NewBee Machinery is a professional machinery parts manufacturer providing high quality precision bearings, high-quality non-standard transmission components, and intelligent CNC equipment and more.
NewBee Machinery is a professional machinery parts manufacturer providing high quality precision bearings, high-quality non-standard transmission components, and intelligent CNC equipment and more.
Double Row Cylindrical Roller Bearings are heavy-duty mechanical parts.They use two parallel lines of cylindrical rollers to hold very high radial loads.They offer high stiffness and low friction,making them ideal for strict industrial uses like machine tool spindles and large gearboxes.
Two main structural series are available:
NN series:Inner ring with double ribs,outer ring without ribs
NNU series:Outer ring with double ribs,inner ring without ribs
Both series are offered in cylindrical bore and tapered bore (suffix K) versions.Tapered-bore models allow radial clearance adjustment during mounting.As non-locating bearings,they permit limited axial displacement between shaft and housing,but are not intended to sustain substantial axial loads.
The bearing rings and rolling elements adopt GCr15,GCr15SiMn or G20Cr2Ni4A materials.Precision grades cover P0,P6,P5,P4; clearance groups include C0,C3,C4.The size range covers bore diameter 200 mm-1500 mm,outer diameter 250 mm-2300 mm with custom sizes supported.Operating temperature ranges from -40 °C to +120 °C.Grease lubrication,oil lubrication and custom lubrication solutions are all optional.Standard stock items can be shipped within 5-12 working days.
Exceptional Radial Load Capacity:By doubling the number of cylindrical rollers compared to single row bearings,the load distribution area increases significantly,delivering maximum radial load-carrying capabilities.
High Radial Rigidity:The multi-roller layout minimizes elastic deformation under load,making them ideal for precision machinery requiring high structural stiffness and shaft support stability.
Compact Radial Cross-Section:Provides substantial load capacity relative to its radial height,making it a space-efficient choice for heavy-duty drive systems and spindles.
Tapered Bore Option (K-Suffix):Frequently manufactured with a 1:12 tapered inner bore (e.g.,NN30K series).This allows precise adjustment of radial internal clearance or preload during installation using locknuts or tapered shaft sleeves.
Separable Ring Design:The inner or outer ring can be mounted independently from the roller and cage assembly,streamlining installation,dismounting,and maintenance inspections in complex machinery.
Low Axial Load Tolerance:Standard non-locating designs (NN and NNU series) accommodate thermal shaft expansion without axial stress,but cannot support axial thrust loads.Auxiliary thrust bearings are required if axial forces are present.
Machine Tool Spindles (Lathes,Milling & Machining Centers):Super-precision double row bearings (such as the NN30 and NNU49 series) are widely used as main spindle bearings.They provide high radial stiffness and minimal radial runout under heavy cutting forces.
Metal Rolling Mills & Pinion Stands:Used on roll necks,drive shafts,and stand transmissions where extreme dynamic and static radial loads occur during high-pressure metal forming.
Heavy-Duty Industrial Gearboxes:Installed on high-torque intermediate shafts and planetary gear assemblies where standard single row bearings cannot handle the peak radial forces.
Crane Sheaves & Winch Drums:Full complement double row variants (such as the sealed NNF series) are applied in crane cable pulleys,overhead hoists,and winch systems to support static and shock radial loads in compact sheaves.
Printing Presses & Paper Mill Machinery:Employed in heavy plate cylinders and press rolls where precise radial positioning and deflection resistance are critical for consistent print and paper quality.
Mining & Material Handling:Used in cone crushers,vibratory screens,and conveyor drives that experience continuous vibration,heavy loading,and shock forces.
Newbeetrans is a specialised full-cycle manufacturer for NN / NNU-series double-row cylindrical roller bearings,covering independent R&D,large-size forging,integral heat-treatment,precision grinding and comprehensive performance testing workshops,certified to ISO 9001 international quality-management standards.
Stock & Customization Capability
Complete standard NN and NNU-series bearing inventory supports fast delivery.Our engineering group delivers one-stop custom services:tapered-bore modification,special clearance requirements,alternative material selection and non-standard dimension development.Lead-time for custom-built bearings is determined by drawing complexity and raw-material availability.
Strict Full-Process Quality Assurance
Raw materials go through spectral and metallurgical incoming inspection.All finished bearings receive 100 % comprehensive testing including dimensional check,rotational run-out,rigidity,limiting speed and load-fatigue performance.Material certificates and SGS third-party inspection reports can be provided on request.
Advanced Production Facilities
Large heavy-duty CNC lathes,raceway super-finish grinders and dedicated heat-treatment production lines are deployed.MES intelligent production-management system enables full-process traceability for each production batch to guarantee consistent precision up to P4 grade.
Global Sales & Technical Support
We cooperate with worldwide sea-freight and air-freight carriers and support mainstream international trade terms such as FOB,CIP and DAP.Our technical team provides remote application consultation and installation guidance for global industrial equipment customers.
For technical specifications,pricing,or custom bearing solutions:
Email:paul@newbeetrans.com
Website:www.newbeetrans.com
WhatsApp
sales@newbeetrans.com
+8615090185276