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Freudenberg-NOK’s Low Load Seal Design Improves Sealing Performance in General Motors Engines

Customizable offset seals offer simple assembly and component stress reduction

Freudenberg-NOK Sealing Technologies (Freudenberg-NOK) isa global leader in material innovations and custom-engineered sealingsolutions.


So it was only natural that when General Motors Corp.(GM) was searching for a static radial seal for several engine applications,the auto company ultimately selected Freudenberg-NOK’s ergonomicallyengineered, low load seal technology. Today that partnership has grown into additional applications acrossGM’s highest volume four-cylinder and V-6 engines.


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


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


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


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


“The seal’s lip design can be applied to otherstatic radial offset applications. It reduces contact pressure, whichconsequently increases the life cycle of the seal and the components,”said John Wagner, staff design engineer, Freudenberg-NOK and inventor of thelow 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 throughvarious design renderings before arriving at the solution. His work continuesto generate new applications and sealing approaches for GM and Freudenberg-NOKalike.


About Freudenberg-NOK Sealing TechnologiesFreudenberg-NOK Sealing Technologies is the Americas joint venture betweenFreudenberg and Co. in Germany and NOK Corp. in Japan. Freudenberg-NOK is aleading producer of advanced sealing technologies for a variety of marketsincluding: aerospace; agriculture; appliance; automotive; construction; dieselengine; energy; food and beverage; heavy industry; and pharmaceutical. Foundedin 1989 under the legal name Freudenberg-NOK General Partnership,Freudenberg-NOK is headquartered in Plymouth, Mich. and operates more than 20facilities across the Americas. For additional information, please visit