1. The “Heavy-Duty Dilemma“ of Bearing Replacement in Steel & Cement Industries

Steel and cement are classic continuous-operation heavy industries. Bearings in converter trunnions, rotary kiln support rollers, ball mills, bucket elevators, roller presses and other equipment endure hundreds of tons of heavy impact loads, extreme dust and high-temperature radiation year-round. In the cement industry, conveyors are by far the most frequently problematic equipment type. In the mining and cement industry, 43% of accidents occur while workers perform maintenance or checks on conveyors.

 

When bearings in these machines fail, maintenance teams face a far more complex “heavy-duty dilemma“ than ordinary industrial equipment – traditional solid bearing replacement requires disassembly of shafts, gears, couplings, gearboxes and numerous surrounding components, with confined working spaces and massive component weights – the entire replacement cycle takes days or weeks, with downtime losses reaching tens of millions or even hundreds of millions of yuan.

 

Taking the 300-ton converter trunnion bearing at a large North China steel plant as an example: the original design used a solid spherical roller bearing (1850mm outer diameter, over 5 tons). Replacement required first disassembling the drive gear and part of the gearbox. However, due to confined installation space and the large number and weight of surrounding components, disassembly and movement were extremely difficult. The entire replacement project was extremely time-consuming, with downtime losses reaching tens of millions of yuan. In cement plants, bearing replacement for rotary kilns and bucket elevators faces similar challenges – equipment must be completely shut down, heavy lifting equipment is difficult to access, and replacement cycles take weeks.

 

Typical pain points of traditional solid bearings in steel and cement industries:

 

Enormous disassembly workload – Replacing one bearing requires disassembling gears, couplings, gearboxes, frames and numerous surrounding components. On converter trunnions, the drive gear itself weighs several tons – disassembly alone is a major project.

 

Extremely confined working space – Critical bearing positions such as converter trunnions and rotary kiln support rollers are often in confined spaces where heavy lifting equipment cannot access – making hoisting and handling extremely difficult.

 

Dependence on heavy equipment – Bearings and surrounding components weigh several to tens of tons – requiring heavy lifting equipment, whose rental and scheduling is itself a challenge.

 

Downtime measured in weeks – Traditional solid bearing replacement typically takes days or even weeks. For converter trunnion bearings, the solid solution requires weeks of downtime.

 

Production losses measured in tens of millions – Days to weeks of unplanned downtime directly lose tens of millions or even hundreds of millions of yuan.

 

Worker safety risks – 43% of accidents occur during maintenance or inspections. Complex disassembly, heavy lifting and confined space work all significantly increase safety risks.

 

2. NMT Split Bearings for Steel & Cement Industries: Heavy Loads Don‘t Stop Shafts, Quick Bearing Replacement

NMT split bearings for steel and cement industries perfectly combine the core advantage of split bearings – “no-shaft-removal installation“ – with the stringent requirements of heavy-duty applications. The inner ring, outer ring, rolling elements and cage are all split along the axial direction – installation requires no removal of shafts, gears, couplings or any other core components – assembly is completed directly on the shaft in situ. Unlike traditional sliding installation, split bearings are installed directly around the shaft – no need to slide the bearing on or off from the shaft end.

 

More critically – NMT split bearings can be replaced without removing drive gears, without moving shaft systems, without using heavy lifting equipment. This is like installing a “service door“ on heavy-duty equipment in steel and cement industries, enabling true “online“ maintenance.

 

▸ Full Split + Heavy-Duty Construction: Every Piece Can “Go in Separately, Rotate Together“ – Withstanding Heavy Impact

 

Every component of an NMT split bearing for steel and cement industries is split – split inner ring, split outer ring, split cage with rolling elements, split seals. During installation, these half-ring components are assembled sequentially around the shaft. After being locked with high-strength bolts, they form a precision transmission unit with performance fully equivalent to a solid bearing. Precision step-type mating or V-shaped split joint design at the split interfaces ensures load capacity and rotational precision equal to solid bearings.

 

In terms of materials, NMT offers a complete impact-resistant steel system for steel and cement heavy-duty applications – carburized bearing steel with deep-case hardening achieves uniform surface hardness HRC60-64 while the core maintains sufficient toughness to absorb impact loads. For high-temperature applications (rotary kiln support roller bearings), heat-resistant steel and thermal stabilization treatment are available.

 

▸ No-Shaft-Removal Installation: No Gear Removal, No Coupling Removal, No Heavy Lifting Equipment

 

The core value of NMT split bearings for steel and cement industries is – bearing replacement without moving the shaft, without removing the drive gear, without using heavy lifting equipment. This means for converter trunnion bearing replacement, the drive gear stays in place, couplings stay in place, gearboxes stay in place. For cement plant bucket elevator bearing replacement, no drive disassembly is required – the shaft can be supported with jacks for replacement. Maintenance personnel simply open the bearing housing, remove the old bearing halves, install the new bearing halves, and tighten the bolts – complete. The lower portion of the bearing continues to support the shaft throughout the replacement process, while the upper housing and outer ring can be easily removed.

 

▸ Interchangeable with Standard Heavy-Duty Solid Bearings: Seamless Replacement, No Modifications

 

NMT split bearings for steel and cement industries are designed with full interchangeability with standard heavy-duty solid bearings in mind. In most cases, the outer diameter and outer ring width of split bearings are identical to standard spherical roller bearings (222, 230, 231, 239, 240, 241 series). This means steel mills and cement plants can directly replace existing solid bearings in their equipment with NMT split bearings without any machining modifications to bearing housings.

 

▸ Split Housed Bearing Units Option – NMT also offers split housed bearing units that integrate split bearings and housings as a complete assembly, further simplifying installation. These housed bearing units are particularly suitable for bucket elevators, conveyors and other equipment, significantly reducing maintenance costs. Housings are available in steel, gray cast iron or ductile iron to suit different application requirements.

 

3. Full Series Split Bearing Types for Steel & Cement Industries

NMT offers a complete split bearing product system covering multiple steel and cement applications:

 

▸ Steel Industry Split Spherical Roller Bearings

 

Converter trunnion bearings are the most typical split bearing application in the steel industry. NMT split spherical roller bearings are specifically designed for converter trunnions and other heavy impact applications – inner rings, outer rings and cages with rollers are all split in half. Spherical outer ring raceways and barrel-shaped rollers provide self-aligning capability, compensating for shaft deflection during converter tilting. Bearing outer diameters can reach 1850mm and above, with single units weighing over 5 tons. Widely used in converter trunnions, continuous caster segments, rolling mills and other steel equipment. The split structure allows bearing replacement without removing drive gears.

 

▸ Cement Industry Split Spherical Roller Bearings

 

Tube mills, rotary kilns, large motors and other equipment in the cement industry widely use split bearings. NMT split spherical roller bearings are suitable for rotary kiln support rollers, ball mills, roller presses and other heavy impact applications. Self-aligning performance is equivalent to solid spherical roller bearings, effectively compensating for shaft deflection and installation errors. Excellent sealing characteristics ensure reliable operation in the dusty cement plant environment. For high-temperature applications such as rotary kilns, heat-resistant steel and thermal stabilization treatment are available.

 

▸ Split Cylindrical Roller Bearings

 

Split cylindrical roller bearings are mainly used for bearing arrangements in inaccessible locations or on crankshafts. NMT split cylindrical roller bearings use cylindrical rollers to carry high radial loads – inner and outer rings each split in half, with one or two rows of cylindrical rollers in a split cage. Common applications include belt conveyor drive shafts, roller press drive shafts, large ventilation equipment and crankshafts on cold pilger mills. Widely used in steel, cement, mining, power and other industries. Bucket elevators and conveyors are the most frequently problematic equipment types in cement plants – split cylindrical roller bearings can significantly simplify maintenance procedures.

 

▸ Split Tapered Roller Bearings

 

NMT split tapered roller bearings feature two rows of opposed tapered rollers with tapered inner and outer ring raceways, specifically designed for combined loads. They can simultaneously bear radial and bidirectional axial loads, suitable for converter trunnions, rolling mills and other fixed-end bearing positions requiring combined loads. Available in a complete range of specifications, widely used in steel metallurgy, mining and other industries.

 

▸ Split Housed Bearing Units

 

NMT offers split housed bearing units that integrate split bearings and housings as a complete assembly. The core advantage of split housed bearing units is the “split-to-shaft“ design – no drive disassembly required, installation can be completed with jacks supporting the shaft. Housings are available in steel, gray cast iron and ductile iron. Widely used in cement bucket elevators, conveyors, fans and other equipment.

 

4. Specialized Sealing and Lubrication Systems – Adapting to High Dust, High Impact and High Temperature Environments

Steel and cement equipment operates year-round in harsh conditions of high dust, high impact and high-temperature radiation. NMT split bearings for steel and cement industries feature customized sealing and lubrication systems:

 

▸ Heavy-Duty Labyrinth Seal Structure – Non-contact design using centrifugal force from rotation to expel dust, particulates and contaminants. Excellent sealing characteristics ensure reliable operation in dusty cement plants and steel mills. Extensive field experience confirms that sealed split bearings outperform traditional bearings in heavy contamination conditions and severe environments.

 

▸ Contact Seal Upgrade – For high-dust, high-contamination environments (cement plants, slag processing lines), NMT offers contact seal upgrade options. Sealed bearings significantly extend service life through improved contamination resistance.

 

▸ Solid Lubrication and Heavy-Duty Grease Solutions – Conventional grease is easily squeezed out under heavy impact conditions. NMT offers graded lubrication solutions: standard conditions use extreme-pressure heavy-duty grease; high-temperature conditions (rotary kilns, heating furnaces) use high-temperature grease or solid lubrication solutions.

 

5. Installation and Maintenance – An Efficiency Revolution from “Weeks“ to “Hours/Days“

Installation Time Comparison:

 

Traditional heavy-duty solid bearing: Shutdown → disassemble gears, couplings, gearboxes, frames → move shaft → slide bearing on → realign → reassemble → recommission. Typical time: days to weeks.

 

NMT split bearing: Shutdown → open bearing housing → remove old halves → install new halves → tighten bolts → complete. Typical time: just hours to days.

 

NMT split bearings for steel and cement industries can reduce bearing replacement downtime by 80-90%. Taking the 300-ton converter trunnion bearing replacement as an example: the traditional solid bearing solution required weeks of downtime, with total costs reaching 28.2 million yuan (bearing 900,000 + labor/installation 300,000 + downtime loss 27 million). With the split bearing solution, replacement was completed in just 6 days, with total costs reduced to 18.3 million yuan (bearing 1.9 million + labor/installation 200,000 + downtime loss 16.2 million) – saving 9.9 million yuan per replacement. At a US steel plant, three converters converted to SKF split spherical roller bearings achieved total ownership cost savings exceeding $350,000. At a European stainless steel plant, NSK split spherical roller bearings successfully replaced solid bearings for extended service life. At ThyssenKrupp’s steelworks in Italy, FAG split spherical roller bearings (1180mm OD, 900mm bore, 800kg each) were replaced during summer shutdown. Corus Steel Group‘s Scunthorpe plant in the UK saved at least 5 weeks of production time through split bearing solutions.

 

In the cement industry, SKF Cooper split bearings applied to disc feeders saved a cement plant over $1.2 million by avoiding crane use and minimizing downtime. Bucket elevators adopting split housed cylindrical roller bearing units saw significantly reduced maintenance costs. A European cement plant expressed satisfaction after converting its bucket elevator bearings to split housed cylindrical roller bearing unit designs.

 

Maintenance Convenience:

 

No heavy lifting equipment required – Bearings are handled in sections – no large cranes needed.

 

Inspect anytime – Bearing housing can be opened for inspection without disassembly.

 

Split handling – Bearings can be disassembled into smaller components, simplifying lifting and handling.

 

No on-site adjustment – Clearances are preset at the factory – no on-site adjustment or specialized tools required.

 

Improved worker safety – Simplified installation reduces safety risks from complex disassembly work.

 

6. Quality Control – Triple Assurance of Split Precision, Heavy-Duty Strength and Seal Reliability

NMT implements a strict quality control system for steel and cement industry split bearings:

 

Heavy-duty material certification – Each batch of bearing steel undergoes impact load testing and hardness inspection to ensure performance meets heavy-duty requirements.

 

Precision split surface machining – High-precision wire cutting for inner and outer ring split surfaces, ensuring concentricity and strength after assembly.

 

High-strength locking system – High-strength steel clamp rings and multiple bolts ensure split surfaces remain secure during operation.

 

Seal performance verification – Each batch undergoes dust environment seal testing to ensure sealing effectiveness under high-contamination conditions.

 

Post-assembly precision inspection – Each split bearing is inspected for radial clearance, rotational accuracy and vibration after assembly – ensuring performance equivalent to solid bearings.

 

7. Stock Availability + Customization – Rapid Response to Steel & Cement Emergency Needs

Common steel and cement split bearing models (split spherical roller bearings, split cylindrical roller bearings, split tapered roller bearings) kept in stock – Covering over 80% of split bearing needs for converter trunnions, rotary kilns, ball mills, bucket elevators and other applications. Emergency failures receive rapid response – minimizing unplanned downtime.

 

Custom solutions available – Special bore/OD/width (standard range 55mm to 630mm, expandable to 1850mm+), custom heavy-duty materials (carburized bearing steel/heat-resistant steel), special split configurations, custom sealing solutions (heavy-duty labyrinth/contact), custom clearance, split housed bearing units.

 

Rapid customization from samples or drawings – Provide old bearing samples or equipment drawings – NMT completes surveying and custom production quickly. Localization of granulator main shaft split bearings has been achieved, reducing customer procurement costs by 50%. Cost-effective replacement for imported brands (SKF Cooper, FAG, NSK, Timken) with significant procurement savings.

 

8. Lifecycle Cost Optimization – No Gear Removal, No Shaft Removal, Save Millions in Downtime Losses

Unplanned downtime in steel and cement industries often costs tens of millions or even hundreds of millions of yuan. Taking the 300-ton converter trunnion bearing replacement as an example: the traditional solid bearing solution cost 28.2 million yuan, while the split bearing solution cost 18.3 million yuan – saving 9.9 million yuan per replacement. At a US steel plant, three converters converted to split bearings saved over $350,000. At a cement plant, SKF Cooper split bearing application saved over $1.2 million. Localization of granulator main shaft split bearings reduced procurement costs by 50%.

 

Hidden costs of cheap heavy-duty solid bearings:

 

Single replacement requires days to weeks of downtime – downtime losses are hundreds or even thousands of times the bearing price.

 

Disassembly of gears, couplings and surrounding components is time-consuming and may cause secondary damage.

 

Heavy lifting equipment rental costs are enormous.

 

43% of accidents occur during maintenance or inspections – high worker safety risks.

 

Standard heavy-duty bearings have limited life under extreme conditions – frequent replacement compounds the above losses.

 

NMT split bearings for steel and cement industries deliver “no gear removal, no shaft removal, quick bearing replacement without production stoppage“ in converter trunnions, rotary kilns, ball mills and bucket elevators:

 

Downtime reduced by 80-90% – From weeks to days/hours – annual unplanned downtime losses dramatically reduced.

 

No gear or coupling removal – Drive gears and surrounding components stay in place – avoiding secondary damage.

 

No heavy lifting equipment required – Bearings are handled in sections – no large cranes needed.

 

Heavy-duty steel withstands high impact and high temperature – Carburized bearing steel and deep hardening resist impact loads and high temperatures.

 

Superior sealing for high-dust environments – Sealed split bearings outperform traditional bearings in heavy contamination conditions.

 

Extended life of equipment (gears, gearboxes, shafts) – Fewer disassembly cycles – longer overall equipment overhaul intervals.

 

For steel plants, cement plants, mining companies and mineral processing facilities, the total cost of ownership with NMT split bearings for steel and cement industries is significantly lower than the repeated disassembly and replacement costs of traditional heavy-duty solid bearings – what you save is not bearing price difference, but the enormous operational risk of “replacing one bearing, shutting down an entire production line“ in heavy-duty equipment.