thrust bearing can bear jerk load?

Perhaps a better translation of this would be:

"How much shock load can a tapered thrust bearing (manufacturer xxxx, model yyyy) withstand?"

You will need to provide this information, or else dimensions and materials of construction.

ok you can say shock load bearing model is yyyy style bearing has twelve segments six in lower half and six in upper half bearing is lined with tin base white metal every segment has 40% taper area bearing i/d is 4 inches o/d is 7 inches speed is 1100 rpm

Bearings are not meant to withstand jerks. You will peen the races and it ain't nice to peen races. Look for some mechanism to absorb that jerk.

True, but it sounds to me like he is now describing a multi-segment tilting pad bearing - no races here.

Thrust bearings can take some shock load, though they are usually designed to counteract fairly steady axial thrust loads in most machines. How much shock load they can withstand is dependent on too many factors to even try to answer here. Very simply, the shock load should not be big enough to "squeeze out" the lubricating oil film wedge formed between the tilting pad and the thrust collar. If it does you get attrition/boundary conditions (rubbing contact) for a period until the wedge reforms. (If you have the design load of the bearing and you know the magnitude of the shock load you can pretty much work this out for yourself).

Having said that, the shock load, in trying to squeeze out the oil film. will put a high load on the bearing material and onto the thrust pad. This can lead to fatigue of the "white metal" and dis-bonding or cracking and or damage to the pivot surface of the tilting pad.

Contact the bearing manufacturer (or a very reputable bearing repair shop with design capability) to find out actual numbers for your specific bearing design.

True, true. I missed his second post.

my dear bearing is not tilting pad bearing is fix geometry taperland thrust having twelve taper l segment aplicaion. single helical single reduction gear box having speed ratio 5;1

Sorry, I did not read the question properly, I missed the "taperland". However, the answer remains the same except that the the bearing's ability to take sudden increases in load will be less than that for a tilting pad bearing of similar size.

This is because the "taper" is designed to form a suitable hydrodynamic force to compensate for a specific thrust load. If the load increase, this will alter the ratio of the film thickness to the taper.

The chances are that you will push through the oil film and do damage to the small flat lands.

I don't think he is describing a Kingsbury segmented shoe bearing because they are flat. The bearing is probably a tapered land bearing.

Which ever it is, the question is for all practical purposes of no use to anyone. Any bearing thrust or otherwise is designed to handle the intended load with a margin of safety. I can't imagine any one purposely designing with less than 10% overload capability and would have to wonder at the economics of designing anything with more than 20%. Rigging equipment excepted and I am sure many more things of which I am not speaking.

In the end analysis if you try to run a steam turbine on water and you don't fail the thrust bearing you are a lucky individual, and have no argument with anyone if you do.

Hi,

I have seen an application which is subject to shock loads where they had provided compressions springs between the face and the body which ensured the thrust bearing is always loaded and when the shock comes in the compressions springs take the load and pass it on to the bearings which are already loaded.

Ragotham