Insight into a plate roll issue

After a couple hours of use (depending on thickness of material and length of rolling) my Turkish built plate roll starts to make a "grinding" noise, but only when rolling in a clockwise direction (from the operator's position). Thicker material formed to tighter diameters will cause the sound to start quicker than if I am rolling thinner material (ie. when the machine is under more stress). At first I will only hear the noise a little as I change to a clockwise direction in rolling, but it will increase over the next 10-15 minutes until it is a constant grinding noise whether the machine is under pressure or not. If I shut the machine down for the day and come back in the morning, all is fine again. This has been occurring for years and hasn't seemed to be getting any worse. My best guess is that the bearings may be heating up and expanding, thus causing them to grind, but that wouldn't explain why it is happening only when the rolls are turning in one direction.

I've tried to locate the source of the sound and even resorted to a mechanic's stethoscope, but the sound seems to emanate from the entire frame of the plate roll and it's impossible to pinpoint when I am under the plate roll looking for the source.

I've been a plate roll operator for 25 years and this is the only machine I have operated that has had this issue. I've posted a link to a short video I created to try and give you an idea of the sound. You don't really hear it until about the 35 second mark and even then only for a few seconds. I didn't have any more material to roll form after this piece to make the grinding sound more audible, so this is the best I have for now.

Dropbox - 20190503_143854.mp4 - Simplify your life

Any insight? Thoughts?

I have an upcoming project that will require the rolls to work properly for at least a full 8 hour day and I'm hoping someone may have experienced this in the past and can explain what is going on.

Kilroy,

Welcome to the forum.

Your explanation and video are superb, congratulations. What is the prime power source for the rolls..the video makes it appear to be hydraulically powered. If this is true, is each roll powered by its own hydraulic motor? The sound is most likely coming from the drive..whatever that may be.

Stuart

atomarc said:

Kilroy,

Welcome to the forum.

Your explanation and video are superb, congratulations. What is the prime power source for the rolls..the video makes it appear to be hydraulically powered. If this is true, is each roll powered by its own hydraulic motor? The sound is most likely coming from the drive..whatever that may be.

Stuart

Click to expand...

It is a 4 point pinch hydraulic plate roll and I'm quite certain the sound doesn't come from the drives or the planetary gearboxes. The upper and lower center rolls are powered. I will focus on monitoring the drive/gearbox the next time I encounter the sound just to rule it out. Thanks for the suggestion!

Hydrulic pump oil cavitation do to something not dissimilar to a collapsed strainer - collapsed suction hose has that kinda sound, the fact its had it for a while and not failed points to it being something in the hydraulics oil flow causing it as a best guess. Bearings or similar don't sound like that and then not get worse!

Could well be what ever bleed off valve sets the top rollers pressure, one direction of travel leveraging the cylinder that bit harder.

Hydrulics when worked hard - under higher pressures will make a noise resontate through out a whole machine like that too.

adama said:

Hydrulics when worked hard - under higher pressures will make a noise resontate through out a whole machine like that too.

Click to expand...

It sounds similar to my drill rolls when the outfeed hydraulic motor is slightly faster than infeed with a big beam between the two. The infeed motor and lines have that metallic whine that you can not trace as motor is being spun faster than fluid.

ps sweet rolls

Sound like the oil is getting overheated, and then it starts
acting up (making noise) cavitating as listed above.

Try a multi viscosity oil.

Rolling one way rotation a bearing or a gear may side thrust one way and with the other rotation side thrust the other way. bearing may be dry on one side...Hydrulics? Yes that also. I Ran a big old 96" Thompson grinder that started making a grinding noise with one way long travel and that turned out to be a Hydrulic noise.

Nice machine..how thick can you roll?