2.2 Maintenance: 3 months (regularly maintained by the maintenance unit)

2.3 Minor repair: 1 year

2.4 overhaul: 3-4 years

2.5 Restorative maintenance of winding: as required.

3 Maintenance and repair contents

3. 1 Preparation for maintenance work

3. 1. 1 Before maintenance, the bolts, nuts and gaskets of the motor body should be thoroughly checked for looseness and aging;

3. 1.2 Whether the lubricating system of the motor body leaks oil or not;

3. 1.3 Prepare the necessary oil receiving barrel and oil receiving tray to prevent the leakage of waste oil for cleaning the motor;

3.2 Maintenance content

3.2. 1 Operation post maintenance content

A keep the exterior of the motor clean, and the air inlet and outlet are unblocked, and no water drops, oil stains and sundries are allowed to fall into the interior of the motor.

B check the temperature rise of various parts of the motor, whether the bearing is overheated and whether there is oil leakage.

C. check whether the vibration and noise of the motor have abnormal smell.

D for the motor with water-air heat exchanger, check whether the water pipe leaks.

E. clean the dust accumulated on the motor cover.

F check whether the room is poorly ventilated or whether the ambient air temperature exceeds 40℃.

3.2.2 Maintenance Contents of Engineering Department

A. Check the fastening degree of bolts and nuts of various parts of the motor and the reliability of grounding.

B during normal operation, the power supply voltage and frequency are consistent with the nameplate, the three-phase current and voltage are symmetrical, and the load current does not exceed the rating specified in the nameplate.

C. The wound motor should also check the brush device and spark, clean up the dust deposited on the carbon brush in time, and check the abrasion of the carbon brush and the free movement in the brush holder.

D. When using the filter device, check the pollution degree of the filter.

E. add grease to the bearing.

3.3 Minor repair contents

3.3. 1 external cleaning

3.3.2 Check and clean the wiring parts, terminals and nuts of the motor for looseness or damage.

3.3.3 Check the insulation of each outgoing line for signs of overheating or galvanic corrosion.

3.3.4 Check the oil quality and quantity of the bearing, clean the bearing and update the grease if necessary.

3.3.5 Check and clean the slip ring, adjust and replace the brush.

3.3.6 Check the grounding wire of the motor housing and tighten the connecting screws.

3.3.7 Check and clean the ventilation system and cooler.

3.3.8 Measure the insulation resistance of stator and rotor coils. When measuring, use a 2500V megohmmeter, and the insulation resistance should be no less than 10M. The insulation resistance of the coil is quite different from the historical test data. Even if the allowable minimum value is not reached, it is necessary to dry and clean the motor as required.

3.3.9 Take measures to correct the oil leakage at the bearing seal.

3.3. 10 Check the motor cavity for condensation, water accumulation and corrosion.

3.3. 1 1 Check the internal fan itself and its fixation to ensure that the windshield is intact and does not touch the blades.

3.3. 12 Check that the bearing is closely combined with the small end cover and the shaft has no friction.

3.4 Maintenance content

3.4. 1 The motor is disintegrated, the rotor is pulled out or the stator is removed.

When disassembling, all screws, brush holders and pads must be marked, and the explosion-proof surface must be protected by explosion-proof motor.

3.4.2 Clean and check the stator coil.

A. Blow the ventilation trench and coil end with compressed air. The air should be clean, without oil and water. In order to avoid damaging insulation, when removing oil stains from stator coils, care must be taken not to use metal tools, but to use a scraper made of wood or insulation board.

B. Check the stator coil, check whether the stator core is pressed, and check whether there are blue marks caused by internal heating of the core. If there are such traces, a core heating test should be carried out.

C. check the slot wedge of the stator coil.

D. Check the junction box, remove the dust on it, tighten the screws and check its sealing degree.

E check the end of the coil, and pay special attention to the fixing of the end. If the end is found to be loose, add pads where necessary, or fix the end with new pads and wires. If the insulation paint film at the end of the coil cracks and falls off, the insulation should be strengthened again. Check whether the insulation is overheated, showing bubbles, discoloration or carbonization, and check whether the paint film is damaged.

F after pulling out the rotor and before covering the end cover, the stator must be carefully inspected, paying special attention to whether there are any sundries left in the motor, and the insulation resistance and DC resistance of the stator coil must be measured with a shaking table before and after inspection.

G. measure the insulation resistance between the insulating bearing or bearing seat and the steel foundation with a 500-volt megger.

3.4.3 Rotor maintenance.

A. Blow the rotor clean with compressed air.

B. check the welding of coils, rods and joints.

C. check whether the squirrel cage reinforcement is welded.

D. check the fan itself and its fixation. The saw blade guard is intact and not loose. Do not touch the saw blade.

E. check the slip ring. If the surface of the slip ring is uneven more than 0.5mm, it should be turned and the surface should be smooth.

F check the insulation status of rotor coil and binding wire, and strengthen insulation when necessary.

G. check that the bearing and the small end cover are closely combined and there is no friction on the shaft. The bearing inner and outer rings are clean, and the contact surface is smooth without rust and peeling. The bearing should be closely matched with the shaft and end cover, and the amount of grease should be appropriate. Record the bearing specifications.

H there should be a gap of 0.1-0.2mm between the brush and the brush holder, the copper braid between the brush and the brush holder should be well connected, the distance between each brush holder and the slip ring surface should be 2-3mm, and the pressure of the brush on the slip ring should be adjusted to the lowest pressure without generating sparks, generally 0.2-0.3kg/cm2, and the pressure of each brush should not be different by 10%.

3.4.4 The motor affected with damp should be dry.

3.4.5 After the motor is disintegrated, use kerosene or gasoline to clean the bearing and measure the bearing clearance. When the allowable value is exceeded, the bearing should be replaced.

3.4.6 Dust and dirt on the air filter of overhaul motor shall be removed.

3.4.7 Check the cooling system, fans and other accessories.

3.4.8 After the motor is overhauled, the test shall be carried out as required.

3.5 winding recovery overhaul content:

If the stator or rotor winding of the motor is burnt out and the insulation can't meet the requirements and can't be saved, it is necessary to replace the winding.

3.5. 1 Replace the burnt stator and rotor coils.

3.5.2 Deal with the damage of stator and rotor core.

3.5.3 Test and inspection of semi-finished products.

A. visual inspection.

B. measure the dc resistance.

C. measure the insulation resistance.

3.5.4 After semi-qualification, dip in paint and dry.

3.5.5 Do the finished product test.

3.6 Preparation before maintenance.

3.6. 1 cut off the power supply of the high-voltage motor, remove the external wiring of the motor, and make records.

3.6.2 Clean the surface of the motor and clean up the maintenance site environment.

3.6.3 Prepare tools and equipment required for disassembly.

3.6.4 Before maintenance, the operator shall inform the maintenance personnel of the defects in motor operation.

3.6.5 Measure the insulation resistance before disassembly.

3.6.6 The original recorded data before winding disassembly shall be well prepared for winding maintenance, and special tools, insulating materials and wires shall be prepared.

3.7 Maintenance precautions.

3.7. 1 Remove the motor coupling with tools. The movement should be smooth and even, and the working arm should be balanced. It is forbidden to directly strike the coupling with a sledgehammer.

3.7.2 When pumping the rotor, the wire rope used shall not touch the coil, slip ring, bearing and fan blades. Bolted rotor parts should be padded with hardwood.

3.7.3 Before assembly, check whether the binding of slot wedge and winding end is loose, whether the binding line is higher than the core surface, and there shall be no sundries and paint scale in the motor.

3.7.4 For wound motor, generally, the front end cover is removed first, and then the rear end cover is removed (lift the brush first, tie it firmly, and mark the brush holding position); For motors with roller bearings at the load end, the non-load end should be removed first; Remove the heavy big end cover and lift it with a crane or tools to avoid breaking it.

4 quality standards

4. 1 stator parts

A. the nameplate is complete and the shell is clean.

B the slot wedge shall be free from looseness and discoloration, and shall not be higher than the iron core.

C the coil surface should be clean, and the insulation should not be brittle, burnt, swollen or damaged.

D end pads and straps will not become loose or brittle.

E. Lead-out wires and bridge wires shall be insulated without scorching, mechanical damage and broken strands.

F. The wiring board shall be clean, without excessive heat and brittleness, and the pile head screws shall not be loose.

G. the polarity is correct, the star points are spliced and tightened, and there are spring washers.

H. The iron core and laminations are pressed tightly, the mouth is overheated, and the ventilation ditch is not blocked.

First, there is no crack in the frame and end cover, and there are grounding screws.

J. The frame and iron core are firmly fixed, and the welding place is good.

K the end cover is closely combined with the bearing, and there is no yellow water and oil leakage.

The length of the windshield ring is not deformed and the screws are not loose.

4.2 Rotor part

A. The iron core should be clean, the ventilation ditch should be free of blockage, and the welding place should be firm.

B. The blades are good and not loose, and the balance iron is firm.

C. The saw blade guard is intact and not loose. Do not touch the saw blade.

D the squirrel cage and end ring shall be free of looseness, cracks and desoldering.

E. The bearing is smoothly and tightly combined with the small end cover and does not rub against the shaft.

F the bearing should be closely matched with the shaft and the end cover.

G the inner and outer rings of the bearing are clean, the contact surface is smooth, and there is no rust and peeling.

4.3 bearing

A. rolling bearings shall meet the following requirements:

The surface of the ball (column) is smooth and clean, without cracks and corrosion spots. Use the grease specified in the manufacturer or maintenance matrix. The oil filling amount is: high-speed motor12 bearing, and other motors are 2/3. Different greases are not allowed for the same bearing.

Allowable clearance of rolling bearing is as follows:

Axial clearance: 0.3mm.

5 After the motor maintenance and acceptance.

5. 1 The motor disassembly inspection shall be accepted by the maintenance unit and finally by the electrical department.

5.2 When the motor is in trial operation, record the no-load current, the three-phase current is balanced, the phase current difference is ≤ 10%, there should be no obvious heating in all parts of the motor, and the trial operation time of the high-voltage motor must be ≥2 hours.

5.3 The motor has no abnormal vibration and noise. All parts are well fastened without looseness. The vibration value meets the following requirements:

Rotational speed (rpm) vibration value (mm)

3000 0.05

1500 0. 1

1000 0. 13

750 0. 16

5.4 clean appearance

5.5 Motor insulation resistance meets the requirements. When measuring the insulation resistance between phases and the ground, the motor of 10KV should be greater than10mohm.

5.6 Measure the DC resistance of the coil, and the phase difference is less than 2%.

5.7 Measure the gap between the stator and rotor of the motor, and the difference is less than 10%.

5.8 Complete motor maintenance data.

6. Prevention and control of environmental factors/dangerous factors during maintenance.

6. 1 Before equipment maintenance, environmental factors should be well controlled, and wastes should be treated according to company regulations.

6.2 Strictly implement the working ticket system, safety regulations, maintenance manual and other management systems in the maintenance work.

6.3 When entering the site, wear labor protection clothes, confirm the correct working position, and check whether the safety measures meet the safety needs.