Rotary Shaft Seals

Radial shaft seals, also known as lip seals or oil and grease seals, are used to seal rotary elements, such as a shaft or rotating bore. Common examples include strut seals, axle seals, power steering seals, truck seals, and valve stem seals. The use of modern elastomers has greatly increased the range of uses for these seals. The use of a garter spring helps the sealing lip compensate for lip wear and elastomer material changes.

The seal construction will consist of a sprung main sealing lip which has a point contact with the shaft. The point contact is formed by two angles, with the air side angle usually less than the oil side angle. Depending on the seal type these two angles are varied to create a pressure distribution at the seal contact point which has a steeper slope on the oil side of the seal. The shallower the slope on the oil side of the seal the wetter the seal will run. The spring is positioned such that axially the centerline of the spring is biased to the air side of the lip contact point.

In order to exclude contaminants numerous types of dust lips or exclusionary lips may be used. Common elastomers include FKM, ACM, NBR, HNBR, HNBR, VMQ, and EPDM. There are many variations of elastomers that could be used depending on the application. Teflon (PTFE) is another lip material used in the pharma, food/beverage industry. To resist wear the compounds’ durometer (hardness) is typically 70 to 85 Shore A (between that of an automobile tire and a soft inline-skate wheel).

Available in inch or metric sizes, Colonial Seal has over 25,000 molds (profiles and sizes) available. If a standard profile or size is not available, then we can not only design your seal to meet your unique requirements using the standard compression molding manufacturing process, or custom make a seal using either a programmable lathe or a metal spinning process. Design, sampling to PPAP levels 1thru 4, and testing services are also available.

We specialize in replacement for obsolete or discontinued seals and can usually you’re your quantity requirements without a tooling charge. Colonial Seal Company has full cross-reference capabilities for many of the major rotary shaft seal manufacturers. We can offer cost-effective, excellent quality alternatives to brand name seals and typically provide our customers a 10-20% cost savings.

Over the past 26 years we have provided replacement or equivalent seals for the following OEMS: SKF/Chicago Rawhide seals; National/Federal Mogul Oil; Freudenberg; Garlock®; Timken®; JM Clipper-Parker; NOK; and Trostel seals.