How to accurately solve the problems of vibration, jitter and unstable speed of loom reducer

In response to this pain point, we can carry out systematic investigation and solution according to the principle of "safety first, troubleshooting later, external first, then internal, empty load first, then load".

1. The first step: shutdown safety confirmation and external basic investigation

Before conducting any investigation, you must first cut off the power supply, hang a "no closing" warning sign, and wait for the reducer to cool down completely to avoid high temperature deformation from interfering with judgment.

1. Check installation and tightening:

Anchor bolts: Check whether the anchor bolts of the reducer base and motor base are loose. Long-term vibration can cause gaps between the bolt threads or the base and the concrete foundation.

Gasket status: Confirm whether the base gasket is damaged or misaligned. Note that the gasket must use steel pads or cast iron pads, and it is strictly prohibited to use multi-layer rubber pads.

2. Check the coupling and alignment:

Connecting parts: Check whether the coupling bolts and locking nuts are loose, and whether the flat key and keyway are worn and loose (fitting gap should be ≤0.1mm).

Elastic components: Check whether elastic components such as plum blossom pads and rubber sleeves are aged, damaged or fallen off.

Alignment accuracy: This is the most common cause of vibration. Use a dial indicator or laser alignment instrument to check that the radial misalignment of the general reducer should be ≤0.1mm, and the angular misalignment should be ≤0.05mm/m.

2. Step 2: Check the lubrication system

Poor lubrication can lead to high gear meshing resistance and bearing jamming, which can lead to vibration and speed fluctuations.

1. Oil level and oil quality:

Check whether the oil level is between the upper and lower limits of the oil level. If it is too low, it will cause dry friction, and if it is too high, it will cause large oil churning resistance and increase the oil temperature.

Take a sample and observe the oil: if it turns black, has a peculiar smell, contains metal abrasive particles, or is emulsified and turned white (water has entered), it means that the oil quality has failed and needs to be replaced immediately.

2. Breathable cap (respirator):

There is a lot of flying flowers and dust in the loom workshop, which can easily block the breathable cap. If the internal pressure of the box increases, it will cause oil leakage and affect the lubrication cycle, so it needs to be cleaned in time.

3. Step 3: Diagnosis of internal mechanical components

If there are no abnormalities in the exterior and lubrication, further inspection of the internal core components is required.

1. Gears and bearings:

Gears: Check tooth surfaces for wear, pitting, spalling or broken teeth. If the gear meshing clearance is too large (normal backlash is 0.1-0.3mm), it will cause impact, causing the speed to be fast and slow.

Bearings: Bearing wear, cage fracture, or excessive clearance will directly lead to shaking and vibration of the shaft system.

2. Shaft system and key connection:

Check whether the input/output shaft has obvious axial movement (normal ≤0.5mm). Excessive movement indicates bearing thrust failure.

Check whether the key strips (flat keys, splines) are worn. Loose key connections are the direct cause of unstable or slipping output shaft speed.

4. Step 4: Load and electrical control troubleshooting

Looms have extremely high requirements for speed stability, and fluctuations in the electrical system will be directly reflected on the reducer.

1. Load status judgment:

Normal no-load, abnormal load: The fault is most likely at the load end (such as loom load jamming, loose foundation) or the reducer Selection is too small (load overload).

No-load is abnormal: the fault lies in the reducer itself or the motor.

2. Motor and driver:

Motor status: Use a clamp meter to measure the three-phase current of the motor. If it is unbalanced or exceeds the standard, it means that the motor is missing a phase or the winding is damaged, and its vibration will be transmitted to the reducer.

Servo/frequency conversion parameters: If a servo motor is used, improper gain parameter settings (such as too high a speed loop gain) will cause resonance jitter; improper carrier frequency or PID parameters of the frequency converter will also cause speed fluctuations.

3. Sensor feedback:

Check whether the connection of the encoder or tachometer generator is firm and whether there is any interference in the signal line. Inaccurate feedback signals will cause the control system to be unable to adjust the speed correctly.