Hydrodynamic Journal Bearing for Stamping Press

[nickjk]

Hi All,
I am currently trying to determine if the main and connection journal bearings used on a stamping press could be designed to use hydrodynamic lubrication.
The press is rated at 150tons so for approximation I am using 75 tons of load force at each of the 2 main bearings.
The bearing I am currently studying has the following features:
14" I.D.
4 1/2" width
Supporting Load (75tons) 150,000 lbs
Bearing Pressure 2,380 psi
Length/Diameter Ratio .32
Journal Speed 180 RPM or 3 rev. per second
Viscosity 20 Centipoises at 40c
I used the McKee chart to find my k value which I used to solve my friction value.
k was estimated at .008 and friction coefficient was calculated at .0081

When I calculate the S value to be used with Raimondi and Boyd charts I get a very small number like .0037 which seems like a problem.
Also when I calculated the change in heat the value was extremely high - change of 803 F degrees.

I do not know if the normal hydrodynamic calculations apply because the very high load of the stamping press is only present during 1/8 of its rotation and is not constant. Do you know of any information available on a similar application.

Any suggestions or advice on how to continue with these calculations would greatly be appreciated.
This is my first go at trying to solve this type of a problem.

Thanks in Advance

Nick JK

 

[MikeHalloran]

Three rev/sec does not seem credible for a press that large.



Mike Halloran
Pembroke Pines, FL, USA

 

[nickjk]

The Mechanical Press speed is currently 100SPM.
I am looking to see what I can do to increase it to 180SPM.
That is where the 1 rev per 3 seconds is coming from.
Used to blank and draw small parts

 

[SwinnyGG]

Three rev/sec does not seem credible for a press that large.

For a rotary press, that's not really all that fast. If this were a vertical press I'd agree.

 

[nickjk]

Made a mistake in my last post
180 SPM is 3 rev per second

Sorry for confusion
NickJK