Tag Archives: rotary seal

10 Reasons to Replace Metal Case Rotary Seals with Clipper® Oil Seals

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. Continue reading 10 Reasons to Replace Metal Case Rotary Seals with Clipper® Oil Seals

Eclipse Announces MicroLip™ Prototype Program

picture of microlip rotary

Eclipse has been working hard during the Covid-19 downtime on finding solutions to issues that customers have brought to the table over the past few years.

Many new designs have been sent into testing while focusing on processes that will help improve productivity and lower costs.

The MicroLip™ is an example of a viable solution to rotary seal issues that many customers have struggled with. This is especially true when the order volumes are relatively low or the shaft diameters are small, such as with encoders or chemical-processing facilities.

The Eclipse MicroLip™ Prototype Program

When moving from rubber to Teflon lip seals, Eclipse has found that the cost to bring the product to market is often a hindrance. The high cost is due to tooling and the number of pieces that must be manufactured to make the product viable in the prototype phase.

Because of this, many customers sneak by using inappropriately-applied rubber lip seals to solve rotary seal problems.

MicroLip™ seals have proven to be a powerful component in rotary services. Since the MicroLip’s inception, it has been applied to a variety of applications including mobile hydraulics, robotics, surgical drills, and semiconductor processing and encoders.

Over the last 3 years, Eclipse has designed and manufactured various styles of MicroLips in diameter sizes of under 1/8 inch (5mm) and over an inch. Since the components of the MicroLip™ can be machined, Eclipse has made the seal in quantities of less than 10, and batches in the thousands. Continue reading Eclipse Announces MicroLip™ Prototype Program

The Advantages of Crimped Can Seals

A combination of crimped can seals will handle a variety of applications when a rubber lip seal is not your solution.

Rotary seals are often secured in sealing hardware by crimping the sealing element in a metal can. One of the most common rotary seals is a molded rubber lip seal in a can. 

While not crimped, the can retains the sealing element, and stops the seal from rotating in the gland. Rotary sealing elements for low pressure (under 15 psi), are often nitrile or Viton rubber sealing elements.

This style of seal comes in many cross sections, and may include garter springs to help the seal stay engaged with the shaft. These seals are typically low in cost, and produced in high volume.

These seals are found in many low-pressure applications. However, as the pressures begin to climb over 10 psi and speeds run over 500 ft/min, friction generates heat, which accelerates wear on the rubber element and in turn begins to wear the mating shaft material.crimped can seal

Overcoming Friction

Friction or the resultant heat is the largest concern in rotary service.

The crimped can seal with PTFE (Teflon) elements can run with pressures in excess of 500 Psi and PV (pressure- velocity) reaching over 350,000psi-ft/ min. The crimped can allows these elements to remain secure.

The crimped case seal causes all the relative motion to remain at the sealing lip interface. With the crimped can, we have the opportunity to install multiple lips or seal cross sections to handle a variety of loads. This allows us to control leakage, and keep friction to a minimum.

We can seal most any fluid or run dry sealing gases with little or no lubrication. With widely varying temperatures, we can include springs to maintain seal contact, offset some eccentricity of shafts, keep dirt out or keep very light loads.

Continue reading The Advantages of Crimped Can Seals