How To Solve The Problem of Vibration And Jamming of The Reciprocating Screw?

The reciprocating screw rod exhibits shaking and sticking, usually caused by multiple factors such as mechanical structure, installation accuracy, lubrication status, or electrical parameters. It is necessary to initially determine the problem by "listening to sounds to identify positions", and then conduct targeted inspections and repairs. The specific inspections and solutions are as follows:

1. Sticking (high running resistance, jamming) inspection and solution

1.1. Foreign objects intrusion and contamination

Reason: Hard foreign objects such as iron filings and dust invade the raceways, or the lubricating grease dries and forms lumps, causing dry friction between the balls and the raceways.

Solution: Stop the machine for cleaning, thoroughly rinse the internal part of the nut with kerosene or special cleaning agents, remove impurities; check and replace the aged dust-proof sealing ring; reapply appropriate lubricating grease (select low-viscosity or extreme-pressure grease according to the rotational speed) and manually rotate the nut for testing.

1.2. Poor lubrication or incorrect grease selection

Reason: Insufficient lubrication or excessively thick grease, resulting in high resistance during stirring, or grease solidification in low-temperature environments.

Solution: Clean the old grease, replace it with grease suitable for the equipment's working conditions (low-viscosity grease for high-speed equipment, extreme-pressure grease for heavy-load applications).

1.3. Installation accuracy deviation

The screw shaft axis is not parallel to the guide rail, or the coaxiality between the motor shaft and the screw shaft is out of tolerance, causing additional radial force during operation and periodic resistance fluctuations.

Solution: Use a micrometer or laser alignment instrument to re-calibrate the coaxiality (radial deviation ≤ 0.05mm, angle deviation ≤ 0.5°) and parallelism (error ≤ 0.02mm/m), adjust the washers or re-align and tighten after adjustment.

1.4. Component wear or deformation

Reason: The screw rod is bent and deformed (radial runout exceeds a certain limit, such as > 0.05mm) or the nut/roller is severely worn, causing local sticking.

Solution: Minor bending can be straightened, severe deformation or wear requires direct replacement of the screw rod or the entire nut pair.

1.5. Excessive preload

Reason: Excessive preload setting leads to a significant increase in friction resistance, making the operation heavy.

Solution: Adjust the preload to a reasonable range (such as loosening the adjusting ring of the double nut structure and setting it to 5% - 10% of the rated dynamic load).

2. Shaking (unusual noise, resonance, vibration) inspection and solution

2.1. Resonance and excessive length-to-diameter ratio

Reason: The screw rod has a long slender ratio, generating resonance near the critical speed when rotating at high speed, or the pressure bar becomes unstable.

Solution: Reduce the operating speed and avoid the resonance zone; if the structure allows, increase the diameter of the screw rod, shorten the support spacing (install intermediate supports) or optimize the support method (change from single-end cantilever to double-end fixed).

2.2. Coupling loosening or bearing damage

Reason: Loose coupling screws or worn elastic bodies, or damaged supporting bearings (angular contact bearings) cause gaps and impact noises during operation.

Solution: Re-tighten the coupling screws, replace the worn elastic bodies or coupling; replace the damaged supporting bearings and pay attention to the preload during installation.

2.3. Servo parameter mismatch

Reason: Excessive servo rigidity setting or incorrect identification of the inertia ratio, resulting in shock and vibration during acceleration and deceleration.

Solution: Re-perform servo inertia identification, appropriately reduce the speed loop gain, or enable the resonance suppression filter of the servo drive.

2.4. Load sudden change or excessive mechanical clearance

Reason: Excessive load causes mechanical deformation, or excessive clearance between the screw rod and nut causes crawling and vibration during reverse operation.

Solution: Re-check the load, optimize the acceleration and deceleration curves; adjust the preload to eliminate the clearance, or replace the worn screw rod and nut. Inspection suggestions: Follow the principle of "start with the easy and proceed to the difficult", prioritize checking lubrication, cleanliness, and fastening components, then inspect installation accuracy and mechanical wear, and finally inspect electrical parameters.

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