Chromatography Forum

Hello,

We have run into a small problem with our Shimadzu LC 10AD VP pump and i thought i will take a shot at it here for a solution. One of the two roller bearings (a cam follower) doesn't seem to be functioning properly and gets stuck frequently. I am definitely not buying the whole pump because of just a roller bearing and Shimadzu doesn't seem to sell just the bearing (doesn't even have a part number for me to refer to).

Has anybody come across such a problem with the Shimadzu pumps? Does anybody have an idea where to get that specific roller bearing from. It doesnt seem to be a standard bearing and so i have not had success with the bearing suppliers here in Canada. It is about 10mm in length, 5 mm in ID and 10 mm in OD.

Any suggestion/input is welcome. Thanks in advance!

Suresh.

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Are you able to lubricate this part? I remember having to lubricate the cams on these pumps every couple years, but I don't know if that was the "cam follower" you speak of. There is a sponge near the cam and I would place oil on the part above this. I believe gun oil works.

JJG,

Thanks for the response. You are right about the sponge. The original problem appears to be because of the sponge wearing out and the debris collecting and jamming the roller bearing. Apparently it wasn't lubricated as it was supposed to have been done as part of a routine maintenance. I have replaced the sponge and lubricated the cam (basically soaking the sponge with lubrication oil). The bearing works for a while but stops abruptly. We bought this pump second hand only a couple of months back and so i am not sure how well it was maintained earlier.

Suresh.

JJG,

"Cam follower" is the bearing which is in contact with the cam.

Suresh.

You say it works for awhile, and then abruptly stops. Any hope for just lubricating it every couple months? How long does it last, and does re-lubricating it get it going for awhile longer? Unfortunately, I too am unsure where to get a replacement part, unless you order a whole pump assembly from Shimadzu instead.

It has been working for the last 48 hours without any problem. Don't know when it will strike back again. Its well lubricated, but dust particles already in the bearing makes the lubrication oil murky in just a few minutes.. Also, when the bearing gets stuck, the pump still keeps running for a few minutes with a noise and thats when i know that the bearing is not working.

That is only part of the problem. The bearing goes into a pin which is held on either side by the crank (if you still remember the pump assembly). The bearing seems to be touching the crank as well (ideally it should just sit on the pin) and part of the crank is worn out as well. But i can easily fix that by phasing the crank surface.

Suresh.