Rolling mill bearings in addition to the common causes of failure, there are several typical failure conditions. The following Yitong rolling mill bearings are briefly described for you.

Typical failure of rolling mill bearing 1. Normal (typical) fatigue failure

Phenomenon: the surface of raceway and rolling element is broken and there is material peeling; Equipment vibration increased significantly.

Cause: the service life exceeds the calculated fatigue life.

Measures: replace the bearing; Consider installing bearings with higher load capacity.

Typical failure fault of rolling mill bearing 2. Corrosion trace caused by corrosive medium

Phenomenon: Red / brown discoloration and / or slag on rolling element, raceway and cage; Vibration increases and wear intensifies; The clearance increases or the preload decreases.

Cause: the bearing is used in the environment with corrosive medium; Worn seals or improper lubrication.

Measures: do not store corrosive substances in the surrounding environment; Use bearings with seals; Improve the effectiveness of external sealing system; Use a moisture resistant lubricant.

Typical failure fault of rolling mill bearing 3. Foreign particle pollution

Phenomenon: (the pollution caused by foreign particles often produces peeling or dents in the bearing area of the bearing jacket) the dents caused by soft particles are shallow and have flat edge protrusions or peeling; The dents caused by hard particles are deep and have high edge protrusions; Brittle particles are crushed during bearing operation, resulting in a large number of dents on the protrusions with intersecting edges; V-shaped pitting is formed in the rolling direction, and the bottom is the initial dent.

Cause: particles brought into the external environment during assembly; Enter various particles during seal wear and use; The lubricating oil is contaminated and added directly without filtration.

Measures: keep the workplace, hands and tools clean; The workplace is far away from grinding; The bearing package can only be opened before installation; Improve / replace the sealing system.

Typical failure fault of rolling mill bearing 4. Overheating damage

Phenomenon: the bearing ring, rolling element and cage fade and become basket; Plastic deformation occurs between bearing ring and rolling element; The bearing may get stuck.

Causes: (generally, the specific causes cannot be further determined) too small clearance (especially for high-speed occasions); poor lubrication (improper viscosity, pollution); too much or too little lubricant; subsequent damage caused by cage fracture.

Measures: increase bearing clearance; provide lubricant quality (viscosity, cleanliness); avoid over lubrication or poor lubricant; ensure slow and uniform heating when there is external heat source.

Typical failure fault of rolling mill bearing 5. Slipping

Phenomenon: creep occurs on the surface; pitting occurs.

Cause: in the low bearing area, the rolling element slips on the raceway and accelerates when entering the bearing area; rapid speed change.

Measures: use bearings with low bearing capacity; preload bearings (such as spring preloading); reduce bearing clearance; ensure sufficient load (commissioning); improve lubricants.

Typical failure of rolling mill bearing 6. Poor lubrication

Phenomenon: dark gray in raceway in low bearing area; pressure polishing in high bearing area.

Causes: insufficient lubricant supply; high operating temperature (low lubricant viscosity at operating temperature); water pollution in lubricant

Measures: improve lubricant supply; use higher viscosity lubricant; cool lubricant and / or bearing position; use softer grease; improve waterproof performance of sealing system.

Typical failure of rolling mill bearing 7. Biting and sticking in the contact area of retaining edge

Phenomenon: local or large-area welding, deep scratches on the retaining edge of the bearing ring and the end face of the roller; coking of the lubricant in the biting area.

Causes: insufficient lubrication under heavy load and / or high speed; excessive preload on tapered roller bearing; preload caused by thermal expansion; roller skew caused by wear; excessive axial force on cylindrical roller bearing.

Measures: properly adjust the bearing; improve lubrication (increase lubricant viscosity, EP additive, lubricant amount).

Typical failure fault 8 and scratch of rolling mill bearing

Phenomenon: the raceways of cylindrical roller and tapered roller bearings have edge raised scratches in the ax

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