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Mazak FF-660 spindle disassembly

Milling man

Hot Rolled
Joined
Aug 6, 2021
Location
Moscow, Russia
Hello dear colleagues!
I had a problem with disassembling the spindle on the Mazak FF-660 machine. The goal is to disassemble the spindle a little, look at the bearing markings, assemble the spindle, order bearings. During disassembly, decide whether I can change the bearings myself or whether I need to turn to professionals. Then I'll wait 2-3 months for the bearings and change them myself, or have a pro do it. Ok, let's get down to business. Spindle SK-40 15k, oil mist.


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The cooling oil circuit is visible on the left. Right side of flange to bed. Behind the large flange on the right is the rotor, followed by the "gear" of the magnetic encoder. The front cover has already been removed, here it is from the inside:

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And the view of the assembled spindle from the front:

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I thought that the spindle has something like this:

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I thought I'd take the front cover off and just slide the body to the right until it hits the rotor. And I hoped that this would be enough for me to see the bearing markings. But it didn't work, the hull didn't move. Maybe someone has dealt with something like this? I just don't have any ideas. The rotating shaft consists of 3 parts: the main part with bearings, the middle part with the rotor and the outer part with the "gear" for the encoder. The parts of the shaft are separated, I am almost sure, by the supply of pressurized oil. I don't see the point in taking it apart, because I don't see how it will help move the case. I've identified every hole in the case: oil mist, coolant, cooling - nothing that looks like a pressurized oil port.
Judging by what I was taught at the university, and by videos about the repair of "cool" spindles, landing bearings in the housing either with a small gap (a few microns) or with a minimum interference. I applied a force of about 200 kg, more is already scary.
 

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I'll write what bearings are here - I hope this helps someone.
In the front of the spindle - quadro duplex d=55 B=18 D=90 NSK 55BNC10TY DBBCA10P4Y
In the middle of the spindle roller bearing d=45 B=16 D=75 NSK JC21 NU1009 CCG12 P4X
At the rear end, to support the drawbar, there is a bearing d=25 B=22 D=47 NTN RNU 0533CS12 P5
 
I will add some more information.
The entire spindle can be taken out inside the working area of the machine without any problems. The drawbar remains inside the spindle housing. To remove the drawbar, you need to disassemble the knot for supplying the coulant to the spindle and unscrew the nut with a thread of approximately M33x1.5. After that, the drawbar can be removed in the same direction as the spindle.

To replace the bearings, we must first apply oil to the thread (1):

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the motor rotor will fly off the shaft. Then we need to blow into the threads on the sleeve located under the white thin metal cover, the sleeve will fly off the shaft. Bearings and distance rings between them are mounted on the shaft with a noticeable interference fit. We needed a press with a force of about 1.5-2 tons to remove them from the shaft.
 








 
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