As a high-precision bearing brand originating from Japan, EZO bearings are renowned in various fields such as industrial machinery and precision instruments due to their advanced production processes and strict quality control. Their products are characterized by low noise, high stability, and long service life. However, during long-term operation, bearings may experience various operational abnormalities due to factors such as installation, lubrication, and load. Timely investigation of abnormal causes and adoption of targeted solutions are crucial to ensuring the stable operation of EZO bearings and extending their service life. This article will detail the common operational abnormalities of EZO bearings and their corresponding solutions, providing practical references for daily user operation and maintenance.

I. Noise Abnormality: The Most Intuitive Fault Warning Signal

EZO bearings are allowed to produce slight normal operating noise during operation. If obvious abnormal noise occurs, it usually indicates potential faults in the bearings. Different types of noise correspond to different fault causes, which need to be accurately identified and addressed:

• High-pitched metallic noise: This kind of noise is sharp and harsh, mainly caused by four reasons. First, poor lubrication: the correct amount of appropriate lubricant should be added. Second, insufficient clearance: the bearing clearance should be adjusted to the standard range. Third, poor mounting: the accuracy of the shaft and housing, as well as the mounting method, should be checked to ensure standard installation. Fourth, excessive load: the fitting and preload of the bearing should be verified to avoid overload operation.
• Low-pitched metallic noise: The noise is deep and continuous, mostly caused by indentations on the raceway surface, which is common when the bearing is dropped or subjected to impact load during installation. The core solution is to avoid impact during installation and handling to prevent damage to the raceway surface.
• Regular noise: The noise presents a fixed frequency, mainly resulting from two problems. If it is due to rust and/or damage on the raceway, the sealing device should be checked, and clean lubricant should be replaced to prevent further corrosion. If it is due to flaking on the raceway surface, the bearing fitting, clearance, lubrication, and mounting method should be optimized to fundamentally reduce flaking.
• Irregular noise: The noise is disorderly without a fixed frequency, which may be caused by intrusion of foreign matter, excessive clearance, or ball damage and ball flaking. In case of foreign matter intrusion, the sealing device should be checked and clean lubricant should be replaced. If the clearance is excessive, it should be adjusted to an appropriate range. If the balls are damaged or flaked, the proper clearance and load of the bearing should be ensured, and the damaged balls should be replaced if necessary.
• Noise that changes over time: The intensity or frequency of the noise changes with operating time, mainly due to two reasons. First, changes in clearance caused by rising temperature: the materials of the shaft and housing should be checked to ensure that the clearance is suitable for temperature changes. Second, ongoing abnormalities on the raceway: the fitting, clearance, lubrication, and mounting processes should be standardized to completely solve the raceway faults.

II. Heavy Vibration: A Key Hidden Danger Affecting Equipment Stability

If EZO bearings experience heavy vibration during operation, it will not only affect the operating accuracy of the equipment but also accelerate bearing wear and even damage related components, which needs to be investigated and handled in a timely manner. The common causes and corresponding solutions are as follows:

• Raceway and ball flaking: This is one of the main causes of heavy vibration. The bearing fitting method, clearance size, lubrication process, and installation operation should be standardized to fundamentally avoid flaking. If the flaking is severe, the bearing should be replaced in a timely manner.
• Intrusion of foreign matter: The intrusion of impurities or foreign matter into the bearing will cause uneven force during operation and lead to vibration. The sealing performance of the sealing device should be checked, clean lubricant should be replaced in a timely manner, and foreign matter inside and around the bearing should be removed to prevent re-intrusion.
• Excessive clearance: If the bearing clearance exceeds the standard range, obvious shaking and vibration will occur during operation. The clearance should be adjusted to an appropriate value to ensure stable operation of the bearing.
• Poor mounting: Excessive deviation in the perpendicularity of the shaft and housing shoulders will cause uneven force on the bearing and generate vibration. The perpendicularity of the shaft and housing shoulders should be adjusted to ensure that the installation accuracy meets the requirements.

III. Abnormal Temperature Rise: An Important Precursor to Bearing Damage

EZO bearings will generate a certain amount of heat during operation, but if the temperature rises abnormally and remains high, it indicates that the bearing has faults. Long-term high temperature will accelerate the aging of lubricant and damage the internal structure of the bearing, so it is necessary to shut down the machine for investigation immediately. The specific causes and solutions are as follows:

• Insufficient clearance: Too small bearing clearance will intensify friction during operation and cause rapid heat accumulation. The clearance should be adjusted to the standard range to reduce frictional heat generation.
• Poor mounting: Insufficient accuracy of the shaft and housing and non-standard mounting methods will increase the frictional resistance during bearing operation and cause temperature rise. The accuracy of the shaft and housing should be checked, and the installation process should be standardized to ensure proper installation.
• Excessive load: Long-term operation of the bearing under load exceeding the rated range will intensify internal friction and cause abnormal temperature rise. The clearance, fitting, and preload of the bearing should be verified, and the load should be adjusted to the rated range to avoid overload operation.
• Poor lubrication: Insufficient lubricant, incorrect type, or deterioration will lose the lubricating effect, leading to intensified internal friction of the bearing and temperature rise. The correct amount of lubricant suitable for the working conditions should be added, and the deteriorated lubricant should be checked and replaced regularly.
• Creep: Relative sliding (creep) between the bearing and the shaft or housing will generate frictional heat and cause temperature rise. The fitting between the bearing, shaft, and housing should be checked, and the fitting accuracy should be adjusted to avoid creep.

IV. Leakage and Discoloration of Lubricant: Direct Manifestation of Lubrication System Faults

Lubricant is crucial to ensuring the normal operation of EZO bearings. If lubricant leakage, abnormal color change, and other conditions occur, it indicates faults in the lubrication system, which need to be handled in a timely manner. Otherwise, it will lead to insufficient lubrication of the bearing and accelerate damage. The specific causes and solutions are as follows:

• Too much grease: Excessive grease added beyond the required amount of the bearing will cause the grease to overflow due to temperature rise during operation, resulting in leakage. The correct amount of appropriate lubricant should be added according to the bearing specifications to avoid excessive addition.
• Intrusion of foreign matter: The intrusion of foreign matter into the bearing will contaminate the lubricant, leading to discoloration and deterioration of the lubricant, and may damage the sealing device, causing leakage. The sealing device should be checked, the components around the bearing should be cleaned, the contaminated lubricant should be replaced, and the bearing should be replaced in a timely manner if it is severely damaged.

V. Daily Operation and Maintenance Suggestions

To reduce the occurrence of operational abnormalities of EZO bearings and extend their service life, the following points should be noted in daily operation and maintenance: First, standardize the installation process to ensure that the accuracy and installation perpendicularity of the shaft and housing meet the requirements. Second, regularly check the state of the lubricant, timely supplement and replace the appropriate lubricant, and keep the lubricant clean. Third, control the operating load of the bearing to avoid overload operation. Fourth, regularly check the operating state of the bearing, timely investigate abnormal signals such as noise, vibration, and temperature, and achieve early detection and early treatment. Fifth, do a good job in the sealing protection of the bearing to prevent the intrusion of foreign matter.

The stable operation of EZO bearings is inseparable from standard installation, scientific lubrication, and regular operation and maintenance. Mastering the investigation methods and solutions for the above common abnormalities can effectively reduce the incidence of bearing faults, give full play to the high-precision and long-life advantages of EZO bearings, and provide guarantee for the stable operation of equipment.