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The Electrification Initiative
November 14, 2022
Schaeffler’s TriFinity wheel bearing is a fully optimized, three-row, angular contact ball bearing that provides higher stiffness and longer service life by minimizing friction and mass.
“Generally, when we look at wheel bearings, we’re looking for solutions that provide higher load carrying capacity,” said Michael Eastman, Director of BU Wheel Modules for the Americas at Schaeffler. “We’ve been working on high-capacity density solutions for years. How can you provide more life to the bearing in a smaller package?”
This occurs through material selection, bearing design, etc. Over the last three years, Schaeffler took this concept and focused on friction reduction with an eye on the battery electric vehicle (BEV) market. The North American market is focused on larger electric vehicles, so the Schaeffler team thought it made sense to find a lower friction solution to the standard bearings produced today.
A Closer Look at Wheel Bearings
“There are two different types of wheel bearings—ball bearing and tapered hub units. They are typically two row bearings. The tapered hub units have typically been used on trucks,” Eastman said. “We wanted to produce an electric market solution for trucks and SUVs that was really able to bring the rolling resistance down. Along with these benefits, the TriFinity wheel bearing can improve camber stiffness and while meeting life requirements for the application as well.”
The TriFinity wheel bearing can get friction down around 50 percent compared to a tapered hub unit. It can also provide a downsizing solution when a customer is designing a new BEV and the bearing needs a little more capacity.
“If you have a smaller package, your friction is going to be smaller because your seals and your rolling elements are all operating on a smaller diameter. So, we can get decent friction improvements there—somewhere between eight and 20 percent with the downsizing solution,” Eastman added.
While the concept of the TriFinity wheel bearing was created with BEVs in mind, it’s also translatable to ICE vehicles as well.
“We’ve done some similar vehicle level testing in the past. If you take an existing tapered hub unit and replace it with the TriFinity wheel bearing on all four wheels, based on our data we’d expect a one to two percent improvement in fuel economy. It all depends on the motivation of the customer,” Eastman said.
For monitoring purposes, wheel bearings typically use ABS encoders. The wheel speed encoders are integrated.
“Down the road for autonomous vehicles—Level 5, people mover applications—condition monitoring might be something we have to think about because the vehicle needs to know the operating conditions of the components and the wheel bearing is one of them,” Eastman said. “Once these vehicles become more prevalent in the market, we’ll look closer at these technologies.”
Additional Technology
Usually, forces are transferred between the drive shaft and wheel hub via a radial spline. To meet vehicle manufacturer’s growing CO2 reduction requirements and address NVH issues with the radial spline design, a new transfer variant was developed by Schaeffler known as face spline.
The face spline is positioned axially on the half-shaft and at the transmission-side end of the wheel hub. During wheel bearing production, the orbitally formed shoulder and face spline are made in a single step.
“When you look at the BEV market two things come to mind: The vehicles are heavy and they have high torque,” Eastman said. “Face spline gives us the ability to integrate the technology into the TriFinity wheel bearing and hit both of those marks. We can not only manage the loads but also addresses the needs on the torque side.”
Friction benefits happen at the component level, but at the system level it translates into range extension and fuel economy improvements for ICE engines.
Market Reach
Eastman acknowledged that it’s imperative to think ahead when designing and developing these technologies. “Our investment in R&D is one of our greatest assets,” he said. “In fact, we’ve already discussed the TriFinity solution with our Industrial team and shared information to leverage these assets for both the automotive and industrial markets. This includes looking at areas where they reduce friction, reduce mass, bolster energy efficiency, etc.”
Future Considerations
Schaeffler is looking at other improvements to reduce friction and increase life. Some of those areas involve seal development advancement and grease technology.
“Sensor integration is another focus area,” Eastman said. “What type of sensor integration do we need? What type of condition monitoring systems do we need? We’re collaborating with our colleagues to answer those questions.”
The TriFinity wheel bearing will go into production toward the end of 2022 or early 2023. Visit the PTE website to learn more about this and other e-Mobility solutions.
www.schaeffler.us
“Generally, when we look at wheel bearings, we’re looking for solutions that provide higher load carrying capacity,” said Michael Eastman, Director of BU Wheel Modules for the Americas at Schaeffler. “We’ve been working on high-capacity density solutions for years. How can you provide more life to the bearing in a smaller package?”
This occurs through material selection, bearing design, etc. Over the last three years, Schaeffler took this concept and focused on friction reduction with an eye on the battery electric vehicle (BEV) market. The North American market is focused on larger electric vehicles, so the Schaeffler team thought it made sense to find a lower friction solution to the standard bearings produced today.
A Closer Look at Wheel Bearings
“There are two different types of wheel bearings—ball bearing and tapered hub units. They are typically two row bearings. The tapered hub units have typically been used on trucks,” Eastman said. “We wanted to produce an electric market solution for trucks and SUVs that was really able to bring the rolling resistance down. Along with these benefits, the TriFinity wheel bearing can improve camber stiffness and while meeting life requirements for the application as well.”
The TriFinity wheel bearing can get friction down around 50 percent compared to a tapered hub unit. It can also provide a downsizing solution when a customer is designing a new BEV and the bearing needs a little more capacity.
“If you have a smaller package, your friction is going to be smaller because your seals and your rolling elements are all operating on a smaller diameter. So, we can get decent friction improvements there—somewhere between eight and 20 percent with the downsizing solution,” Eastman added.
While the concept of the TriFinity wheel bearing was created with BEVs in mind, it’s also translatable to ICE vehicles as well.
“We’ve done some similar vehicle level testing in the past. If you take an existing tapered hub unit and replace it with the TriFinity wheel bearing on all four wheels, based on our data we’d expect a one to two percent improvement in fuel economy. It all depends on the motivation of the customer,” Eastman said.
For monitoring purposes, wheel bearings typically use ABS encoders. The wheel speed encoders are integrated.
“Down the road for autonomous vehicles—Level 5, people mover applications—condition monitoring might be something we have to think about because the vehicle needs to know the operating conditions of the components and the wheel bearing is one of them,” Eastman said. “Once these vehicles become more prevalent in the market, we’ll look closer at these technologies.”
Additional Technology
Usually, forces are transferred between the drive shaft and wheel hub via a radial spline. To meet vehicle manufacturer’s growing CO2 reduction requirements and address NVH issues with the radial spline design, a new transfer variant was developed by Schaeffler known as face spline.
The face spline is positioned axially on the half-shaft and at the transmission-side end of the wheel hub. During wheel bearing production, the orbitally formed shoulder and face spline are made in a single step.
“When you look at the BEV market two things come to mind: The vehicles are heavy and they have high torque,” Eastman said. “Face spline gives us the ability to integrate the technology into the TriFinity wheel bearing and hit both of those marks. We can not only manage the loads but also addresses the needs on the torque side.”
Friction benefits happen at the component level, but at the system level it translates into range extension and fuel economy improvements for ICE engines.
Market Reach
Eastman acknowledged that it’s imperative to think ahead when designing and developing these technologies. “Our investment in R&D is one of our greatest assets,” he said. “In fact, we’ve already discussed the TriFinity solution with our Industrial team and shared information to leverage these assets for both the automotive and industrial markets. This includes looking at areas where they reduce friction, reduce mass, bolster energy efficiency, etc.”
Future Considerations
Schaeffler is looking at other improvements to reduce friction and increase life. Some of those areas involve seal development advancement and grease technology.
“Sensor integration is another focus area,” Eastman said. “What type of sensor integration do we need? What type of condition monitoring systems do we need? We’re collaborating with our colleagues to answer those questions.”
The TriFinity wheel bearing will go into production toward the end of 2022 or early 2023. Visit the PTE website to learn more about this and other e-Mobility solutions.
www.schaeffler.us
