Bearing maintenance guide: a must-read for operators!
Bearings are an indispensable key component in mechanical equipment, and their performance directly affects the operating efficiency of the entire machine. According to statistics, about 50% of mechanical failures are related to bearing problems. Professional maintenance can not only extend the service life of bearings, but also significantly reduce equipment maintenance costs. This article will systematically introduce the core points of bearing maintenance.
1. Daily inspection specifications for bearings
Operators should establish a regular inspection system, focusing on three indicators: temperature, vibration and noise. The operating temperature of the bearing should not usually exceed 70°C, and abnormal temperature rise often indicates lubrication failure or improper installation. Using an infrared thermometer can accurately monitor temperature changes.
1.1 Vibration detection standard
It is recommended to use a vibration analyzer to detect the vibration value of the bearing every week. When the vibration speed exceeds 4.5mm/s, it is necessary to stop the machine immediately for inspection. Common causes of abnormal vibration include: shaft misalignment (accounting for 38%), imbalance (accounting for 28%) and bearing damage (accounting for 19%).
2. Key points of bearing lubrication
Lubrication is the core link of bearing maintenance. When selecting grease, the operating temperature, speed and load conditions should be considered. Synthetic base oil grease should be used in high temperature environments (>120℃), and NLGI 2 grade grease is recommended for low speed and heavy load conditions.
2.1 Grease filling specifications
The filling amount should be controlled within 30%-50% of the internal space of the bearing. Excessive filling will cause stirring and heating. The pressure of the electric grease gun is recommended to be maintained at 200-400psi, and the filling frequency is adjusted according to the working conditions. Generally, it is replenished every 500 hours of operation.
3. Bearing cleaning and anti-rust treatment
Contaminants are the main cause of early bearing failure. After disassembly, special cleaning agents (such as kerosene or solvent oil) should be used for thorough cleaning, and compressed air should be used to blow dry immediately after cleaning. Bearings that are stored for a long time need to be coated with anti-rust oil and use gas phase anti-rust packaging.
4. Key points of bearing installation technology
The correct installation method can avoid 90% of early failures. It is recommended to install cylindrical bore bearings using oil pressure method, and control the oil pressure not to exceed 300MPa. Tapered bore bearings require precise preload through locking nuts, usually 3%-5% of the basic rated dynamic load of the bearing.
5. Common fault diagnosis and treatment
When abnormal noise occurs, the fault type can be determined by frequency analysis: 1-3 times the rotation frequency is mostly wear fault, and high-frequency components may be spalling damage. Early pitting can be repaired by grinding, but the bearing must be replaced if the spalling area exceeds 10%.
By implementing the above maintenance measures, the average service life of the bearing can be extended by 2-3 times. It is recommended that enterprises establish a complete bearing maintenance file to record the parameters and status of each maintenance to provide data support for preventive maintenance.