Roller bearings
Double-Row Cylindrical Roller Bearings
Two rows of rollers with a high stiffness-to-section ratio — the usual answer for a machine-tool spindle or a pinion shaft that must not deflect under cut.
- Series
- NN · NNU
- Bore
- 30 – 500 mm
- Class
- P5 / P4
Design
Stiffness in a small section.
Every batch is measured on the finished part, and the measurement file travels with the goods. Send a designation, a drawing or a photo of the failed part and an engineer will answer with a lead time and a price, usually inside 48 hours.
- NN and NNU designsNN takes both rows in the inner ring, NNU in the outer, so the mounting direction follows the shaft.
- Cylindrical or tapered boreA 1:12 tapered bore lets the fit be adjusted to control preload.
- Preload on the customer gaugeWhere preload is specified, the set is measured on the gauge agreed before the order.
- Radial onlyAxial location is left to a separate bearing, so thermal growth never loads the rollers.
Technical data
NN · NNU| Designs | NN · NNU · NN30 series with tapered bore |
|---|---|
| Bore range | 30 – 500 mm |
| Outer diameter | 55 – 720 mm |
| Rows | 2 |
| Accuracy | P5 / P4, running accuracy measured on the finished part |
| Cage | Machined brass |
| Bore taper | Cylindrical or 1:12 |
| Lubrication | Oil or grease, spindle greases on request |
Where it is used
Common applicationsMachine-tool spindles
Front and rear spindle positions in lathes and machining centres.
Pinion shafts
Gear grinding and hobbing machine work heads.
Roll grinders
Wheel-head spindles running at high speed under preload.
Printing cylinders
Cylinder journals where deflection shows in register.
Send the part number.
We will send the answer.
A designation, a drawing, or a photo of the failed part is enough to start. Technical questions reach an engineer, not a mailbox.
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