Automated rotary tables, rotary joints of robotic manipulators and small rotary tooling equipment sustain radial loads, bidirectional axial loads and overturning moments during operation. Conventional single-row angular contact bearings can only bear axial force in one single direction. To withstand bidirectional axial loads, paired installation is required, occupying extra assembly space and increasing assembly difficulty and component costs. Ordinary double-row bearings feature bulky structure and fail to fit lightweight rotary mechanism design. Simple slewing supports suffer poor precision and uncontrollable operating clearance. Clearance expansion easily occurs after long-term rotation, leading to turntable shaking and positioning deviation. Many automated rotary units require compact bearings that bear positive and reverse axial loads in a single set, together with radial load capacity and anti-overturning performance. Traditional rotary bearings have unstable heat treatment performance. Under low-speed continuous swing conditions, rolling element abrasion and surface pitting readily emerge. Frequent maintenance shutdowns directly reduce the operating efficiency of automated production lines. The market demands four-point contact ball bearings capable of bearing multi-directional loads with simplified structure.

Automation equipment keeps upgrading toward lightweight design and integration. Internal installation space of various rotary worktables and robot rotary joints is limited. The traditional solution of installing two sets of angular contact ball bearings to sustain bidirectional axial loads increases component quantity and sets extremely high requirements for assembly coaxiality. Assembly procedures become complicated and labor costs rise. Rotary mechanisms continuously endure alternating loads and overturning moments during operation. Insufficient bearing rigidity causes turntable shaking, directly triggering positioning deviation during workpiece processing or handling. Some tooling turntables work under low-speed intermittent swing with limited lubrication. Ordinary bearings easily generate local stress concentration and premature fatigue failure. Equipment manufacturers prefer bearings that sustain bidirectional axial loads with a single unit, simplifying transmission structure, lowering assembly difficulty and securing stable long-term rotary precision to reduce equipment commissioning and maintenance frequency.

NMT Precision Four-Point Contact Ball Bearings adopt special curved raceway design. A single bearing unit bears radial loads, bidirectional axial loads and overturning moments simultaneously. Paired bearing installation is no longer needed, saving internal equipment space and simplifying the overall structure of rotary mechanisms. Four-point contact forms between balls and raceways realize balanced force distribution, stably coping with composite alternating loads generated during low-speed rotation and reciprocating swing. High-precision steel balls go through strict dimensional screening with tiny dimensional dispersion for balanced stress distribution, preventing fatigue damage induced by local stress concentration. Bearing inner and outer rings are manufactured from high-purity bearing steel with stabilized quenching and tempering treatment. Raceways receive ultra-precision grinding with high contour accuracy and stable friction coefficient to avoid creeping during low-speed operation. High-precision machined cages separate steel balls evenly to prevent collision and mutual friction and maintain smooth rotation. The bearings fit automated rotary platforms, robot joints, small CNC rotary tooling and material turnover mechanisms. Dust-proof sealed structures are optional to block dust and impurities invading raceways, adapting to industrial workshop environments. Abundant standard specifications support direct replacement on new and existing automated rotary equipment and match long-term grease lubrication solutions to meet intermittent non-stop production demands.

Inner and outer rings are forged from high-purity bearing alloy steel and processed via complete stabilized heat treatment to balance surface hardness and core toughness, delivering balanced wear resistance, shock resistance and anti-fatigue performance. Ultra-precision grinding is applied on inner and outer raceways to strictly control curved contour accuracy and surface roughness for smooth steel ball rolling. High-precision steel balls pass automatic grading screening to guarantee uniform dimensions within each bearing unit for even load distribution. Integrated machined cages are thoroughly deburred to avoid scratches on raceways and steel balls during assembly and operation. All finished products pass composite load durability tests, rotary clearance inspection and rotation smoothness testing. Products with insufficient precision and rotation jamming are eliminated to guarantee consistent batch quality.

A complete range of specifications is available. Widely applied in automated CNC rotary tables, rotary joints of industrial robots, material turnover tooling, small rotary conveying platforms, rotating mechanisms of testing equipment and machine tool indexing rotary units, satisfying supporting demands of rotary mechanisms under composite load conditions.

Core Product Advantages

Special four-point contact raceway structure enables a single bearing to sustain radial loads, bidirectional axial loads and overturning moments. Paired bearings are eliminated to save assembly space;

Balanced force distribution via four-point contact adapts to low-speed continuous rotation and reciprocating swing to resist impacts from composite alternating loads;

Precisely screened steel balls distribute loads evenly, reduce stress concentration and delay fatigue failures including raceway pitting and peeling;

Ultra-precisely ground inner and outer raceways deliver stable friction and prevent creeping under low-speed conditions to secure rotary positioning precision;

Precision integrated cages restrict steel ball positions effectively to avoid mutual friction and collision for stable low-noise rotation;

Stabilized heat-treated raw materials feature outstanding resistance to plastic deformation and excellent dimensional stability under long-term overturning moments;

Optional dust-proof seals block dust and cutting debris from entering bearings, adapting to dusty factory production environments;

Standardized series specifications provide excellent interchangeability, fit long-lasting grease lubrication and support direct replacement on new and old rotary tooling equipment.

Typical Application Scenarios

Automated CNC rotary worktables; rotary joints of small industrial robots; rotary supports for material turnover tooling; rotary platforms of testing instruments; machine tool indexing units; automated conveying rotary mechanisms; rotary bases for welding tooling; supporting parts of light-duty rotary conveying machinery.

Quality Assurance

NMT Precision Four-Point Contact Ball Bearings adopt high-purity bearing alloy steel raw materials. Incoming materials pass composition inspection and non-metallic inclusion screening. After forging, inner and outer rings go through precision turning, stabilized heat treatment and ultra-precision raceway grinding to continuously control curved raceway contour accuracy. High-precision steel balls are sorted automatically to ensure uniform dimensions inside each bearing. Machined cages receive elaborate deburring to eliminate risks of scratches on bearing working surfaces caused by sharp edges.

All components pass visual flaw inspection and full-dimensional precision measurement. Workpieces with cracks, collision marks and out-of-tolerance dimensions are eliminated completely. Assembled finished products undergo composite load cyclic durability tests, axial & radial clearance inspection and low-speed rotation smoothness testing. Defective goods are sorted out to guarantee stable rotary precision and load capacity among batches, supplying reliable bearing solutions for automated rotary equipment and robot joint mechanisms.

Product Range

Standard four-point contact ball bearings, dust-proof sealed four-point contact ball bearings, reinforced heavy-duty four-point contact ball bearings. Selection depends on load type, rotation speed, magnitude of overturning moment and on-site operating environment.

Brand Strength

NMT specializes in R&D and manufacturing of precision rotary bearings. Targeting common pain points of automated rotary tables and manipulator rotary joints including compact structure requirements, multi-directional composite loads and easy abrasion under low-speed swing, NMT continuously optimizes curved raceway machining technology and steel heat treatment schemes. The bearings effectively mitigate common failures such as rotary positioning drift, premature bearing fatigue abrasion and rotation jamming, simplify mechanical design of rotary equipment, extend bearing replacement cycles of automation equipment and cut operation and maintenance costs of intelligent manufacturing production lines.