1 Structural Composition and Working Principle of NMT Ball Screw Bearings

Ball screw bearings mainly consist of inner rings, outer rings, steel balls, cages, seals and angular contact raceway structures. Their core feature is simultaneously withstanding axial loads, radial loads and overturning moments, and improving screw system rigidity through preload control.

Japan NMT ball screw bearings commonly include thrust angular contact ball bearings, double-direction thrust angular contact ball bearings, combination bearings and high-precision angular contact bearings. Compared with ordinary bearings, ball screw bearings emphasize axial rigidity, positioning accuracy, preload stability and low-heat performance. Their core function is to provide stable axial support for ball screw assemblies, reducing friction, temperature rise and accuracy drift during high-speed feed, rapid traverse and precision positioning. Ball screw bearings are widely used in machining centers, CNC lathes, grinding machines, boring and milling machines, gantry machines and precision automation equipment. They are key components affecting machine tool positioning accuracy, feed rigidity and machining stability.

2 Core Performance Advantages of Japan NMT Ball Screw Bearings

First, angular contact structure, suitable for combined axial load, radial load and overturning moment conditions.

Second, high-precision raceway and steel ball combination provides stable rotational accuracy, suitable for precision positioning.

Third, high-rigidity design, suitable for heavy cutting, high-speed feed and high-load conditions.

Fourth, optional preload structure allows adjusting bearing condition according to rigidity and speed requirements.

Fifth, low-friction design, helping reduce heat generation, torque fluctuation and driving energy consumption.

Sixth, internationally standard mounting dimensions ensure good interchangeability for direct replacement of imported ball screw bearings.

3 Main Industrial Application Scenarios of NMT Ball Screw Bearings

3.1 Machining Centers

Screw support bearings for vertical machining centers, horizontal machining centers, gantry machining centers and five-axis machining centers.

3.2 CNC Lathes

Screw bearing parts for CNC lathes, turn-mill centers, precision lathes and slant bed lathes.

3.3 Grinding Machines

Screw support bearings for cylindrical grinders, internal grinders, surface grinders and high-precision grinding machines.

3.4 Boring and Milling Machines

Screw bearings for jig boring machines, CNC boring and milling machines, precision boring machines and gantry boring and milling machines.

3.5 Precision Automation Equipment

Screw bearings for precision assembly equipment, inspection equipment, electronic equipment and automated linear motion platforms.

3.6 General Machine Tool Feed Systems

Bearings for machine tool X-axis, Y-axis, Z-axis, feed axes, screw fixed ends and support ends.

4 Model Selection, Assembly and Daily Operation & Maintenance Guidelines

4.1 Key Points for Structure Selection

Load type: thrust angular contact ball bearings for dominant axial loads; combination bearings for combined loads;

precision grade: high precision grade preferred for precision machine tools and grinding machines;

preload grade: heavy preload for heavy cutting; light preload or medium preload for high-speed low-heat applications;

installation method: confirm screw shaft diameter, bearing housing, mounting distance, lock nut and preload structure;

speed requirement: low-friction high-speed structures preferred for high-speed feed axes.

4.2 Assembly Specifications

Before installation, check that bearings, screw shafts, bearing housings, lock nuts, spacers and mating surfaces are clean, free of burrs, chips and oil contamination.

Ensure coaxiality and axial positioning during ball screw bearing installation to avoid raceway damage and accuracy loss caused by uneven loading.

Pay attention to orientation, spacer thickness and preload sequence when installing paired bearings to prevent insufficient axial rigidity or excessive preload.

Apply assembly pressure evenly on the corresponding ring bodies; never press directly on rolling elements and cages.

Keep assembly environment highly clean; fine particles entering the bearing cause raceway pitting, noise and accuracy loss.

4.3 Lubrication Suggestions

High-speed spindle bearing oil or special high-speed bearing grease is recommended for ball screw bearings for periodic lubrication replenishment.

Regularly check oil or grease condition and replace when blackened, contaminated, emulsified or with abnormal temperature rise.

Control grease filling quantity for high-speed feed axes to avoid temperature rise and vibration increase caused by overfilling.

Regularly check pressure, flow and pipeline condition in oil-air lubrication, oil mist lubrication and jet lubrication systems.

Do not mix different types of lubricating materials to avoid lubricating film failure.

4.4 Daily Inspection Focus

Monitor screw temperature rise, axial play, reversal error, positioning accuracy and noise changes continuously.

Increased positioning error, abnormal reversal error, rapid temperature rise or abnormal noise in machine tools is commonly caused by insufficient lubrication, improper preload, raceway damage, screw thermal deformation or seal failure.

For high-speed feed axes, 重点检查 temperature rise, vibration and lubrication condition; for precision machine tools, 重点检查 positioning accuracy and repeat positioning accuracy.

Regularly check seals, cooling systems, lubrication lines and lock nuts; replace promptly when leakage, blockage or looseness is observed.

Inspect or replace the bearing promptly when abnormal bearing noise, excessive axial play or poor rotation is observed.

5 Import Substitution Value and Supply Chain Advantages of NMT Ball Screw Bearings

Manufacturers of CNC machine tools, machining centers and precision machine tools often face long lead times for high-precision preloaded ball screw bearings, high prices, complex pairing and long maintenance cycles when sourcing imported ball screw bearings. Japan NMT ball screw bearings are made of high-purity bearing steel with precision raceway machining technology. Their axial rigidity, positioning accuracy, preload stability and low-heat performance match imported products, suitable for new machine spindle assembly and equipment maintenance replacement.

All products comply with international standard mounting dimension specifications; most sizes can be directly replaced without modifying screw shafts, bearing housings and cooling structures. Popular ball screw bearing sizes are stocked to quickly fulfill precision machine tool bulk orders and urgent maintenance demands. Streamlined supply chains reduce intermediate costs and control long-term component procurement expenditure for machine tool manufacturing and after-sales service.

Ball screw bearings combine high precision, high rigidity, adjustable preload and low heat generation, ensuring stable operation of precision machine tools such as machining centers, CNC lathes and grinding machines. They reduce axial play, thermal deformation and accuracy drift, optimize the feed system supply chain for precision machine tools and ease production risks caused by unstable delivery cycles of imported ball screw bearings.