With continuous upgrading of intelligent manufacturing equipment, industrial robots, CNC indexing tables and automatic rotary workstations impose strict requirements on rotary support components. Traditional double-row ball slewing bearings feature heavy structure and occupy large axial and radial space, failing to meet assembly demands of lightweight and compact joint structures. Ordinary roller bearings can only bear loads in a single direction. To support multi-directional loads, multiple sets of bearings need to be combined, which greatly increases structural volume and assembly procedures. Rotary joints of industrial robots and precision CNC rotary tables require continuous high-precision positioning. Obvious rotary clearance must be avoided during equipment start-stop and angle indexing. Excessive clearance will directly lead to machining positioning deviation and jitter of robot movements. Many precision equipment has limited internal installation space. Equipment developers urgently need thin integrated bearings capable of bearing composite loads with tiny rotary clearance, meeting multiple requirements of high precision, miniaturization and high rigidity simultaneously.

Intelligent automation equipment is continuously evolving toward precision, miniaturization and lightweight. Rotary joints of industrial manipulators, CNC rotary indexing tables of machine tools and optical inspection rotary platforms operate under complex working conditions, bearing radial loads, axial loads and overturning moments during operation. Conventional bearing solutions require multiple bearing sets for matching, resulting in high assembly difficulty and difficult coaxiality control. Clearance gradually expands after long-term operation, and positioning precision declines continuously. Large slewing bearings feature large thickness dimensions and cannot be installed on small six-axis robots and medium-small precision rotary tables. High-precision working scenarios set strict standards for rotary clearance. Excessive clearance easily causes inaccurate indexing and track offset, reducing product processing yield. Meanwhile, many precision equipment pursue overall weight reduction design, and rotary support components cannot occupy excessive axial space. The market is in urgent need of cross roller bearings. With cross arranged rollers, integrated composite load bearing can be realized. High rigidity and ultra-small rotary clearance can be maintained under ultra-thin dimensions, simplifying rotary mechanism design and reducing the number of parts.

NMT Precision Cross Roller Bearings adopt rollers arranged at 90 degrees crosswise. A single bearing can bear radial loads, bidirectional axial loads and overturning moments simultaneously to realize integrated support for composite loads. The unique compact thin structure greatly reduces axial height, effectively saving internal installation space of equipment and adapting to narrow assembly cavities of robot joints and precision rotary tables. Rollers pass precision dimensional sorting, and raceways receive superfinishing grinding. Ultra-small rotary clearance can be realized. Preload options are available for partial specifications to further eliminate clearance and guarantee high-precision indexing and stable rotary operation. Inner and outer rings are equipped with standard mounting through holes, supporting direct bolt locking assembly without additional flange transition structures and simplifying overall assembly procedures. Manufactured from high-purity bearing alloy steel with complete heat treatment processes, raceways feature uniform surface hardness and excellent fatigue resistance, capable of enduring alternating loads brought by frequent forward-reverse rotation and intermittent start-stop for a long time. Optional dust-proof sealing structures prevent cutting dust and environmental impurities from invading raceways, adapting to complex working conditions in machine tool workshops and automatic production lines. Widely applied to six-axis industrial robot joints, CNC indexing tables, automatic rotary platforms, rotary mechanisms of optical inspection equipment, small precision manipulators and 4th-axis rotary tables of vertical machining centers. Specifications of multiple precision grades cover standard clearance, micro-clearance and preloaded products, satisfying selection demands of automation equipment with different precision standards.

Inner and outer rings are forged from premium bearing alloy steel. Quenching and tempering as well as surface hardening are conducted to balance overall toughness and surface hardness of raceways, resisting fatigue damage caused by alternating composite loads. Cylindrical rollers go through fully automatic dimensional classification and sorting to guarantee highly unified dimension and stable uniform stress distribution. Composite technology of forming grinding and superfinishing grinding is adopted for raceways to reach precision standards of contour accuracy and surface finish, lowering rolling friction and maintaining stable operation precision for long term. Cages are made of low-friction tough materials to separate rollers orderly and avoid collision, skew and jamming between rollers. Sealed versions are equipped with oil-resistant and aging-resistant sealing gaskets to block invasion of dust and cutting fluid impurities. All finished products pass rotary clearance inspection, radial and axial runout testing and non-destructive visual inspection. Products with excessive precision error and internal defects are eliminated to ensure stable rigidity and precision indicators among batches.

Complete precision specifications are widely matched to rotary joints of industrial robots, CNC indexing tables, automatic rotary tooling platforms, visual inspection rotary mechanisms, precision manipulators, machine tool 4th-axis rotary tables and semiconductor automatic rotary devices, meeting composite load support demands of various high-precision rotary mechanisms.

Core Product Advantages

Rollers arranged crosswise at 90°. Single bearing bears radial force, bidirectional axial force and overturning moment at the same time, replacing multi-bearing combination schemes and simplifying mechanical structures;

Thin integrated structure features compact axial size. Thickness is greatly reduced compared with traditional slewing bearings, supporting miniaturization and lightweight design of equipment;

Superfinishing grinding technology for raceways with optional micro-clearance and preload structures. Ultra-small rotary clearance suppresses rotary jitter effectively and ensures high-precision positioning and indexing;

Mounting holes are reserved on inner and outer rings for direct bolt fixing without extra transition flanges, shortening assembly working hours and lowering overall component costs;

Bearing alloy steel substrate together with mature heat treatment technology provides sufficient rigidity and strong anti-overturning capacity. Precision attenuation hardly occurs under long-term frequent forward-reverse rotation;

Optional sealing structures against dust and cutting fluid adapt to complex operating environments with dust and splashing cooling medium in machining workshops;

Stable rolling friction resistance enables sensitive start-stop response. Temperature rise stays controllable during intermittent indexing rotation and reduces precision drift caused by continuous operation;

Complete series of multiple precision grades, inner and outer diameter specifications with good interchangeability of standard parts, directly applicable for new machine R&D and renovation of old precision rotary tables.

Typical Application Scenarios

Rotary joints of six-axis industrial manipulators; CNC indexing tables and 4th-axis rotary tables for machine tools; rotary tooling platforms on automatic production lines; rotary mechanisms for optical visual inspection equipment; small precision grabbing manipulators; semiconductor inspection rotary devices; medical precision imaging rotary platforms; small automatic welding rotary toolings.

Quality Assurance

NMT Precision Cross Roller Bearings adopt high-grade bearing alloy steel as raw materials. Incoming materials pass inspection on metallographic structure, hardness and impurity content. After forging, inner and outer rings go through precision turning, heat treatment, raceway forming grinding and superfinishing grinding. Contour precision and dimensional tolerance of raceways are strictly controlled in the whole process. Full inspection and sorting are carried out for cylindrical rollers to ensure dimensional error of rolling elements inside one bearing is limited within tiny range. Synchronous quality screening is implemented for cages and sealing accessories to eliminate raw material defects. All components pass dimensional verification and surface defect detection. Workpieces with collision marks, burrs and out-of-tolerance dimensions are completely eliminated. Each assembled finished product undergoes rotary clearance, end face runout and radial runout testing. Samples are selected for durability alternating load tests. Defective goods are sorted separately to guarantee smooth rotation, qualified rigidity and stable precision of every bearing, supplying reliable support solutions for rotary mechanisms of high-end precision intelligent equipment.

Product Range

Open cross roller bearings, single-side sealed cross roller bearings, double-side sealed cross roller bearings; classified into ordinary grade, precision grade and ultra-precision preloaded grade according to precision. Selection depends on load magnitude, dust prevention requirements and positioning precision demands.

Brand Strength

NMT focuses on R&D and manufacturing of high-precision rotary bearings. Targeting common industry pain points of industrial robots and CNC rotary tables including composite load bearing, limited installation space and long-term precision retention, NMT continuously optimizes raceway processing technology, roller sorting standards and heat treatment schemes. The bearings effectively mitigate frequent failures such as enlarged rotary clearance, rapid precision decline and operating jitter, improve positioning stability of intelligent manufacturing equipment, reduce regular calibration frequency of equipment and help automation equipment manufacturers develop compact and stable high-end precision rotary equipment.