NMT Ltd.
Corporate Communications Department
NMT Split Bearings for Mining – No-Shaft-Removal Quick Replacement Solutions for Conveyors, Hoists, Crushers & Ball Mills
1. Core Pain Points of Mining Bearing Replacement
Mining equipment bearings are located in inaccessible or trapped positions. Conveyor head pulley bearings are wedged between the pulley and gearbox; bucket elevator bearings are in enclosed heads; mine hoist bearings are at the top of headframes surrounded by equipment. Traditional solid bearing replacement requires disassembly of shafts, couplings, motors, gearboxes and surrounding components – taking days or weeks, with downtime losses reaching millions.
A Colorado mine with a 16km conveyor through snowy mountains needed 9 days for traditional replacement, exceeding the 6-day stockpile buffer. Pilbara Iron needed 72 hours for bucket wheel excavator bearing replacement, losing 1,110 euros per hour. 43% of accidents in mining and cement occur during maintenance or inspections.
2. NMT Split Bearings: No-Shaft-Removal Quick Replacement
NMT split bearings feature inner rings, outer rings, rolling elements and cages all split along the axial direction – installation requires no removal of shafts, gears, couplings or any core components – assembly is completed directly on the shaft in situ.
Core value: No motor removal, no coupling removal, no shaft movement, no heavy lifting equipment. At a BHP Billiton Australian mine, a 23180K solid bearing was replaced with a split bearing during scheduled downtime – with no additional equipment downtime. No gearbox removal, no realignment, no hydraulic nuts required.
Structural advantages: Full split construction with “saw tooth“ outer ring interface for precise axial alignment – wire cutting ensures precise geometric alignment of the two halves. Split spherical roller bearings offer higher load capacity and better adaptability to confined and hard-to-reach positions.
Dimensional interchangeability: Outer diameter and width identical to standard spherical roller bearings (222, 230, 231, 239, 240, 241 series) – no bearing housing modifications required.
3. Product Series
Split Spherical Roller Bearings: Most widely used type in mining – for hoists, conveyor pulleys, crushers, ball mills. Self-aligning compensates for shaft deflection and installation errors. Sealed versions perform reliably in dusty environments.
Split Cylindrical Roller Bearings: For inaccessible locations – conveyor drive rollers, bucket elevator head and tail pulleys, crusher drive shafts.
Split Tapered Roller Bearings: Handle radial and bidirectional axial loads – for hoists, crushers and other fixed-end positions.
Split Housed Bearing Units: Radial installation and removal – no need to disconnect motors, gearboxes or couplings.
4. Specialized Sealing and Lubrication
Three-barrier sealing: first barrier – the seal itself; second – V-ring; third – grease surrounding the bearing. Sealed split bearings operate from -40°C to 90°C, reduce grease consumption and significantly extend service life.
5. Installation Efficiency Comparison
Traditional solid bearing: Shutdown → disassemble couplings, motors, gearboxes → move shaft → slide bearing on → realign → reassemble → recommission. Time: days to weeks.
NMT split bearing: Shutdown → open housing → remove old halves → install new halves → tighten bolts → complete. Time: hours to days.
SKF Cooper split bearings reduce MTTR by 70% – from 24 hours to 8 hours. Schaeffler split bearings reduce maintenance time by 67%.
6. Quality Control
Heavy-duty material certification
High-precision wire-cut split surfaces
High-strength steel clamp rings
Dust environment seal testing
Post-assembly precision inspection
7. Stock Availability & Customization
Common split spherical, cylindrical and tapered roller bearings kept in stock – covering over 80% of mining needs. Extra-large bearing lead times are 12-18 months – pre-stocking split bearing spares dramatically shortens emergency downtime.
Custom solutions: special dimensions, materials, sealing, clearance, housed units.
8. Cost Optimization
Colorado mine: 9-day downtime → 4 days. Pilbara Iron: 36 hours saved → 40,000 euros. BHP Billiton: replacement completed with no additional downtime. Single maintenance cost reduced by 67%.
NMT split bearings deliver no motor removal, no shaft removal, quick replacement without production stoppage:
Downtime reduced by over 80%
No motor or coupling removal
No heavy lifting equipment
Heavy-duty steel withstands extreme mining conditions
Superior sealing for high-dust environments
Improved worker safety – 43% accident risk reduced
Extended equipment life
For mining operations, NMT split bearings deliver significantly lower total cost of ownership – what you save is not bearing price difference, but the enormous operational risk of shutting down an entire production line.