Sinusoidal Vibration

<...vibration should be sinosidal ...>

How about a sine-wave signal generator, an amplifier and a loudspeaker instead, then?

Use a shaft with an offset weight. Vary the frequency by changing the shaft rotation speed (this may also vary the amplitude). Vary the amplitude by adjusting the weight's distance to the shaft centerline.

The advantage of this over the cam method is only one moving part with no wear surface. The cam method may provide better amplitude control based on your application.

If you need cam like control, study an IC engine valve train arrangement. Movement of a cam, cam follower, and return spring that maintains cam to follower contact can be set up for a very specific movement.

You span an awkward frequency range to recommend one vibration technique. Spinning an offset counterweight will give you an excellent low frequency vibration control in both frequency and amplitude. Since the counterweight will be spinning in a circle, the vibrations must be sinusoidal. Amplitude can be controlled by changing the counterweight mass or the length of the offset. Frequency can be controlled by changing the motor speed. (Oh by the way, if you choose the motor to be an induction motor you will need a variable frequency drive to be able to change the speed.) But 150 hertz is 9000 RPM for a motor shaft speed. You're not going to find many motors capable of that speed that can spin an offset counterweight without destroying some bearings.

Now the speaker approach will easily be able to vibrate at 50 hertz and into higher frequencies. You will have to have some mechanical linkage between the voice coil and the object you are vibrating to transfer this energy. But lower than 50 hertz gets to be very difficult for a voice coil to move air, let alone whatever you are shaking. (Yes, those of you familiar with Velodyne, Hsu Research, Caton, PSB and the makers of other fine sub-woofers know, this can be done. But it isn't easy. )

So I suggest you use two shakers for your earth quake test rig. (Just a wild guess on the test rig.)

That is a fairly large range.

What Mass are you trying to vibrate?

What Amplitude at what Frequency?

Hi,

any decentered circular cam will give a pure sine motion if this motion is guided with a linear stage.

This is pur geometry with inertial forces and deformations neglected.

RHABE

Hydraulic actuators were designed for just that purpose. You can probably buy one cheap off EBAY.