The guide plate plays a critical role in ensuring smooth and stable movement of the protective cover during lifting and lowering operations. If abnormal resistance, noise, or incomplete travel occurs, timely inspection and corrective action are necessary to prevent further mechanical damage and maintain safe operation.
This guide provides a structured procedure for identifying common causes, performing preliminary inspections, and carrying out step-by-step troubleshooting to restore proper guide plate function.
¶ Symptom Description
During protective cover lifting/lowering, noticeable sticking or abnormal noise occurs and the motion becomes unsmooth; in severe cases, the protective cover cannot complete the full travel.
¶ Possible Causes
- The U-shaped bearing at the guide plate has become loose or detached.
- The retaining screw for the U-shaped bearing has fractured.
- Long-term vibration has caused thread wear on the retaining screw.
¶ Preliminary Assessment Steps
- Manually push the protective cover and check for tilting, sticking, or abnormal noise. Feel for any looseness or displacement at the guide plate area.
- Inspect whether the U-shaped bearing has come out of its slot and is exposed, and check whether the retaining screws are missing, fractured, or stripped.
- Check the screw heads of the U-shaped bearing for any signs of loosening or deformation.
¶ Troubleshooting
Steps 1–6 are relatively straightforward and require minimal operational skill. It is recommended to verify and inspect them sequentially in the order listed.
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Stop the machine and disconnect the main power supply.
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Using a hex key (Allen wrench), gently remove all screws from the column top cover one by one.
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Continue using the hex key (Allen wrench) to remove the retaining screws of the protective cover guide plate.
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Raise the guide plate to its upper limit position, remove the internal spring, and then remove the nylon screws on the side and at the upper limit position.
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Using the hex key (Allen wrench), secure the removed spring in a parallel position onto the upper side of the machine housing.
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The guide plate can then be removed easily to inspect the components for any abnormalities.
¶ Corrective Actions
1. Detachment: Reposition and align the U-shaped bearing, then tighten the retaining screws;
2. Fracture: Remove the broken screw and replace the guide plate assembly;
3. Thread wear: Replace the screw and, if necessary, add an anti-loosening washer.
¶ Verification Test
- Manually press to raise and lower the mechanism multiple times to confirm the guide plate moves smoothly.
- After installing the protective cover, confirm it reaches the upper limit position. Verify the protective cover lifts/lowers normally with no sticking or abnormal noise, and that the in-position signal is normal.