In simple words, seals are used in minimizing or preventing any leakage forms in the joints. Since they give such essential roles, it needs some consideration before selecting the required seals. Apart from knowing more about the seal, the purchaser needs to see the effect that the seal can have in various environments as well as understanding the place the seal need to reside.
When selecting the bearing seals for its purposeful applications, you need to look at the seal’s physical dimensions and the operating conditions. Despite being many things to consider, here are primary considerations for you to select the bearing seals that best suits your requirements.
Temperature
Temperature happens to be the main factor in the seal’s environment since it dictates material of the seal, which also is one of the important factors for seal manufacturers to make different types of seals. Bearing seal has a stated optimal temperature which can range from 4 - 49 degrees. If your operating environment happens to be cold, then the seal can be brittle, and the climate is hot, then the seal may be more elastic. When the temperature is increased, the rubber aging will be high too. When the seal happens to be exposed above its recommended temperature, then the sealing edge axial cracks will be visible. If air temperature can increase by 10 degrees, then rubber’s life will be reduced by half, which is not fair. Apart from air, the environmental temperature may also fluctuate due to:
• The pressure applied
• The velocity at the circumference
• The rotation at high speed since it can lead to excess heat
• Thermal management capabilities and insufficient lubricating from the lubricant.
Size Or Position
For one to select a proper bearing seal, there should be the measurement. The place that the seal should be placed needs to be correctly measured to ensure the fit is perfect. It should always be considered since if there is no fit in the seal, their won't be viability meaning there can be contamination or leakage. To determine the seal size, you need to know the seal bore, housing hole diameter where the seal needs to be fitted, Inner and Outer diameters of the seal, together with the width of the seal that is total for outer and inner shells.
• The seal bore will represent the hole diameter that the seal needs to be fitted.
• The outer diameter of the seal should have its measurement taken almost three places that are spaced equally around the seal, and its average diameter will be the outer diameter.
• The seal width refers to the height of seal when it's laid onto the flat surface and is comprised of outer and inner shells.
• The inner diameter shaft is used when making inside dimensions since the inner diameter of the seal may vary. To get the actual diameter of the shaft, you can measure the inside dimensions of the seal.
Pressure
When the pressure amount grows, then sealing lip friction and radial load increases when it's contacting the shaft. Every seal has a recommended pressure for it to perform well. When the pressure is too much, the seal can shorten its life by wearing out faster. Here, the specified peripheral values are forced to be lowered depending on the pressure magnitude; hence, their specified values won't be constant. If your environment is of high pressure, then you can prevent the joint leakages together with the housing bore when you apply the rubber-covered cases seals. There can be some axial movement risks at the housing bore if the seal is placed under pressure, and this can be prevented when the seal is located against the shoulder that has the spacer ring.
Speed
For the bearing seals to effectively operate in particular speed condition, then they will be affected with temperature, pressure, seal design, shaft finish, and the fluid lubrication is used. When there is lubrication between the moving surface and a seal lip, then the friction will be reduced, which is very important degradant of the seal. The frictional level is established by the lubricating film thickness. When the frictional forces are at a higher velocity, they can start climbing hence causing wearing out. Some seal designs allow several maximum peripheral speeds where; higher peripheral rates can well be used in larger shaft diameters as compared to the smaller shaft diameters. Here, their cross-sectional area will increase as the diameter square increases; hence, they will increase heat dissipation capacity. Where high speeds reduce the seal’s life, speeds out of the recommended range can increase the friction; consequently, the seal material will be affected.
When selecting the best bearing seals, you should always consider the above primary factors for the best results of your sealant.