Small & Affordable Electronic Actuators that Withstand -40°C to 85°C?

[Joseph H]

Hi guys. As the title states, I am looking for your favorite small actuator or device that can handle the mentioned ambient temperatures.

Basically , I do a lot of temperature chamber testing that requires I move parts a few mm (usually less than 100 mm) with a force of about 50 N at around 20 mm/s.
-so there are not massive forces or travel distances involved.

In the past I struggled with air cylinders which freeze up, or custom low-temperature(expensive) stepper motors which cost 400 USD each, plus controller which is 200 USD.
I am looking for your favorite method or brand of actuator for extended ambient temperature operation because I know there must be a cheaper option.

What has been done in the past?

thank you.

 

[TugboatEng]

Have you considered running your air cylinders off compressed nitrogen? It doesn't sound like you need a tremendous amount of volume. Nitrogen gas is cheap and very dry. This would help with the freezing.

 

[Joseph H]

We might not have that option if the goal is affordability. We have to use compressed air from our facility. We also do millions of cycles, so I would probably need a lot of nitrogen over time.

 

[LittleInch]

The minus 40 bit is never going to be cheap.

Can you have the motor part outside the chamber? Some sort of motor and screw jack arrangement or worm drive?

Diffiuclt to know without some sort of diagram or picture of what your limitations are?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Joseph H]

These are very large testing chambers and any sort of cable or rod actuator would very long I think.
Also we test a lot of parts at once, so there would need to be a lot of cables going through the port in the side of the temperature chamber.

 

[TugboatEng]

Just spitballing here. You have a system that kind of works but has a few problems. So it seems that the most economical approach would be to fix the problems. If you must use air, another thought would be to pre-cool the air to a temperature below the chamber temperature. This means that any moisture that would have frozen in the test chamber should have already iced up in the pre cooler.

 

[Joseph H]

No that's good. That is the brainstorming that I am looking for right now.
That certainly is an option. Our compressor system does like to pass a lot of oil as we tap from compressors that support our main production.
Basically we have a lot of low quality air from some large roots compressors.

This is why we are trying to get away from pneumatics and go strictly electrical. A single AC power cord is much easier than power, plus air and the hassle of coalescing filters and air dryers which need periodic maintenance because there is so much oil being passed through the system.

 

[JohnRBaker]

Perhaps you need to invest is a dedicated compressor, particularly one that could be equipped with a pre-cooler/dryer as Tug suggested.

John R. Baker, P.E. (ret)
EX-'Product Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[Joseph H]

Perhaps an option.

 

[MintJulep]

What does the motion profile need to be?

Do you need to accurately control the position and velocity? Or just slam things against an end stop? Do you need a dwell at one or both ends, or can it be a continuous oscillation?

A simple slider-crank mechanism could be driven by a cheap induction motor that would be relatively insensitive to temperature changes.

Solenoid driving a lever.

Voice coil working against a spring driving a lever.

Air spring actuators would get away from the challenges with seals over the temperature range, but you may not find a material that will work over the range.

 

[Pud]

Some years ago we had an ancient compressor. Bought a new one (two actually - as backup)
With the old one we had to empty the water separators daily.
New ones which had single dryer attached never had to empty water separators in 5 years!
Air ran sprue pickers in injection moulding shop.


Politicians like to panic, they need activity. It is their substitute for achievement.

 

[TugboatEng]

I hear this anecdote a lot. The water is in the air and the amount of water in the system is based on the amount of air pumped. Unless the old compressor had a lot of leaks replacing it with new won't change the amount of water pumped. However, simple things like gill ring aftercoolers that may be standard on the new compressor can make huge differences where the water ends up in your system. Receivers make good water separators if you can keep them from getting hot.