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Schatz Bearing Corporation has introduced an advanced seal for ball bearings used in aerospace applications.

Standard aircraft bearing PTFE based seals are inadequate for many aerospace bearing applications because they do not offer positive lip contact at the sealing surface. In order to alleviate this problem, Schatz has developed a lip contacting seal that utilizes an advanced Fluoroelastomer material. The seal has far superior sealing characteristics when operated in environments with fluid or dust and dirt contamination.

Advantages of Schatz’s New Aerospace Bearing Seal:

  • Positive lip contact keeps out contamination
  • Protects bearing grease from leakage and washout to extend operating life of bearing
  • Seal material is resistant to aircraft fluids such as de-icing fluids and hydraulic fluids
  • Can be used in variety of bearing designs including
    • Airframe ball bearings
    • Thin section ball bearings
    • Specialty aerospace bearings

Traditional Aircraft Seal: Torque Tube Aircraft Bearing has PTFE flat “disc” seal and has gaps which allow contamination to enter the bearing cavity

Traditional Aircraft Seal diagram with detail

Traditional Aerospace Bearing Seal

Traditional Aeorspace Bearing Seal photo

Traditional Aerospace Bearing Seal

Schatz’s New Aerospace Bearing Seal keeps contamination out of bearing cavity

Schatz New Aerospace Bearing Seal diagram

Schatz New Aerospace Bearing Seal

Schatz New Aerospace Bearing Seal photo

Schatz New Aerospace Bearing Seal


A comparison test was run where bearings with the new design and traditional design were run in a dust box with Arizona road dust circulating while the bearings were rotated. The test duration was 48 hours.

New seal test result

New Seal: Post test, after seals removed, no presence of silica dust inside the bearing cavity.

Traditional seal test result

Traditional Seal: Post test, after seals removed, significant presence of silica dust. No grease observed.


After test, the new seal design units all rotated smooth by hand. The grease inside the bearings still appeared green in color, which is consistent with new Aeroshell 33 grease color (MIL-PRF-23827C Type 1).

The traditional seal design units all rotated rough, gritty by hand. Upon seal removal, little, to no grease remained inside the bearing. Black silica dust was present, indicating contamination is able to ingress into the bearing cavity. In a harsh environment, reduced bearing life can be anticipated.

Given the conditions observed in the bearing internal cavities, it can be concluded the new seal design is superior at preventing, and/or significantly reducing the occurrence of contamination ingress into the bearings.