Combined Needle Roller Bearing (Needle Roller/Angular Contact Ball Bearing, Needle Roller/Thrust Ball Bearing)

Specifications

How to choose Needle roller bearings

Points to check when selecting, with the values for this product (Combined Needle Roller Bearing (Needle Roller/Angular Contact Ball Bearing, Needle Roller/Thrust Ball Bearing)).

1. 1. Select dimensions by shaft diameter and presence of inner ring

   Types without an inner ring use the shaft directly as the raceway, so the roller pitch circle diameter Fw corresponds to the applicable shaft diameter. In this case the shaft requires sufficient hardness and surface finish. If the shaft cannot serve as the raceway, select a type with an inner ring and match the shaft diameter using the bore diameter d.

2. 2. Check housing dimensions by outside diameter and width

   The outside diameter D determines the housing bore diameter, and the width C determines the axial installation space. Shell types have thin walls and allow a smaller outside diameter, but they are retained by press fit, so the housing bore tolerance and rigidity must be verified.

3. 3. Verify life and static strength with rated loads

   The basic dynamic load rating Cr is used for calculating rolling fatigue life, and the basic static load rating C0r is used for examining permanent deformation under shock loads or stationary loads. The listed Cr values range widely from 1.23 to 13200 kN, and are larger for double-row types and larger diameters.

4. 4. Choose the type suited to the application

   Select shell types for space savings and solid types for high load and high rigidity. Select self-aligning types where shaft tilt is present, combined types with thrust bearings for fixed-side positions that also carry axial load, and cam followers for applications rolling along cams or rails.

5. 5. Match rotational speed with lubrication method

   The limiting speed varies with the lubrication method, and generally oil lubrication allows higher speeds than grease lubrication. Confirm that the operating speed is below the limiting speed for each lubrication condition.

6. 6. Consider sealing and operating environment

   In environments where foreign matter or moisture may enter, selecting contact-seal types such as RS or 2RS, or grease-packed types, helps retain lubricant and reduces relubrication effort. However, the seal increases rotational resistance and imposes limits on operating temperature, so these points should be considered.

This guide was written by AI based on the listed products' documents and specification items.

About Needle roller bearings and all products

Description

The needle roller/angular contact ball bearings come in two series: NKIA (unidirectional axial load) and NKIB (bidirectional). The needle roller/thrust ball bearings come in two series: NX full-complement thrust bearings and NKX thrust ball bearings with cage. They can be used in back-to-back arrangement and with preload.

FAQ

Q. What series of SKF combined needle roller bearings are available? Please explain the differences between NKIA 59, NKIB 59, NX and NKX.

A. The needle roller/angular contact ball bearings come in two series: NKIA (unidirectional axial load) and NKIB (bidirectional). The needle roller/thrust ball bearings come in two series: NX full-complement thrust bearings and NKX thrust ball bearings with cage.

Q. What is the axial clearance range of NKIB 59?

A. The axial clearance of NKIB 59 is 0.08 to 0.25 mm.

Q. Can combined needle roller bearings accept radial and axial loads simultaneously? What applications are they suited for?

A. They can accept radial and axial loads simultaneously. They are suited for fixed-side bearing arrangements and equipment with high rotational speeds or difficult lubrication.

Q. Can combined needle roller bearings be used with preload?

A. They can be used in back-to-back arrangement and with preload. Preload prevents ball skidding.

Written by AI based on the content of the source documents.

Source documents

• Catalog 針状ころ軸受 (SKF 製品カタログ・技術資料抜粋) 124 pages
  Found on: https://azuma-eg.com/catalogue/