The past few decades a considerable amount ofimprovement is made in the design of hydrodynamic journal bearing to increasethe working life of journal bearings. At the same time many experiment werecarried out to see the effect of parameters like speed (rpm), pressure of thelubricant, lubricant types etc on the bearing performance as well as the lifeof bearings.
Journal bearing designed for work where load andspeed is variable and may reach very high values. In this condition bearing mayoperate in the stable lubricant region and that operating temperature of thebearing may not exceed some fixed values. Samuel A. McKee, 1937.Experimentaldata obtained in this paper indicates that the minimum point obtained in thecurve f-ZN/p occurs at a values ranging from 1 to 50 and also depending uponthe bearing materials, machining of the bore and the amount of running-in. Thevalue 30 would be good for bearing having reasonable amount of running-in. Compressivestudy of different factors affecting the heat dissipation for different typesof bearings were also studied.
A journal bearing consist of shaft which rotatesfreely in metal sleeve or shell and has no rolling contact. Two differentcommercial lubricant oil SAE20W50 and SAE90 were used to study the lubrication,types of pressure distribution, and the stresses developed in the bearings andthe stresses developed in the bearing under varying loads and speed.Srinivas,Dr.Mohammed Yunus, Dr.Shadi M.Munshi, Dr.Iftekar Hussain,2015.
It was foundthat SAE90 is better than SAE20W50 in terms of load carrying capacity.Different profiles of Journal bearings are also experimentallystudied. Stability analysis of a lemon bore journal bearing Evgeny Kuznetsov,SergeiGlavatskih, ESDA 2008.polymer composite linings hydrodynamic journal bearingprovide improved performance during startup by decreasing the break-away torque.
Lemon bore journal bearing with PTFE surface are compared with the rigid babbittedlemon bore journal bearing. The result obtained shows that the load carryingcapacity of the bearing is increased at low eccentricities and reduced at high eccentricities;stability of the journal bearing is also increased at high eccentricities. Study of pressure profiles in hydrodynamic journal bearingsChetan Mehra, Amar Singh kokadiya, Neelesh Khandare, 2014.The pressurecondition of the fluid is critical to ensure a good lubrication of hydrodynamicjournal bearings. In this study, an experimental work was carried out todetermine the pressure distribution around the circumference of thehydrodynamic journal bearing and fluid frictional force of the bearing causedby shearing actions.
The result obtained were experimental pressure data foundto be higher than theoretical data and the point of maximum pressure was notchanged with respect to loads however the position of minimum film thicknessvaried with the loads.Performance characteristic of finite hydrodynamicjournal bearing under micro polar lubrication with turbulent effect SubrataDas, Sisir Kumar Guha,2013. In this analysis, the turbulent shear stresscoefficients are used based on the Constantinescu’s turbulent model suggestedby Taylor and Dowson with the assumption of parallel and inertia-less flow.Thenumerical solution of the modified Reynolds equation has yielded thedistribution of film pressure which determines the static performancecharacteristics in terms of load capacity, attitude angle, end flow rate andfrictional parameter at various values of eccentricity ratio, non-dimensionalcharacteristics length, coupling number and Reynolds number.
The resultsobtained were load carrying capacity reduces with the increase in nondimensional micro-polar length; with the increase ofaverage Reynolds number improves the load capacity at any value of non-dimensionalcharacteristics length.Analysis of Pressure distribution and frictioncoefficient of hydrodynamic journal bearing Akash S.Patel, Prof.
N.D Patil,Pramod R. Mali, Mr.Kaustubh S. Zambre,2017.
The aim of this work was to developdata for better design methods for lubricated journal bearings. The frictionalcoefficient increases with the degree of misalignment at lower values of theeccentricity ratio. Pressure generation is due to fluid being driven from thickend to thin end of wedge shaped fluid film by the surface movement, thevariation of the surface velocity from place to place and the variation ofsurface gap (film thickness). Journal bearing vibration and ssv hash Scan M.
DeCamillo,Minhue Hi, C.Hunter Cloud, James M.Bryne,2008.Peculiar, low frequency, radialvibrations are observed in journal bearings. This paper presents data fromvarious tilt pad journal bearing test.
The vibrations characteristics aredefined under the condition of speed, load, oil flow and bearing orientation.Similarly, Active vibration control by using piezoactuator.Jaroslav Los,Jaromir Skuta. The actively controlled journal bearing consistsof a movable bushing, which is actuated by two piezoactuators. The journalvibration is measured by a pair of proximity probes.
The control system enablesrun-up, coast-down and steady-state rotation.