EN |  FR |  DE



( unknown )

Previous posts

My Blog

Bearings Selection Guide  
by   braincelery1

The ARMD software package is capable of facilitating comprehensive evaluations of fluid-film bearings. 10. A fluid bearing system journalling a rotatable shaft, comprising a deformable journal sleeve surrounding said shaft, support means for supporting said sleeve about its outer circumference along three axial lines at least one of said support means being freely movable radially of said sleeve, means resiliently prestressing said one support means to deform said shell to create at least one wedge with respect to said shaft and supplying fluid to said wedge whereby on rOtation of said shaft said wedge displaces said fluid and causes the same to create a pressurized film layer continuously about the shaft, to cause said sleeve to overcome said prestressing.
The friction coefficient values shown in Figure 8 were taken from both "Machinery's Handbook, 24th ed." and from "Design of Machine Elements", by M.F. Spotts, Professor of Mechanical Engineering, Northwest University ( ref-2:2:302 ). Both reference works agreed that the low-point is about 0.001, the fluid film range is from 0.001 to at least 0.005, the boundary region is greater than 0.1 to as high as 0.03, and the mixed region is between the other two, as shown on the plot.
When the bearing is in operation, the rotating part of the bearing carries fresh oil in to the pad area through viscous drag Fluid vertical bearing pressure causes the pad to tilt slightly, creating a narrow constriction between the shoe and the other bearing surface.

To keep the film of fluid compressed, it is necessary to prevent the sheets 3 from separating too far from the shaft 6. The restraining means 4 acts on the sheets 3 separated from the shaft 6; the restraining means 4 only have a very slight, or no, action on the sheet 3 when they are in contact with the shaft 6.
The present invention is intended to overcome the problem presented by uneven support pressure acting on the underside of the belt that can result in uneven belt wear by providing an improved air box construction which produces an evenly balanced support pressure and thus promotes long belt life.

An increase in this stability reserve can be achieved by adapting active servo control systems on the conventional bearings, as was presented by Santos (1994), Santos and Russo (1998) and Santos and Scalabrin (2000) in the theoretical and experimental investigations of two different kinds of active tilting pad journal bearing, and by Bently et al. (2000) in the experimental work with a hydrostatic journal bearing.
1. The fluid ports 56 of the ring assembly pass fluid directly to the squeeze film 61 through the annular stationary ring assembly 50. Just inside of the squeeze film cylinder are two annular fluid plenums 64 that receive fluid from fluid ports 62. Fluid in these plenums is contained by seals 66 and 68 that seat between the squeeze film cylinder and the spring support 20. These fluid plenums provide a reservoir of fluid that is supplied to a thin oil film 80 surrounding the journal bearing through fluid ports 70 in the spring support and the bearing sleeve.