1. Purpose and scope of application
This instruction is intended for replacement of bearings in electric motors used in industrial installations. The procedure is carried out when wear, knocking out or damage to the bearings is detected, which affects the efficiency of the engine. Replacing the bearings is necessary to ensure the reliability, durability and economy of the electric motor.
2. Safety and Warnings
Stopping the machine: Before starting any work, ensure a complete stop of the electric motor and perform the lockout/tagout (LOTO) procedure according to the requirements of DSTU 3065:2012 and ISO 12100. Protective equipment: Use protective clothing, gloves, goggles and protective shorts. Work in an area where there are no shock or knock-out risks. Electricity: When working with the electric motor, ensure that the power is turned off and check that there is no voltage using a multimeter in the voltage measurement mode. Use at least a 100 W tester. Contacts with power lines: Do not use power tools that do not meet CE and UkrSEPRO standards. Ensure that all tools are grounded.
3. Necessary tools and materials
| Name of the tool | Specification | Quantity |
|---|---|---|
| Torque rifle | Ranging 10-60 Nm | 1 |
| Multimeter | Voltage measurement mode 0-500 V | 1 |
| A laser for measuring parallelism | Length 5 m, accuracy 0.02 mm | 1 |
| Bearing bones | Diameter 25-50 mm | 2 |
| Hydraulic tool for unscrewing | Pressure 150 bar | 1 |
| Wrench with bearing size | Diameter 10-25 mm | 1 |
| Lubricant for bearings | Maslyana, ISO 46 | 1 |
4. Pre-launch check
| Point | Verification | Acceptance/rejection criteria | Notes |
|---|---|---|---|
| 1 | Engine stop | Complete power outage | Play LOTO |
| 2 | Checking for voltage | There is no voltage | Use a multimeter |
| 3 | Workplace preparation | Free and lighted space | Use special devices |
| 4 | Opening access to bearings | Bearings are available | Use the key |
| 5 | Lubricant consumption check | No or insufficient lubrication | Replace the lubricant |
5. Sequence of actions
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Power cut-off: Perform lockout/tagout procedure for the electric motor. Check the absence of voltage at the motor output. Use the multimeter in voltage measurement mode, range 0-500 V. No voltage is considered acceptable.
Error: Using tools without a voltage check can cause injury.
-
Housing Opening: Open the motor housing using a wrench or hydraulic tool. Check that the bearings are accessible.
Error: Improper opening of the shell can cause damage to internal components.
-
Removing Old Bearings: Use the bearing balls to remove old bearings. Check for wear or dents.
Error: Improperly removing the bearings can cause damage to the mount.
-
Parallelism measurement: Use the laser to measure the parallelism of the motor axis. Set the permissible deviation of 0.05 mm. Use a laser with an accuracy of 0.02 mm.
Error: Deviation from parallelism can lead to engine failure.
Installing New Bearings: Install the new bearings, making sure they are installed correctly. Use a wrench with bearing size. Install bearings with an allowable gap of 0.01-0.03 mm.
Error: Improper installation of bearings can cause knock-out.
-
Grease: Apply bearing grease to the bearing surfaces. Use grease ISO 46. Apply grease to all bearing surfaces.
Error: Insufficient lubrication can lead to rapid wear.
-
Secure: Use a torque screw to secure the bearings. Set the tightening torque to 25-30 Nm. Check that the tightening torque meets the requirements.
Error: Incorrect tightening torque can lead to chipping or knocking out.
-
Shell Return: Return the engine shell to its original position. Check that the bearings are accessible.
Error: Improper shell assembly can cause damage.
-
Restoring Power: Restore power to the engine. Perform the LOTO procedure. Check for no voltage.
Error: Returning the power supply without checking the voltage can cause injury.
6. After performing the check
| Test | Expected result | Actual result | Pass/Fail |
|---|---|---|---|
| 1 | Lack of tension | There is no voltage | Pas |
| 2 | Axis parallelism | Deviation 0.05 mm | Pas |
| 3 | Bearing clearance | 0.01-0.03 mm | Pas |
| 4 | Tightening torque | 25-30 Nm | Pas |
| 5 | No noise | There is no noise | Pas |
7. Occurrence tracking
| Symptom | Reasons | Correction |
|---|---|---|
| 1 | Knocking out bearings | Remove the old bearings and install the new ones |
| 2 | Increased temperature | Check the lubrication and measure the clearance |
| 3 | Engine failure | Check the parallelism of the axis and install the bearings |
| 4 | Bearing noise | Remove the old bearings and install the new ones |
| 5 | Wear and tear | Remove the old bearings and install the new ones |
8. Recommended maintenance schedule
| The task | Frequency | Estimated time | Skill level |
|---|---|---|---|
| 1 | Replacement of bearings | 12 months | Average |
| 2 | Check clearances | 6 months | Average |
| 3 | Lubricant | 3 months | Low |
| 4 | Voltage check | monthly | Low |
| 5 | Measurement of parallelism | Quarter | Average |
9. Links to spare parts
| Description of the spare part | Typical specification | UNITEC-D category |
|---|---|---|
| Bearing 6205 | Diameter 25 mm, weight 0.5 kg | UNITEC-D 1234 |
| Bearing 6207 | Diameter 35 mm, weight 0.8 kg | UNITEC-D 1235 |
| Bearing 6209 | Diameter 45 mm, weight 1.2 kg | UNITEC-D 1236 |
| Bearing 6210 | Diameter 50 mm, weight 1.5 kg | UNITEC-D 1237 |
| Bearing 6212 | Diameter 60 mm, weight 2.0 kg | UNITEC-D 1238 |
10. Links
- DSTU 3065:2012 — Safety of production processes
- ISO 12100 - Machine safety
- ISO 46 — Lubricant for bearings
- CE, UkrSEPRO — Certification
- OEM documentation — Detailed requirements of the manufacturer
