Whistling sound in the Rotary-Joint?

[amp-cnc.]

Whistling sound in the rotating joint? Cnc Vertical Center. At all spindle speeds and directions: High pressure coolant (CTS) through the spindle makes a whistling noise in the rotary joint? When CTS is switched off, the whistling sound disappears. Could it be air bubbles coolant from the CTS pump?

 

[Milling man]

@amp-cnc. Rotary joint heating up more than usual?

 

[amp-cnc.]

@amp-cnc. Rotary joint heating up more than usual?

No - it's not each time CTS turn on - When CTS is off no whistling!

 

[BT Fabrication]

I wonder if a fitting is packed with chips in it up on top?

 

[dandrummerman21]

What brand is it? Deublin?

Depends on the model. Our fancy machine with air thru the spindle has a spring loaded seal (which are carbide faces, by the way) that only goes forward when backpressure from the thru spindle coolant is present. When no coolant is coming in, it springs apart so no contact is made.

It could be damaged.

I would pull off the coolant supply, see how dirty it looks. blow it out if dirty. Could squirt some oil in it and see if that helps too.

Or like you said, could be sound from the flow of coolant going thru some chips stuck in a fitting. I hope you run with a filter bag for your pump.

 

[Milling man]

which are carbide faces, by the way

Most likely, inside the rotary joint is not carbide, but graphite. It is a classic material for rotating mechanical seals.

When no coolant is coming in, it springs apart so no contact is made.

Maybe I'm wrong, but it seems to be a slightly different scheme. When the culant is supplied, the seal is compressed, and when air is supplied, it is not completely compressed. That is, when air is supplied, the seal does not experience dry friction.