electricpete
Electrical
- May 4, 2001
- 16,774
See attached, which was taken from page 22 here:
Which is also accessible by clicking on: Module 2
"Hydrodynamic Lubrication of Journal Bearings Theory and Practice"
under "journal bearings" here:
The lines going from upper right to lower left make good sense to me.
For simplicity, if we assume constant/fixed values for radius r, clearance c, speed N, and alas viscosity mu, and fixed L/D=1 for example, then the chart simply tells me that as we increase applied load P, we move to the left on the graph which gives lower values of min film thickness hmin. So far so good.
What I don't understand is the lines marked "min f" and Max F" which accompanying label "The left shaded zone defines the optimum ho for minimum friction; the right boundary is the optimum ho for maximum load"
The min f I think I can cope with (either min friction factor or min product friction factor times load, I'm not sure which). The max load F,I'm having a problem with. For one thing the load of bearing matches applied load anywhere on the curve. If we're looking at the right-most boundary of this triangular region, that would be minimum load. For another thing, there are several things which can limit bearing load (hmin at low Stribeck number, temperature at high stribeck number, possibly material yield from pressure in between).... which of these is being described in this load limit curve?
=====================================
(2B)+(2B)' ?
Which is also accessible by clicking on: Module 2
"Hydrodynamic Lubrication of Journal Bearings Theory and Practice"
under "journal bearings" here:
The lines going from upper right to lower left make good sense to me.
For simplicity, if we assume constant/fixed values for radius r, clearance c, speed N, and alas viscosity mu, and fixed L/D=1 for example, then the chart simply tells me that as we increase applied load P, we move to the left on the graph which gives lower values of min film thickness hmin. So far so good.
What I don't understand is the lines marked "min f" and Max F" which accompanying label "The left shaded zone defines the optimum ho for minimum friction; the right boundary is the optimum ho for maximum load"
The min f I think I can cope with (either min friction factor or min product friction factor times load, I'm not sure which). The max load F,I'm having a problem with. For one thing the load of bearing matches applied load anywhere on the curve. If we're looking at the right-most boundary of this triangular region, that would be minimum load. For another thing, there are several things which can limit bearing load (hmin at low Stribeck number, temperature at high stribeck number, possibly material yield from pressure in between).... which of these is being described in this load limit curve?
=====================================
(2B)+(2B)' ?