Rolling Bearing Troubleshooting Guide: From Failure Diagnosis to Maintenance Pitfall Avoidance
From: XingMao DATE: 2026/8/14 Hits: 25
Rolling Bearing Troubleshooting Guide: From Failure Diagnosis to Maintenance Pitfall Avoidance
Common "Scrap Modes" of bearings
In industrial settings, rolling bearing failures don't always present in a single way. The most common include:
Fatigue Spalling: Under long-term alternating loads, pitting and flaking occur on the raceway or rolling element surfaces, a typical sign of the bearing's end-of-life.
Abrasive Wear and Adhesive Wear: Intru...
Common "Scrap Modes" of bearings
In industrial settings, rolling bearing failures don't always present in a single way. The most common include:
Fatigue Spalling: Under long-term alternating loads, pitting and flaking occur on the raceway or rolling element surfaces, a typical sign of the bearing's end-of-life.
Abrasive Wear and Adhesive Wear: Intrusion of foreign matter or poor lubrication leads to gradual wear of the rolling surface material, resulting in severe cases of scuffing and abrasion.
Plastic Deformation: Overload or impact loads cause pitting in the raceway, particularly prominent under low-speed, heavy-load conditions.
Corrosion and Electrolytic Erosion: Intrusion of moisture, acidic or alkaline media, or stray currents leads to surface corrosion or electrospark erosion pits.
Fracture and Cracks: Cage fracture and cracking of inner and outer rings caused by violent impacts during installation, excessive interference fit, or material defects.
Accurately identifying the failure mode is the first step in tracing the root cause and preventing the recurrence of similar failures.
Three Major Abnormal Signals: On-site Interpretation of Vibration, Noise, and Temperature Rise
During equipment operation, the "distress signals" emitted by bearings are often hidden in three dimensions:
Vibration Signals – Early Warning Signs of Faults. Through vibration acceleration, effective velocity values, and envelope spectrum analysis, abnormal characteristic frequencies of the inner ring, outer ring, rolling elements, and cage can be detected, enabling fault location.
Noise Changes – Experienced maintenance personnel can distinguish the "clunking" sound of raceway spalling, the "hissing" sound of insufficient lubrication, and the "clattering" sound of a loose cage using only a stethoscope or tactile pen.
Temperature Abnormalities – A sudden increase or sustained high temperature rise in bearing temperature usually indicates lubrication failure, loose fit, or abnormal load. Regular inspections combined with infrared thermography are recommended to establish a temperature trend record.
Fit Selection: An Easily Overlooked "Hidden Killer"
The fit between the bearing and the shaft/housing directly affects its operating condition:
Rotating Load (load direction rotates with the shaft): Bearing rings subjected to rotating loads should have an interference fit to prevent slippage and fretting wear on the mating surfaces.
Static Load (load direction remains constant): Bearing rings subjected to static loads can appropriately use a clearance fit or transition fit to facilitate installation and disassembly while avoiding stress concentration.
There have been several cases in the field where incorrect fit selection led to premature bearing failure—a transition fit was used where an interference fit should have been, resulting in ring creep, burning of the mating surfaces, and bearing failure within months.
Lubrication: A Key Variable Determining Bearing Life
The impact of lubrication on bearing life far exceeds most people's imagination. In practice, three core elements need attention:
Grease Selection: Select the appropriate consistency grade, base oil viscosity, and additive system based on speed, temperature, load, and environmental conditions. For high-temperature conditions, choose lithium-based or complex lithium-based grease; for low-speed, heavy-load conditions, extreme pressure (EP) additives are required.
Filling control: Generally, filling the bearing's internal space to 1/3 to 1/2 is appropriate. Too much filling will cause oil churning and overheating, while too little filling will result in insufficient lubrication. High-speed bearings should use the lower limit.
Refilling cycle: A relubrication plan should be developed based on operating hours, temperature, and grease aging. Avoid the passive maintenance approach of "adding only when it breaks down."
Selection and maintenance points for special operating conditions
Not all equipment can use universal bearing solutions. Special operating conditions require special treatment:
Vibration motors: Bearings subjected to high-frequency vibration forces should use copper cages (not ordinary stamped steel cages). The grease must contain EP additives to handle boundary lubrication conditions, and the relubrication cycle should be shortened.
Mining machinery: High risk of dust and mud intrusion. Bearings with sealed or dust cover structures should be prioritized, along with labyrinth seals and regular cleaning and maintenance.
High-temperature fans/kiln equipment: The dropping point, oxidation stability, and thermal expansion compensation of the bearing clearance of the high-temperature grease must be considered.
Installation and Disassembly: Details Determine Success or Failure
Many bearing failures are not due to the product itself, but rather human error during installation and disassembly:
Common Mistakes:
Directly striking the bearing races with a hammer, causing damage to the raceway.
Heating to excessively high temperatures (above 120℃) or uneven heating, causing changes in material structure.
Pulling only one point during disassembly, causing misalignment and jamming of the inner and outer rings.
Correct Procedures:
During installation, apply force to the interference fit races using a dedicated press-fit tool or induction heater.
Control the heating temperature between 80 and 110℃, heat evenly, and quickly install the bearing.
During disassembly, use a puller to apply force symmetrically, and use hydraulic tools if necessary.
In Conclusion
Bearings, though small, are the "joints" of reliable equipment operation. From failure mode identification and abnormal signal interpretation to fit selection, lubrication management, and standardized installation, every step requires on-site technicians to accumulate experience and develop a systematic maintenance strategy. Prevention is worse than cure—this is the core logic of equipment management shifting from "firefighting" to "prevention before disease."
