Vitesco EMR4 Electric Drive System Bearing Application

Vitesco’s EMR4 electric drive system represents a highly integrated electric drivetrain platform designed for modern electric vehicle applications.

For this application, the bearing system needed to achieve reliable performance under demanding EV operating conditions, including high rotational speed, continuous operation, low noise requirements, and compact installation space.

MTWB developed a customized EV motor bearing solution based on 6006 and 6206 deep groove ball bearings, optimizing bearing design parameters including cage structure, internal clearance, lubrication performance, and precision control.

This case demonstrates MTWB’s capability to support electric vehicle applications through customized bearing engineering, from application analysis and bearing selection to production support.

Vitesco EMR4 EV Bearing Case Overview

Applied to 20+ vehicle models ，The MR4 is highly integrated, modular and scalable, with a power range covering 80 kilowatts to 230 kilowatts. At the same power level, the fourth-generation electric shaft drive system has reduced by 25% compared to the previous generation. Has been used in the PSA electric vehicle project.

Product design features, max. operating speed

• OEM： Vitesco

• Application：Electric Drive System

• Max.Speed：16000 RPM

Special channel curvature design enhances rotational accuracy.

• PA46 high-performance polyamide cage: High rigidity & high heat resistance (<250℃):

1. Reduces deformation of the cage during high-speed rotation.

2. Torque resistance is reduced by 50%.

3. Extremely high wear resistance hence longer life span.

4. Lighter weight, lower noise (V4 group or above).

• Internal size adjustment improves lubrication efficiency and rotational accuracy.

• Selects high-temperature resistant, high-speed silent grease.

• Selects high-grade bearing steel from Jiangyin Xingcheng Special Steel

Electric Drive System EMR4 Application Background

The EMR4 electric drive system is a modular and scalable electric drivetrain platform with a power range covering 80 kW to 230 kW.

Key application characteristics include:

• High-speed electric motor operation

• Compact drivetrain integration

• Continuous operating conditions

• Increased requirements for efficiency and reliability

Compared with conventional industrial motors, EV drivetrain systems place additional requirements on EV motor bearings.

The bearing solution must maintain stable operation while managing:

• High rotational speed

• Frequent acceleration and deceleration

• Temperature variation

• Low vibration and noise requirements

• Long service life expectations

Application Challenge: EV Motor Bearing Requirements for EMR4

During the development of the EMR4 electric drive system, the bearing assembly faced several engineering requirements beyond standard industrial bearing applications.

High-Speed Rotation Stability

The electric drive system required reliable bearing performance at speeds up to 16,000 RPM.

At high rotational speeds, bearing performance is affected by:

• Increased friction

• Cage stress

• Lubrication behavior

• Rotational accuracy

The bearing configuration required optimized internal design to maintain stable operation under continuous high-speed conditions.

Cage Performance Under High RPM Operation

For high-speed EV applications, cage design directly influences bearing reliability.

The application required a cage structure with:

• High rigidity

• Improved heat resistance

• Wear resistance

• Stable guidance performance

A suitable cage design helps reduce instability during high-speed rotation.

Lubrication Performance Under Temperature Variation

Electric drive systems operate under changing thermal conditions.

The bearing lubrication system needed to provide:

• Low friction operation

• Stable lubrication performance

• Long-term reliability

The grease selection and bearing configuration were optimized according to EV operating requirements.

Low NVH Performance Requirements

Noise, vibration, and harshness (NVH) performance is a critical consideration in electric vehicles.

Because EV motors operate with lower background noise compared with combustion engines, bearing-related vibration and noise become more noticeable.

The bearing solution required:

• Precision manufacturing control

• Smooth rotational performance

• Reduced vibration characteristics

MTWB Engineering Approach

Based on the EMR4 application requirements, MTWB optimized the EV motor bearing configuration through targeted engineering improvements.

High-Speed PA46 Cage Design

The customized PA46 polyamide cage was selected to improve bearing performance under high-speed operating conditions.

Key advantages include:

• Higher cage rigidity

• Improved heat resistance

• Reduced deformation during rotation

• Better wear resistance

• Improved high-speed stability

This design supports reliable operation of high-speed EV bearings in electric drivetrain applications.

Optimized Internal Clearance and Bearing Geometry

Bearing internal geometry plays an important role in EV motor performance.

MTWB optimized:

• Internal clearance

• Raceway geometry

• Rotational accuracy

• Lubrication compatibility

These improvements help achieve:

• Stable rotation

• Controlled friction

• Improved operating reliability

• Better adaptation to electric drive conditions

For applications requiring advanced accuracy and customized configurations, MTWB provides high precision bearings for demanding rotating equipment.

Customized 6006 & 6206 Bearing Solution for EMR4 Application

MTWB selected 6006 and 6206 deep groove ball bearings for this electric drive application because these bearing types provide:

• Compact structure

• Reliable radial load capacity

• Stable rotational performance

• Suitability for high-speed electric motor applications

For customers requiring application-specific performance, MTWB supports customized deep groove ball bearings with adjustments including precision grade, cage material, sealing structure, internal clearance, and lubrication selection.

MTWB 6006 Deep Groove Ball Bearing Specification

MTWB 6206 Deep Groove Ball Bearing Specification

Optional Electrical Erosion Protection for EV Bearings

Modern electric vehicle platforms, especially high-voltage architectures, may experience shaft current issues that can affect bearing service life.

Electrical current passing through bearings may cause:

• Raceway damage

• Electrical pitting

• Bearing fluting

• Premature failure

For applications requiring additional protection, MTWB provides optional electrical insulation bearing solutions, including:

• Hybrid ceramic bearings with Si₃N₄ ceramic rolling elements

• Ceramic-coated bearing components

• Electrically insulated bearing designs

These solutions help reduce risks associated with shaft current and electrical erosion in advanced EV drivetrain systems.

Project Outcome

Through customized bearing design and engineering optimization, MTWB provided an OEM-compatible EV motor bearing solution for the EMR4 electric drive application.

The project outcome included:

• Successfully validated for high-speed electric drive operation

• Improved rotational stability under continuous operating conditions

• Supported low-noise drivetrain requirements

• Provided a customized bearing configuration based on EV application requirements

This application demonstrates MTWB’s ability to support electric vehicle manufacturers and drivetrain suppliers with customized bearing engineering solutions.

Why Choose MTWB for EV Motor Bearing Development?

Developing reliable EV motor bearings requires more than selecting standard bearing dimensions.

The bearing solution must consider:

• Motor operating speed

• NVH requirements

• Lubrication conditions

• Thermal environment

• Electrical protection requirements

• OEM integration requirements

MTWB supports customers through:

• Bearing application analysis

• Bearing selection support

• Customized bearing design

• Prototype evaluation

• Precision manufacturing

• OEM production support

This Vitesco EMR4 application demonstrates MTWB’s capability to support EV manufacturers from initial bearing evaluation through customized production.

Frequently Asked Questions

What is an EV motor bearing?

An EV motor bearing is a precision bearing designed for electric vehicle motors and drivetrain systems. Compared with conventional bearings, EV motor bearings require higher speed capability, lower friction, lower noise, and improved durability.

Why are 6006 and 6206 bearings used in electric drive systems?

The 6006 and 6206 bearings provide a compact structure, reliable load capacity, and stable rotational performance, making them suitable for electric motor and drivetrain applications.

Can MTWB customize EV motor bearings?

Yes. MTWB provides customized EV motor bearing solutions including cage design, internal clearance adjustment, lubrication optimization, sealing structure, precision grade, and OEM specifications.

How can EV bearings prevent electrical erosion?

For high-voltage EV applications, MTWB can provide hybrid ceramic bearings and electrically insulated bearing solutions to reduce risks caused by shaft currents and electrical erosion.

Customized EV Motor Bearing Solution for Your Project

Developing a high-speed electric drive system requires bearings that deliver stable performance under demanding operating conditions.

MTWB provides customized EV motor bearings, including high-speed drivetrain bearings, OEM replacement bearings, and application-specific bearing designs.

Contact MTWB for:

• Bearing selection support

• Technical specifications

• Customized solutions

• Sample evaluation

and discuss your next electric vehicle bearing application.

About MTWB

MTWB (Mighty Way Industrial Limited) is a customized bearing manufacturer specializing in high precision bearings and application-specific bearing solutions.

With advanced manufacturing capabilities, quality control systems, and engineering expertise, MTWB supports global customers developing reliable bearing solutions for demanding applications including electric vehicles, industrial equipment, and high-speed rotating systems.

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