The automotive industry has long viewed motorsports-borne technology as a great test bed for new development and innovations for road vehicles. Lessons learned on the track help develop new hardware, systems, and equipment that power and protect motorists on the road.
Race track testing can make it especially easy to understand how the smallest of parts such as seals, bearings, rings, and diaphragms have to be evaluated and re-engineered to work with the automotive industry’s constantly evolving car systems and parts.
Protecting turbocharger shafts
With turbochargers, the best and newest versions tend to hit the track before going into mainstream vehicles. Those racing turbos run hotter and can have an unintended impact on the materials used for seals and bearings.
Turbochargers use plain bearings, lubricated with oil, under pressure from the engine’s oil pump. The bearing is in the middle of the turbocharger, between the intake and exhaust sides. Additionally, residing on the intake side and on the exhaust side, there are two oil seals, keeping lubricant from escaping from the bearing.
According to Ray Gillies, general manager, Great Lakes Trelleborg Sealing Solutions, “We have several turbocharger seal and bearing applications in the motorsports industry. We have found that it is really important as a material supplier to work closely with customers, in this case the turbocharger manufacturers. It ensures that proper testing is conducted and achieves the desired outcome.
“For example, our radial oil seals have been designed to deliver longer-lasting sealing efficiency, providing high tolerance to heat while still maintaining resistance to wear and, most importantly, lowering friction,” Gillies continues. “It is a matter of material science, design expertise, and advanced manufacturing techniques that are needed to achieve the kinds of results that the motorsports industry requires.”
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Race-born vehicle technologies Keen collaboration between motorsports specialists and suppliers helps develop parallel or complementary materials and innovations, while recent partnerships show several racing advancements making their way into consumer vehicles. Shell Co. works with engine and seal specialists to develop lubricants to match the environments and materials used on the race track. Alternative fuels, such as the ethanol blend used by NASCAR, may cause contaminants in engine oils, so scientists have set their scope on designing oils with better seal compatibility. “As new, fuel-efficient systems emerge, our scientists have been able to create innovative lubricants that have helped support greater fuel efficiency in a vehicle,” says Istvan Kapitany, president, Shell Commercial Fuels and Lubricants Americas. “For engine oils, the lower the viscosity of the oil, the less fuel you need to power your engine. The challenge is to determine the lowest viscosity that still provides the right level of engine protection, durability, and performance.” Shell Commercial Fuels and Lubricants Americas |
Since there is less regulation and fewer price considerations being made in the world of motorsports than within the automotive industry for the general public, it makes perfect sense to use the cars on the race track as an open test ground for pushing the limits of innovation. This can generate solutions that could have far-reaching influences on the future of motor vehicles. It gives seal, bearing, and ring providers, as well as the coatings and lubricant makers, a place to try out their latest concoctions in some of the most extreme vehicular conditions around.
Weight shaving even the smallest parts
Weight reduction is a critical concern for racing and performance cars, and it is a factor that is being investigated and streamlined right down to the seals and bearings. With every ounce of weight under scrutiny, suppliers are paying attention.
Trelleborg is manufacturing even lighter weight, friction-reducing seals that have been put to test in Formula One and Indy car races. Torque and power consumption values vary with the seal design and material, which is why it has become so important to use the right seal configurations to achieve the best possible performance.
There have been some substantial changes. For instance, the first-generation shaft seals with leather or rubber lips have given way to the use of a lighter lip to reduce torque loss. This is a long way from the old assembled designs that functioned using sheer force and tended to have aggressive springs, wide contact bands, large interferences, and high radial loads. Today’s modern, molded seals work longer and more effectively with narrow contact bands and minimal radial loads that are uniform over time.
Radial shaft seal designs
Trelleborg’s collaboration with race car systems and parts manufacturers proved that on the track, differences still sprout, even between new designs. Scientists work with the seal engineers to determine the best design parameters, such as lip radial cross-section (and therefore radial load), which can result in considerable differences in torque drag. As a result, the science involved in making seals can be quite complex.
Seals made for the same shaft and bore dimensions, but from various manufacturers, can have different power consumption characteristics. The principal role of a rubber radial lip seal is to retain lubricants and exclude contamination in mechanical systems, yet the most critical seal parameter, the robbed horsepower and power loss caused by the seal, often goes overlooked.
Another important area of contention has to do with radial shaft seals, which are a lot like bearings in that these seals require an oil film to support the lip load. The performance of these seals really depends on the control of the oil film thickness under the lip, which must be controlled across a wide range of conditions. The early hours of seal operation have proven important in order to establish a complementary directional pattern in the rubber material. The formation of this pattern must support a positive pumping action by the seal lip while simultaneously smoothing the shaft.
New seal materials, designs
Nevertheless, seals do cause friction, which does consume power. The total amount of power consumed by radial lip seals in contact can be substantial in any car system. Overall the interference between lip and shaft, the elasticity of the rubber, and the spring force creates a radial load, resulting in additional torque, something Trelleborg has been working to perfect.
“We have seen advanced polymers and elastomers gaining wider acceptance in racing circles because they boost performance and cut weight. Components made from these materials can be manufactured in complex geometries and offer high-temperature resistance and exceptional durability,” Gillies states. “It is for this reason that we’ve started to see the replacing of metals in many traditional sealing, cylinder, and housing application with race car grade elastomer materials.”
Everyone knows that a split second can make the difference between winning and losing. This is why race teams in Formula One, IndyCar, and NASCAR are always on the lookout for parts that perform better, are more reliable, and weigh less.
Trelleborg Sealing Solutions
www.trelleborg.com