High-speed bearing endurance to 70,000 RPM.

Ultra-high-speed, combined-load bearing life testing

In critical systems, bearings are often the weakest single point that can bring an entire machine down. A seized bearing in an aero-engine, a failed bearing in a high-speed gearbox, or a thermal runaway in a turbocharger can mean mission abort, unscheduled shutdown, or catastrophic damage. Yet, in most programmes, bearing life is still predicted largely from catalogue data, safety factors and assumptions. The High Speed Bearing Endurance Test Rig exists to remove those assumptions — recreating the real punishment bearings see in service and producing hard, instrumented evidence of how a bearing actually behaves and fails.

Functional objective & test capability

The core purpose of the rig is to answer a fundamental question: “How do high-speed bearings really behave over their life under my specific operating conditions?” To serve that purpose, the rig is engineered to:

• Measure endurance life of rolling bearings under variable radial load, variable axial (thrust) load, speeds from low rpm up to ~70,000 rpm, controlled lubrication flow/pressure, and controlled oil temperature (including high-temperature endurance)
• Capture and log key performance indicators throughout the test — torque/friction evolution, speed and speed stability, radial and axial load levels, oil pressure/temperature/flow, and vibration levels via external analyser input
• Enable realistic test scenarios — constant-load/constant-speed endurance runs, multi-step or ramped loads at fixed speeds, temperature-accelerated life tests, and comparative tests for bearings, lubricants or coatings

The system is designed for long-duration, partially unattended testing, with adequate interlocks and monitoring to protect both the operator and the equipment.

System architecture, subsystem by subsystem

The rig is built around a high-power drive train, a precision high-speed gearbox, a bearing loading fixture, and independent lubrication systems, all integrated with a PC-based control and data acquisition system on a cast-iron base frame.

Drive system & high-speed gearbox

The drive motor is a ~113 kW, 415 V 3-phase AC machine paired with an industrial vector control drive, nominal speed ~2900 rpm with capability up to ~5000 rpm, encoder feedback for closed-loop speed control, and configurable acceleration/deceleration ramps to minimise mechanical shock. To reach spindle speeds up to 70,000 rpm, the motor drives a dedicated two-stage, single-helical, parallel-shaft gearbox designed to AGMA 6011 I-03, with hydrodynamic journal bearings (steel backing, white-metal lining) for continuous high-speed operation with low vibration.

Bearing housing, spindle & mechanical structure

The entire assembly — motor, gearbox, bearing fixture — is mounted on a cast-iron bed for high bending stiffness (maintains shaft alignment under load) and excellent vibration damping. The bearing loading fixture consists of a precision-ground spindle shaft carrying the test bearing and supporting bearings/discs, customisable discs and spacers to match test-bearing geometry (e.g. 20 × 47 × 14 mm), and a two-part housing that separates support (lower housing) from load transfer (upper housing). A dedicated engagement and dismantling fixture avoids damage during mounting/demounting and speeds up bearing changes between tests.

Radial & axial load application

Radial load is generated by a pneumatic air bellow acting through a radial loading pin onto the upper housing, measured by a radial load cell — up to approximately 25 kN (≈2.5 tonnes), smoothly adjustable via air pressure. Axial (thrust) load is applied via compact pneumatic cylinders arranged for pure axial force on the bearing disc, measured by axial load cells — up to approximately 2.5 kN. Filter-regulator units, electro-pneumatic (E/P) regulators, and 5/2 & 3/2, 24 V DC solenoid valves complete the pneumatic control system for well-defined loading profiles.

Lubrication & thermal management

The bearing lubrication power pack supplies oil at controlled pressure, flow and temperature — reservoir, pump, filtration and return lines for continuous operation, an electric heater raising oil temperature from ambient (~35°C) up to approximately 200°C, and a proportional flow control valve for electrical flow adjustment. A separate gearbox lubrication power pack maintains a stable hydrodynamic oil film at high speed. Depending on site utilities, both systems can be connected to an external chiller or cooling water circuit for heat rejection during long tests.

Instrumentation, monitoring & data acquisition

Typical instrumentation includes a non-contact torque sensor (0–50 N·m typical), speed measurement to 0–80,000 rpm sensor capability, radial load cell (up to ~25 kN), axial load cells (up to ~2.5 kN total), oil pressure and temperature transmitters, flow rate indication, and digital status signals for pumps, heaters, level/limit switches, emergency stops and interlocks. Local panel indicators display real-time torque, speed, load, pressure, temperature and flow with configurable alarm setpoints. A PC or industrial PC with dedicated DAQ hardware collects all analogue and digital signals, displays real-time values and trends on the HMI, and logs all relevant data with time stamps and test identifiers — supporting statistical life analysis, failure investigations, supplier comparisons, and reporting.

Safety & operating philosophy

Due to the high speeds and stored energy involved, the rig is designed with a multi-layer safety concept:

• Mechanical guarding around all rotating components and moving parts
• Emergency stop circuits — a drive E-stop to cut motor power and decelerate the system, and a system E-stop to safely shut down lubrication and auxiliary systems
• Interlocks that prevent a test from starting if lubrication pressure/flow is insufficient, oil temperatures are out of range, pneumatic pressure for loading is unavailable, or any critical alarm is active
• Operating procedures that require lubrication systems to be started and stabilised before applying speed/load, defined warm-up times to be observed, and no manual intervention while the test is running or components are rotating

The overall principle: no high-speed operation is possible unless lubrication, loading and safety conditions are confirmed healthy.

Key benefits

• Realistic, high-fidelity endurance data under combined speed, load and temperature conditions
• Strong repeatability, driven by a rigid mechanical structure and precise control of lubrication and loads
• Deep insight into bearing behaviour, enabling better design choices and supplier management
• Comprehensive digital records that support qualification, certification and troubleshooting
• Flexibility to adapt to different bearing sizes, load levels and test concepts