Hydrodynamic Bearing Design Data
Hydrodynamic Bearing Design Data
(OP)
Hi there
can anyone refer me to some freeware or similar for the design of a journal bearing.
Approx scantlings are:
Load: around 200T
Diameter: 1.5m
Width: 0.6m
Surface speed: 1 m/s
Lube: ISO 220 cSt (I hope)
Its a 180 degree bearing on an old ball mill that we are putting back in service. I want to do a check on heat, lube flow, and to estimate the runnning lift.
Can do by hand/spreadsheet, but it takes an age.
Thanks in anticipation,
Steve McKenzie
can anyone refer me to some freeware or similar for the design of a journal bearing.
Approx scantlings are:
Load: around 200T
Diameter: 1.5m
Width: 0.6m
Surface speed: 1 m/s
Lube: ISO 220 cSt (I hope)
Its a 180 degree bearing on an old ball mill that we are putting back in service. I want to do a check on heat, lube flow, and to estimate the runnning lift.
Can do by hand/spreadsheet, but it takes an age.
Thanks in anticipation,
Steve McKenzie





RE: Hydrodynamic Bearing Design Data
http://www2.latech.edu/~mcorley/me462/bearing/Bearing.htm
RE: Hydrodynamic Bearing Design Data
Your lift will only be a few thousands of an inch, approximately 0.002” to 0.010” depending on your bearing design and oil characteristics. More important than the amount of lift is the bearing lead-in taper. Trust me; I’ve fought with bearing problems on several old ball mills and kilns, with good and bad journal conditions.
Whatever you do, don’t’ use less that 0.0015” radial clearance measured across the diameter, per inch of journal diameter. So in your case the journal bearing should be machined 0.090” larger in diameter that the journal (minimum). Then you can adjust the lift as needed using oil viscosity and oil type. Surface roughness and radial run-out are also important considerations in old ball mills.
Also, be sure to NOT allow the installing contractor to scrape your new bearing to get “100% contact”. Most installers don’t know how to measure bearing contact, and they end up ruining a new bearing during the installation process.
If you need more information, feel free to call me at 641-423-9363 with more details about your application. Good Luck, Paul Juhnke, Maintenance Engineering Services.
RE: Hydrodynamic Bearing Design Data
thanks for that. We stayed with the manufacturers recommended clearances of 0.030" each side (0.024" measured 8" down from the top of the 180 deg slipper bearing). Kept a 40 degree non-clearanced bed at the bottom. /getting around 0.008" static lift at 30 deg C, although I think the running lift is higher. The oil feed horns are staying full of oil and there is no sign of distress to the bearing or lube system.
The web site suggested by Balu gave a fairly good approximation of the operating conditions. Used SAE 50 oil which is not too far away from VG220. I also worked it out by hand using the correct parameters for a 180 deg slipper bearings. Reasonably good correlation.
Cheers
Steve McKenzie
RE: Hydrodynamic Bearing Design Data
RE: Hydrodynamic Bearing Design Data
Cheers
Steve McKenzie