I. Geometric Accuracy Inspection of Steel Wheel Surface
The flatness, roundness, and straightness of the steel wheel are fundamental to ensuring uniform road compaction. Any slight deformation can lead to "vibration" or insufficient compaction in certain areas.
1. Measurement of Surface Straightness and Roundness
Using the straightedge + feeler gauge method: Place a standard straightedge tightly against the generatrix of the steel wheel and use a feeler gauge to measure the maximum gap between the straightedge and the roller. This value should not exceed 1.5%D of the steel wheel diameter (D is the diameter).
Non-contact, high-precision inspection can be performed using a laser alignment instrument or a coordinate measuring machine, suitable for factory inspection.
2. Radial Runout and Axial Movement Inspection
Install a dial indicator on a fixed bracket, contacting the surface of the steel wheel. Manually rotate the roller and record the maximum runout value.
Acceptance Standard: Radial runout ≤ 0.5mm, Axial movement ≤ 0.3mm.
II. Material Properties and Structural Strength Testing Steel wheels must withstand high-frequency vibrations and enormous impact forces; therefore, material strength and internal structural integrity are crucial.
1. Surface Hardness Testing
A hardness tester (such as a Leeb hardness tester) is used to measure surface hardness at multiple points on the steel wheel.
Acceptance Criterion: Surface hardness is typically between HRC50 and 60, ensuring wear resistance and minimal indentation.
2. Internal Defect Detection
Ultrasonic testing is used to detect internal defects in the steel wheel, such as cracks, porosity, or inclusions.
Special attention is paid to welded areas and bearing mounting locations, as these areas are prone to fatigue cracking.
3. Residual Stress Detection
The residual compressive stress on the steel wheel surface is determined using X-ray stress testing (GB7704-1987), which helps assess its fatigue resistance.
Excessive grinding time may cause surface damage, actually reducing residual compressive stress; process parameters must be controlled.
III. Dynamic Performance Verification under Operating Conditions
After passing the static test, the performance of the steel wheel under vibration conditions must be verified through actual operation.
1. Vibration System Response Test
Activate the vibration function and use a vibration analyzer to monitor the stability of the excitation force output of the steel wheel at different frequencies and amplitude levels.
Check for abnormal vibrations or "resonance points," which may reflect structural imbalance or bearing problems.
2. Dynamic Balancing Test
Perform calibration on a dedicated dynamic balancing machine to ensure that the steel wheel exhibits no significant vibration during high-speed rotation.
The imbalance should be controlled within the G6.3 level specified in ISO 1940.
3. Bearing Temperature Rise and Noise Monitoring
After one hour of continuous operation, use a thermal imager to detect the temperature rise of the bearing area. Generally, it should not exceed 40°C above the ambient temperature.
The noise level should be below 85 dB(A); excessively high noise levels may indicate poor lubrication or component wear.
IV. Corrosion Protection and Surface Treatment Quality Inspection
Steel wheels are exposed to humid and dusty environments for extended periods, and their corrosion resistance directly impacts their service life.
1. Paint Film Adhesion Test
Use the "cross-cut" method to draw a 1mm grid on the painted surface. Apply adhesive tape and quickly peel it off, observing whether the paint film peels off.
Acceptance Standard: Peeling area ≤ 15%.
2. Surface Roughness Inspection
Use a surface roughness measuring instrument or a comparison sample to test the surface smoothness of the steel wheel.
Excessive roughness makes it easy for materials to stick, while excessive smoothness affects adhesion. It is recommended that the Ra value be controlled between 3.2–6.3μm.
V. Overall Machine Linkage and Load Test
Finally, a comprehensive verification should be conducted under simulated working conditions:
Perform a load compaction test in the test section, observing the uniformity of compaction of the steel wheel on different materials.
Check for phenomena such as "polarization," "vibration," or "deviation," which may indicate installation errors or uneven mass distribution of the steel wheel.
