Servohydraulic and Electrohydraulic Actuators

What is high forces?

There are some high frequency developments going high over 150 Hz the problem is the stiffness of the system so that it is important to know as well how stiff is the whole force loop wher the force generator will be working.

high forces as i meant was forces in the range of 5-10 kN.

The load and the frequecy is possible using even modern industrial servovalves. The problem is the stiffness of your loaded component. The higher it is the easier to generate high forces with high frequencies. The loads you mention are not a problem but it should be cleared before i give you a direction to look for what you test and as well how. Is it a sinusoïdal load you expect? any other profile? Is it a single direction load or it has to push and pull? Please give the input and i can give you the indications where to look for.

actaully its about getting reciprocatory motion, in microns (0-150) at a frequency of 150hz, i am developing a fretting wear testing machine.. so the actuator has to push n pull, i came to know that servohydraulics are the ideal for this..so wanted to get more info on the servohydraulics or electrohydraulics.. i am still in the starting stages.. not yet coneptulised how it has to operate.. but basically there'll b one stationary flat specimen and a pin which is reciprocating..or vice versa..if its possible to have sinusoidal load, or other types.. i'll b interested in that option as well...

Look up test machine, such as MTS The industry can tell you more than you can get in this forum.

Although MTS is one of the best they do not have all last developments in their programme. It seems that the problem is not a trivial one so that only industrial sources will not always be of help.

From an other point of view why somebody participating at this forum should not know enough to give the right hint?

Do not forget that we are very different so that if you cannt there is may be one who can.

I did not mean to imply that no one participating in this forum can NOT give information. I merely meant to inform the person asking the question that they can find a wealth of information on the internet, and save everyone from typing a lot.

Another test machine manufacturer is Instron.

Depending on your application, other technologies may be more suitable. For example a piezo stack or Terfenol-D actuators will give you force, speed and micron movement.

If you are on a budjet, I can help you find cost effective building blocks to fit the application.

i enquired about piezostack, i got info from the company PI, it satisfies the displacement criteria, the force generation is also good about 16kN, but i read in an article that, these piezo stack have a limited life cylce and the life of them varies when the operating voltage changes.. is it worth goin for piezostack? they are quite expensive also..

I never heard about lifecycle limits. Do you have a reference?

PI is about the most expensive you can find, quality is up there also.

You can find as good an actuator as PI. Unless you nanometer feedback, UHV compatibility, you can save some money there.

What is the environnement? University, R&D company and quantity?

Also what is your expertise regarding high voltages, in the 150V range?