High-speed miniature actuators

J

Thread Starter

James Ingraham

Anybody know about high speed, high-duty cycle miniature linear actuators? All the stuff I'm used to for linear motion is for moving big pieces of machinery around. I want something relatively inexpensive, with very short travel (about 2mm, maybe less) but high speed, continuous use, around 5 to 10 strokes a second. Solenoids seem like the obvious answer, but it's tough to find exactly what I'm looking for. I've been reading about artificial muscle for over a decade, and I understand there are some real-world examples, but I can't find any. Ditto piezoelectric linear actuators. I only need "bang-bang," going out to full stroke and then all the way back. Any ideas?
 
Hi James,

We use small pneumatic cylinders with high flow SMC valves and often get 30ms-50ms response for those kinds of strokes with relatively light loads. You can also use a rotary pneumatic actuator with an eccentric and a pneumatic speed control fitting if you want a bit more control over the profile. These can also have quite a bit of mechanical advantage if you hit them at the right point in the eccentric rotation.

If you need electric I've looked at voice coil actuators. They are not inexpensive but seem to be spec'ed great for small high performance moves. Definitely not a cheap or simple solution if you have compressed air at your disposal.

KEJR
 
J

James Ingraham

Thanks, Ken. I guess I was thinking that air would be too slow, not to mention overkill for something with such a short travel. I realize I didn't talk about the load, partly because I haven't actually figured out what it is, but it should be relatively small. I'd actually prefer not to use air if possible, but it's not a deal breaker. Do you know what series of valves and cylinders you use?

The rotary pneumatic actuator idea is possible. I actually don't need any control over the profile. But that would mean a little more thought in to the mechanical engineering of the thing, and again I'd like to avoid that if possible.

As for voice coils, I haven't found anything that seems to be a complete actuator. As for price, I would think by the time I get done with a valve and cylinder I'd already be putting in a good chunk of change.

Thanks,
James Ingraham
 
Hi James,

We have found that pneumatics have just about the best performance per mechanical volume. Any time I've looked at replacing an air cylinder with a servo solution it is quite a bit larger for the same thrust. You can't beat the simplicity either if you need a 2 position solution (you can buy 3 position cylinders too, and they have some applications that are valid).

The trick for getting fast pneumatics is to use valves and tubing designed for high speed spooling and high flow rates and to use short runs of high flow tubing. For anything under a 1" bore we have had good luck with using 5/32" tubing for the most part.

For large installations (6-24 valves) I've used the SMC VVQ1000 series of valves with the VQ1101R-5B valves installed. These are all around very high performance valves. If you only need 1-6 valves I'd look at using the VQD1151U-5MO valves and buying the appropriate machined aluminum manifold that they sell for them (Its nice to leave blank valve positions for future expansion). As with anything though, you might want to check with your SMC distributor to find out if there are updated products that replace these series for new projects. We have been using these series for years and stock many spares so there is no need to switch for us.

The voice coils I've seen packaged are for serious motion control and come with bearings and linear encoders. I'd doubt if these are under $1000 all packaged. I haven't looked in a while so I can't be of much help there.

KEJR
 
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