Unitized mud-lubricated angular contact bearing

To address the maintenance and loose-ball concerns of many motor rebuilders, QA Bearing Technologies has developed a unitized, mud-lubricated, angular contact ball bearing.

Design features include the following:

• a single, high angle of contact (typically 45° to 60°) in thrust;
• thrust shoulders are increased to accept the higher contact angle, and a chamfer on the outer shoulder edge of both races provides additional space for mud flow through the assembly;
• a full complement of large Rockbit balls is used in the bearing; and
• a patent-pending, "wear-gauge retaining ring."

The assembly is physically held together with its wear-gauge retaining ring. This ring keeps the bearing in a unitized assembly until the balls have worn to a predetermined amount. At that point, the bearing will disassemble once the gauge ring ID is able to pass over the worn balls. A disassembled bearing is to be considered "worn out" and should be replaced with the other bearings being used in its stack. No measurements or matching of races is necessary, and no loose balls are required.

A number of unitized mud-lubricated ball bearings may be assembled into a single stack. The high contact angle produces a much higher thrust capacity; however, a number of bearings must be mounted facing in the opposite direction to account for the off-bottom thrust load.

The result is a mud lubricated bearing stack that is less expensive to operate, easier to maintain, and better suited to the drilling loads in the application.