Double Row Angular Contact Ball Bearings In Centrifugal Pumps.

Abstract

Double row angular contact ball bearings are used extensively in ANSI type end suction centrifugal pumps and other fluid machinery. The double row angular contact ball bearing supports combined axial and radial loads, provides high shaft stiffness and limits the movement of the pump impeller, shaft, and seal. Recent studies, tests, and analysis of double row ball bearings operating in various conditions have both confirmed and contradicted some long held opinions, regarding the application of these bearings in centrifugal pumps. The studies indicate the Conrad type (e.g., without filling slot) double row angular contact ball bearings operate at lower temperatures than the maximum capacity failing slot type double row bearings at 3,600 rpm rotational speed. These lower operating temperatures result in longer bearing and lubricant life and greater pump reliability. The filling slot of the modern design maximum capacity double row bearing has been redesigned so that it seldom has direct influence n the bearing life and performance when correctly applied in the pump. Double row angular contact ball bearings having moderate to high contact angle and normal axial internal clearance operate at lower temperature and have better internal motion than bearings having lower contact angles and greater clearances in typical pump application conditions. The results and conclusions of the studies made with the double row angular contact ball bearings are discussed. The presentation also provides specific recommendations for obtaining the best performance and longest life of double row angular contact ball bearings in centrifugal pump applications.