Rotary Sealing Solutions
Rotary Sealing Solutions
Rotary sealing systems are designed to retain lubricants, prevent media leakage, and block external contaminants on rotating shafts. Unlike static seals, rotary seals must maintain stable sealing performance under continuous shaft movement, varying speeds, pressure fluctuations, and changing temperatures. Selecting the correct sealing solution directly impacts equipment reliability, bearing life, and maintenance costs.
Whether used in gearboxes, hydraulic pumps, electric motors, agricultural equipment, or industrial machinery, the right rotary seal minimizes downtime while extending service life. The performance of a rotary sealing system depends on the proper combination of seal design, elastomer material, shaft finish, and operating conditions.
Common Rotary Seal Solutions
Oil seal
Oil seals are the most widely used rotary shaft seals for retaining lubricants and excluding dust, dirt, and moisture. Available in multiple lip configurations, they are suitable for gearboxes, reducers, pumps, motors, and transmission systems.
Our oil seals feature diverse lip structures and shell designs, making them adaptable to various application environments. They effectively seal the lubricant within the system while reliably preventing the intrusion of external contaminants, ensuring stable equipment operation. For more detailed product information, please visit our dedicated oil seal product page.
V-Rings
V-Rings are all-rubber axial shaft seals that rotate with the shaft and seal against a stationary surface. They are frequently installed as secondary seals to protect primary oil seals from dust, water, and abrasive particles.
This product series includes three main lines: VA, VC, and VS. Materials available include nitrile rubber or fluororubber (Viton®), and various sizes are offered to meet different operational requirements. For more product details, please visit the V-type seal product page.
Hydraulic Seals
Hydraulic seals are core components of hydraulic systems, primarily used to seal the hydraulic oil and fluids inside hydraulic equipment, while also preventing the intrusion of external contaminants such as dust, moisture, and impurities. This ensures the sealing performance, stability, and efficient operation of the hydraulic system under high-pressure, high-frequency reciprocating or rotary motion conditions. Their sealing performance directly determines the working efficiency, service life, and safety and reliability of the hydraulic system, making them a crucial barrier to ensure the normal operation of hydraulic equipment.
KODA supplies a full range of high-quality Hydraulic Seals, covering all types and material options mentioned above, and precisely matching various standard sizes such as AS568 and metric. Manufactured using precision molding processes, the products strictly control material compatibility and sealing performance, adapting to various hydraulic conditions from conventional low pressure to ultra-high pressure, and from normal temperature to extreme temperatures. All products comply with relevant industry standards such as FDA and NBR, and are widely used in engineering machinery, industrial manufacturing, energy extraction, and other fields, providing reliable sealing guarantees for the stable and efficient operation of hydraulic systems. For detailed information on our hydraulic seals, please visit our hydraulic seals product page.
U-Cup Seals
U-Cup Seals, or U-shaped seals, are a type of lip seal. They are named for their U-shaped cross-section and are core components of reciprocating motion seals. They are widely used in piston and piston rod sealing applications in hydraulic and pneumatic systems. Compared to O-rings, they offer higher pressure resistance and sealing stability.The cross-section of the U-shaped sealing ring consists of a top lip, two side lips, and a bottom cavity. Some models are designed with a spring-loaded structure (built-in helical spring) to compensate for wear and insufficient sealing force under low pressure.The medium pressure acts on the inner side of the U-shaped cavity, causing the lips on both sides to fit tightly against the sealing surface (cylinder inner wall/piston rod surface), forming a sealing contact zone. The higher the pressure, the tighter the lip fit and the stronger the sealing effect; under low-pressure or no-pressure conditions, the spring-loaded type can maintain the sealing performance through spring tension.
Groove design: Groove dimensions must be designed strictly according to standards (such as ISO 6072, GB/T 10708.1) to avoid excessive interference causing lip deformation or excessive gap causing extrusion. For more detailed information about our end caps, please visit our U-Cup Seals product page.
Combination gasket
KODA's Combination Gasket is a composite sealing element that integrates the advantages of multiple materials. It is usually composed of a metal skeleton and a non-metallic sealing layer. It is mainly used in static sealing scenarios, and is especially suitable for flange connections, pipe joints and other working conditions with high temperature, high pressure and strong corrosion. Its sealing reliability is far higher than that of gaskets made of single materials.Metal skeleton: Serving as the supporting structure, commonly used materials include carbon steel, stainless steel (304/316), copper, and aluminum, which determine the gasket's pressure resistance and heat resistance. Some models feature corrugated or serrated structures to enhance resilience.Non-metallic sealing layer: Attached to both sides or one side of the metal skeleton, commonly used materials include rubber (NBR, FKM), flexible graphite, PTFE, and asbestos (gradually phased out). The elasticity of non-metallic materials fills the microscopic gaps in the sealing surface, achieving a seal.
Selection and matching are based on the temperature, pressure, and medium of the operating conditions, choosing the appropriate metal frame and sealing layer materials; for example, for highly corrosive media, a combination of 316 stainless steel and PTFE is preferred. Flange requirements: The flange sealing surface must be flat, free of severe burrs and cracks; bolt preload must be uniform to avoid localized overtightening that could damage the gasket. For more detailed information about our end caps, please visit our Combination gasket product page.
How to Select the Right Rotary Seal
Choosing the correct rotary sealing solution requires evaluating several operating factors rather than focusing only on seal dimensions.
| Selection Factor | Why It Matters |
|---|---|
| Shaft speed | Determines friction and heat generation |
| Working pressure | Influences seal lip design |
| Temperature | Affects material durability |
| Media compatibility | Prevents chemical degradation |
| Shaft surface finish | Ensures stable sealing performance |
| Environmental contamination | Determines whether auxiliary seals are required |
For harsh environments involving mud, dust, or water, combining an oil seal with a V-Ring or Gamma seal often provides significantly better long-term protection than using a single seal alone.
Why Choose Our Rotary Sealing Solutions
- Comprehensive range of standard and specialty rotary seals
- Multiple material options including NBR, FKM (Viton®), EPDM, Silicone and PTFE
- Support for custom dimensions and engineered sealing solutions
- Fast production for OEM and aftermarket requirements
- Technical assistance for seal selection based on application conditions
If you’re unsure which rotary seal is suitable for your equipment, our engineering team can recommend the optimal solution based on shaft size, operating speed, pressure, temperature, and media compatibility, helping improve sealing reliability while reducing maintenance costs.