Rocker Arm Bearing

Specifications

How to choose Needle roller bearings

Points to check when selecting, with the values for this product (Rocker Arm 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

A bearing for the valve train of automotive engines, adopting a needle roller system in place of the slipper system. The standard product receives HL treatment, and the FA-treated product uses grain refinement to increase service life to 3.7 times and fatigue strength to 1.2 times the conventional levels. Installation is basically by snap ring or press fit, and crimping is not supported.

FAQ

Q. What are the applications of the Rocker Arm Bearing (FA type), and how does it replace the slipper system?

A. It is a bearing that adopts a needle roller system in place of the slipper system in automotive engine valve trains. Its application is engine rocker arms.

Q. How much have the service life and fatigue strength of the FA-treated Rocker Arm Bearing improved?

A. The FA-treated product uses grain refinement to increase service life to 3.7 times and fatigue strength to 1.2 times the conventional levels.

Q. What are the installation methods for the Rocker Arm Bearing (FA type), and is crimping supported?

A. Installation is basically by snap ring or press fit. Crimping is not supported.

Q. What effect does the HL treatment have on the Rocker Arm Bearing (FA type)?

A. HL treatment is standard and prevents peeling on the outer ring outer diameter surface.

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

Source documents

• Catalog ニードルローラベアリング ハンドブック 80 pages Open page 49
  Found on: https://www.ntn.co.jp/japan/products/catalog/ja/2203/index.html