How to replace the high-pressure cleaning motor assembly of papermaking machinery parts?

Replacement process of high-pressure cleaning motor assembly for papermaking machinery

> Important note: The papermaking site is wet and watery, and it must be operated by certified electricians and mechanics; Strictly implement the power failure check, lock and tag, and the inverter drive equipment needs to wait for the capacitor to discharge completely; This procedure is a general operation instruction, and the final instruction of the original equipment factory shall prevail.

First, preparation before operation

1. Safety isolation

1. Disconnect the circuit breaker of the main circuit of the motor, control the power supply, execute locking and listing, hang a warning sign that closing is prohibited and someone is working.

2. For the inverter power supply model, let it stand for 510 minutes without power supply, and release the residual energy of the capacitor. Check the electricity phase by phase at the terminal to confirm that there is no voltage.

3. Close the high-pressure cleaning water inlet valve, drain the residual water pressure in the pipeline, and remove the pressure at the assembly end to prevent water spraying during disassembly.

4. Clean up the surrounding paper pulp, water and oil, ensure the working space, and wear safety helmet, protective glasses and insulating labor protection shoes.

2. Check spare parts and tools

1. Check the parameters of the new motor assembly: power, voltage, rotating speed, flange/foot installation size, shaft diameter and protection grade (IP54 and above are preferred in paper-making field) to match the original assembly; Confirm the bearing grease model and complete seals.

2. Tools: socket wrench, puller, level gauge, dial indicator, megger, multimeter, chain hoist/chain block, copper bar, insulating tape, marker, bolt gasket and new sealing gasket.

3. Unpacking inspection of the new motor: the shell is free from bumping, the manual rotation of the rotor is smooth and free from jamming, the junction box is intact, and the insulation resistance is measured and recorded.

Second, the old motor assembly disassembly steps

1. Electrical wiring removal

Open the junction box, mark and number the power cord, grounding, temperature sensor and heater cable one by one, and take photos to keep the line sequence; Dismantle the cable, protect the cable head with insulation package, and do not damage the cable sheath.

2. Disconnect the mechanical connection

-If the coupling is directly connected: loosen the coupling fastening bolt and mark the alignment; Dismantle the coupling with a puller. It is forbidden to directly knock the coupling and the shaft end with a hammer. When necessary, evenly heat the coupling for disassembly to protect the shaft journal from being damaged.

-In case of belt drive: remove the protective cover, loosen the tensioning mechanism and take off the belt.

-Disconnect the cleaning end: remove the connecting flange on the high-pressure pump side, remove the pipeline and properly place the sealing ring.

3. Remove the anchor/flange fixing bolts

Mark the position and thickness of the original adjusting gasket (it must be reset according to the original gasket to ensure alignment) and loosen all the fixing bolts.

When the assembly is unbalanced, use the lifting chain to hang the motor assembly safely, then remove all bolts and lift it off the frame smoothly to avoid bumping the threads of the pump body, frame and rotating shaft.

4. Clean the installation base, remove pulp, rust and old gasket residue, and check the base for cracks and deformation.

III. Reinstallation of the new motor assembly

1. Pre-install transmission parts

Install the coupling/pulley to the new motor shaft, and the copper bar shall be evenly tapped or hot-fitted in place. Hard hammering on the shaft end face is strictly prohibited; The keyway and Ping Jian are assembled in place.

2. Hoist in place

Hoist the motor assembly to the installation position by the chain hoist, put back the original adjusting gasket, and thread the fixing bolt. Do not lock the bolt immediately.

3. Find the right alignment (key, high-pressure cleaning of papermaking runs at high speed, and poor alignment can easily burn bearings)

-Coupling connection: use a dial indicator to detect radial and axial runout, adjust the motor position, and ensure that the coaxiality meets the equipment requirements;

-Belt drive: adjust the parallelism and tension gap of pulley.

After the alignment is qualified, lock the anchor bolts diagonally for several times, and check the alignment accuracy again to prevent deviation after locking.

4. Restore the high-pressure water side flange connection, replace the new sealing gasket, and tighten the flange bolts diagonally evenly.

5. Electrical wiring recovery

Connect the power cable, grounding, temperature sensor and heater according to the previous marks; The sealing rubber ring of the junction box is in place, and the box cover is pressed tightly to prevent water vapor and pulp from entering the junction box.

After the wiring is completed, retest the insulation resistance of the motor to the ground with a megger.

Fourth, commissioning and acceptance

1. Manual turning: the motor pump assembly is driven by the disc, which is flexible in rotation and free from friction, sticking and abnormal sound.

2. Unlock and tag, jog for test run, and confirm that the rotation direction of the motor is consistent with the original equipment, and it is forbidden to reverse.

3. No-load operation for 3‑5min: Monitor the motor sound, observe the vibration, measure the three-phase current, and check the temperature rise without abnormality.

4. Connect the waterway to run with load: turn on the water inlet, put into high-pressure cleaning condition, and observe the vibration, noise and leakage. The three-phase current is within the rated range.

5. Check whether the anchor bolts, couplings and flange bolts are loose; Clean up the site and make maintenance records: replacement date, assembly model, insulation resistance and alignment data.

Five, the papermaking site special matters needing attention

1. The environment is wet and pulpy, and the motor protection level must meet the site working conditions, and the junction box seal must be in place to prevent water from burning the winding.

2. The load impact of the high-pressure cleaning pump is large, and the coupling elastomer is aged and damaged, and the damage is replaced synchronously.

3. Bearing lubrication: Fill the corresponding grease according to the equipment requirements, and don't overdo it to avoid oil leakage during high temperature operation.

4. In case of large vibration and high current during operation, the coupling centering and base gasket should be rechecked first, and the paper machine frame is prone to slurry accumulation and deformation, resulting in centering deviation.

5. After the overhaul, it is confirmed that all protective covers are reset before putting into production.