DEVELOPMENT OF A 250,000 LB THRUST BEARING TEST RIG WITH EXPERIMENTAL RESULTS

As the power density of rotating machinery increases, individual component requirements stay the same, while also needing to decrease in size. The design of high-load roller-element thrust bearings involves minimizing the bearing envelope while also maintaining load capacity and life. This paper introduces a new thrust-bearing test rig that uses spherical point loading to deliver up to 250,000 lbf of axial load at speeds up to 60 rpm. This test rig is unique to the literature both in its bearing load and its ability of the rig to test a bearing to the point of failure. The test shaft is spun by a 25 hp motor with a 50:1 speed reducer. The load is applied from a hydraulic pump and a stinger onto a stationary housing. The test rig uses two thrust bearings in a back-to-back arrangement for transferring the applied thrust. The first bearing is the test-bearing, and shaft / housing sleeves allow for a range of sizes and types. The second bearing is a standard tapered roller thrust bearing and is rated for 20 rpm and 1,100 kN (250,000 lbf). A third bearing provides additional radial support to the system. The rig is capable of testing a range of bearing sizes. The bearing housing and shaft use spacers to accommodate bearings from five to eleven inches in diameter, and zero to two inches in length. The rig measures bearing performance through axial displacement and test-bearing drag torque. Water cooling maintains bearing temperature throughout the test. The paper also presents experimental results for a 10-hour test of a new roller element bearing.