1、 Mechanical transmission system malfunction

1. Stirring shaft stuck or difficult to rotate
   • reason：
     • The material adheres to the mixing blade or shaft, causing an increase in resistance.
     • Friction is generated due to bearing wear or insufficient lubrication.
     • The gap between the mixing blade and the inner wall of the mixing bucket is too small, resulting in collision.
   • process：
     • Clean the residual materials on the mixing blade and shaft after shutdown.
     • Check the condition of the bearings, replace worn bearings, and replenish lubricating grease (such as lithium based grease).
     • Adjust the position of the mixing blade or replace it with a blade of appropriate size.
2. Loose or broken drive belt/chain
   • reason：
     • Long term use leads to belt or chain elongation and wear.
     • The tensioning device is malfunctioning or improperly adjusted.
   • process：
     • Replace the belt or chain with a new one and adjust the tensioner to the appropriate position.
     • Regularly check the tensioning device to ensure its sensitivity and effectiveness.
3. Abnormal noise or overheating of the gearbox
   • reason：
     • The internal gears of the reducer are worn or the lubricating oil is insufficient.
     • Poor alignment of input/output shafts leads to vibration.
   • process：
     • Supplement or replace gearbox lubricating oil (such as ISO VG220 industrial gear oil).
     • Check and adjust the axis alignment accuracy, with a deviation of ≤ 0.1mm.

2、 Electrical control system malfunction

1. The motor cannot start or trips frequently
   • reason：
     • The power supply voltage is unstable or lacks phase.
     • Motor overload protection device action (such as thermal relay triggering).
     • Poor contact or open circuit in the control circuit.
   • process：
     • Check if the power supply voltage is within the rated range (e.g. 380V ± 10%).
     • Confirm if the load exceeds the rated power of the motor, adjust the material quantity or mixing speed.
     • Use a multimeter to check the control circuit and repair open circuits or oxidized contacts.
2. Inverter alarm or inability to adjust speed
   • reason：
     • Inverter overload, overheating, or incorrect parameter settings.
     • Input/output signal interference (such as electromagnetic interference).
   • process：
     • Check if the cooling fan of the frequency converter is running properly and clean the dust.
     • Reset the parameters of the frequency converter, such as acceleration time and deceleration time.
     • Install shielding layers on signal lines or keep them away from power cables.
3. Abnormal sensor signal
   • reason：
     • The temperature/pressure sensor is damaged or the wiring is loose.
     • Material adhesion leads to sensor false triggering.
   • process：
     • Test the sensor output with an analog signal generator and replace the faulty sensor.
     • Regularly clean the surface of the sensor to prevent material accumulation.

3、 Mixing effect abnormal fault

1. Uneven mixing
   • reason：
     • The type or speed of the stirring blade does not match the material characteristics (such as the use of helical blades for high viscosity materials).
     • The inner wall roughness of the mixing bucket is insufficient, resulting in material hanging on the wall.
     • Excessive differences in material particle size or improper feeding sequence.
   • process：
     • Replace the mixing blades (such as paddle, turbine, anchor) according to the characteristics of the material.
     • Polish or spray anti stick coating on the inner wall of the mixing bucket.
     • Optimize the feeding sequence (such as feeding large particle materials first, followed by powder materials).
2. Mixing time too long
   • reason：
     • Insufficient mixing power or low rotation speed.
     • Poor material fluidity (such as high moisture content).
   • process：
     • Increase the motor power or increase the stirring speed (confirm the allowable range of the equipment).
     • Adjust the material formula (such as adding flow aids).
3. Material stratification or precipitation
   • reason：
     • There is a significant difference in material density and insufficient mixing intensity.
     • The bottom design of the mixing bucket is unreasonable (such as flat bottom that is prone to material accumulation).
   • process：
     • Switch to high shear mixing blades or add auxiliary mixing devices.
     • Change the bottom of the mixing bucket to a conical shape and install a discharge valve.

4、 Sealing and leakage failure

1. Shaft seal leakage
   • reason：
     • Mechanical seal wear or improper installation.
     • O-ring aging or size mismatch.
   • process：
     • Replace the mechanical seal dynamic ring and static ring, and adjust the compression amount.
     • Choose corrosion-resistant and high-temperature resistant O-ring materials (such as fluororubber).
2. Leakage of mixing bucket
   • reason：
     • Cracks or sand holes at the welding joints of the barrel body.
     • The sealing gasket at the flange connection is damaged.
   • process：
     • Perform repair welding or re welding on the welded area.
     • Replace the gasket and tighten the flange bolts evenly.

5、 Security protection failure

1. Emergency stop button failure
   • reason：
     • Button contact oxidation or circuit disconnection.
     • The emergency stop circuit fuse has blown.
   • process：
     • Clean or replace the emergency stop button, and check if the wiring is loose.
     • Replace the fuse with the same specification (such as 10A slow melting type).
2. Frequent triggering of overload protection
   • reason：
     • The actual load of the motor exceeds the rated value.
     • The setting value of the thermal relay is set too low.
   • process：
     • Reduce the amount of material in a single mixture or lower the stirring speed.
     • Adjust the setting value of the thermal relay according to the rated current of the motor (usually 1.1-1.2 times the rated current).

6、 Other common faults

1. Excessive vibration of the equipment
   • reason：
     • Loose anchor bolts or uneven foundation.
     • The impeller of the mixing blade is unbalanced.
   • process：
     • Tighten the anchor bolts and adjust the levelness of the equipment.
     • Perform dynamic balance correction on the impeller (deviation should be ≤ G1 level).
2. Abnormal noise
   • reason：
     • Bearing damage or poor gear meshing.
     • Hard impurities (such as metal particles) are mixed into the material.
   • process：
     • Replace bearings or repair gear tooth surfaces.
     • Install metal detectors or screens to filter impurities.

7、 Preventive maintenance recommendations

1. Regular lubricationAdd lubricating grease to friction components such as bearings and gears every 500 hours.
2. Cleaning and maintenanceClean the mixing bucket and paddle after each use to prevent material residue from hardening.
3. Parameter monitoringRecord key parameters such as motor current and temperature, and promptly troubleshoot any abnormalities found.
4. Spare parts reserveReserve commonly used vulnerable parts (such as bearings, sealing rings, belts) to shorten downtime.