I. The "Joint Revolution" in the Era of Robots

Industrial robots are penetrating every corner of the manufacturing industry at an unprecedented speed. In 2025, the global market size of robot bearings will reach 8.74 billion US dollars, an increase of 18.6% compared to 2024. Among them, the market size in China will be 3.21 billion US dollars, accounting for 36.7%. It is expected that by 2030, the total market size of robot bearings worldwide will exceed 18 billion US dollars.

 

In the field of industrial robots, the global market size of industrial robot bearings in 2025 is approximately 1.557 billion US dollars. Among them, the sales volume of industrial robot thin-walled bearings reached 542 million US dollars, and it is expected to reach 753 million US dollars in 2032. In 2026, the industrial robot field became a high-growth sub-sector in the bearing industry, with an annual market size expected to reach 2.86 billion yuan, a year-on-year growth of 31.5%. The demand for harmonic drive bearing components and RV drive bearing components accounted for over 70% of the total.

 

Industrial robot bearings are metaphorically referred to as the "joints" of robots, and they are key components that affect the motion accuracy, load capacity, and reliability of the entire machine. The reducer is the core component of industrial robots, and the bearing is the key part of the reducer. Equal-section thin-walled bearings and cross cylindrical roller bearings are the two main types used in industrial robot applications.

 

NMT has been deeply engaged in the bearing field for nearly a hundred years. Through fourfold breakthroughs in material purification, process refinement, scenario customization, and intelligent upgrading, it provides high rigidity, high precision, and long-life precision bearing solutions for industrial robot joints and reducers.

 

II. Equal-section Thin-Walled Bearings: Making Robot Joints More Compact

Today, as the design of robot joints moves from "able to rotate" to "precise rotation", the selection of bearings has gone beyond the simple supporting function and has become the underlying variable that defines the performance of the entire machine.

 

NMT's equal-section thin-walled bearings are breakthrough products specifically designed for robot joints. Their unique feature is that the cross-sectional size does not change with the increase in installation diameter. Designers can make the joint thinner, lighter, and larger with a hollow structure without sacrificing rigidity. For robots with extreme space requirements such as collaborative robots, SCARA robots, and parallel robots, this is not only convenient for cable routing but also the structural foundation for achieving a compact layout.

 

In NMT's manufacturing logic, there is a clear belief: precision is not measured but grows through process control. The ring of equal-section thin-walled bearings is prone to releasing residual stress and twisting after grinding. NMT achieves precise connection through phased stabilization treatment and ultra-precision grinding, ensuring the true roundness and roughness of the raceway at demanding levels. The raceway adopts nanoscale ultra-precision grinding technology, with surface roughness controlled within 0.01 μm, and rotational accuracy reaching the ISO P2 standard.

 

The equal-section structure naturally avoids the shock and vibration caused by sudden changes in raceway rigidity. Combined with NMT's strict selection of rolling body dimensions and precise calculation of lubricant dosage, the bearing can maintain low noise and low vibration even after restarting after high-speed rotation or long-term static operation. The operating noise is controlled within 20 dB. From AGV steering wheels to exoskeleton robot hip joints, from the lifting axis of SCARA to the active arm of parallel robots, NMT's equal-section thin-walled bearings are compatible with various forms of robots.

 

III. Cross Roller Bearings: Bearing Multiple Forces with a Single Set

Precision cross roller bearings are one of the core components of industrial robot reducers. Harmonic drive bearings include flexible bearings and cross roller bearings, where the flexible bearing is the core component of the harmonic drive, and the lifespan of the harmonic drive mainly depends on the lifespan of the flexible bearing. RV drive bearings include various types such as thin-walled angular contact ball bearings used as the main bearing of the reducer.

 

 

NMT precision ball bearings adopt a cylindrical roller orthogonal dense arrangement structure - the rollers are vertically and perpendicularly interlaced at 90° between the inner and outer rings. This structure expands the contact mode from points to lines, allowing the stress to be uniformly dispersed on the raceway surface like flowing water. A set of bearings can simultaneously bear radial loads, axial loads, and overturning moments. The robot wrist or transfer machine no longer needs to stack multiple sets of bearings to distribute the forces.

 

NMT cross roller bearings strictly control the convexity curve of the rollers and the surface integrity of the raceways, effectively smoothing the stress peaks in the rolling contact area. Even after millions of alternating loads, the rotational accuracy of the bearings remains stable as before. For high-precision reducer bearings, the precision grade needs to reach the ultra-high precision standard of P4 to P2. NMT cross roller bearings precisely meet such precision standards and serve as the core transmission requirements for harmonic reducers and RV reducers.

 

IV. Materials and Precision: NMT's Technical Barriers

Industrial robot bearings face four technical barriers: extremely high precision requirements (requiring P4 to P2 ultra-high precision standards), thin-walled structures are prone to deformation during processing and heat treatment, and they need to cope with high-frequency alternating loads. NMT's technical system is built around these challenges.

 

NMT uses vacuum degassing high-carbon chromium bearing steel, through precise forging and secondary quenching processes, reducing the content of non-metallic inclusions in the material to an extremely low level, increasing the fatigue limit by 38% compared to ordinary products. After "Ottabain" special heat treatment, the surface hardness of the bearings reaches HRC62-64, improving the wear resistance by 40%, while the core toughness ensures that it does not fracture under high-frequency impact loads. This "outer hard and inner flexible" characteristic enables the bearings to stably withstand alternating loads in the frequent forward and reverse rotations and high overturning moments of robot joints, with the rated lifespan exceeding the industry standard by more than twice.

 

The cage is optimized through dynamic characteristic simulation and combined with self-lubricating steel balls, reducing the friction coefficient to 0.0015. NMT offers a full range of sealing solutions for different application environments: the IP54 basic dustproof model is suitable for ordinary workshops, the IP68 high-pressure waterproof model can cope with high humidity environments, and the fluorine rubber seal can resist weak acid and weak alkali erosion. The long-term low-volatile lubricating grease has a volatility of ≤0.003mg/g, achieving a maintenance cycle of up to 30,000 hours in a wide temperature range of -45°C to 155°C.

 

V. Intelligent Upgrade: From Mechanical Components to Data Nodes

In the context of Industry 4.0, NMT upgrades precision bearings to "mechanical-electrical integration" units. Specialized robot bearings are equipped with micro lubricant sensors to monitor the lubrication film status in real time, achieving precise lubrication on demand. The "Zero Drift Bearing System" uses thermal-thermal coupling adaptive technology to ensure that the joint temperature rise of the robot's rotating joint is only 8.2°C for 24 hours of continuous operation, and the positioning accuracy degradation is controlled within ±0.003mm. This leap from "mechanical components" to "intelligent nodes" provides data support for predictive maintenance.

 

VI. Value Summary

Industrial robots are redefining the production methods of manufacturing, and bearings are redefining the performance boundaries of robots. From uniform cross-section thin-walled bearings to cross roller bearings, from harmonic reducers to RV reducers, NMT integrates material purification, precise manufacturing, and scenario adaptation with nearly a century of technical accumulation, providing high rigidity, high precision, and long-life precision transmission solutions for robot joints and reducers.

 

Mainstream specifications are in stock ready, supporting non-standard customization, and the professional technical team provides selection and technical support. NMT makes every rotation more precise, quieter, and more durable - whether in the waist joint of a six-axis robot or the lifting axis of a SCARA robot; whether in the flex wheel of a harmonic reducer or the main bearing of a RV reducer.