NSK Case Study
Application
Cold Rolling Mill
Cost Savings: $17,472
A steel manufacturer was experiencing continued failures of bearings on their Cold Rolling Mill. NSK engineers conducted an application review and found the highly contaminated operating conditions were causing the unexpected failures. This resulted in costly unplanned shutdowns and a reduction in production ratios. NSK STF bearings, made of a long-life Super-Tough Steel, were recommended. STF is developed specifically to combat debris contamination that enters the lubricant. After a four-month running trial, the bearings were returned for inspection. The laboratory found a residual life between 29-50 months. To date, the customer has replaced the bearings once per year during the annual scheduled maintenance.
PDF DownloadKey Facts
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Cold Rolling Mill |
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Highly contaminated operating conditions |
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Extremely short bearing life: 3-4 months |
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Bearing and grease analysis revealed contamination caused the failures |
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NSK Solution: Long-life Super-Tough Steel Spherical Roller Bearings |
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Longer life with superior resistance against wear, seizure and heat |
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Significant increase of bearing life to 29-50 months |
Cold Rolling Mill
Value Proposals
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The NSK Technical Department analyzed grease samples and inspected bearings to find the root cause of failure |
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NSK Engineers recommended Spherical Roller Bearings in Super-Tough Steel |
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After a four-month trial (equivalent to the original bearing lifetime), bearings were disassembled and returned to the plant for analysis |
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The results showed that the bearing still had additional operating life (10 times the initial lifetime) |
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Significant cost savings were achieved based on reduced bearing replacement rate, reduced line stoppage and associated maintenance costs |
Product Features
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Advanced Super-TF material composition containing appropriate levels of chrome and molybdenum for increased hardness |
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Innovative heat treatment technology to optimize retained austenite and formation of finer carbide and carbonitride particles |
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Significantly outperforms standard bearing steel |
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Up to 10 times service life with contaminated lubrication; 2 times in clean lubrication |
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Up to 4 times the service life at 160°C/320°F |
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Less than one-third the rate of wear |
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40% improvement in seizure resistance |
Spherical Roller Bearings
of STF Steel composition
of STF Steel composition
Cost-Savings Breakdown
| Before | Cost | NSK Solution | Cost | |||
|---|---|---|---|---|---|---|
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Standard Spherical Roller Bearing spend | $10,290 | Super Tough Spherical Roller Bearings spend | $3,430 | ||
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Unplanned production downtime | $9,647 | No unplanned downtime | $0 | ||
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Bearing replacement maintenance | $1,286 | Bearing replacement maintenance | $321 | ||
| Total Costs | $21,223 | Total Costs | $3,751 | |||
| Before | Cost | |
|---|---|---|
|
Standard Spherical Roller Bearing spend | $10,290 |
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Unplanned production downtime | $9,647 |
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Bearing replacement maintenance | $1,286 |
| Total Costs | $21,223 | |
| NSK Solution | Cost | |
|---|---|---|
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Super Tough Spherical Roller Bearings spend |
$0 |
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No unplanned downtime | $0 |
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Bearing replacement maintenance | $321 |
| Total Costs | $3,751 | |
Your Partner for Machine Optimization
Our AIP Added Value Program is based around a simple proposition: ‘improvement pays’. By working with you throughout the AIP Value Cycle, we will help you achieve improvements in machine reliability, productivity and performance, all of which carry a tangible and measurable cost benefit – and we have the tools to prove it! That’s what we mean by improvement pays.
