Bearings Applied in Electrical Vehicle Applications

The global shift toward electrification is transforming industries at an unprecedented pace, with electric vehicles (EVs) at the forefront of this revolution. Bearings, though often overlooked, are integral to this transformation, providing support for high-speed, energy-efficient, and durable EV systems. 

The bearings market, driven by advancements across sectors such as automotive, aerospace, and industrial automation, is projected to grow from $136.29 billion in 2024 to an estimated $211.5 billion by 2029, with a steady CAGR of 9.3%. This growth is fueled by rising demand for high-performance bearings capable of withstanding the unique challenges posed by EVs — challenges that traditional bearings are ill-equipped to handle.

Electric vehicles require precision-engineered bearing solutions to address issues such as elevated rotational speeds, high thermal loads, and compact design constraints. Unlike internal combustion engines (ICEs), EV motors often reach speeds of 15,000 RPM or higher, placing immense stress on bearings. The global surge in EV sales — doubling to 6.6 million units in 2021 and continuing to grow — has also accelerated the demand for specialized bearings designed for electric powertrains. Simultaneously, the broader automotive industry, which produced 85.4 million vehicles in 2022, relies on bearings to meet stringent efficiency and durability standards.

PIB Sales has long been a reliable partner for engineers and manufacturers. We offer customized bearing solutions that address the industry’s ever-changing needs. With extensive experience across a variety of applications, we provide everything from standard automotive bearings to cutting-edge smart systems designed specifically for EV powertrains. 

This article delves into the role bearings play in electric vehicle applications, and highlights significant market trends. 

Understanding EV-Specific Bearing Requirements

The unique demands of EVs create a challenging design environment for engineers. Bearings, as critical components of the powertrain, axles, and auxiliary systems, are pushed to their limits in terms of speed, temperature, load, and durability. Meeting these requirements isn’t just a matter of adapting existing solutions but designing with precision and deep technical understanding. Below is a technically detailed breakdown of the critical factors, calculations, and solutions for bearings in EV applications.

High-speed operation and rotational stress

EV motors operate at speeds far exceeding those found in internal combustion engines (ICEs). Where an ICE engine typically spins at 6,000–8,000 RPM, EV motors regularly reach 15,000–20,000 RPM. At these speeds, bearings experience substantial centrifugal forces, which can cause deformation, increased friction, and premature wear.

DN Value To evaluate a bearing’s suitability for high-speed applications, the DN value is calculated: 

DN=D×N

Where:

• D = bearing bore diameter (mm),
• N = rotational speed (RPM).

Practical bearing recommendations:

• 6206HC: A hybrid ceramic deep groove ball bearing designed for high-speed and low-friction performance.
• 7205AC-T-P4S: A precision angular contact bearing ideal for radial and axial load applications in high-speed motors.

Thermal management and lubrication

Thermal performance is a critical factor in EV bearings. Compact powertrains generate significant heat, particularly in electric motors and inverters, which bearings must endure without compromising lubricant performance or structural integrity.

Heat generation and material stability: Bearings in EV motors can experience temperatures up to 150°C, requiring materials like silicon nitride (Si₃N₄). This ceramic material offers:

• Thermal conductivity: 25–30 W/m·K.
• Expansion coefficient: 3.2×10⁻⁶/°C, ensuring stable tolerances under fluctuating temperatures.

Lubrication selection: Lubrication plays a critical role in heat dissipation. Synthetic greases like SKF LGLT 2 offer:

Heat dissipation insight: Engineers can estimate heat generation using the following:

• Low viscosity for high-speed operation,
• Stability up to 180°C, ensuring long service life even in extreme environments.

Q=μ⋅F⋅v

Where:

• Q = heat generated (W),
• μ = friction coefficient (dimensionless),
• F = load (N),
• v = bearing surface speed (m/s).

Load distribution and compact design

EVs prioritize lightweight and compact designs, meaning bearings must handle significant loads in smaller spaces. Proper load distribution is essential to avoid bearing fatigue and ensure long service life.

• The equivalent dynamic load P for a bearing is calculated as:

P=X⋅Fr​+Y⋅Fa​

Where:

• F_r = radial load (N),
• F_a = axial load (N),
• X and Y = load factors, depending on bearing type.

Noise, vibration, and harshness (NVH) Control

In the near-silent environment of EVs, even minor bearing noise becomes noticeable. NVH optimization is essential to maintain a premium driving experience.

• Bearings like 6202V1 feature super-finished raceways to reduce vibration and noise. A precision surface finish of Ra < 0.1 μm minimizes mechanical noise.
• Improper alignment or imbalance during assembly can amplify vibrations. Tools like finite element analysis (FEA) are employed to simulate and mitigate NVH issues in EV bearings.

Electrical insulation 

Electric motors in EVs often produce stray currents, which can flow through the bearings, causing electrical erosion. This manifests as pitting or fluting on the bearing raceways, leading to premature failure.

• Bearings like INSOCOAT 6312M/C3VL0241 feature a ceramic coating on the outer ring to prevent electrical conductivity.
• Alternative solutions: Conductive greases are also used to safely dissipate electrical charges without causing damage to the bearing. These greases are particularly effective in low-voltage systems.

Types of Bearings Used in EV Applications

Each type of bearing addresses a specific need in EV design, providing critical support for powertrains, axles, and auxiliary systems. Below is an in-depth exploration of the most commonly used bearings in EVs, combining technical insight with practical application examples.

Deep groove ball bearings are among the most versatile components in EV systems. Their ability to handle both radial and axial loads makes them indispensable for high-speed applications like electric motors and cooling systems.

Why they are critical in EVs:

• They excel in high-speed environments, often exceeding 15,000 rpm without performance degradation.
• Bearings like the 6206HC combine steel raceways with ceramic balls, reducing friction and heat generation — two key challenges in EV motors.
• Sealed versions, such as the 6305-2RS, protect against contamination, ensuring long-term reliability in cooling pumps and fans.

Deep groove ball bearings are especially valued for their simplicity and durability, making them a reliable choice for various EV subsystems.

Tapered roller bearings are specifically designed to handle combined radial and axial loads. Their robust construction and tapered geometry distribute forces evenly across the bearing, making them essential in EV axles and drivetrains.

In-wheel hubs and axle assemblies, and tapered roller bearings like the 30206 provide excellent stability and durability. They manage the dynamic forces generated during acceleration and braking, reducing wear and ensuring long-term performance. Additionally, their ability to minimize rolling resistance contributes to improving an EV’s overall energy efficiency — an increasingly important consideration as manufacturers seek to extend vehicle range.

Key benefits of tapered roller bearings:

• Exceptional load-carrying capacity for heavy-duty applications.
• Enhanced durability under fluctuating forces.
• Reduced rolling resistance for improved drivetrain efficiency.

When properly selected and maintained, these bearings ensure the reliability and longevity of EV powertrains under demanding conditions.

Angular contact ball bearings are integral to EV powertrains and transmissions, where they handle both axial and radial loads with exceptional precision. Unlike deep groove ball bearings, angular contact designs are optimized for applications with thrust-heavy demands, making them well-suited for high-speed motor shafts and gear assemblies.

Bearings like the 7205BEP are specifically engineered for high rotational speeds while maintaining alignment under load. In compact EV transmission systems, these bearings often work in pairs or sets to accommodate bidirectional thrust loads, ensuring smooth power transfer without compromising space.

This type of bearing also contributes significantly to noise, vibration, and harshness (NVH) reduction. The precise manufacturing tolerances and polished surfaces minimize mechanical noise, a critical factor in the quieter operating environment of electric vehicles.

Hybrid ceramic bearings are at the forefront of innovation in EV applications. By combining ceramic rolling elements with steel raceways, these bearings offer a unique combination of high-speed performance, thermal resistance, and electrical insulation.

For electric motors operating at speeds exceeding 20,000 rpm, hybrid ceramic bearings like the 7206C-T-P4S reduce centrifugal forces and friction. This allows the motor to maintain efficiency and avoid overheating during prolonged operation. The ceramic components also provide electrical insulation, preventing damage from stray currents—an issue that can lead to pitting and surface degradation in traditional steel bearings.

Why hybrid ceramic bearings excel in EVs:

1. Lightweight ceramic balls improve energy efficiency and reduce wear at high speeds.

2. Exceptional thermal stability makes them suitable for use in high-performance motors and inverters.

3. Non-conductive properties protect against electrical erosion in high-voltage systems.

These bearings are often chosen for critical applications where performance and durability cannot be compromised.

Cylindrical roller bearings are used in EV gearboxes and rotor shafts, where radial loads dominate. Their design minimizes friction, making them ideal for applications requiring both efficiency and load capacity.

A bearing like the NU205 offers smooth torque transfer in compact gearbox designs, while larger models such as the NJ2309 handle higher torque loads without sacrificing compactness. The ability to withstand high radial forces while maintaining consistent performance is particularly valuable in EV powertrains, where space and weight constraints are key design considerations.

Electrical insulation is an essential feature for bearings used in EV motors. Stray currents from high-voltage systems can cause electrical pitting, which can lead to premature failure. Insulated bearings address this issue by incorporating non-conductive coatings on the raceways.

The INSOCOAT 6312M/C3VL0241, for example, uses a ceramic coating on the outer ring to block current flow while maintaining full mechanical performance. This design is particularly effective in preventing electrical erosion, ensuring reliability in high-voltage applications like inverters and motor housings.

In cases where physical insulation isn’t feasible, conductive greases offer an alternative solution by safely dissipating electrical charges through controlled pathways.

Explore the PIB Sales online shop for a comprehensive selection of high-quality bearings tailored for electric vehicles. Our range of advanced bearing solutions is designed to meet the unique demands of EVs, combining precision engineering with trusted reliability. Visit us today to find the right bearings for your application.

Top Bearing Manufacturers for EV Applications

The electric vehicle (EV) market relies heavily on high-quality bearings to meet the demands of modern powertrain designs, extreme rotational speeds, and compact system requirements. Several global manufacturers lead the way in producing innovative bearing solutions tailored for EVs. Below is an overview of the key players and their contributions to this rapidly evolving industry.

AB SKF

AB SKF is a global leader in bearing technology, offering cutting-edge solutions for EV applications. With a strong focus on sustainability and advanced materials, SKF produces bearings that address the unique challenges of electric motors and powertrains. Their hybrid ceramic bearings and insulated bearings, such as those in the INSOCOAT series, are widely used to mitigate the effects of stray currents and ensure long-term reliability in high-speed electric motors.JTEKT Corporation

Schaeffler Technologies AG & Co. KG

Schaeffler is a global innovator in bearing technology, with a dedicated focus on e-mobility solutions. Their portfolio includes precision angular contact ball bearings, cylindrical roller bearings, and hybrid ceramic options tailored for EV powertrains. Schaeffler’s expertise in system integration allows them to develop bearings that optimize energy efficiency and reduce noise across the drivetrain.

E-Axle RepSystem-M for Hyundai Ioniq

One of Schaeffler’s latest innovations is the E-Axle RepSystem-M, specifically developed for replacing bearings in the electric motor of the Hyundai Ioniq. This solution addresses a critical gap in the market, where traditional repair options are limited to full axle replacements, which are both costly and inefficient.

The E-Axle RepSystem-M repair kit includes:

• Two high-performance bearings for the electric motor.
• Flat seals, rotary shaft seal, O-ring, and sealing paste to ensure complete and durable repairs.

To enhance the repair process, Schaeffler has also partnered with GEDORE Automotive to develop specialized tools that enable contactless separation of the stator and rotor, protecting components from damage during disassembly. Repair guides and training courses accompany this solution, ensuring technicians can efficiently execute repairs.

This system not only reduces costs but also minimizes waste, aligning with Schaeffler’s commitment to sustainability in mobility.

Schaeffler’s INA thermal management modules are designed to optimize cooling circuits in electric motors, inverters, and hybrid systems. These modules regulate coolant flow on demand, ensuring optimal operating temperatures and extending the lifespan of EV components.

Additionally, Schaeffler has introduced electric auxiliary water pumps for battery and inverter cooling, meeting the needs of over 50 million vehicles globally. These solutions are manufactured to original equipment (OE) standards, delivering reliability and performance.

Schaeffler’s advanced bearing solutions and repair systems for EVs illustrate the company’s dedication to innovation, sustainability, and supporting the transition to climate-friendly mobility. With a comprehensive portfolio of products and repair kits tailored for electrified powertrains, Schaeffler continues to lead in creating practical and efficient solutions for the evolving needs of the automotive industry.

For more information about Schaeffler’s products and to explore a full range of high-quality bearings for electric vehicles, contact PIB Sales at [email protected].

Checklist for Engineers: Selecting the Right Bearings

Choosing the correct bearing for an electric vehicle (EV) application requires attention to both practical and technical details. To make the process efficient and effective, PIB Sales has compiled a concise yet detailed checklist. Follow this guide to ensure you select the most suitable bearings for your EV system.

1. Define the application
Start by identifying where the bearing will be used. Is it for the electric motor, gearbox, axle, wheel hub, or auxiliary systems like cooling pumps or fans? Each application has specific requirements in terms of load, speed, and durability.

2. Understand load requirements
Determine the type of load the bearing will need to handle:

• Radial load: Common in rotating shafts and gearboxes.
• Axial load: Typically present in wheel hubs and differential assemblies.
• Combined loads: Found in high-stress systems like axles and powertrains. Ensure the bearing can handle both the magnitude and direction of these forces.

3. Consider speed limits
Assess the operational speed of the system. Bearings for high-speed motors (e.g., 15,000–20,000 RPM) often require hybrid ceramic designs to minimize friction and heat buildup. Verify the bearing’s speed rating to ensure compatibility.

4. Evaluate environmental conditions

• Temperature: For high-temperature areas, such as motors and inverters, choose materials like silicon nitride or hybrid ceramics.
• Contaminants: If the bearing will face dust, water, or other debris, opt for sealed bearings like 6305-2RS.
• Electrical currents: In systems with high voltages, such as EV motors, use insulated bearings like INSOCOAT 6312M/C3VL0241 to prevent electrical erosion.

5. Select the appropriate bearing type
Match the bearing type to the application:

• Deep groove ball bearings: Suitable for motors and general-purpose applications.
• Tapered roller bearings: Ideal for axles and heavy-load systems.
• Hybrid ceramic bearings: For high-speed, high-temperature, and electrically insulated needs.
• Cylindrical roller bearings: For gearboxes and radial load-heavy applications.

6. Confirm load and speed ratings
Verify that the bearing’s dynamic and static load ratings exceed the expected forces. Also, check that the bearing’s speed rating matches the application to prevent overheating or premature failure.

7. Optimize lubrication and thermal performance
Use a lubricant compatible with the application’s speed and temperature. For example, SKF LGLT 2 synthetic grease is effective for high-speed and low-friction environments. Proper lubrication minimizes wear and improves efficiency.

8. Account for design constraints
Evaluate space and weight limitations. In compact systems, consider thin-section bearings like CSXG080. For lightweight applications, hybrid ceramic bearings reduce overall mass without sacrificing performance.

9. Test and validate your selection
Before finalizing, test the bearing in real-world conditions to confirm it meets performance expectations. Review the bearing’s datasheet and consult with suppliers for additional insights.

10. Consult experts when needed
Reach out to trusted suppliers like PIB Sales for technical support and recommendations. They can provide access to a wide range of bearings and help you tailor solutions to your specific application.

For expert guidance, technical insights, or to explore our catalog of high-quality bearings, contact PIB Sales at [email protected]. We’re here to help you make the best choice for your project.