1. Industry Working Condition Pain Points

In the design of high-end equipment such as industrial robots, collaborative robots, medical manipulators and semiconductor equipment, engineers have long been plagued by a persistent problem: as joint bore diameters increase, the width and thickness of traditional bearings increase proportionally. To gain larger hollow spaces for cables, air tubes and sensors to pass through, designers must accept the simultaneous expansion of bearing volume, leading to increased overall machine weight, bulky joints, and rising motion inertia.

 

More critically, from the wrist to the base of a robot, the bore diameter span can range from tens of millimetres to hundreds of millimetres. If each joint adopts proportionally enlarged traditional bearings, the overall volume and weight of the machine will surge dramatically, directly compressing payload capacity. In applications such as collaborative robots, humanoid robots and exoskeleton devices that are extremely sensitive to self-weight, the contradiction of "sacrificing lightweight for large hollow space" is particularly acute.

 

Domestic thin-section bearings commonly suffer from insufficient thin-ring deformation control, difficulty balancing raceway roundness and roughness, and poor rolling element consistency, leading to fluctuating running resistance, short precision retention time, and uncontrollable noise levels. Imported thin-section bearings offer excellent performance but have long procurement cycles and high prices, making them unaffordable for small and medium manufacturers. During equipment precision advancement, excessive bearing volume leads to bulky machines and sluggish dynamic response; insufficient space restricts cable routing and limits protection rating improvement.

 

For applications requiring lightweight, compactness, large hollow space and high precision, specialised equal-section thin-section bearings with constant cross-section design, thin-wall high rigidity, predictable accuracy and multi-joint adaptability are urgently needed.

 

2. Product Core Positioning

NMT equal-section thin-section bearings adopt a constant cross-section design philosophy—the cross-section dimensions of the bearing do not change as the bore diameter increases. Whether applied to the slender joints of a robot wrist or the large slewing supports of a base, the radial thickness remains consistent. This consistency across the entire series frees robot designers from spatial constraints, allowing cables, sensors and drive components to be optimally positioned, resulting in a more compact and orderly overall machine structure.

 

Thin-section structures are inherently sensitive to deformation. Through appropriate material selection and carbonitriding heat treatment processes, NMT maintains sufficient rigidity reserve in rings while keeping cross-sections slender. The equal-section structure naturally avoids impact and vibration from sudden changes in raceway rigidity. Combined with NMT's strict screening of rolling element dimensional consistency and precise calculation of lubricant quantity, bearings maintain low-noise, low-jitter operation even at high speeds or after long静止 followed by restart. Precision grades up to P4 and P2 are available, meeting diverse requirements from general precision equipment to high-end applications.

 

3. Structural Classification & Functional Advantages

(1) Thin-Section Deep Groove Ball Bearing Series

 

Classic general-purpose structure, suitable for applications primarily requiring radial load capacity, with smooth operation, low friction and simple structure. Suitable for automation equipment, general manipulators, stepper motors, rotary encoders and more.

 

(2) Thin-Section Angular Contact Ball Bearing Series

 

High-precision combined load capacity, capable of simultaneously handling radial and axial combined loads, with 15°/25° contact angles available. Suitable for precision turntables, optical instruments, medical imaging equipment and other applications with high precision requirements.

 

(3) Thin-Section Four-Point Contact Ball Bearing Series

 

A single bearing carries radial, axial, tilting moment and other multi-directional combined loads, with compact structure and high load efficiency. Suitable for robot waist, elbow, wrist and other joints subjected to combined loads.

 

(4) Thin-Section Crossed Roller Bearing Series

 

Cylindrical rollers arranged at 90° perpendicular crossings, line-contact high rigidity load carrying with thin-section hollow design. Suitable for robot bases, heavy joints and precision turntables with extreme rigidity requirements.

 

General advantages summary: Constant cross-section design, cross-section unchanged as bore diameter increases, all joints sharing the same thin-section structure; thin-section lightweight, significantly reducing overall machine weight and motion inertia; hollow design facilitating cable and tube passage; precision grades up to P4 and P2 available; low friction, low vibration, low noise; comprehensive variety with 6700 and 6800 series offering various dust cover types, flanged types, stainless steel types and wide types.

 

4. Two-Grade Material & Process Selection

Grade 1: Through-Hardened Bearing Steel (General Version)

 

Integral quenching and low-temperature stabilizing tempering achieve uniform overall hardness with excellent wear resistance. Suitable for conventional industrial robot joints, automation equipment, medical equipment and other stable conditions, with outstanding cost performance for complete machine supporting.

 

Grade 2: Carburized Bearing Steel (Heavy-Duty Reinforced Version)

 

Inner and outer rings undergo carbonitriding heat treatment, forming a high-hardness wear-resistant layer on raceway surfaces while maintaining core impact toughness. Suitable for heavy-duty palletising robots, large six-axis robots, humanoid robot hip and ankle joints and other high-load applications, withstanding instantaneous peak loads and impacts while maintaining sufficient rigidity reserve in thin-section structures.

 

5. Japanese Precision Manufacturing Process

Vacuum degassing refining of high-purity special steel forging, controlling non-metallic inclusions to extremely low levels and eliminating fatigue crack initiation points;

 

Precision forging + carbonitriding heat treatment, forming a high-hardness wear-resistant layer on raceway surfaces while maintaining core impact toughness;

 

Staged stabilisation treatment—equal-section thin-section bearing rings are prone to residual stress release and distortion after grinding; NMT employs staged stabilisation treatment precisely coordinated with ultra-precision grinding to bring raceway roundness and roughness to demanding levels;

 

Fully closed-loop ultra-precision grinding system with nanoscale online measurement, achieving sub-micron raceway geometry accuracy;

 

Strict screening of rolling element dimensional consistency—the subtle balance among raceway accuracy, rolling element consistency and clearance control directly determines joint rotational smoothness and repeat positioning accuracy;

 

Superfinishing of raceways with stable surface roughness control and high matching accuracy;

 

Low-particle lubrication solutions developed specifically for equal-section thin-section bearings, combined with special phosphating treatment processes, maintaining low particle generation rates even during long-term low-speed oscillation;

 

Assembly in temperature-controlled dust-free workshops with precise preload and clearance control;

 

100% full inspection including torque, vibration, rotational accuracy and run-in tests, with complete data archived.

 

All dimensions comply with international standards for direct interchange with mainstream equal-section thin-section bearings.

 

6. Precision Grades & Customisation Options

P5 Grade: General precision grade, suitable for most industrial robot joints and automation equipment;

 

P4 Grade: High precision grade, suitable for precision turntables, medical imaging equipment and optical instruments;

 

P2 Grade: Ultra-high precision grade, suitable for semiconductor equipment, aerospace-grade precision mechanisms and high-end robots.

 

Customisation options: special clearance configurations, high/low temperature resistant materials, stainless steel materials, special grease adaptation, non-standard sizes, dust cover types, flanged types, wide types and more.

 

7. Wide Application Fields

Industrial Robots: Bases, shoulders, elbows, wrists, finger joints—all joints sharing the same thin-section structure for lightweight compact overall machine;

Collaborative & Humanoid Robots: Wrists, ankles, hips—dual requirements of thin-section and rigidity;

Medical Equipment: CT scanners, surgical robots, rehabilitation equipment, medical manipulators;

Semiconductor Equipment: Wafer handling robots, vacuum transfer chambers, IC manufacturing equipment;

Precision Measurement & Optical Equipment: Precision testing instruments, optical adjustment stages, rotary encoders;

Aerospace: Satellite mechanisms, lightweight rotating components for aircraft;

New Energy & Automation: Solar tracking systems, AGV chassis steering mechanisms;

General Machinery: Stepper motors, reduction gear devices, direct drive motors.

 

8. Brand Supply & Customisation Service

NMT maintains sufficient spot inventory of mainstream 6700 and 6800 series equal-section thin-section bearings for urgent equipment repair and mass complete machine supporting with short lead time. Customisation services include P4/P2 high precision grades, special clearance, high/low temperature resistant materials, stainless steel materials, special grease, non-standard sizes, dust cover types, flanged types, wide types and more. Professional engineers provide targeted selection schemes based on equipment load spectrum, installation space, accuracy requirements and speed range to optimise bearing configuration and structural selection, improve overall machine lightweighting, control motion inertia, extend precision retention cycles and cut the overall life cycle cost of equipment. NMT's equal-section thin-section bearings provide not just single bearing performance parameters, but a trustworthy quality consistency—every bearing set maintains high consistency in operating noise, rotational resistance and life performance, enabling equipment manufacturers to predict maintenance cycles and failure windows with greater accuracy.