Motor bearing failure is a common problem in mechanical equipment, which can cause abnormal noise, increased vibration and decreased efficiency. This article will introduce in detail the judgment method, on-site handling skills and preventive measures of bearing failures to help technicians quickly solve problems and extend the service life of equipment.
Identification method of bearing failure
- Listen to the sound to determine the type of fault: The sound of normal bearing operation is uniform and slight. Regular “clucking” sounds usually indicate damage to the rolling element or raceway. Continuous “rustling” sounds may be insufficient lubrication. Sharp metal friction sounds often mean that the bearing is seriously damaged.
- Measure the vibration value to analyze the fault: Use a vibration measuring instrument to detect the vibration value of the bearing in all directions. Excessive axial vibration usually reflects assembly problems. Abnormal radial vibration is mostly due to bearing wear. The vibration peak of a specific frequency can accurately locate the damaged part.
- Observe the temperature change trend: A sudden increase of more than 10°C in bearing temperature needs to be taken seriously. Continuous high-temperature operation will accelerate the deterioration of grease. Regular inspection with an infrared temperature gun can detect potential problems in time.
On-site treatment of common faults
1. Solution to poor lubrication: First clean the oil injection nozzle and oil outlet, select the appropriate type of grease, and control the oil injection amount to 1/3-1/2 of the internal space of the bearing. Excessive lubrication will increase the running resistance.
2. Treatment steps for foreign matter intrusion: Immediately stop the machine for disassembly and inspection, thoroughly clean the bearing and bearing chamber with kerosene, check whether the seal is intact, and ensure that the working environment is clean before reassembly.
3. Emergency measures for minor damage: The load can be temporarily reduced by 20%-30%, and the operating parameters can be adjusted to reduce vibration, but replacement should be arranged as soon as possible. Continued use may cause greater losses.
Bearing replacement operation specifications
- Disassembly precautions: Use special puller tools to apply force evenly, avoid directly hitting the bearing, record the original installation position, and protect adjacent precision parts such as encoders.
- Key points for installing new bearings: Check the bearing clearance and rotation flexibility before installation, use appropriate installation tools to ensure uniform force, and strictly control the interference within the range of 0.002-0.005mm.
- Inspection items after assembly: Manual rotation to confirm no jamming, measure axial and radial clearances, and run the motor without load for 1 hour to observe temperature and vibration changes.
Preventive maintenance measures
- Establish a regular lubrication system: formulate an oil replenishment cycle according to the working environment. Generally, grease is replenished every 2,000 hours of operation and completely replaced once a year. The cycle should be shortened in high temperature or humid environments.
- Implement a condition monitoring plan: record vibration and temperature data every month, establish a trend analysis chart, and handle abnormalities in a timely manner. Important equipment can be installed with an online monitoring system.
- Improve the operating environment: Keep the area around the motor clean and dry, avoid dust and water vapor intrusion, improve heat dissipation conditions, and regularly check the alignment and foundation tightening status.
Correctly handling motor bearing failures requires accurate diagnosis and standardized operation. Through scientific maintenance management and timely fault handling, the bearing life can be significantly extended and the stable operation of the equipment can be ensured. It is recommended to establish a complete maintenance file to achieve preventive maintenance.