Listed below are some common types of installation damage that may occur in needle bearings.These types of damage may occur if the installation guidelines listed on the front of this sheet and the specific recommendations of your equipment suppliers are not followed.
If a bearing is installed with an improper installation tool, such as a hammer and punch or a piece of tubing, the thin-walled cup may become badly damaged, causing the rollers to lock up. Use of a hammer – even with a correct tool – may cause lip damage (Fig. 1).
A ball detent is important when installing a full complement bearing. It forces the rollers apart, gathering circumferential clearance in a single location. This action straightens the rollers within the cup, making them parallel with the bearing axis. If the rollers are cocked or skewed, it is likely that they will lock up when installed, creating the potential for the bearing to burn up during service (Fig. 4).
The installation tool should have a 15-degree angle on its shoulder. This assures that the press load is delivered in line with the cup wall. A lip on the bearing may collapse, fracture or break during assembly if the proper angle is not used (Fig. 3).
When the bearing was installed using a pusher without a ball detent to align the rollers, the rollers locked in place as the cup shrunk during installation. The shaft then spun against the locked rollers.
If no pilot is used to guide the bearing, the bearing may become tipped or cocked relative to the housing. As the bearing is pressed in, the housing bore corner will crimp the cup outer diameter against the rollers damaging the bearing (Fig. 2). This damage could result in reduced service life, increased operating noise level or lead to other damage.
ech ips is not intended to substitute for the specific recommendations of your equipment suppliers.
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Every reasonable effort has been made to ensure the accuracy of the information contained in this writing, but no liability is accepted for errors, omissions or for any other reason.
© 2006, 2009 The Timken Company 10-09 Order No. 10066
WARNING Failure to observe the following warning could create a risk of serious injury.
Proper maintenance and handling procedures are critical. Always follow installation instructions and maintain proper lubrication.