Mechanical vibrators — VR and VU unbalance motors

Exciter or vibrator motor ?

A vibrator motor contains its own electric motor and is wired directly. A mechanical exciter does not : it is a set of eccentric weights on bearings, driven by an external motor that you select and size yourself. That is why the catalogue quotes a rating in kW rather than a voltage or a current.

This approach is the norm on medium and large machines : separating the vibrating part from the driving part reduces mechanical loads and extends service life. It is the solution used by builders of vibrating machinery, not a unit you bolt onto an existing hopper.

Rotational or linear

This is the first question, and the answer depends on the machine. The VR produces rotational motion : mounted in pairs, and two pairs in parallel, they give a directional vibration. They drive screens.

The VU produces linear motion and can be installed in line, connected by cardan shafts, to add up the forces. They drive long vibrating conveyors and troughs.

Adjustment is made through the weights

On these machines the force is not adjusted by phasing weights as on a vibrator motor : you choose the additional weights. Each model is listed in two extreme configurations, with intermediate values available. The trade-off is constant : more weights mean a higher static moment but a lower maximum speed.