Scissor lifts are prone to the following three major issues during operation, along with their corresponding solutions:
Failure to Lift or Lower Properly
Symptoms: After startup, the equipment fails to reach the intended height, or the lifting/lowering process is unstable. Root Causes:
Hydraulic System Failure: Insufficient hydraulic fluid or clogged oil lines hinder pressure transmission.
Limit Switch Failure: The switch position is misaligned or damaged, preventing the accurate triggering of the stop signal.
Power Supply Issues: Phase loss or voltage instability causes abnormal motor operation.
Solutions:
Inspect the Hydraulic System:
Verify that the hydraulic fluid level falls within the standard range; replenish immediately if insufficient.
Check oil lines for kinks, blockages, or leaks; clean or replace any damaged lines.
Calibrate Limit Switches: Adjust the switch position to the designated height, or replace damaged switches.
Troubleshoot Power Supply:
Use a multimeter to verify that the three-phase voltage is balanced; repair any circuits experiencing phase loss.
Check if the power indicator light is illuminated; confirm that the contactors within the control cabinet are engaging properly.
Abnormal Noise During Operation
Symptoms: The equipment emits jarring or irregular sounds while running. Root Causes:
Roller System Failure: Insufficient roller hardness, surface wear, or a lack of lubrication leads to sliding friction.
Guide Wheel Impact: Damaged bearings or deformed guide rails trigger metallic clanking sounds.
Worn Transmission Components: Components such as rollers and bushings experience dry friction due to a lack of lubrication.
Solutions:
Roller Maintenance:
Replace rollers with new ones that meet standard hardness specifications, ensuring a smooth and even surface finish.
Clear debris from the guide channels; repair any scratches or deformations on the guide channel surfaces.
Guide Wheel Inspection & Repair:
Remove the guide wheels to inspect for seized or damaged bearings; replace with new bearings. Adjust the clearance between the guide wheels and the guide rails to 2–3 mm to prevent direct collision.
Lubrication and Maintenance:
Apply lithium-based grease to components such as rollers, working arms, and bushings; replenish every 3 months.
Replace worn transmission components to ensure that fitting clearances meet design specifications.
Hydraulic System Inspection:
Verify that the hydraulic oil level falls within the standard range; replenish immediately if insufficient.
Check hydraulic hoses for bending, blockages, or leaks; clean or replace any damaged hoses.
Limit Switch Calibration: Adjust the switch position to the specified height, or replace any damaged switches.
Power Supply Troubleshooting:
Use a multimeter to check for balanced three-phase voltage; repair any open-phase circuits.
Verify that the power indicator light is illuminated and confirm that the contactors within the control cabinet are engaging correctly.
Shaking or Instability During Operation
Symptoms: The equipment exhibits noticeable shaking, trembling, or lateral deviation during lifting or load-bearing operations. Root Causes:
Structural Looseness: Support legs or outriggers are not fully extended, or connection bolts are loose.
Insufficient Lubrication: Dry friction at the articulating joints of the support arms leads to increased resistance during movement. Uneven Loading: Cargo offset or overloading causes a shift in the center of gravity.
Solutions:
Structural Reinforcement:
Verify that the outriggers are fully extended; the contact area between the outrigger feet and the ground must be ≥ 80%.
Tighten all connection bolts; torque values must reach 90%–100% of the design specifications.
Lubrication:
Apply molybdenum disulfide lubricant to the boom pivot points, pins, and other articulated areas.
Regularly clean the lubrication channels to prevent the accumulation of sludge.
Load Management:
Ensure the cargo's center of gravity is positioned at the center of the platform; the offset distance must be ≤ 1/3 of the platform width.
Strictly limit the load to within 80% of the rated capacity to avoid overloading during operation.
Hydraulic System Failure: Insufficient hydraulic fluid or clogged oil lines hinder pressure transmission.
Limit Switch Failure: The switch position is misaligned or damaged, preventing the accurate triggering of the stop signal.
Power Supply Issues: Phase loss or voltage instability causes abnormal motor operation.
Solutions:
Hydraulic System Inspection:
Verify that the hydraulic fluid level falls within the standard range; replenish immediately if insufficient.
Check oil lines for kinks, blockages, or leaks; clean or replace any damaged lines.
Limit Switch Calibration: Adjust the switch position to the specified height, or replace any damaged switches.
Power Supply Troubleshooting:
Use a multimeter to check for balanced three-phase voltage; repair any circuits experiencing phase loss.
Verify that the power indicator light is illuminated, and confirm that the contactors within the control cabinet are engaging correctly.
Preventive Maintenance Recommendations
Daily Checks: Before powering on, verify the hydraulic oil level, power indicator status, and outrigger condition.
Monthly Maintenance: Clean the hydraulic system filter elements and check the sensitivity of the limit switches.
Annual Overhaul: Replace the hydraulic oil and inspect the welds on structural components for cracks.
If a malfunction involves complex components-such as electrical controls or hydraulic valves-it is recommended to contact professional maintenance personnel for service to avoid causing secondary damage through improper operation.
