How does this piezo transducer couple?

[DaveC]

<
http://www.ebay.com/itm/100W-28KHz-Ultrasonic-Piezoelectric-Cleaning-
Transducer-Ultrasonic-Cleaner-
/171095661313?pt=LH_DefaultDomain_0&hash=item27d6189b01>

The bolt running through the center appears (repeat: appears) to bolt the
ends of this transducer together. Which defeats the goal of a transducer of
this type (to vibrate in the axial direction).

How does this transducer couple the brown ceramic disc piezos to the
"business end" (upper, in the main photo)?

Someone suggested that the bolt is actually a threaded tube with some kind of
driver stud in the center (if you look closely there does appear to be 2
separate pieces that make up what looks like the "bolt").

??

 

[DaveC]

I would think the bolt is to mount it and the energy coupled by inertia.

I agree with your assumption. But if the bolt goes completely through the
transducer, it cannot allow piezo (mechanical) movement in the axial
direction.

Note:
1. The non-business end is very heavy, steel or such
2. What you see protruding from the cone end (the "business end") is just a
short stud. This can be welded or otherwise adhered to whatever you want to
drive with this transducer and the transducer screwed onto the stud. I think
this stud is not the other end of the bolt head you see at the heavy end.
3. The bolt begins at the back (steel end) and goes... where? This is the
conundrum. It can't go all the way through.
4. The heavy end acts as the large mass (I think of it like an anchor)
against which the piezo works the other end (the "business end") of the
transducer.

But the question remains: where does the allen bolt thread into? ::

<http://tinyurl.com/mxkg9t8>

 

[Joerg]

<
http://www.ebay.com/itm/100W-28KHz-Ultrasonic-Piezoelectric-Cleaning-
Transducer-Ultrasonic-Cleaner-
/171095661313?pt=LH_DefaultDomain_0&hash=item27d6189b01>

The bolt running through the center appears (repeat: appears) to bolt the
ends of this transducer together. Which defeats the goal of a transducer of
this type (to vibrate in the axial direction).

How does this transducer couple the brown ceramic disc piezos to the
"business end" (upper, in the main photo)?

Someone suggested that the bolt is actually a threaded tube with some kind of
driver stud in the center (if you look closely there does appear to be 2
separate pieces that make up what looks like the "bolt").

One guess is that the bolt might be supposed to go through the surface
you want to insonicate and continues into some sort of support post or
structure. It's probably not to be torqued down with gusto, only meant
to hold the transducer in place.

Alternatively, the device may be mountable using a large soft washer and
insonication occurs by using its large mass, as Rheilly wrote. That
washer would have to be able to tolerate a lot of stress.

The red stuff around the bolt could be some sort of spacer material that
makes sure the bolt won't touch the PZT.

Why not ask the seller about the manufacturer's name?

 

[Kevin McMurtrie]

<
http://www.ebay.com/itm/100W-28KHz-Ultrasonic-Piezoelectric-Cleaning-
Transducer-Ultrasonic-Cleaner-
/171095661313?pt=LH_DefaultDomain_0&hash=item27d6189b01>

The bolt running through the center appears (repeat: appears) to bolt the
ends of this transducer together. Which defeats the goal of a transducer of
this type (to vibrate in the axial direction).

How does this transducer couple the brown ceramic disc piezos to the
"business end" (upper, in the main photo)?

Someone suggested that the bolt is actually a threaded tube with some kind of
driver stud in the center (if you look closely there does appear to be 2
separate pieces that make up what looks like the "bolt").

??

Various poorly translated web pages say that the bolt is a spring and
the metal cone is for impedance matching. It sounds like you shouldn't
mess with the bolt.

It looks like you need some high grade epoxy adhesive:
http://bluewaveinc.com/ultrasonic-cleaning-101/
http://hessonic.com/wp-content/uploads/2012/02/fundamentals.pdf

 

[Shaun]

"DaveC" wrote in message

<
http://www.ebay.com/itm/100W-28KHz-Ultrasonic-Piezoelectric-Cleaning-
Transducer-Ultrasonic-Cleaner-
/171095661313?pt=LH_DefaultDomain_0&hash=item27d6189b01>

The bolt running through the center appears (repeat: appears) to bolt the
ends of this transducer together. Which defeats the goal of a transducer of
this type (to vibrate in the axial direction).

How does this transducer couple the brown ceramic disc piezos to the
"business end" (upper, in the main photo)?

Someone suggested that the bolt is actually a threaded tube with some kind
of
driver stud in the center (if you look closely there does appear to be 2
separate pieces that make up what looks like the "bolt").

??


Stick it up your ass, I'm sure it will couple to the inside of you colon!!