Precision ball bearing assembly with squirrel cage for vibration damping.
Precision ball bearing assembly with squirrel cage for vibration damping.

Comprehensive product development and testing of rolling element bearings has become a noteworthy technical capability of New Hampshire Ball Bearings (NHBB). For well over three years now, NHBB’s New Product Development Center (NPDC) has been partnering with NHBB HiTech Division and CEROBEAR GmbH to support the next-generation aero engine development initiatives of a select group of customers.

Since September of 2013, when NHBB acquired and installed two endurance test rigs and one high-speed test rig, the NPDC has been running accelerated life tests and high-speed tests on ball and roller bearings up to a bore size of four inches. This capability covers a significant cross-section of bearings utilized in aero engine mainshafts, gearboxes, and accessories.

NHBB utilizes the first endurance test rig to perform accelerated life tests on roller bearings under radial load. Currently, this rig is being used in a joint research project between NHBB and CEROBEAR to study the effects of a proprietary advanced manufacturing methodology on the life of an aero engine roller bearings.

The second rig enables NHBB to conduct accelerated life testing of ball bearings under axial load. It is being used to study the performance of aero engine ball bearings containing ceramic balls. A subsequent collaboration between NHBB and CEROBEAR will focus on the effects of contamination on the life of hybrid ball bearings. The third and most sophisticated test rig is dedicated to high-speed testing of rolling element bearings for main shaft and gearbox applications. This rig enables NHBB to replicate the actual operating conditions of an aero engine. The shaft rotates up to 45,000 rpm. Oil inlet temperatures can reach 250° F, and ring temperatures can reach 450°F using high-velocity jets.

With this rig, the NPDC is collecting data on a myriad of variables, including load, speed, shaft torque, inlet oil flow rates, inlet oil temperature, outer ring temperature, inner ring temperature, oil debris monitoring, and vibration. The information gives engine manufacturers a complete picture of bearing performance. At the moment, NHBB is using the rig for a joint research project that is studying the high-speed performance of hybrid ceramic bearings.

With the successful establishment of a rolling element testing regime, NHBB has achieved a higher degree of technical readiness as an aero engine bearing specialist. This capability shall grow and mature as the knowledge and insight of other MinebeaMitsumi companies like CEROBEAR and myonic is brought to bear on customer-specific problems and challenges. The motivation behind this initiative is NHBB’s passionate commitment to adding increasing value to every customer relationship.

Customers interested in learning more about the new product development and testing capabilities of the NPDC are invited to contact NHBB. Visit nhbb.com for more details.