NSK 6808DDUM Deep Groove Ball Bearing (Double-Sided Contact Seals)

Product Characteristics:

The core advantage of the NSK 6808DDUM lies in its highly effective contact seal system.The sealing lip precisely contacts the inner ring shoulder,forming a powerful barrier that effectively prevents grease from leaking out and blocks the ingress of external liquids(like water droplets)and fine dust.This design makes it exceptionally suitable for operation in humid or contaminated environments.The bearing is made from vacuum degassed steel,ensuring high purity and long fatigue life.The optimized internal geometry(raceway curvature,ball size,and count)delivers higher load capacity and lower noise levels.The pre-filled grease ensures virtually maintenance-free operation throughout the bearing's service life and maintains stable lubrication performance over a wide temperature range,significantly enhancing equipment reliability.

Product Specifications:

This bearing has a bore diameter of 40 mm,an outer diameter of 68 mm,and a width of 15 mm,belonging to a thin-section series that aids in equipment miniaturization.Its dynamic load rating is 16.8 kN,and the static load rating is 11.6 kN.Due to the slight friction from the contact seals,its limiting speed is 8,000 r/min(grease lubricated),which still meets the needs of most industrial applications.The standard radial clearance is the CN group.The seal material is typically Nitrile Rubber(NBR),known for good oil and wear resistance.The cage is made from high-performance engineering plastic(e.g.,glass-reinforced nylon 66),offering advantages like self-lubrication,light weight,impact resistance,and low noise.

Product Applications:

The NSK 6808DDUM is widely used in applications requiring high sealing reliability.In the automotive industry,it is a key component in wheel hub units,alternators,and starter motors.Industrially,it is used in submersible pumps,underwater robots,food and beverage processing equipment(requiring water and corrosion resistance),and on machine tool transmission shafts.Additionally,its requirements for low noise and cleanliness are perfectly met in office automation equipment(e.g.,high-performance printers,scanners)and medical devices.It is the ideal solution for precision drive systems that may be exposed to moisture,chemical vapors,or high concentrations of dust.