oil holding rotary shaft

[Stefano0308]

Good morning.
I'm working on an oil bath clutch.

the tree that you see in the image, has a room below which is filled with oil not under pressure.
the radial seal, circled with red, is a hn2390 ptfe seal with the metal body.

the problem and that friction must be able to work in all positions, but when placed below it exudes oil after a few hours. the clutch will have to work up to 5000 rpm with an alternate cycle, " 3 seconds in braking, 3 seconds at rest. "

I chose this estate because at low friction as the clutch will be used as a control tool for other equipment and will be examined the pair curves.

I also tried the estate hms5 v , but unfortunately in the test phase adds too much torque due to the highest friction of the same.

do you have ideas/solutions on what kind of seal could I use to solve the problem?
Thank you for any answer you can give me.

Have a good day.

 

[TETRASTORE]

the type of seal indicated has characteristics suitable for your application type.
first glance would be to say to try the same model but with double lip and, possibly, with traces of hydrodynamic recovery but this approach is not the correct one.
first of all it is necessary to understand, if possible, why the used estate loses.
it begins with a visual examination of the lip and the surface on which it works to exclude strips or other damages suffered during the assembly of other organs, for example bearings, also check the possible presence of bachelization due to a poorly lubricated lip that generates high temperatures in the contact area
then proceed with the examination of the shaft by checking whether there are radial and axial oscillations or vibrations during operation.
important is also the concentricity of the tree, the hardness and superficial finish.
Also check if viscosity and the type of lubricant are compatible with the material of the seal and that a possible excessive quantity does not determine an increase of temperature resulting in increase of the internal pressure thus exceeding the declared maximum limit.

 

[Stefano0308]

thanks for the answer,
before changing seal I will check the shaft finish assembly and radial oscillations.

 

[Stefano0308]

the type of seal indicated has characteristics suitable for your application type.
first glance would be to say to try the same model but with double lip and, possibly, with traces of hydrodynamic recovery but this approach is not the correct one.
first of all it is necessary to understand, if possible, why the used estate loses.
it begins with a visual examination of the lip and the surface on which it works to exclude strips or other damages suffered during the assembly of other organs, for example bearings, also check the possible presence of bachelization due to a poorly lubricated lip that generates high temperatures in the contact area
then proceed with the examination of the shaft by checking whether there are radial and axial oscillations or vibrations during operation.
important is also the concentricity of the tree, the hardness and superficial finish.
Also check if viscosity and the type of lubricant are compatible with the material of the seal and that a possible excessive quantity does not determine an increase of temperature resulting in increase of the internal pressure thus exceeding the declared maximum limit.

the problem arises from the fact that the operators in the assembly damaged the hold with the toothing present on the tree. solved the thing with a centring equipment that drives the operator in assembly. everything now works great. Thank you.

about hydrodynamic recovery strips, they told me they're only fine if the tree turns in one direction, right?
thanks again for the support.

 

[TETRASTORE]

about hydrodynamic recovery strips, they told me they're only fine if the tree turns in one direction, right?

Yes, but since you solved this solution is no longer necessary, even if it was damaged during assembly it would have had the same problem.

 

[czar]

we also use them in our machines for years and one of the requirements to use them is the surface hardness of the rotating part (50 hrc) as well as the surface finish.
even in our case in the first installs the problems were related to poor insertion of the lip that compromised its integrity. another problem found was the effectiveness of the hermetic seal of the metal cage using mastic, we went to grip with or.