replacing bearings in Akira Seiki prototype machine 12k rpm spindle

[erikh]

This Akira Seiki RT-320 is a prototype machine from bankruptcy auction. It came with no manuals. I have contacted Akira Seiki to request manuals, but neither they nor any of the Akira Seiki resellers in the US have manuals for any machine remotely similar.

The particular peculiarity with this machine is its spindle: HSK-63 using a pin for retention. Which is insane. I've never heard of anything like it before. That's not how HSK is supposed to work. It should be clamped from the inside, so it presses against the spindle taper. It should NOT be pulled up like cat-40. But, it's a prototype machine, and it cost only $15k at auction.

When the machine arrived at my shop, much of the wiring and all of the pneumatic tubing had been essentially randomly reconnected by unknown people. It took approximately 100 hours of effort to make the machine and automatic tool changer function, again.

I only got approximately 120 hours of spindle time out of it, before the lower spindle bearings failed. I now realize that the spindle is meant to have oiled air going into it. I did attach the air-oiler to it, but it bled far too much air, so I disabled it. What I should have done, in retrospect, is turn down its pressure regulator, so it still received its oiled air but didn't keep my compressor running 24/7.

The only indication of spindle manufacturer is a single imprint on the spindle, which says "CAM". That's entirely useless, as a search term.

I have attempted to disassemble the spindle. There is an SC-050 coupling on the spindle drive shaft. With all bolts removed from the spindle motor and the bolts removed from the coupling, and the threaded part of the coupling wound as far down as it will go, 2500lbs of lifting force is insufficient to remove the spindle motor. I'm pretty sure any more force will simply break the Y axis casting.

Has anyone here seen anything like this ridiculous piece of shit? It made good parts, when it ran. I'd prefer to get it running again over parting it out and melting down the 18,000lb casting.

 

[mottrhed]

Your pictures aren't great, but I doubt that you have to remove the motor to drop that spindle. Im unclear what you "unthreaded", but I dont think that coupling needs to be unthreaded, unbolting the right parts should do the trick. You sure you arent unthreading something on the drawbar?

Also, you may want to be a little more critical of you oil system, depending on what this machine uses some systems simply wont function on lower psi, therefore your rebuilt spindle will die once more. What does the oil system look like? If you post a pic I can probably help.

 

[erikh]

Your pictures aren't great, but I doubt that you have to remove the motor to drop that spindle. Im unclear what you "unthreaded", but I dont think that coupling needs to be unthreaded, unbolting the right parts should do the trick. You sure you arent unthreading something on the drawbar?

Also, you may want to be a little more critical of you oil system, depending on what this machine uses some systems simply wont function on lower psi, therefore your rebuilt spindle will die once more. What does the oil system look like? If you post a pic I can probably help.

Thanks so much for replying. In the images above, you can see a flange part labeled "M50x1.5P" (text is upside down). This flange part was bolted to the flange above it. With those bolts removed, the lower flange rotates a few revolutions, and moves downward as if on threads. I assume it is on M50 external threads.

My motivation for removing the spindle motor is to get a clearer view down into the spindle cassette area, where there are additional bolts that are currently inaccessible. These bolts can be seen in the last image of my initial post in this thread.

These are what I'm guessing are the oiled air inputs to the spindle.


And this is the oiled air system. I think the little tank half full of light oil on the right is the reservoir from which the compressed air picks up oil.

 

[NAST555]

I suspect that you were meant to have an oil cooler on that machine. That would be what the "inputs" are for. On my Akira it sits in the cabinet just below the air lines inside the enclosure.
I don't think those machines came to South Africa but if you havent tried Akira themselves yet to get manuals I would start there. If you don't get a reply then email MJH Machine tools over here and see if they can get manuals for you.

 

[NAST555]

To add, the oil that you refer to in your picture is just to lubricate your air.

 

[mottrhed]

That m50x1.5 is almost certainly a nut. 50mm x 1.5mm pitch. The motor is not going to be held to the spindle with a nut, so that nut is serving another purpose and likely does not need to be removed to get it apart.

Looks like a basic oil mist setup, which is easier in this case than oil injection would be, but yes without that system operational the bearings will fail in short order.

Is the drawbar actuator above the motor? As in, does it push through the motor shaft to actuate the spindle drawbar? If so, naturally you may have to take that assembly off the top before going any further.