Kalsi Engineering produces innovative hydrodynamically lubricated rotary shaft seals for pressure retention and abrasive environments. We provide a range of seal styles and materials to meet various industry specific needs. Contact us to learn more about our standard and customized seal solutions. If our seals are not a good fit with your particular application, we still may be able to direct you to an appropriate solution.
What is the ideal rotary shaft seal design?
The best shaft seal design is the one that meets the specific needs of the application. For this reason, the rotary shaft seal industry provides a wide range of seal designs that are targeted at a multitude of unique operating conditions and application constraints. No one seal design is ideal for all operating conditions. The seals manufactured by Kalsi Engineering are typically designed for applications that require some level of pressure retention, and may also have an abrasive operating environment. They provide superior service in such conditions because they incorporate hydrodynamic inlets that cause the seal to hydroplane on a microscopic film of oil in response to rotation of the shaft. This lubricating effect allows the seal to run cooler for better extrusion resistance, and minimizes or eliminates adhesive wear.
Kalsi-brand rotary shaft seals are available in a wide range of styles, to address specific operating conditions and application constraints. One design variable is lip width. With all other factors being the same, narrower lips run cooler in lower differential pressure applications, while wider lips resist high pressure extrusion better, and offer more sacrificial material for axially acting wear mechanisms such as extrusion damage and third body wear. Another design variable is the degree of lubrication the hydrodynamic inlets provide. More aggressive hydrodynamic inlets increase lubrication and promote cooler operation, and support higher differential pressure, and allow the use of lower viscosity seal lubricants, but have a higher hydrodynamic pumping related leak rate. Certain seal designs incorporate a feature that causes elevated contact pressure near the environment edge of the interfacial contact footprint, for improved exclusion of environmental abrasives in low or reversing pressure conditions. Certain seal designs are also designed with installed axial seal body constraint, to improve abrasive exclusion in applications with low levels of reversing pressure.
Kalsi Seals are also available in a wide range of materials that are directed at specific operating conditions. HNBR is widely used for its good resistance to abrasion and extrusion damage. FKM and composite FKM/FEPM materials are used in applications with higher temperature, reduced breakout torque, or unique chemical resistance requirements. (A special treatment is available to reduce the breakout torque of HNBR seals.) Dual durometer construction allows the use of a high modulus seal material at the shaft to housing extrusion gap clearance, without the associated increase in interfacial contact pressure that would result from the high modulus material being used throughout the seal body. Plastic liners, when used with aggressive hydrodynamic inlets, provide better extrusion resistance than the best dual durometer construction, and also provide low breakout torque.
Additional information on Kalsi-brand rotary shaft seals, including implementation guidelines, is provided in our rotary shaft seal handbook. Please contact us for assistance in seal and material selection, and for feedback on hardware design.
How do rotary shaft seals protect the lifespan of a bearing?
When oil-lubricated bearings are exposed to contaminants, the contamination can shorten the life of the bearings, and reduce the reliability of the equipment. Many liquid contaminants, including water, dilute and reduce the efficiency of the oil, while others, including acids or alkalines, can destroy the essential lubricating properties. Abrasive contaminants abrade the bearing, leading to premature wear and eventual failure.
Contaminants typically reach the bearings through the necessary clearance gap that exists between the bearing housing and the shaft. Rotary shaft seals are used to seal the gap, in order to retain the lubricant, and exclude potential contaminants.
Kalsi-brand rotary shaft seals are a field-proven solution for retaining lubricants and excluding contaminants in harsh abrasive environments. Contact us today to discuss your application. For additional information about our products, and hardware design tips, see our rotary shaft seal handbook.