Through rigorous material selection, advanced heat treatments and innovative design solutions, FARO ensures superior performance and reliability. In this article you’ll learn more about the key technical aspects of these largescale bearings and the meticulous engineering behind their development and the certified testing procedures that guarantee their quality.
After a careful and thorough analysis of the specific machine tool market segment, FARO has decided to design and manufacture a new axial bearing characterized by very high rotational speed in relation to its extremely large dimensions (diameter of 1990 mm). Thanks to extensive research, FARO’s team has identified the best materials components.
For the bearing rings, the selection of steel led to the choice of 42CrMo4, in accordance with the reference standard EN 10083-3. This material has high hardenability, good heat resistance, excellent forgeability, and good machinability.
The importance of raw materials and design
To enhance its properties, a special induction heat treatment was developed and perfected through a rather complex custom work cycle due to the large dimensions. However, this process allowed the expected results to be achieved.
After careful evaluation, Ergal 7075 was identified as the most suitable material for the cage. This aluminum alloy is distinguished by its excellent mechanical strength combined with a
very low specific weight. Another key feature of the cage is its highly elaborate design, optimized to minimize contact areas between the cage and both the shaft and the rolling elements.
Certified reliability and performance for a highquality bearing
In this sector, FARO also manufactures ultra-precise radial-axial bearings capable of absorbing radial and bidirectional axial loads as well as overturning moments without clearance. These bearings are particularly suited for support systems with high operating precision, such as rotary tables.
For these bearings, FARO has decided to certify certain technical specifications through dedicated testing and inspection. The test bench was entirely designed and built by FARO’s technical team, specifically customized to offer customers an additional service. In fact, beyond standard certifications for origin dimensions, and geometry, the test bench measures the minimum torque required to set the bearing in motion.
Once the bearing under test is fixed onto the measurement plate, simulating the real mounting conditions (clamping torque and number of screws), the operator can select the test torque via the PLC panel, setting the starting torque, the maximum torque, and the rate of increase and decrease. The system rotates the inner ring using a stepper motor with a reducer while continuously monitoring the working torque.
A load cell on the outer ring captures data up to 5,000 times per second to measure torque.
These data are recorded and can be displayed on-screen or summarized in a graphical report. This allows for the evaluation of the stability of the bearing’s working torque, ensuring that it is free from vibrations and/or noise. The same data recorded by the load cell are attached to the test certificate provided with each individual bearing.
