I. Product Introduction

In the operation of rolling mill bearings, sealing and lubrication systems承担 multiple functions including preventing contaminant ingress, maintaining lubrication condition and carrying away frictional heat. The effectiveness of sealing and lubrication directly affects whether bearings can achieve their design service life under rolling conditions. NMT configures corresponding sealing and lubrication solutions for bearing products according to mill type, operating conditions and user maintenance capabilities.

 

Sealing Systems: The sealing configuration of NMT rolling mill bearings is selected according to mill operating conditions. In conditions with less cooling water spray, labyrinth seals are used, utilizing multi-stage annular gaps and centrifugal force to block water and particles. In conditions with higher water pressure and continuous water spray, the combination of labyrinth seals and contact rubber seals is used, forming a multi-stage protection system. For environments with significant dust, metal shields can be added as an auxiliary protective layer. Seal materials are selected from FKM (fluororubber) or HNBR (hydrogenated nitrile rubber) according to operating conditions, maintaining sealing performance under water spray and high-temperature environments.

 

Lubrication Systems: NMT rolling mill bearings are pre-filled with specialized grease. The base oil viscosity and additive formulations of the grease are matched to bearing type, load, speed and temperature conditions. Grease fill quantity is controlled at 30% to 50% of the bearing's internal free space. For mills using oil-mist or oil-air lubrication, NMT provides corresponding lubrication adaptation solutions.

 

II. Core Product Advantages

Tiered Seal Configuration: NMT provides different levels of seal solutions according to mill operating conditions. Labyrinth seals are suitable for general water environments, with non-contact operation and no friction heat generation. Contact rubber seals provide active blocking, achieving protection levels of IP65 or higher. The combination of labyrinth and contact seals forms a “coarse filtration + precision blocking” two-stage protection system, suitable for high-pressure water spray environments.

 

Seal Material Adaptation to Conditions: Seal materials are selected according to operating temperature and media conditions. FKM fluororubber is suitable for high-temperature environments of 150-250°C, maintaining elasticity and sealing performance through repeated thermal cycling. HNBR hydrogenated nitrile rubber excels in wear resistance and water resistance, suitable for water spray and abrasive environments. Seal lip interference and contact pressure are calculated to balance sealing effectiveness with friction heat generation control.

 

Targeted Grease Selection: NMT selects grease according to bearing operating conditions. Base oil viscosity ranges from ISO VG 150 to ISO VG 1000, with higher viscosity for heavy-load low-speed conditions and lower viscosity for high-speed conditions to reduce churning heat generation. Proportions of extreme-pressure anti-wear additives, rust inhibitors and water-resistant additives are adjusted according to operating conditions. For mill conditions with severe water spray, grease formulations with excellent water resistance are selected, resisting emulsification and washout under cooling water spray.

 

Grease Fill Quantity Control: Grease fill quantity is controlled at 30% to 50% of the bearing's internal free space. Insufficient fill quantity fails to form a continuous oil film, while excessive fill quantity causes churning heat generation and increased energy consumption. For large four-row bearings, a staged filling method is used——fill 50% first, rotate several turns, then fill the remaining portion, ensuring all rows of rollers and raceways are fully lubricated.

 

Systematic Coordination of Sealing and Lubrication: Sealing and lubrication are not independent of each other. Effective sealing keeps external water and contaminants out, protecting grease from emulsification and degradation;良好的 lubrication condition reduces dry friction and abnormal wear of seal lips. NMT configures sealing and lubrication as a system, enabling them to work together to extend bearing service life.

 

III. Typical Application Scenarios

Hot Roughing and Finishing Mills——High-temperature and water spray environments. Bearing housing temperatures can reach 150-250°C, with continuous cooling water and descaling water spray. NMT employs the combination of labyrinth seals and contact rubber seals, with FKM fluororubber as the seal material. Grease with high-viscosity base oil and water-resistant additives is selected to maintain stable lubricating films under high-temperature and water spray conditions.

 

Cold Rolling Mills——Emulsion environments and high-speed operation. Emulsion has chemical attack effects on seal materials and grease. NMT employs contact rubber seal solutions, with HNBR selected for emulsion corrosion resistance. Grease with excellent anti-emulsification properties is selected to maintain lubricating performance under emulsion contact conditions.

 

Continuous Caster Segments——Low-speed, heavy-load, continuous water spray. Bearing speeds are very low, making grease flow and distribution difficult. NMT optimizes internal grease channel design to ensure grease reaches rolling contact areas even at very low speeds. The sealing system uses the combination of labyrinth and contact seals to effectively block continuous caster cooling water spray.

 

Sendzimir Mills——Compact space and high precision requirements. Bearing arrangements are compact, with limited space for sealing and lubrication. NMT configures adapted seal solutions and grease fill quantities according to specific mill types, achieving reliable sealing and lubrication within limited space.

 

IV. Quality Assurance

Seal Material and Dimensional Control: Seal materials are selected according to operating conditions, with critical dimensions (lip interference, labyrinth gaps, etc.) controlled to design values. Labyrinth gaps are controlled to radial single-side 0.6-1.5mm and axial 4-6mm according to bearing size. Contact seal lip compression is controlled between 0.5-1.0mm——excessive compression causes friction heating and accelerated wear, while insufficient compression leads to inadequate sealing effectiveness.

 

Grease Filling and Inspection: Grease undergoes consistency verification before filling to ensure batch-to-batch consistency of consistency, dropping point, penetration and other parameters meet technical requirements. Fill quantity is calculated based on bearing internal space, using定量 grease filling equipment to control filling accuracy. Filled bearings undergo rotation testing to confirm even grease distribution and no abnormal heat generation.

 

Seal Performance Verification: Finished bearings undergo seal performance testing to verify sealing effectiveness under simulated operating conditions. Tests include static seal testing (confirming seals are properly installed with no leakage paths) and dynamic seal testing (verifying labyrinth seal centrifugal drainage effectiveness and contact seal active blocking effectiveness under rotation).

 

Grease Compatibility Management: When users switch grease brands or types, NMT provides compatibility assessment recommendations. Mixing greases with different thickener systems (lithium complex, polyurea, calcium sulfonate complex, etc.) may cause structural breakdown or additive precipitation. NMT recommends flushing procedures during grease changes to minimize residual old grease.

 

V. Product Range

NMT offers the following sealing and lubrication related products for steel metallurgical rolling equipment:

 

Labyrinth Seal Components: Non-contact seals suitable for general water environments. Multi-stage annular gap design utilizing centrifugal force for water and particle drainage.

 

Contact Rubber Seal Components: Available in FKM (fluororubber) and HNBR (hydrogenated nitrile rubber) materials, respectively适配 high-temperature and water spray conditions.

 

Metal Shields: Auxiliary protective layer suitable for environments with significant dust.

 

Combined Seal Kits: Combination solutions of labyrinth seals + contact rubber seals + metal shields, suitable for conditions with both high-pressure water spray and dust.

 

Specialized Mill Greases: Grease products with different viscosity grades and additive formulations matched to operating conditions.

 

Air Curtain-Assisted Seals (Optional): Introducing compressed air or nitrogen into the seal cavity to form a positive pressure air curtain, suitable for stands with intense high-pressure descaling water impact.

 

VI. Brand Strength

NMT has accumulated sustained application experience in the field of rolling mill bearing sealing and lubrication.

 

Application Experience in Seal Technology: NMT has accumulated application data in labyrinth seal gap control, contact seal lip material selection, combined seal solution design and other areas based on different mill types and operating conditions. Based on this data, NMT can provide seal configuration recommendations according to users' specific operating conditions.

 

Condition Matching of Lubrication Solutions: NMT has accumulated understanding of base oil viscosity selection, additive formulation adjustment, fill quantity control and other aspects based on bearing operating parameters (load, speed, temperature) and environmental conditions (water spray, dust, media corrosion). Grease selection recommendations are based on actual operating data rather than general recommendations.

 

System Configuration Capability: NMT configures sealing and lubrication as interrelated systems. Seal solution selection considers the impact on lubrication condition——better sealing slows grease degradation; lubrication solution selection considers the impact on seal life——adequate lubrication slows seal lip wear. This system configuration capability helps users find the balance between sealing and lubrication.

 

Field Service Experience: NMT has accumulated service experience in seal installation guidance, grease change recommendations, seal failure cause analysis and other areas at user sites. Based on this experience, NMT can help users identify seal and lubrication issues and propose improvement measures.

 

VII. Global Collaboration

NMT provides system configuration services for rolling mill bearing sealing and lubrication to steel mills, non-ferrous metal processors and metallurgical equipment manufacturers worldwide.

 

Service Reach: Sealing and lubrication solutions are适配 for various hot rolling, cold rolling, continuous casting and non-ferrous metal rolling production lines.

 

Technical Support Content: Based on users' specific mill parameters and operating conditions, NMT provides seal solution selection recommendations, grease selection recommendations and fill quantity setting recommendations. When anomalies occur in sealing and lubrication, NMT can assist in cause analysis and improvement plan development.

 

On-Site Services: NMT can provide seal installation guidance, grease change operation guidance and seal condition inspection services based on user needs.

 

Lubrication Management Recommendations: NMT provides grease change interval recommendations, in-service grease sampling and testing recommendations, and grease compatibility assessment recommendations to assist users in establishing standardized lubrication management practices.