Heidenhain
rotary encoders operate on the principle of photoelectrically scanning
very fine gratings. The measuring standard for incremental rotary encoders
is a graduated glass disk with a radial grating of lines and gaps forming
an incremental track. A second track carries a reference mark. At a small distance from the rotating graduation is a scanning reticle
with a grating in each of four fields, and a fifth field for the reference
mark.
Angle
encoders are found in applications requiring precision angular measurement
to accuracies within several arc seconds for example:
Controlling systems for servo
drives require measuring systems that provide feedback for the position
and speed controllers and for electronic commutation. The characteristics
of encoders have decisive influence on important motor characteristics
such as:
Rotary tables on machine tools
Swivel heads on machine tools
C-axes of lathes
Positioning accuracy
The accuracy is influenced mainly by:
Measuring machines for gears
Speed stability
The directional deviation of the radial grating
Printing units of printing machines
Bandwidth, which determines drive command-signal response and disturbance
rejection capability
The eccentricity of the graduated disk to the bearing
Spectrometers
Power loss
The radial deviation of the bearing
Telescopes
Size
The error resulting from the connection with the rotor couplings
Angle encoders can have one of three
different mechanical designs integral bearings, hollow shaft and integral
stator coupling. See the selection table on the angle
encoders page for more information.
Quietness
The interpolation deviation during the signal processing in the internal
or external digitizing electronics
All Heidenhain position encoders for servo
drives involve very little cost and effort for the motor manufacturer to
mount and wire. Encoders for rotary motors are of short overall length.
Some encoders, due to their special design, can perform functions
otherwise handled by safety devices such as limit switches. For a
catalogue to help you select the encoder for your needs fill in the feedback
form.
See the selection table on the rotary
encoder page for more details.
