Double-Row Tapered Roller Bearings (TDI Type / TDO Type)

How to choose Tapered Roller Bearings

Points to check when selecting, with the values for this product (Double-Row Tapered Roller Bearings (TDI Type / TDO Type)).

1. 1. Dimension series matching shaft and housing

   Bore d matches the shaft diameter and outside diameter D matches the housing bore. Tapered roller bearings come in metric and inch series, and bearings of similar size are not interchangeable. When replacing bearings in existing machinery, confirm the series of the boundary dimension designation, and check inner ring width B and outer ring width C against the step dimensions of the mounting section.

2. 2. Managing preload with assembled width T and tolerance

   Width T is the overall width of the inner and outer rings when assembled, and it affects axial mounting dimensions and the adjustment amount for preload or clearance. The assembled width tolerance class changes the effort required for adjustment, so when used in pairs, confirm T and its tolerance class.

3. 3. Estimating life with basic dynamic load rating

   Basic dynamic load rating Cr is the basis for life calculation. From radial and axial loads, the dynamic equivalent load is obtained using factor e and load factor Y1, and rated life is calculated from the ratio to Cr. The listed Cr values range from 9.5 kN to several tens of thousands of kN and vary greatly with the number of rows.

4. 4. Checking shock and low-speed use with static load rating

   For applications with stationary operation, very low speed, or shock loads, check the margin against permanent deformation using the ratio of basic static load rating C0r to the static equivalent load (calculated with Y0). For heavy-duty rolling mills and similar uses, secure capacity with double-row or four-row types.

5. 5. Determining shaft support by load action point position

   Tapered roller bearings have load action points located away from the end face, and the span between supports changes depending on back-to-back or face-to-face arrangement. Use the load action point position a for calculating shaft deflection and reaction forces, and determine the mounting direction accordingly.

6. 6. Matching rotational speed and lubrication method

   The permissible rotational speed is set higher for oil lubrication than for grease lubrication. Confirm that the operating speed is within the value for each lubrication method. For differentials and other applications where energy saving is required, low-torque types showing the friction torque reduction rate are also candidates.

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

About Tapered Roller Bearings and all products

Description

The TDI type consists of two single-row outer rings and one double-row inner ring, and is used with an outer ring spacer. The TDO type consists of one double-row outer ring and two single-row inner rings, and is suitable for locations with moment loads.

FAQ

Q. What are the differences in construction and application between TDI type and TDO type double-row tapered roller bearings?

A. The TDI type consists of two single-row outer rings and one double-row inner ring, and is used with an outer ring spacer. The TDO type consists of one double-row outer ring and two single-row inner rings, and is suitable for locations with moment loads.

Q. What are the features of the TDI/TDO series double-row tapered roller bearings?

A. They have bearing clearance pre-adjusted with an outer ring spacer. They also feature oil grooves and oil holes for lubrication.

Q. What applications are TDI/TDO type double-row tapered roller bearings used for?

A. They are used in medium-load applications such as rolling mill roll necks, speed reducers, and winding machines.

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

Source documents

• Catalog JTEKT 大形転がり軸受カタログ（技術解説・軸受寸法表）
  Found on: https://koyo.jtekt.co.jp/support/catalog-download/