1. Common Faults Caused by Shaft Misalignment of Heavy-Duty Transmission

After long-term heavy-load operation of large conveying equipment, heavy-duty reducers and stereoscopic warehouse traveling vehicles, the steel structure frame will produce elastic deformation. The long-span transmission shaft bends under its own weight and material load. Coupled with assembly errors during equipment installation, the bearings at both ends of the transmission shaft are prone to axis misalignment. Ordinary roller bearings have no self-aligning ability. After axis offset, the bearing rollers bear pressure on one side, and the local contact stress rises sharply, resulting in raceway point peeling and roller fragmentation in a short time. Bearing failure directly causes major equipment accidents such as conveyor belt tearing, reducer gear tooth breakage and stereoscopic warehouse vehicle derailment.

Ordinary bearings have weak sealing in dusty environments. Dust enters the bearing to form abrasive wear and further accelerate bearing loss. Under the high-temperature working condition of the reducer, the cage is deformed and broken by heat, and the rollers scatter to seize the whole machine. The unplanned shutdown maintenance cost of the factory is extremely high. The hoisting and maintenance period of large equipment is long, which directly interrupts the operation of the entire production line.

2. Core Product Advantages of NMT Spherical Roller Bearings

(1) Spherical self-aligning structure adapts to axis offset

The inner and outer ring raceways are spherical, and the double-row spherical rollers can deflect adaptively inside the bearing. It can compensate for the coaxial deviation of the axis up to 1.5°, offset caused by transmission shaft bending, frame deformation and installation errors are completely offset. The rollers are evenly attached to the raceways all the time to avoid unilateral eccentric wear, which is the core rigid demand structure for long-shaft heavy-load equipment.

(2) High toughness bearing steel for heavy load and impact resistance

Adopt vacuum degassing refined bearing steel with extremely low content of internal non-metallic inclusions. After deep carburizing and quenching treatment, the surface has high hardness and wear resistance, and the core has high toughness and impact resistance. No overall cracking occurs under heavy-load start-stop and material impact load, suitable for alternating load conditions such as conveyor belt blanking impact and vehicle starting impact.

(3) Flexible selection of two versions of cages

Solid brass cage: high temperature resistance, dust resistance and deformation resistance, suitable for high-temperature closed cavities of reducers and fans, not easy to break and deform during long-term high-temperature operation;

Stamped steel cage: light weight and high cost performance, suitable for open-air conveyor belts and normal temperature heavy-load traveling mechanisms with lower batch installation cost.

(4) Optional reinforced sealing structure to isolate dust impurities

Customizable double-sided skeleton oil seal structure to block coal powder, sand and dust from entering the bearing cavity, reduce abrasive wear and extend the service life of bearings under dusty working conditions. The open structure is convenient for grease filling maintenance and adapts to regular oil filling maintenance schemes for large equipment.

3. Main Application Scenarios

Intelligent warehousing: heavy-duty traveling trolley bearings of stereoscopic warehouse, elevator spindle bearings, stacker reducer bearings

Logistics transportation: main drum bearings of long-distance belt conveyor, support bearings of turning conveyor, spindle of heavy-duty chain conveyor

Industrial power: output end bearings of large gear reducer, industrial induced draft fan spindle, centrifugal fan support bearing

Light industry heavy load: large paper rewinder spindle, textile chemical fiber curling heavy-duty spindle, rubber mixing equipment support bearing

4. Professional Clearance Selection Suggestions

Normal temperature conventional heavy-load working condition: standard radial clearance, universally applicable to most transmission equipment;

High-temperature reducer and fan working condition: C3 increased clearance to compensate for thermal expansion of high-temperature bearings and avoid operating seizure;

Low-temperature outdoor winter equipment: C4 extra-large clearance to adapt to gap reduction caused by low-temperature shrinkage.

5. Comprehensive Benefit Analysis

The service life of domestic ordinary spherical roller bearings under heavy-duty conveying conditions is 3–5 months. Frequent replacement requires hoisting large parts with a maintenance period of 1–3 days. The service life of imported low-cost spherical roller bearings is 6–8 months with rapid accuracy attenuation. Japan NMT spherical roller bearings can work stably for 12–18 months, greatly reducing the frequency of hoisting maintenance of large equipment and avoiding sudden shutdown of production lines. For continuously operated logistics, warehousing and power equipment, the stable production capacity benefit far exceeds the bearing purchase price difference.

6. Delivery and Customization Service

Two major domestic storage bases are deployed with spot goods for large-size heavy-duty bearings. Special vehicle delivery for large cargo logistics reduces logistics loss of ultra-long and overweight goods. Support internal bearing clearance adjustment, dust-proof sealing transformation and surface phosphating anti-rust treatment. Provide technical schemes for working condition adaptation to cooperate with equipment manufacturers to complete complete machine bearing selection and supporting.