Wuxi Ruike Machinery Parts Co., Ltd. brings you insights on what to consider during the installation of rubber seals.
Rubber seals play a crucial role in sealing gaps to prevent fluid leakage and protect the interior of enclosures from dirt, dust, and other contaminants. However, improper installation or usage can lead to fluid leaks, affecting the normal operation of machinery and potentially causing serious damage such as burned bearings, broken gears, or snapped drive shafts.
When installing framed oil seals, special equipment should be used to prevent the seal lip from being stretched, deformed, or scratched. If such equipment is not available, the following method can be used: Wrap a layer of transparent plastic film (commonly known as cellophane) around the journal and even the shaft end, apply a small amount of oil to the surface, slide the oil seal onto the shaft end covered with plastic film, and gently push the oil seal onto the journal while removing the plastic film.
It's important to note that the lip direction must not be installed incorrectly. It should face the inner side where the oil is stored, with the trademark and specifications facing outwards. Since the lip can only seal in one direction, installing the oil seal backwards will cause oil leakage, weakening or rendering the sealing effect ineffective. Avoid installing the oil seal crookedly or using tools like hammers on the oil seal surface, as this can easily damage the seal.
Sealing materials are not limited to rubber but also include graphite and metal (mechanical seals). Different types of sealing equipment have different sealing effects provided by rubber seals. However, the unique elasticity and resilience of rubber used for sealing are fundamentally similar in all types of sealing equipment. Therefore, rubber seals are particularly useful in fluid sealing.
Rubber seals are installed in the groove under tension and undergo significant elastic deformation (interference fit) after assembly. This allows the sealed cavity to rely on the resilience of the rubber seal to generate the allowable sealing force within the tolerance range. The elastic deformation of rubber enables it to maintain its sealability under different motion states and even when the working surfaces are not concentric. This is a large deformation under low stress.
Due to the high Poisson's ratio of rubber, the rubber seal can automatically exhibit a radial sealing force proportional to the applied axial fluid pressure (the volume remains essentially unchanged before and after deformation). Therefore, the rubber seal can be successfully installed in relatively simple and less precisely machined sealing cavities, with wider tolerances than required for other sealing materials.
The fundamental reason why rubber seals can automatically generate energy effects under the pressure of the sealing fluid is due to the elasticity and resilience of rubber. This valuable characteristic of rubber is essential for both static and dynamic sealing.
