.... The bearings have a bore diameter of 60 mm and 90 mm, respectively. Jet and under-race lubrication techniques have been used to supply oil to the bearings under test. The custom-made aero-engine test bearing features special channels to allow under-race lubrication of the rollers/races contacts as well...

...S. Adnan Qasim; M. Afzaal Malik; M. Ali Khan; R. A. Mufti A fully established elastohydrodynamic lubricating (EHL) film between the piston and the liner surfaces during normal engine operation minimizes piston slap and prevents adhesive wear. Wear cannot be prevented in the initial engine start up...

...Alejandro Cerda Varela; Ilmar Ferreira Santos This work is aimed at a theoretical study of the dynamic behavior of a rotor-tilting pad journal bearing (TPJB) system under different lubrication regimes, namely, thermohydrodynamic (THD), elastohydrodynamic (EHD), and hybrid lubrication regime...

...Adolfo Delgado; Giuseppe Vannini; Bugra Ertas; Michael Drexel; Lorenzo Naldi This paper presents the identification of the rotordynamic force coefficients for direct lubrication five-pad and four-pad tilting pad bearings. The bearing is 110 mm in diameter with a L/D of 0.4 pad axial length (44 mm...

...J. Aidarinis; D. Missirlis; K. Yakinthos; A. Goulas The continuous development of aero engines toward lighter but yet more compact designs, without decreasing their efficiency, has led to gradually increasing demands on the lubrication system, such as the bearing chambers of an aero engine...

... resolved measurement of the forces on the cylinder along three axes—in the axial direction, the thrust direction, and along the wrist pin. Three different lubricants with differing properties were tested to observe the friction characteristics of each. The experimental results showed that the floating...

...Moussa Diaby; Michel Sablier; Anthony Le Negrate; Mehdi El Fassi On the basis of ongoing research conducted on the clarification of processes responsible for lubricant degradation in the environment of piston grooves in exhaust gas recirculation (EGR) diesel engines, an experimental investigation...

...Yaguo Lu; Zhenxia Liu; Shengqin Huang; Tao Xu A software, general analysis software of aero-engine lubrication system ( GASLS ), for simulating aero-engine lubrication system is presented. The software is capable of analyzing the flow, pressure, and temperature distribution in the lubrication...

...Manish Kumar; Daejong Kim Airfoil bearings offer many advantages over oil-lubricated bearings, but they have reliability issues during start∕stops (wear) and limited heat dissipation capability. To address these issues, a hybrid airfoil bearing (HAFB) combining hydrodynamic airfoil bearing...

... at high speeds are employing gas bearings, thereby eliminating costly mineral lubricant supply systems and allowing for more compact units satisfying severe environmental constraints. The development of gas bearing technology for these applications follows a path of extensive experimentation accompanied...

... to carry out a survey aiming to reduce power losses in bearing chambers. The test bearing was a 124 mm PCD ball bearing with a split inner ring employing under-race lubrication by two individual jets. The survey was carried out in two parts. In the first part, the investigations were focused on the impact...

... was proportional to U 0.6 . A linear fit to the same data, setting friction force proportional to U and consistent with hydrodynamic lubrication, gives a significant offset at zero relative bearing speed. A possible explanation is that the bearings were not fully flooded and/or may have operated...

...Ilmar F. Santos; Rodrigo Nicoletti; Alexandre Scalabrin In this paper the complete set of modified Reynolds’ equations for the active lubrication is presented. The solution of such a set of equations allows the determination of stiffness and damping coefficients of actively lubricated bearings...

... processes at rotating radial holes (Glahn, A. et al., 2001, “Disintegration of Oil Films Emerging From Radial Holes Inside a Cylinder,” ASME Paper No. 2001-GT-0202) and has used the same approaches in simulating one of the droplet generation sources in aeroengine lubrication systems. Both papers aim...

... of an axial bore profile on radial dynamics of a ring is investigated. Radial ring motions within grooves due to the axial bore profile can generate significant inertial effects and also have an impact on ring end-gap sizes and lubrication conditions at the ring-liner interfaces. The magnitude of such effects...

... similar engines were operated using optimum biodiesel blend and mineral diesel oil, respectively. These were subjected to long-term endurance tests. Lubricating oil samples drawn from both engines after a fixed interval were subjected to elemental analysis. Quantification of various metal debris...

... engines lubrication liquid films size effect high-temperature effects temperature distribution heat transfer viscosity One method utilized to promote energy savings in internal combustion engines is to reduce the power loss caused by mechanical friction on lubricated surfaces of engines...

... . Hoffman , J. G. , 1979 , “ Crankcase Lubricants for Four-Cycle Railroad and Marine Diesel Engines ,” Lubr. Eng. , 35 , pp. 189 – 197 . Pratt , T. N. , et al. , 1981 , “ HVI and MVI Locomotive Diesel Engine Oil—Open Forum ,” Lubr. Eng. , 37 , pp. 577 – 591 . Brockett , T. S...

... actuators are introduced into the equations of the lubricant, resulting in a new form of Reynolds’ equation for active lubrication. The global model of the system is obtained by coupling the equation of motion of the rigid rotor with the stiffness and damping of the active oil film. This global model...

..., and the use of cryogenics as lubricants. The importance of using appropriate simulators that duplicate the actual equipment in evaluating the application of compliant bearings is demonstrated via two specific examples; one, a simulator to evaluate bearings for an air cycle machine and another for an advanced...