Numerically controlled machine tools, industrial robots and automatic indexing equipment are widely applied in intelligent manufacturing. During operation, rotary support parts bear radial loads and bidirectional axial loads simultaneously. Frequent start-stop and reciprocating positioning will trigger alternating load impacts. Ordinary single row angular contact bearings can only withstand unidirectional axial force. Paired installation occupies larger assembly space, increases working procedures and raises difficulty in coaxiality control. Conventional deep groove ball bearings have weak axial load capacity. Axial shifting easily occurs under high-speed reciprocating positioning conditions, directly reducing repeated positioning accuracy of equipment. Many automatic equipment feature compact internal space. Equipment designers tend to adopt integrated bearing structures to simplify assembly and shrink the volume of transmission units. Meanwhile, precision automatic equipment sets strict standards for operation noise, rotary runout and temperature rise at high speed. Insufficient bearing accuracy will cause workpiece machining errors and jitter of robot movements. The market urgently demands integrated double row angular contact ball bearings. Equipped with two rows of built-in balls, the bearings can carry bidirectional axial force and radial force at the same time, satisfying compact installation space and high-precision positioning requirements of precision automatic equipment.

The intelligent manufacturing industry keeps upgrading. Machining accuracy of machine tools, movement speed and positioning requirements of industrial robots are continuously improved. Various automatic rotary joints, machine tool feed shafts and rotary tables need to maintain stable positioning performance for a long period. Single row angular contact ball bearings must be used in pairs to withstand bidirectional axial loads. Uneven preload control easily emerges during paired installation. Clearance variation occurs after long-term high-speed operation and undermines long-term accuracy stability of equipment. Ordinary bearings generate massive friction heat at high speed. Poor heat dissipation will lead to raceway expansion and change internal clearance, triggering vibration and noise. Many robot joints and CNC rotary tables have limited cavity dimensions, making it impossible to arrange two sets of single row bearings and imposing great restrictions on structural layout. Besides, automatic production lines operate continuously all year round. Frequent commutation brings sustained alternating loads. Inferior bearings are prone to fatigue pitting on raceways and shorten equipment overhaul cycles. NMT Double Row Angular Contact Ball Bearings adopt integrated integral design with two rows of rolling elements. They can independently bear radial loads and bidirectional axial loads, simplify mechanical structures and comply with the miniaturization and high-precision development trend of precision equipment.

NMT Double Row Angular Contact Ball Bearings adopt integrated layout of double row rolling elements with built-in contact angle structure. They can bear radial loads and bidirectional axial loads simultaneously without combined paired installation, effectively saving internal installation space of equipment and simplifying assembly procedures. Optimized curved profile of raceways improves stress state of steel balls, reduces friction loss during high-speed rotation, controls operation temperature rise and adapts to long-term continuous high-speed operation. Manufactured from high-purity bearing alloy steel via stabilized heat treatment, the material delivers uniform surface hardness of raceways and outstanding anti-fatigue performance. Precisely machined cages guide rolling elements to run smoothly, restrain sliding of rolling elements under high speed and reduce wear and vibration. Multiple sealing options are available including open type, metal dust shield and rubber sealing ring. Sealed bearings can block dust and cutting fluid from penetrating into bearings, suitable for complex working conditions in machine tool workshops. The bearings feature excellent rigidity to resist axial movement and guarantee stable and reliable repeated positioning accuracy of automatic equipment. Widely used in rotary tables of CNC machine tools, joints of industrial robots, automatic indexers, precision servo transmission modules, rotary mechanisms of packaging automation and rotary spindles of testing instruments. Complete standard specifications are compatible with mainstream domestic and foreign automatic equipment, applicable for new machine matching and renovation replacement of old automatic production lines.

Inner and outer rings are processed via forging, precision grinding and ultra-finishing. Geometric precision of raceways, surface roughness are strictly controlled to lower rolling friction. The whole heat treatment process accurately manages metallographic structures to restrain dimensional creep induced by long-term high-speed operation and sustain bearing precision continuously. Polymer or solid cages are formed by precision molding with high guiding accuracy and stable rotation. All finished products pass radial runout inspection, clearance screening and rotation smoothness test. Products with poor precision are eliminated to guarantee consistent accuracy among bearing batches.

Complete specification series are extensively matched with rotary mechanisms of CNC processing equipment, multi-joint industrial robots, automatic indexing devices, servo precision transmission assemblies, rotary units of automatic packaging and spindles of precision testing instruments, supplying high-rigidity integrated rotary support for various intelligent equipment.

Core Product Advantages

Integrated double row structure, independently bearing radial loads and bidirectional axial loads without paired installation, saving assembly space and simplifying mechanical design;

Optimized raceway profile design reduces rolling friction and temperature rise at high speed, suitable for long-term continuous operation of automatic equipment;

High-purity bearing steel matched with precision heat treatment technology delivers excellent anti-fatigue performance, resisting alternating load impacts caused by frequent start-stop;

Precision cage structure guides steel ball movement stably, suppresses high-speed sliding and reduces vibration and operation noise;

Optional multi-type sealing structures effectively block pollution from dust and cutting fluid, extend bearing service life and cut maintenance frequency;

Excellent structural rigidity efficiently limits axial shifting and maintains long-term stable repeated positioning accuracy of robots and CNC rotary tables;

Balanced operation friction resistance and stable dynamic performance, adapting to automatic working conditions of reciprocating motion and frequent commutation;

Abundant standardized dimensional specifications with good interchangeability, meeting demands of new intelligent equipment development and renovation replacement of old equipment.

Typical Application Scenarios

Rotary tables and feed transmission mechanisms of CNC machine tools; rotary joints of multi-joint industrial robots; automatic indexing plates and rotary positioning devices; precision servo transmission modules; rotary assemblies of automatic packaging machinery; spindles of precision testing instruments; small intelligent conveying rotary mechanisms.

Quality Assurance

NMT Double Row Angular Contact Ball Bearings adopt high-quality refined bearing alloy steel as raw materials. Incoming materials pass sampling inspection on material composition and hardness. Bearing rings go through forging, heat treatment, repeated precision grinding and ultra-finishing processes. Contour precision, dimensional tolerance and surface finish of raceways are strictly controlled. Steel balls pass high-precision grading screening to guarantee highly unified specifications of rolling elements inside each bearing. Cages are formed by precision machining to eliminate stress deformation and improve stability during high-speed operation. All components receive flaw detection and dimensional inspection. Workpieces with collision marks, cracks and out-of-tolerance dimensions are completely eliminated. Internal clearance, radial runout and rotation smoothness of each assembled finished product are tested one by one. Samples are regularly selected for continuous high-speed operation durability tests. Defective goods are sorted separately to ensure every bearing possesses sufficient positioning rigidity, stable rotation precision and controllable temperature rise, supplying integrated high-precision rotary support solutions for intelligent manufacturing automatic precision equipment.

Product Range

Open double row angular contact ball bearings, double row angular contact bearings with metal dust shields, rubber sealed double row angular contact ball bearings. Selection depends on operation speed, dustproof & waterproof grade and magnitude of axial loads.

Brand Strength

NMT devotes to R&D and manufacturing of precision industrial bearings. Targeting industry demands of CNC machine tools, industrial robots and automatic equipment including bidirectional loads, limited installation space and high-speed high-precision positioning, NMT continuously optimizes internal structures, raceway processing technology and sealing design of double row angular contact bearings. The bearings effectively mitigate failures such as excessive temperature rise at high speed, positioning drift and premature fatigue wear, help automatic equipment manufacturers improve overall machine stability, extend equipment service cycles and reduce maintenance costs of production lines.