Core port and marine equipment including container quay cranes, portal cranes, rubber tyred gantry cranes, ship winches, deck cranes and bulk cargo loaders are deployed along coastal terminals and on ocean-going ship decks. They operate under harsh conditions: intermittent sudden impact loads, continuous erosion by marine salt mist, scouring by rain and sea spray, high atmospheric humidity, seasonal and diurnal temperature fluctuation, frequent start-stop variable loads and all-weather outdoor operation. Port handling schedules are tight. Equipment shutdown directly leads to container congestion and ship berthing delays, resulting in heavy demurrage charges and logistics losses. Ordinary cylindrical roller bearings cannot withstand severe coastal salt mist environments, becoming a widespread operational pain point for terminals. Sudden impact loads occur when containers are lifted and landed. Ordinary bearings lack sufficient toughness and tend to develop raceway indentation and fatigue peeling after repeated impacts, causing jitter of travelling mechanisms and offset spreader positioning. Offshore air contains chloride salt mist, which easily penetrates simple seals, corrodes raceways and rolling elements and triggers pitting and rust. In rainy and windy weather, continuous rain and sea spray splash into bearings, causing grease emulsification and failure due to water absorption. Large temperature swings at sea create repeated condensation inside bearings and accelerate corrosion. Dust and sand carried by sea wind enter seal gaps and form abrasive impurities that accelerate wear. Maintenance of large port equipment is difficult and time-consuming. Frequent bearing replacement greatly raises operation costs and operational interruption losses.

Focusing on transmission supporting field for port and marine equipment, Japan NMT specially develops heavy-duty salt-mist moisture-proof anti-rust long-life cylindrical roller bearings dedicated for marine and port machinery to solve industry pain points of ordinary port bearings such as insufficient impact resistance, vulnerability to salt mist erosion, inadequate waterproof sealing, rapid rusting in humid environments and short service life outdoors. Through five core upgrades including high-corrosion-resistance high-toughness forged alloy steel matrix, multi-layer labyrinth salt-mist-proof waterproof composite sealing, full-range anti-salt-mist passivation anti-corrosion technology, wide-temperature hydrolysis-resistant long-life lubrication and alternating impact load stress equalization optimization, it fully adapts to outdoor high-salt and high-humidity variable-load working conditions of coastal terminals and ocean-going vessels. It fundamentally solves problems including bearing impact wear, salt mist rust, rainwater ingress and lubrication failure, ensuring all-weather stable operation of port handling and ship deck equipment.

Core Product Advantages

1. High-corrosion-resistance high-toughness forged alloy steel matrix withstands intermittent impact heavy loads: Adopting refined corrosion-resistant forged bearing steel specially for port and marine equipment with multiple quenching & tempering stabilization heat treatments to balance high toughness and resistance against chloride corrosion. It stably bears instantaneous impact and alternating loads during container handling and effectively restrains raceway plastic deformation and fatigue peeling.

2. Multi-layer labyrinth salt-mist-proof waterproof composite sealing blocks ingress of salt mist and rainwater: Equipped with exclusive multi-layer labyrinth and seawater-resistant wear lip sealing system for marine and port conditions. It intercepts salt-laden mist, rainwater, sea spray and sand debris layer by layer, prevents grease emulsification by water absorption and greatly lowers risks of internal pitting induced by chloride ions.

3. Full-range anti-salt-mist passivation anti-corrosion technology resists marine chloride erosion: Special salt-mist-resistant passivation protection is applied to bearing inner rings, outer rings and rolling elements to seal micro-pores on metal surfaces, block adhesion and penetration of chloride ions, significantly improve rust resistance in coastal high-salt environments and delay corrosive wear.

4. Wide-temperature hydrolysis-resistant long-life lubrication system adapts to marine temperature variation: Custom lubrication formula developed for marine high-humidity salt mist conditions features excellent hydrolysis resistance and anti-salt-pollution performance. It hardly leaks at high temperature or solidifies at low temperature, maintains stable protective oil film for a long time and extends lubrication maintenance intervals for offshore equipment.

5. Alternating impact load optimized structure evenly disperses vibration stress: Optimizing roller arrangement and internal clearance parameters to improve load distribution, relieve local stress concentration caused by frequent start-stop and sudden load application, reduce precision loss from long-term cyclic operation and guarantee stable running of travelling mechanisms and hoisting drums.

Application Scenarios

Container quay cranes, portal cranes, rubber tyred gantry cranes, bulk ship loaders, belt conveyors, ship winches, deck cranes, floating cranes, various travelling mechanisms and drum supporting transmission parts of port terminals.

Precision Quality Assurance

NMT heavy-duty cylindrical roller bearings for marine and port machinery are manufactured strictly in accordance with Japanese marine heavy equipment manufacturing standards. Selected special bearing steel with salt mist resistance, impact resistance, waterproof and anti-rust performance undergoes ultimate impact durability test, long-term neutral salt spray corrosion test, rain spray sealing test, high-low temperature cycle aging test and continuous variable load fatigue test. The products feature powerful load capacity, reliable salt-mist-proof and waterproof sealing and outstanding marine corrosion resistance, fully adapting to all-weather continuous handling conditions with heavy salt mist and high humidity at coastal ports and on ocean-going vessels.

Product Range

Heavy-duty cylindrical roller bearings for travelling mechanisms of quay cranes and portal cranes, salt-mist resistant long-life bearings for rubber tyred gantry cranes, waterproof anti-rust bearings for ship deck winches, dust-proof wear-resistant bearings for bulk cargo handling equipment, impact-resistant heavy-duty bearings for floating cranes, customized non-standard ultra-heavy-load bearings for port and marine equipment.

Brand Strength

Japan NMT focuses on R&D and manufacturing of bearings for heavy port handling, ocean-going marine machinery, marine salt mist corrosion and outdoor variable impact loads, specializing in performance optimization under scenarios of chloride corrosion, high-humidity condensation, frequent start-stop and abrasive wear by sea-borne impurities. With Japanese corrosion-resistant steel heat treatment technology, exclusive salt-mist-proof waterproof sealing technology for port and marine equipment and strict marine working condition simulation testing system, it accurately solves industry problems of port bearings such as salt mist rust, rainwater ingress, abrasive wear failure and frequent maintenance replacement, supplying high-load, salt-mist resistant and all-weather long-life core transmission components for global container terminals, bulk cargo ports and ocean shipping marine equipment industries.