A new generation of angle encoders—the ERA 4000 series
Simple mounting, compact dimensions and high signal quality together with a large number of signal periods: these are the outstanding characteristics of the new generation of modular angle encoders in the ERA 4000 series. They're perfectly suited for highly dynamic applications requiring precision angular measurement to accuracies within a few angular seconds.
The graduation substrate of the scale drum is steel. The grating structure is produced with a new method that applies several layers of gold, a transparent spacer and chromium on a cylindrical surface. HEIDENHAIN calls this innovative way of combining materials METALLUR®. A laser works the chromium layer to provide the desired graduation structure. Graduations manufactured with this method are characterized by their very high edge definition and homogeneity. Together with the photoelectric scanning method, this high edge definition is a precondition for the high quality of the output signals and permits high interpolation factors. The scale drum is available in differing shapes depending on the application. Besides the scale drums with compact cylindrical shape, there are scale drums with a T-profile for applications that permit only low weight and moments of inertia.
Because a control loop for position and velocity requires a position encoder, the position information has significant influence on performance, particularly on the performance of direct drives. The quality of the position information directly affects positioning accuracy and rotational speed stability. In manufacturing processes using cutting tools, position error within the signal period of the velocity loop can lead to wave-shaped dimensional inaccuracy of the workpiece surface. Position error also aggravates noise and heat generation in the motor. With its high signal quality and large number of signal periods, this encoder is ideal for the requirements placed by direct drive technology.
The installation of the scale grating and the adjustment of the scanning head also have decisive influence on the accuracy of angular measurement. With the ERA 4000 series, HEIDENHAIN has therefore implemented new ideas for the quickest, simplest and most accurate installation possible.