High precision measurement of wheel-bearing roll-resistance
With the purpose of achieving significant CO² reduction in On-Road Trucks, EU-Regulation 2025/258 was introduced. Years after certifying drive-axle efficiency, the roll-resistance of non-driven wheel-bearing units must now be measured with high accuracy under various wheel load and driving speed conditions.
A simulation approach using the VECTO tool was selected, as individual type-testing on test benches used for passenger cars is impractical for commercial vehicles due to the variety of applications. High-accuracy standardized mapping of roll resistance is needed for VECTO simulation. The Annex VIIA describes the measurement procedure, the very high accuracy requirements, and the defined format for post-processing the data for the certification.
ZF Test Systems has over 20 years of experience in test benches for high precision rolling resistance measurement for tires. Such expertise enables us to create the best solution for this new application.
ZF TS bearIN
The new wheel bearing test bench ZF TS bearIN
ZF Test Systems has developed a new, specialized test bench solution as no existing test bench met the required accuracy. The ZF TS bearIN (Bearing Investigator) not only meets technical measurement regulations with higher accuracy; it also supports fully automated test runs with changes in wheel loads up to 70kN, driving speed, and direction.
The new wheele bearing test bench ZF TS bearIN
The Bearing assembly as a test object can be integrated in its original surrounding conditions, with the original shaft, and further components like Rim adapter or brake disc. The pneumatic cylinder can simulate changing wheel load between 0 and 70kN at individual positions. Furthermore, it has a good vibration damping function and can be used as handling support for the installation process.
Our automation system "ZF TS tescon" and the equipment architecture enable the user to program test sequences for norm specific testing of 26h and much longer tests as configured by the customer. Upon meeting the defined signal and temperature stability conditions, the system generates the certification protocol according to the regulation. Additionally, the test bench is user-friendly and requires minimal test area and media supply.
Highlights
Highlights ZF TS bearIN
- Fully automated certification measurements in accordance with the latest EU Regulation 2025/258 and VECTO Simulation
- Measurement failure of the roll resistance including all parasitic effects better than requested by the EU-Regulation, DAkkS-Calibrated measurement system
- Test procedure with fully automated adaptation of speed, wheel load and driving direction
- Automated generation of test certification protocol
- Possibility to integrate original OEM Wheel end parts
- Movable system with optimized requirements to the test area and media supply