clipper
- August 26, 2020
Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.
Original content can be found on Parker’s Website and was written by Alan Wiedmeyer, application engineer, Parker Engineered Polymer Systems Division.
Clipper® Oil Seals are one of the Parker Engineered Polymer Systems (EPS) Division's most widely used rotary seal products. They are an effective solution – especially when used as direct replacements for traditional metal case seals. This is a testament to their precision-molded rubber/aramid fiber heel construction which eliminates the metal case (see image above). In this blog we will review the benefits of using Clipper® seal profiles as direct replacements for metal case seals:
1. Improved sealing in an imperfect housing
The composite rubber/aramid fiber heel provides a gasket-like seal for improved sealing against the bore. The surface conditions of bore housings are frequently riddled with imperfections due to damage during improper seal installation and removal, or simply due to cost sensitivity in their original manufacture. Metal can seals lack the ability to conform to such imperfections, frequently necessitating the use of supplemental gaskets or bore sealants during installation to prevent bore leakage.
2. No need for compression or bore plates
The outside diameter of the flexible, composite elastomer/aramid fiber heel is slightly oversized to create a tight interference press fit. The tight fit and compression-set-resistant heel construction eliminate the necessity of compression plates for bore retention1. It’s essential to note that bore plates (shown in green) can cost as much as $100 per inch of shaft diameter because of additional part cost and added assembly time.
3. Corrosion-resistant
Clipper seals have a composite elastomer/aramid fiber heel and rubber elastomeric lip so there is no concern for rust or corrosion. The only metal component is a 302 stainless steel garter spring. The stainless spring handles higher operating temperatures and resists rust/corrosion better than carbon steel springs used in other rotary shaft seals.