sealing performance, dynamic sealing and static sealing should have a suitable surface roughness. Usually static sealing Ra6.3μm ~ Ra3.2μm, dynamic seal Ra3.2μm ~ Ra1.6μm. But not the roughness of the higher the better, if the installation is too high surface roughness, flatness is poor, there will be some ribs. This latter aspect hydraulic seal O-ring is compressed, and some surface due Mifengbuyan oil spills. With the other hand, the O-ring will be high pressure to low pressure in the direction of the direction of the slide in the groove, causing the hydraulic seal O-ring damage, causing leakage.

 

Hydraulic seal elongation is too large, it will cause stress relaxation, causing the inner diameter of the O-ring hydraulic seal is increased. Resulting in the formation of the contact gap and the shaft surface, the installation process will make it fall off because of vibrations. At the same time, the hydraulic seal O-ring squeeze due to uneven efforts to affect the life of the O-ring. Stretching ratio is calculated as follows: δ = (d'-d1) / d1X100% where: d '- to take over the diameter; Tips

 

Chamfer seal is sealing a connector at the surface, with an O-ring to be fitted into a groove by chamfering generated, then squeezed through the housing to create a seal. The main consideration when designing the product must be slightly stretched, appropriate to reduce the amount of compression, appropriate to increase the fill rate. Chamfering is generally 15 ° ~ 30 °, according to the working pressure selected, under pressure, to an angle close to a small value. On the contrary, whichever is greater.

 

Couplings Hydraulic seals are static seal ring is mounted without considering the hydraulic pressure to the O-ring groove ring assembly deformation and other effects of simple calculations joint diameter (d ') unilateral interference amount to 10 to 20 wire, or 0.1 ~ 0.2mm.

 

Of course, taking into account the dimensional tolerances of the parts (O-ring cross-section diameter, O-ring diameter, inner diameter of the sealing surface, O-ring groove and the ring groove dimensions shore size), coaxial and eccentric position of equipment, assembly may further calculate a single occurrence when the edge closer to the limit, to ensure that this time the loose side interference is not negative. In order to further define the sealing surface, O-rings groove, groove dimensions and tolerances shore. Then calculate D 'value (O-ring groove outer diameter) D' = d2 2H where: d2 = d1 / 1.03-1.07D1 - O-ring seal in accordance with the actual inner diameter of the gap and to select the appropriate operating pressure hydraulic seal hardness, hardness of the rubber ring should be level with the working pressure varies with the size of the gap, the pressure is high, the gap is large hardness should be slightly larger, otherwise smaller.

 

One important reason for the hydraulic seal damage is at operating pressure is extruded inside the gap C, the gap allowed values ??and working pressure, hydraulic seals rubber hardness and size of cross-sectional diameter d0, see Table 4.

 

Hydraulic compression ring size can directly affect the sealing performance and service life, the amount of compression is too small, the sealing effect is not good; the amount of compression is too large for O-ring assembly adverse, increasing frictional resistance movement, life will be shortened. Therefore, seal design process, to control the amount of compression reasonable O-ring, generally 7% to 30% compression rate prevail. Diameter compression section of a hydraulic mounting ring 5% to 3.5%, for the fixed value is too large to obtain seal, for sealing activities taking small value.

 

To ensure a reasonable sealing performance, dynamic sealing and static sealing should have a suitable surface roughness. Usually static sealing Ra6.3μm ~ Ra3.2μm, dynamic seal Ra3.2μm ~ Ra1.6μm. But not the roughness of the higher the better, if the installation is too high surface roughness, flatness is poor, there will be some ribs. This latter aspect hydraulic seal O-ring is compressed, and some surface due Mifengbuyan oil spills. With the other hand, the O-ring will be high pressure to low pressure in the direction of the direction of the slide in the groove, causing the hydraulic seal O-ring damage, causing leakage.

 

Hydraulic seal elongation is too large, it will cause stress relaxation, causing the inner diameter of the O-ring hydraulic seal is increased. Resulting in the formation of the contact gap and the shaft surface, the installation process will make it fall off because of vibrations. At the same time, the hydraulic seal O-ring squeeze due to uneven efforts to affect the life of the O-ring. Stretching ratio is calculated as follows: δ = (d'-d1) / d1X100% where: d '- to take over the diameter;