Oil Seal VC - Rotary Shaft Seal

Technical description

The VC rotary shaft seal uses a form-pressed sealing lip to keep a consistent pressure on the rotating shaft. Because there’s no radial spring this sealing is best suitable for applications with low friction and limited heating. The sealing lip prevents oil or grease from escaping, while the outer diameter provides static sealing within the bore. The soft elastomer outer diameter allows the seal to compensate for minor bore imperfections, making it suitable for housings with increased surface roughness or slight thermal expansion.

The entire elastomer construction offers installation advantages: the seal presses easily into place, absorbs minor vibration, and adapts well to housings with standard tolerances. That’s why the oil seal VC type is especially suited for applications where there’s limited space, cost efficiency is important, and a spring-loaded lip is not required. The temperature stability, chemical resistance and lifespan of the oil seal depends on the material. This allows the VC seal to be matched to various operating environments, from general machinery to applications with temperature fluctuations or specific media conditions. Because the lip is not spring-loaded, wear on both the lip and the shaft surface is reduced, which contributes to longer service life in low-duty applications. 

Construction information

Material options

Functional performance and operating parameters

The oil seal VC performs best in depressurised applications and at low to medium rotary speed. Because it’s doesn’t have a spring-loaded sealing lip the sealing pressure is less high than oil seals which do have a spring-loaded sealing lip. This results in reduced wear and less frictional heat. The VC type is suitable for shaft speeds up to approximately 6 m/s, depending on size and material, in line with standard rotary shaft seal performance charts. The temperature range and the chemical compatibility depend on the chosen material. For higher temperatures and synthetic lubricants, FKM is usually the preferred material, while on the other hand NBR is an excellent choice when using mineral oils.

Installation and design requirements

For an oil seal to be reliable, the rotating shaft and housing must meet standard tolerances. The shaft should be free of burrs and have an appropriate surface finish, and the lip should be slightly lubricated with a compatible grease or oil before installation. For optimal performance, the shaft should have a minimum hardness of 45 HRC to prevent premature groove formation. The seal should be pressed straight into the bore without tilting. An installation tool prevents the oil seal VC from getting damaged or deformed. Because the VC is made of elastomer, it tolerates minor housing deviations better than metal-cased designs. However, correct alignment and surface preparation remain essential for long service life.

Specifications

• Type oil seal: VC rotary shaft seal
• Design: Fully elastomer with a single non-spring-loaded sealing lip
• Materials: ACM, EPDM, FKM, NBR, VMQ
• Pressure capability: Low pressure, depressurised application
• Rotating speed: Low to medium
• Temperature range: Depends on chosen material
• Function: Keeps lubricants inside and keeps light contamination outside

Use Cases

The VC rotary shaft seal is used in a wide variety of industries, including machinery, workshop equipment, HVAC systems, small motors, fans, pumps, and basic drive assemblies. Thanks to the different material options this oil seal can be used in greasy, dry, and lightly humid environments. 

Because there's a lot of different brands/suppliers, these sealings go under a variety of names/codes. The table underneath shows a selection of brands/suppliers and their corosponding codes.

When do I choose an oil seal VC?

Choose the VC type when:

• A simple, reliable seal is required
• Low friction is desired
• The application is light to medium duty
• Installation space is limited
• A cost-efficient solution is sufficient

DON’T choose the VC type when:

• Heavy contamination (dust, mud, slurry) is present
• High axial or radial loads occur
• Pressure loading is expected

In such cases, KC (with dust lip) or SC (spring-loaded) are better choices. And you might even consider the TC which has a spring-loaded sealing lip as wel as a secundairy dust lip to keep out contaminents. 

Property comparison: VC vs. SC vs. KC

FAQ