Cylinder noise, creeping, or leaks? 5 troubleshooting and repair tips

1. Abnormal Noise Troubleshooting and Troubleshooting

• Metallic Knocking Sound (Typical Characteristics: A crisp "clicking" sound)

Possible Causes:

Improper cushion adjustment (cushion throttle valve opening too wide)

Loose piston end cap (inadequate bolt torque)

Loose piston rod nut (axial clearance > 0.3mm)

Repair Steps:

Check the cushion adjustment screw and adjust to the standard (usually turning clockwise reduces cushion).

Tighten the end cap bolts with a torque wrench (refer to the manufacturer's specified value ±10%)

Retighten the piston rod nut and install a lock washer.

• Friction Whistling Sound (Typical Characteristics: A high-frequency "squeaking" sound)

Possible Causes:

Insufficient lubrication (oil mist supply < 1 drop/minute)

Worn guide bearing (radial clearance > 0.1mm)

Dry seal friction (surface roughness Ra > 0.8μm)

Repair Steps:

Adjust the lubricator to 2-3 drops/minute (ISO 14001). VG32 pneumatic oil)

Replace the guide bearing (copper-based oil-retaining bearings are recommended)

Clean and lubricate the seal groove (use silicone grease)

2. Analysis and Solution of Slippage

• Inconsistent Movement (Typical Characteristics: Intermittent Speed)

Root Cause:

Supply pressure fluctuations (pressure differential > 0.1 MPa)

Load eccentricity (lateral force > 10% of rated value)

Excessive pipe resistance (pipe diameter < 20% of cylinder interface)

Optimization Solution:

Install an air tank (volume ≥ cylinder stroke volume × 3)

Use a floating joint to eliminate lateral forces

Replace with a larger diameter pipe (control the flow rate within 15 m/s)

• Low-speed creep (typical characteristic: trembling at speeds <50 mm/s)

Key parameters:

Frictional resistance (starting pressure > 0.03 MPa is abnormal)

Load ratio (>70% requires reselection)

Minimum stable speed (standard cylinders are typically ≥30 mm/s)

Improvement measures:

Use a precision pressure regulator (adjustment accuracy ±0.005 MPa)

Use a dedicated low-speed cylinder (with a precision guide mechanism)

Add a gas-liquid damping device (speed fluctuation <±5%)

3. Leakage Troubleshooting and Repair

• External Leakage Diagnosis (Typical Leak Points)

Detection Methods:

Soapy water test (bubble diameter >3 mm indicates a severe leak)

Ultrasonic detector (sensitivity 0.5 ml/min)

Flowmeter measurement (leakage >5% of rated flow requires treatment)

Treatment of common leak locations:

4. Cylinder maintenance points: key guidelines to ensure long-term stable operation

Daily Maintenance Items

Lubrication Management

Lubricator Adjustment: Normal operating conditions: 1-2 drops/minute (ISO VG32 pneumatic oil); High-frequency operating conditions: 3-5 drops/minute; Non-lubricated cylinders: Do not add lubricant; Check the lubricator reservoir monthly and refill if the level drops below 1/3; Clean the lubricator filter element quarterly (using compressed air for reverse purging); Condensate Drainage; At the end of each day: Open the drain valve at the bottom of the filter (until no water drips out); The water level in the triplex water reservoir must not exceed 1/4 full; In cold weather: Install an automatic drain (set to 2 hours per operation); Install a drain valve at the lowest point in the pipeline;

Regular Inspection Specifications

Sealing System Inspection

Monthly Inspection: Piston Rod Seal Wipe with a white cloth to check for oil seepage (a slight oil film is permitted).

End cap seals: Observe for bubbles (use soapy water for testing).

Annual replacement: All dynamic seals (including piston and rod seals).

Static O-rings (replace if hardness changes by more than 15%).

Mechanical component maintenance.

Piston rod: Surface roughness Ra ≤ 0.2 μm (tested with a portable roughness meter).

Straightness deviation < 0.05 mm/m (measured with an optical collimator).

Cylinder inner wall: Monthly inspection with an endoscope for scratches (depth > 0.01 mm requires treatment).

Annual polishing with ultra-fine abrasive paste (grade W5).