Jaw crushers, cone crushers, vibrating screens, heavy hammer crushers and ball mills are core production equipment in sand and stone mines. Main shafts, eccentric shafts and transmission supporting parts operate under harsh working conditions: ultra-large alternating combined crushing loads, violent instantaneous impact generated by ore collision, pervasive massive rock dust, flying gravel and slag, large temperature difference between day and night in open-pit mining areas and uninterrupted 24-hour crushing operation. Sand and stone crushing production lines require extremely high continuity. Once bearing failure causes shutdown, accumulated ore inside crushing chambers cannot be cleared, the whole production line stops, and ore mining and aggregate processing are suspended, leading to massive production losses. Ordinary tapered roller bearings cannot adapt to dusty and high-impact harsh environments in mining areas, becoming a common pain point for sand and stone mines. Violent impact loads occur the moment ore is squeezed and crushed. Eccentric shafts continuously bear radial loads and axial thrust to form bidirectional composite stress. Ordinary bearings have insufficient fatigue resistance and tend to form raceway indentation and roller surface peeling under long-term cyclic loads, aggravating main shaft runout and causing uncontrolled crushed product particle size. Ultra-fine rock dust and gravel particles are continuously generated during crushing. Simple seals cannot block hard dust from penetrating into bearing housings. Rock dust mixes with grease and forms powerful abrasive medium that continuously wears raceways and rolling elements. Mining areas are dry and dusty; rainwater will form mud that easily seeps into bearings and triggers rust. Continuous impact of gravel scours seal lips, resulting in seal tearing and grease leakage. Lack of lubrication makes bearings heat up rapidly and seize up. Crushing equipment is bulky with complicated disassembly, inspection and maintenance procedures. Hoisting and bearing replacement consume a great deal of time, and frequent maintenance continuously increases mine operation costs.

Focusing on transmission supporting field for mining crushing equipment, Japan NMT specially develops heavy-duty dust-proof tapered roller bearings dedicated for crushing machinery to solve industry pain points of ordinary crusher bearings such as insufficient impact resistance, easy ingress of rock dust and gravel, susceptibility to fatigue spalling under alternating crushing loads, vulnerable seals prone to grease leakage and short service life under long-term continuous crushing conditions. Taking advantage of bidirectional linear load-bearing structure of tapered rollers, combined with five core upgrades including high-toughness wear-resistant special bearing steel, multi-layer labyrinth dust & gravel-proof composite sealing, deep-hardening super-finishing technology for raceways, dust-resistant long-life lubrication and precise clearance matching for crushing loads, it fully adapts to harsh working conditions of ultra-large impact loads, rock dust and flying gravel for all types of crushing equipment. It fundamentally solves problems including bearing impact spalling, abrasive wear by rock dust, seal leakage and overheating seizure, stabilizes rotation precision of main shafts and guarantees long-cycle continuous operation of sand and stone crushing production lines.

Core Product Advantages

1. Bidirectional ultra-large combined load bearing withstands ore crushing impact and axial thrust: Adopting tapered roller linear contact structure, it bears high-strength radial loads and persistent axial thrust simultaneously with uniform load distribution in contact zones. It effectively buffers instantaneous impact during ore squeezing and crushing, improves stress condition under eccentric load of eccentric shafts, restrains excessive unilateral raceway wear and stably controls axial play of main shafts.

2. High-toughness wear-resistant bearing steel matrix resists impact and fatigue spalling: Selecting high-purity bearing alloy steel specially for mining crushing equipment with deep quenching & tempering heat treatments to optimize metallographic structure and balance matrix toughness and surface hardness. It withstands long-term alternating impact loads during crushing and effectively lowers risks of raceway indentation and roller fatigue spalling.

3. Multi-layer labyrinth dust & gravel-proof composite sealing blocks ingress of hard rock dust particles: Equipped with exclusive thickened impact-resistant wear lip & multi-labyrinth sealing structure for mining conditions. It resists continuous impact and scouring by gravel and is not easy to tear or age. It intercepts ultra-fine rock dust and gravel slag layer by layer, prevents abrasive wear induced by hard dust entering bearing cavities and reduces outward leakage and loss of lubricating grease.

4. Deep-hardening super-finishing grinding technology for raceways reduces temperature rise and suppresses vibration: Deep hardening treatment plus micron-level super-finishing grinding is applied on contact surfaces of raceways and rollers to optimize contact profile and improve oil film formation conditions, lower frictional heat generation, slow precision attenuation under long-term impact loads, maintain stable operation of crusher main shafts and stabilize quality of crushed output materials.

5. Customized clearance matching for dusty conditions & anti-pollution long-life lubrication system: Internal clearance is precisely matched according to operation characteristics of crusher eccentric shafts to avoid seizure under low temperature and seizure caused by thermal expansion under continuous heavy loads. Matched with long-life lubrication formula resistant to dust pollution, it resists grease deterioration caused by rock dust ingress and extends lubrication maintenance intervals on mining sites.

Application Scenarios

Eccentric shaft bearings for jaw crushers, main shaft support bearings for cone crushers, transmission bearings for heavy hammer crushers, support bearings for vibrating screens, bearings for impact crushers, heavy-duty transmission supporting positions of ball mills and all kinds of crushing & screening equipment on sand and stone production lines.

Precision Quality Assurance

NMT tapered roller bearings for mining crushers are manufactured strictly in accordance with Japanese heavy mining equipment manufacturing standards. Selected special bearing steel with high toughness, impact resistance, dust and wear resistance undergoes ultra-large impact durability test, rock dust sealing test, high-low temperature cycle aging test, continuous heavy-load temperature rise test and alternating load fatigue test. The products feature outstanding bidirectional load capacity, excellent impact resistance and reliable dust & gravel-proof sealing performance, fully adapting to all-weather continuous crushing conditions with heavy dust and strong impact in open-pit mines.

Product Range

Heavy-duty tapered roller bearings for jaw crusher eccentric shafts, long-life main shaft bearings for cone crushers, dust-proof wear-resistant bearings for vibrating screens, impact-resistant bearings for impact crushers, customized large-size non-standard tapered roller bearings for large crushing equipment.

Brand Strength

Japan NMT focuses on R&D and manufacturing of bearings for heavy mining crushing and screening equipment under working conditions of ultra-large combined crushing loads, instantaneous ore impact, erosion by rock dust and gravel and open-air temperature variation, specializing in technical optimization of bidirectional load balance, impact fatigue wear prevention, dust sealing protection and high-temperature temperature rise control. With Japanese high-toughness steel heat treatment technology, exclusive dust & gravel-proof sealing technology for mining crushing equipment and strict mining condition simulation testing system, it accurately solves industry pain points of crusher bearings such as impact spalling, abrasive wear failure by rock dust, seal damage and grease leakage, overheating seizure and frequent shutdown replacement, supplying high-load, impact-resistant, dust-proof and long-life core transmission bearing components for global sand aggregate and metal mining crushing equipment manufacturers.