A New Fluid Film Bearing Test Rig for Oil and Water Bearings

Abstract

Ever-increasing demands on the turbomachinery industry result in faster, lighter machines with higher rotational speeds and power densities. Modern, well-established thermoelastohydrodynamic (TEHD) analyses predict static and dynamic bearing characteristics in the presence of a turbulent lubricant and reduced lubricant flows. Proper design of tilting-pad journal bearings (TPJB) is required for successful operation of rotating machinery. Bearing static effects include pad temperature, bearing pressure profile, and static operating position. Bearing dynamic effects include stiffness, damping, and added mass coefficients. The current body of experimental data does not include the entire range of speed and load for which TEHD analyses are thought to be valid or where industrial machines operate. Experimental data for both oil-lubricated and water-lubricated bearings is desired. Oil lubricated bearings are used in high-speed turbomachinery. Water bearing data are of interest for applications that use the process fluid as the bearing lubricant. This paper describes a new Fluid Film Bearing Test Rig (FFBTR) which is being designed to experimentally verify the TEHD analyses, both in the laminar and in the turbulent regime, and support industrial needs. Static bearing characteristics will be measured with temperature probes, pressure probes, and displacement measurements. The dynamic bearing coefficients will be identified by rotor perturbation with active magnetic bearing force actuators. The rotational speed range of the FFBTR will be 9000–22000 rpm. The test bearing size is 127 mm, giving a range of surface speeds of 60–146 m/s. The range of bearing length-to-diameter (L/D) ratios that can be tested will be 0.5–0.75. Separate lubrication systems for water-lubricated and oil-lubricated bearings will be provided. Two magnetic bearings will be used as non-contact force actuators for rotorbearing system perturbation. The designed capacity for the magnetic force actuators is 13 kN/exciter, for a total static plus dynamic load of 26 kN that can be applied to the test bearing. The actuators are designed to apply forces to the test rotor at non-synchronous frequencies up to 560 Hz. Bearing static characteristics will be measured. Static measurements will include lubricant pressure profile, lubricant and pad temperatures, and static eccentricity. During dynamic testing, test shaft and bearing tilting pad motion will be measured. Dynamic bearing stiffness, damping, and added mass coefficients will be identified from force and displacement measurements. The frequency dependence in tilting-pad journal bearing coefficients will be investigated. The combination of static and dynamic measurements will be used to validate the TEHD analyses and provide design information to industry.

Selected Problems of Experimental Testing Marine Stern Tube Bearings

“…Technological development allows to create more and more perfect testing stand solutions. A very interesting concept close -for many reasons -to an ideal is the stand for testing a single bearing, in which, instead of supporting roll bearings, active magnetic bearings are used [70], [71], [72]. Owing to that, it is possible to fluently exert a load coming from the two-sided support and, additionally, to set a skew position which usually has a destructive effect on slide bearing and practically always happens in spite of the measures to reduce it to a minimum regardless the costs.…”

Experimental Evaluation of Lubrication Characteristics of a New Type Oil-Film Bearing Oil Using Multi-Sensor System

“…Under all comprehensive rigorous experimental conditions, bench testing can realize the operation under different conditions of devices and can intuitively reflect the operating performances of oil. Testing oil-film bearing oil is mainly done on the oil-film bearing test rig [11][12][13]. The final procedure of oil development is the running test, and the test for oil-film bearing oil is required to be conducted on an on-site rolling mill [14,15], but too many influential factors need to be considered, and even the normal production of enterprise will be influenced or interrupted, so it is difficult to implement this method.…”

Thermal Characteristics of Water-Lubricated Ceramic Hydrostatic Hydrodynamic Hybrid Bearings

“…Zhang et al [11] studied pressure distribution, temperature field and dynamic characteristics of hydrostatic hydrodynamic hybrid bearings through experiments. Dimond et al [12] described a fluid film bearing test rig which was designed to experimentally verify the thermoelasto-hydrodynamic analysis, both in the laminar and in the turbulent regime. In this test rig, separate lubrication systems for water lubricated and oil lubricated were provided.…”