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Dust Seals for Helicopter Bearing Assemblies

Dust seal rings, custom molded from Nitrile elastomeric compounds and bonded to G-10 fiberglass, are made by Pelmor® Laboratories, Inc. to stringent specifications for use in helicopter precision rotor bearing assemblies.

Due to the extremely close tolerance requirements of these dust seals, their production requires a number of special considerations by the manufacturer. These include the use of a specially developed polymeric formulation that bonds well to G-10 fiberglass, and precision in both the engineering stage and the molding operation to ensure that the bearing assembly components are adequately protected in the field.

Incorporated into the main rotor bearing assembly of a variety of commercial and military helicopters, the dust seals are subjected to many aggressive elements. The Nitrile elastomer was selected because of its ability to withstand temperature extremes of -50° to +250° F and to resist attack by over 750 corrosive oils, chemicals, and other liquids. Other properties include excellent abrasion resistance; tensile strength of 2030 psi; Shore A durometer of 60+/- 5; and 385% elongation.

Pelmor® offers a number of capabilities that are crucial to the production of high quality dust seal rings including: an in-house molding press which can manufacture components as large as 44", while maintaining tolerances on the part’s diameter as tight as +/- .010" and a thickness as close as +/- .003"; accurate secondary trim operations; and superior machining of the G-10 fiberglass from sheet stock. The long-lasting bonding of rubber to other substrates, such as G-10 fiberglass, is another specialty of Pelmor® Laboratories.

For additional information, contact Pelmor® Laboratories, Inc., 401 Lafayette Street, Newtown, PA 18940-0309; Phone: 800-772-6969 or 215-968-3334; Fax: 215-968-3676; E mail: sales@pelmor.com.