I've a question and hope someone could help me with I need to transmit some rotational motion provided from a rotational stage present in air inside a chamber filled with water. the chamber is around 5x5 cm has anyone an idea if something exists like a waterproof rotation stage or even better (considering I have a normal rotational stage) a waterproof axis taht could trasnmit the motin from air within the chamber without any leaking?
tahnks -Claudio
ClaudioV wrote in news:1189617173.414630.214440 @k79g2000hse.googlegroups.com:
I am somewhat confused by your description, but if the essential question is, "Is is possible to put a drive shaft with a water tight seal through a wall ?" The answer is yes, easily.
There are many ways to do it and the specific answer depends on things like rotational speed and pressure differential.
A common example is the agitator drive shaft in a standard washing machine. The solution in that case is a ceramic face seal.
Supposing the internal pressure is nominal, you would place the stage in a waterproof box, then arrange means to transmit rotation into the box. Here are several methods
1) seal a bowden cable of the type used by mechanical speedo drives into the box, and out of the chamber and rotate it remotely. 2) Use a non-contact torque transmitter - such as a disk on a coaxial shaft each side of the water proof box with strong magnets glued to both disks 3) Use a waterproof shaft seal (!!) into the box. Smaller diameter is better. etc., etc., etc.Brian W
A sketch would help. If you do not have any web space, you can email the sketch to me, and I'll post a link to the image here.
Some alternatives:
- magnetic drive pumps generate rotary motion, without any seals.
- there are devices available that will allow transmission of electrical power (a hundred watts or so) via RF. The water may make this problematic.
David A. Smith
Claudio, Maybe you could use device like a magnetic stirrer. A motor outside your chamber rotates a strong magnet. Inside your chamber you have an impeller made out of magnetic material that rotates as the magnetic field rotates. See:
You could also try a vortex mixer which moves the entire chamber in a circle. See:
Good luck,
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