Abstract: This paper elaborates on the equipment composition, working principle, installation and debugging, maintenance, and troubleshooting methods of the air bearing plate-type roller. This equipment supports the rotor through an air film, enabling high-precision plate measurement. It has been successfully applied in the production of new energy aluminum foil.

Key words: Air bearing; Plate-type roller; Aluminum foil rolling machine 

In the application of plate shape rollers in aluminum foil rolling machines, the traditional piezoelectric plate shape rollers have been unable to meet the higher precision requirements for plate shape in the field of electric vehicle manufacturing. Li Island New Energy Anhui Co., Ltd. was the first to introduce pure imported air-bearing plate shape rollers and integrate them with the Level 2 control system in the operation room, forming a new rolling process technology, which significantly improves the measurement accuracy of aluminum foil plate shape. 

1 Equipment Composition

The air bearing plate-type roller equipment consists of plate-type rollers, sensor boxes, calibration weight sets, and an air supply system (including a freeze dryer, filtration system, air control board, and angle rollers).

1.1 Plate-type Rollers

The core component is a hardened high-precision grinding rotor, which is supported on a stainless steel core shaft by air film bearings. The inner liner of the rotor is made of composite drying bearing material, featuring low rotational inertia and nearly zero friction coefficient. Two rows of nozzles supply air to the rotor from the air collection chamber, and the pressure difference signal is transmitted to the control system through pneumatic sensors to achieve tension distribution measurement along the width of the aluminum strip.

1.2 Sensor Box

The sensor box is a steel sealed cabinet (IP55 protection level), with pneumatic sensors inside, connected to the core shaft of the plate-type roller by a signal soft cable, and capable of maintaining rapid response and high-precision detection under low-speed rolling conditions.

1.3 Air Supply System

The freeze dryer of the filtration system has a minimum pressure dew point of +3°C, and a three-stage filtration system (40μm → 3μm → 0.01μm) ensures that the oil mist residue is ≤ 0.01 ppm [1].

The pressure control air control board provides pressure regulation for the core shaft (0.6 - 0.8 MPa) and thrust bearings (0.4 - 0.5 MPa) [1].

1.4 Angle Rollers

It is linked with the machine alarm and automatically rises when there is abnormal air pressure or when the load exceeds the limit. 

2 Working Principle

The pressure difference of each rotor is measured by an integrated pressure sensor. The pneumatic pressure signal is transmitted to the sensor via a pipeline transmission method. The signal is continuous and stable, and can provide fast response and high-precision continuous data even when the main machine speed is very low. The pressure sensor converts the pneumatic pressure signal into an electrical signal and presents the electrical signal intuitively on the human-machine interface through the PLC input module.

2.1 Load Calculation

The formula for calculating the load of a single rotor [1]:

W = 2 × T × sin(α/2) …………………………… (1)

Where: W - Rotor load (N); T - Wire tension (N); α - Pitch angle (rad).

2.2 Signal Processing

The pneumatic pressure signal is transmitted to the sensor box via the pipeline, converted into an electrical signal, and displayed on the human-machine interface through the PLC input module, enabling continuous measurement at a rolling speed ranging from 0 to 600 m/min (response time < 50 ms). 

3 Installation and Commissioning

3.1 Installation Requirements

The air dryer should be kept at a 1-meter distance from surrounding objects to ensure good heat dissipation. The main gas source pipeline protection should prevent mechanical damage, and key valves should be locked or the handles removed to prevent accidental operation.

3.2 Commissioning Key Points

The core shaft pressure (0.6 - 0.8 MPa) and thrust bearing pressure (0.4 - 0.5 MPa) are verified by the pressure sensor inside the sensor box. Signal testing uses a handheld tachometer (with an accuracy of ±1 rpm) to check the rotor speed signal, ensuring consistency with the output of the plate-type roller sensor. 

4 Maintenance and Fault Diagnosis

4.1 Routine Maintenance

Daily checks include verifying the free rotation of the rotor (≥125 rpm) and zero adjustment [2]. Regular maintenance involves inspecting the hose path and fastening bolts every 3 months; detecting rotor clearance (≤0.05 mm) and inner sleeve height every 6 months [2].

4.2 Fault Cases

During a hot load test of a rolling mill, it was found that the rotor was not rotating smoothly. Upon disassembly, burrs (polytetrafluoroethylene debris) were found on the core shaft holes and 3 rotor inner sleeves were loose. The handling measures included:

① Grinding the core shaft holes to remove the burrs; ② Replacing the Printron UK original rotor; ③ Tightening the loose pipe joints. After maintenance, the plate shape measurement accuracy increased by 15%, and the error in the low-load area was controlled within ±2 μm. 

5 Conclusion

The air bearing plate-type roller is supported by a low-friction air film and equipped with a high-precision sensing system, meeting the strict requirements of new energy aluminum foil for plate shape measurement. Practical applications have shown that in the aluminum foil rolling process ranging from 0.01 to 0.1 mm, the plate shape measurement error can be controlled within ±3 μm, significantly improving the product qualification rate. To ensure long-term stable operation, the author suggests conducting rotor gap detection and pressure calibration on a regular basis. 

[References]

[1] Li Dao New Energy Anhui Co., Ltd. Air Bearing Plate-Type Roller Technical Manual [Z]. 2023.

[2] Prévot Metallurgical Technology. Plate-Type Roller Maintenance Guide [Z]. 2022.