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 HEIDENHAIN ERA 4000 series.
This new range of encoders is ideally suited to use in highly dynamic applications where measurement within a few angular seconds is a pre-requisite. This dynamism and accuracy is achieved through use of HEIDENHAIN’s innovative METALLUR® method of manufacturing the grating structure, which comprises several layers of gold, a transparent spacer and chromium on a cylindrical surface. This chromium layer is then worked by a laser to create the required graduations.
Through investment in research and development HEIDENHAIN found this to be the optimum method by which to produce graduations with 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 graduation of the scale drum is steel with the drum being available in differing shapes depending on the application. For example, 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.
Due to the fact that 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. Therefore, the quality of the position information directly affects positioning accuracy and rotational speed stability. As a result, in metalcutting applications, 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. This latest development from HEIDENHAIN, with its high signal quality and large number of signal periods, eliminates these problems, making it ideal for the requirements demanded by direct drive technology.
The installation of the scale grating and the adjustment of the scanning head also have a 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.