1 Structure and Operating Characteristics of NMT Outer Spherical Bearings

Outer spherical bearings are modular support units integrating bearing cores and bearing housings, mainly consisting of outer spherical ball bearing cores, cast iron or cast steel bearing housings, seals, end covers and fasteners. The outer ring outer diameter adopts a spherical surface, which fits with the inner spherical surface of the bearing housing, enabling self-aligning within a certain range and compensating for coaxial deviation between the shaft and the bearing housing.

Japan NMT outer spherical bearings include pillow block bearings, plummer block bearings, flange bearing housings, take-up bearing housings and adjustable bearing housings. Manufactured from high-purity bearing steel cores and high-strength cast iron housings through precision machining, heat treatment, surface painting and sealing optimization, they feature stable load capacity, flexible alignment, convenient disassembly and assembly and reliable protection. They are commonly used in agricultural machinery, conveyor equipment, fans, conveyors, elevators and outdoor industrial equipment, serving as heavy-duty support units frequently used in on-site installation and maintenance scenarios.

2 Core Performance Advantages

Strong self-aligning capability: The outer spherical structure can compensate for shaft deviation, base deformation and installation misalignment, reducing assembly accuracy requirements.

High radial load capacity: The combination of deep groove ball bearing structure and reinforced bearing housing can withstand large radial loads and impact loads.

Convenient installation and maintenance: The integrated design of bearing core and bearing housing simplifies on-site disassembly and assembly, shortening replacement time.

Complete sealing protection: Multiple sealing structures block dust, mud, moisture and oil contamination ingress, suitable for outdoor and harsh working conditions.

Long maintenance-free cycle: Built-in grease and reliable sealing design extend the grease replenishment cycle and reduce daily maintenance frequency.

Stable and durable structure: High-strength cast iron housing with painted surface provides good rigidity and rust resistance, suitable for continuously operated equipment.

3 Main Application Scenarios

3.1 Agricultural Machinery

Harvesters, seeders, threshers, feed processing equipment, tractor attachments and agricultural conveyor machinery.

3.2 Conveyor Equipment

Belt conveyors, screw conveyors, bucket elevators, scraper conveyors and conveyor line support positions.

3.3 Fans and Industrial Fans

Centrifugal fans, induced draft fans, blowers, industrial fans and fan transmission support positions.

3.4 Mining and Building Material Equipment

Crushers, ball mills, dryers, cement equipment and mining conveyor support units.

3.5 Light Industry and Food Equipment

Food conveyors, packaging machinery, drying equipment and light industrial conveyor systems.

3.6 General Industrial Equipment

Pumps, reducers, lifting mechanisms, tilting mechanisms and transmission support positions requiring quick disassembly and assembly.

4 Selection Direction and Assembly Key Points

4.1 Selection Direction

Select according to installation method: Prioritize pillow block bearings for vertical installation; prioritize plummer block bearings for horizontal fixing; prioritize take-up or adjustable bearing housings when axial adjustment is required.

Select according to load type: Prioritize reinforced bearing housings and large clearance models when radial heavy loads and impact loads are large.

Select according to working environment: Prioritize models with seals, dustproof and end cover structures in environments with high dust, mud, moisture and oil contamination.

Select according to maintenance requirements: Prioritize maintenance-free, long lubrication cycle and easy-to-disassemble structures for equipment with inconvenient on-site maintenance or continuous operation.

4.2 Assembly Key Points

Before installation, clean shaft journals, bearing housings, bases, bolts, shims and mating surfaces, removing dust, mud, chips, rust and oil contamination.

Confirm shaft diameter, bearing housing center height, mounting hole distance and coaxiality, avoiding forced installation causing skewed bearing stress.

Control bolt tightening torque during assembly, ensuring stable fitting of the bearing housing base and avoiding single-point force and base suspension.

After installation, check shaft rotation flexibility, alignment condition, seal position and fastener status, confirming no jamming, abnormal noise or looseness.

For outdoor agricultural machinery and conveyor equipment, confirm complete sealing structure after installation to prevent mud and rainwater from entering the bearing interior.

5 Lubrication Management and Operation Maintenance

5.1 Lubrication Recommendations

Lithium grease, extreme pressure lithium grease or special bearing grease can be used for outer spherical bearings. The specific filling quantity should be determined according to load, speed, ambient temperature and sealing structure.

Check lubricating medium condition regularly and replenish or replace promptly when grease drying, contamination, emulsification or loss is observed.

Keep sealing structures clean, avoiding mud, dust and impurity accumulation that causes seal failure.

Do not mix different types of lubricating materials, and clean old grease residues before replenishing lubrication.

5.2 Operation Monitoring

During daily operation, pay attention to bearing sound, rotation flexibility, temperature variation, sealing condition and fastener status.

Persistent abnormal noise, excessive temperature rise, jamming, increased vibration or grease leakage in equipment is usually related to insufficient lubrication, seal failure, contaminant ingress, installation misalignment or loose bearing housing.

Agricultural machinery focuses on sealing performance under muddy environments; conveyor equipment focuses on continuous operation and impact load; fans focus on temperature rise and vibration stability.

Regularly inspect seals, dustproof structures, fasteners, bearing housings and shaft journals, and promptly handle when aging, leakage, looseness or abnormal wear is observed.