Freudenberg-NOK’s low load seal design improves sealing performance in GM engines

Freudenberg-NOK Sealing Technologies (Freudenberg-NOK), which develops material innovations and custom-engineered sealing solutions, is working with General Motors Corp (GM) with its customizable offset seals that offer simple assembly and component stress reduction.

The company says when GM was searching for a static radial seal for several engine applications, it chose Freudenberg-NOK’s ergonomically engineered, low load seal technology. Today that partnership has grown into additional applications across GM’s highest volume four-cylinder and V-6 engines.

Freudenberg-NOK’s low load seal, a type of offset seal that can be easily installed and removed by hand, reduces installation force by more than 70 percent. GM adopted the design for several engine applications including a spark plug tube, vacuum pump seal and two solenoid-to-cam cover seals.

“Offset seals control independent loading on mated components and can be easily assembled or removed, allowing options for serviceability,” said David Pehlman, engineering manager, Freudenberg-NOK. “The design allows for the use of dissimilar mated materials and reduces stress on components, which contributes to increased durability.”

The basic premise of low load sealing is that instead of squeezing an O-ring bonded to a metal case, rubber is trapped in various shapes and allowed to move a little more, which creates a lower assembly force and more improved sealing.

After validation tests were completed, GM adopted the design for both the spark plug tube seal and mechanical vacuum pump seal. Freudenberg-NOK engineered the seals to GM material specifications and they now appear on some of the auto manufacturer’s latest 2014 model offerings including the Cadillac CTS Sedan, GMC Acadia and Chevrolet Malibu. While the design is ideal for engine applications, it is not limited to engine alone.

“The seal’s lip design can be applied to other static radial offset applications. It reduces contact pressure, which consequently increases the life cycle of the seal and the components,” said John Wagner, staff design engineer, Freudenberg-NOK and inventor of the low lead seal technology. “It’s a practical, user-friendly solution, particularly when both improved ergonomics and sealing are desired.”

Wagner’s patent pending innovation took him through various design renderings before arriving at the solution. His work continues to generate new applications and sealing approaches for GM and Freudenberg-NOK alike.