On gear shafts in automotive transmissions, bearings must simultaneously withstand radial loads from gear meshing and axial thrust from helical gears. In construction machinery hydraulic pumps, bearings endure radial forces from high-pressure oil and axial forces from piston motion during high-speed rotation. On input and output shafts of industrial gearboxes, bearings withstand radial loads from transmitted torque and axial components from gear forces. In injection molding machine clamping mechanisms, bearings withstand enormous axial clamping forces and radial forces from eccentric loads. In these applications with simultaneous radial and axial combined loads, combined bearings—with their integrated composite load-bearing design—become the optimal solution for compact-space combined load requirements.

 

Combined bearings are specialized bearing types that integrate radial bearings and axial bearings into a single unit. They typically consist of a radial bearing portion (such as needle roller bearings, cylindrical roller bearings or deep groove ball bearings) combined with an axial bearing portion (such as thrust ball bearings, thrust needle roller bearings or thrust cylindrical roller bearings). Through this integrated design, combined bearings can simultaneously withstand radial and axial loads within minimal axial and radial space, greatly simplifying equipment structural design, reducing component count and lowering assembly difficulty and costs.

 

Combined bearings are available in various configurations——needle roller and thrust ball combined bearings, needle roller and thrust cylindrical roller combined bearings, cylindrical roller and thrust ball combined bearings, etc., accommodating different load directions, load magnitudes and speed requirements. The radial portion typically uses needle roller bearings for minimal radial cross-section height and maximum radial load capacity; the axial portion uses thrust ball bearings, thrust needle roller bearings or thrust cylindrical roller bearings based on load magnitude and direction. Combined bearings are widely used in automotive transmissions, construction machinery, industrial gearboxes, hydraulic equipment, injection molding machines, machine tool spindles, textile machinery, packaging machinery and various compact equipment requiring simultaneous radial and axial combined loads.

 

NMT Combined Bearing Technology Solutions

 

Japan NMT combined bearings are specialized product series developed specifically for the stringent requirements of combined-load compact equipment——high load capacity, high rigidity, long life and high reliability.

 

Integrated Combined Load-Bearing Design——NMT combined bearings integrate radial and axial bearings into a single precision unit, providing both radial and axial load capacity within limited installation space. The radial portion utilizes needle roller bearings or cylindrical roller bearings for maximum radial load capacity with minimal radial cross-section height; the axial portion utilizes thrust ball bearings, thrust needle roller bearings or thrust cylindrical roller bearings optimized based on axial load direction and magnitude. This integrated design not only saves installation space but also eliminates cumulative tolerances and alignment errors from multiple independent bearings, improving overall bearing system precision and rigidity.

 

High-Precision Radial Bearing Unit——The radial portion of NMT combined bearings utilizes high-precision needle roller bearings or cylindrical roller bearings, with rollers precision-ground and superfinished, diameter deviation controlled to minimal ranges, and raceways precision-machined with surface roughness controlled to extremely low levels. Radial bearing clearance is precisely set to achieve optimal radial support stiffness after installation. Needle roller bearing outer rings are precision-formed with optimized wall thickness for maximized roller quantity within limited space. Cylindrical roller bearing rollers undergo precision crowning to eliminate edge stress concentration, ensuring uniform load distribution along the full roller length.

 

High-Capacity Axial Bearing Unit——The axial portion of NMT combined bearings offers multiple configurations based on load requirements. Thrust ball bearing units suit medium-speed light-load axial loads, with precision-graded balls with minimal sphericity and diameter deviation, and superfinished raceways for extremely low friction torque. Thrust needle roller bearing units suit heavy-load low-speed axial loads, with high roller quantity, large diameters and minimal axial cross-section height, providing extremely high axial load capacity within limited space. Thrust cylindrical roller bearing units suit heavy-load medium-speed axial loads, with line contact between rollers and raceways for excellent load capacity and rigidity. NMT provides optimal axial bearing unit configurations based on specific load directions, magnitudes and speed requirements.

 

High-Rigidity Integrated Design——Combined bearing radial and axial bearing units are integrated into the same ring or housing, eliminating alignment errors and clearance accumulation from independent bearing installation. NMT combined bearing integrated design minimizes load paths with direct load transmission, significantly improving system rigidity. Bearing axial preload can be precisely controlled to eliminate axial clearance while establishing stable preload, further improving overall bearing system stiffness. Validated through rigorous stiffness testing, NMT combined bearings maintain extremely low deformation under combined loads, ensuring equipment positioning accuracy and operational stability under heavy-load conditions.

 

Precision Lubrication and Seal Design——Combined bearings integrate both radial and axial rolling element systems, imposing higher requirements on lubrication distribution and sealing. NMT combined bearings are pre-filled with specialized grease formulated with high-quality synthetic base oils and extreme-pressure anti-wear, rust-preventive additives, forming stable lubricating films under combined-load conditions. Bearings feature internal oil passages and distribution grooves to ensure uniform lubrication supply to both radial and axial bearing portions. Sealing systems employ high-performance contact rubber seals, effectively blocking external dust, moisture and contaminant ingress while preventing grease leakage.

 

Compact and Lightweight Design——The integrated structural design of combined bearings is itself an expression of compactness. NMT combined bearings minimize axial and radial dimensions while maintaining load capacity through optimized radial and axial bearing layout. Needle roller radial portions provide minimal radial cross-section height, while thrust needle roller axial portions provide minimal axial cross-section height——the combination makes overall combined bearing dimensions far smaller than the sum of multiple independent bearings. Lightweight cage designs and optimized ring wall thicknesses further reduce weight and rotational inertia.

 

Diverse Combination Options——NMT combined bearings offer diverse radial-axial combination options for different load directions, magnitudes and speed requirements. Needle roller and thrust ball combination (NKIA series)——Radial needle roller bearings combined with axial thrust ball bearings, suitable for medium-speed, moderate axial load applications. Needle roller and thrust cylindrical roller combination (NKIB series)——Radial needle roller bearings combined with axial thrust cylindrical roller bearings, suitable for heavy-load, higher axial load applications. Cylindrical roller and thrust ball combination——Radial cylindrical roller bearings combined with axial thrust ball bearings, suitable for high radial loads and medium-speed axial loads. NMT provides precise bearing selection and combination recommendations based on specific operating parameters.

 

Long-Life and Reliability Validation——Combined bearings operate under combined loads for extended periods, imposing stringent requirements on fatigue life and reliability. NMT combined bearings undergo a series of rigorous testing validations——combined-load life testing (simultaneous radial and axial loads), high-speed durability testing, impact testing and seal performance testing. Every product is processed through fully automatic grinding and superfinishing in temperature-controlled clean workshops, with critical dimensional tolerances strictly controlled—ensuring combined load capacity, long life and high reliability.

 

Why Choose NMT Combined Bearings?

 

Compared to conventional bearings and industry-standard combined bearings, NMT combined bearings offer distinct advantages:

 

Radial and axial bearings integrated into a single unit for simultaneous combined load capacity

 

Needle roller radial portion for minimal radial cross-section height and maximum radial load

 

Thrust ball/thrust needle roller/thrust cylindrical roller multiple axial options for different loads

 

Integrated design eliminating cumulative tolerances and alignment errors for improved system precision

 

Shortest load paths and direct load transmission for significantly improved system rigidity

 

Precision axial preload control for clearance elimination and stable preload establishment

 

Internal oil passages and distribution grooves for uniform radial and axial lubrication supply

 

High-performance contact rubber seals for dust, moisture and leakage protection

 

Compact layout with overall dimensions far smaller than multiple independent bearings

 

Lightweight cages and optimized wall thicknesses for reduced weight and inertia

 

NKIA/NKIB multiple combination options for different operating conditions

 

Thermally stabilized materials + wide-temperature grease for -30°C to 120°C stability

 

Passed combined-load life, high-speed durability, impact and seal testing

 

These performance advantages establish NMT combined bearings as the core precision components for gearboxes, automotive transmissions, construction machinery, hydraulic equipment, injection molding machines and various combined-load compact equipment.

 

Application Scenarios

 

Automotive transmission gear shaft bearings

 

Construction machinery hydraulic pump bearings

 

Industrial gearbox input/output shaft bearings

 

Injection molding machine clamping mechanism bearings

 

Machine tool spindle combined load bearings

 

Textile machinery winding and drive bearings

 

Packaging machinery combined motion bearings

 

Robot joint compact combined bearings

 

Precision Manufacturing

 

Produced strictly according to ISO precision standards and combined bearing manufacturing specifications, with zero-defect quality execution, NMT combined bearings utilize high-purity bearing steel, processed through vacuum degassing treatment, precision heat treatment, radial raceway precision grinding and superfinishing, axial raceway precision grinding and superfinishing, precision rolling element screening and grouping, cage precision forming, integrated precision assembly, specialized grease precision filling, rotational accuracy inspection, combined-load life testing, high-speed durability testing, impact testing and seal performance testing. Every product is processed through fully automatic machining and superfinishing in temperature-controlled clean workshops, with critical dimensional tolerances strictly controlled—ensuring combined load capacity, high rigidity and long-life reliability.

 

Product Range

 

Needle roller and thrust ball combined bearings (NKIA type)

 

Needle roller and thrust cylindrical roller combined bearings (NKIB type)

 

Cylindrical roller and thrust ball combined bearings

 

Double-row combined bearings

 

High-precision combined bearings

 

Heavy-load combined bearings

 

Custom non-standard combined bearings

 

Global Industrial Service

 

Japan NMT supplies high-quality combined bearings to global gearbox manufacturers, automotive component companies, construction machinery suppliers and compact drive system users. With combined-load high-rigidity precision engineering and long-term stable reliable performance, NMT continuously empowers the efficiency and reliability of global combined-load compact drive equipment.