Dynamic performance testing method for bearings

As the core basic component in mechanical systems, the performance of bearings directly determines the accuracy, lifespan, reliability, and efficiency of the host. Static parameters such as dimensional accuracy and clearance are certainly important, but in actual working conditions, bearings operate in dynamic environments with high-speed rotation and complex loads. Therefore, testing and evaluating its dynamic performance is a key step in measuring its true quality, predicting its service life, and even conducting fault diagnosis.

Dynamic performance testing aims to simulate the real working conditions of bearings and obtain key performance indicators under motion through a series of precise measurements. Here are several core dynamic performance testing methods:

1、 Core testing items and methods
Vibration and noise testing

Purpose: Vibration and noise are the most intuitive and sensitive "stethoscopes" for bearing operation status. Its level directly reflects the manufacturing defects (such as scratches, dents, roughness) and assembly quality inside the bearing.

Method: Install the bearing on a dedicated spindle unit and operate it under the set load and speed. Use a piezoelectric accelerometer to approach the outer ring of the bearing and measure its vibration acceleration values in low, medium, and high frequency bands. Noise is usually measured using a sound level meter at a certain distance from the bearing in a specific background noise environment.

Standard: The international standard ISO 15242 (Rolling bearings - Vibration measurement methods) is widely used to classify vibration levels (such as Z1, Z2, Z3, Z4) based on the effective value (RMS) or peak value of vibration velocity. The higher the level, the smaller the vibration and the better the performance.

Temperature Rise Test

Purpose: To evaluate the friction characteristics, lubricant effectiveness, and heat dissipation performance of bearings. Abnormal temperature rise usually indicates poor lubrication, excessive load, or improper installation.

Method: During the testing process, use thermocouples or infrared thermometers to monitor the temperature of the bearing outer ring or nearby key points in real time. Record the temperature rise curve and final stable temperature from start-up to reaching thermal equilibrium state (usually with a temperature rise of no more than 5 ℃ per hour).

Evaluation: Under the same operating conditions, the lower the temperature rise, the lower the friction loss of the bearing and the higher the operating efficiency.

Life and reliability testing

Purpose: To verify the design life and reliability of bearings, and provide data support for the design and selection of host products.

Method: Accelerated life testing is used to induce fatigue failure (such as material peeling) of bearings in a short period of time by applying loads or speeds higher than the rated conditions, and the failure time is recorded. Using statistical methods such as Weibull distribution to process a large amount of test data, calculate the rated life (L10) and median life (L50) under normal operating conditions.

Equipment: Usually conducted on dedicated life testing machines, multiple sets of tests can be conducted simultaneously with high efficiency.

Friction torque test

Purpose: For fields with high requirements for precision instruments, aerospace, and energy conservation, the starting torque and dynamic operating torque of bearings are crucial.

Method: Install the bearing on the test spindle and directly measure its resistance torque against rotation at different speeds and loads through a torque sensor. The starting torque is usually obtained by slowly rotating the spindle and recording the peak torque required to overcome static friction.

2、 Composition of testing system
A complete dynamic performance testing system for bearings typically includes:

Drive unit: Provides precise and controllable rotational speed.

Loading unit: Simulate radial, axial, or composite loads, usually using hydraulic, pneumatic, or mechanical methods.

Precision spindle unit: provides high-precision and high rigidity installation reference for the tested bearings.

Sensor system: including vibration sensors, temperature sensors, torque sensors, speed encoders, etc.

Data acquisition and analysis system: Collect sensor signals, and perform real-time processing, display, storage, and generate test reports.

3、 Testing process
The typical testing process follows the "PDCA" cycle:

Preparation: Determine testing parameters such as speed, load, lubrication conditions, etc. based on testing standards or custom specifications.

Installation: Install the tested bearing precisely on the testing platform to ensure accurate alignment and avoid introducing additional errors.

Operation and data collection: Start the test bench, run according to the preset program, and the system automatically collects all sensor data.

Analysis and Report: After the test is completed, analyze the data (such as vibration spectrum analysis that can be used for fault location), compare it with standard or expected values, and issue a performance evaluation report.

4、 Conclusion
The dynamic performance testing of bearings is an important component of quality control and R&D innovation in modern manufacturing industry. It is not only the final screening of product quality, but also the cornerstone for a deeper understanding of bearing behavior, optimizing product design, and improving host performance. With the advancement of Industry 4.0 and intelligent manufacturing, dynamic testing data is deeply integrated with concepts such as condition monitoring and predictive maintenance, transforming bearings from simple components into perceptible and predictable intelligent units that continue to provide reliable operation support for high-end equipment.