Exposed linear encoders are designed for use on machines and installations that require high accuracy of the measured value. Typical applications include measuring and production equipment in the semiconductor industry, PCB assembly machines, ultra-precision machines, high-accuracy machine tools, measuring machines and comparators, measuring microscopes, and other precision measuring devices and direct drives.

Sealed linear encoders from Heidenhain are protected from dust, chips and splash fluids and are ideal for operation on machine tools. An aluminum housing and elastic sealing lips protect the scale, scanning carriage and guideway from chips, swarf, dirt and splashwater. The scanning carriage travels in a low-friction guide within the scale unit. It is connected to the external mounting block by a coupling that compensates unavoidable misalignment between the scale and the machine guideways.

Sealed linear encoders are available with full-size scale housings for high resistance to vibration up to 30 m measuring length, as well as slimline scale housing for limited installation space up to 2040 mm measuring length.  

Length gauges from Heidenhain offer high accuracy over long measuring ranges. These sturdily made gauges are available in application-oriented versions.  They have a wide range of applications in production metrology, in multipoint inspection stations, measuring equipment monitoring, and as position measuring devices. 

In rotary encoders with integral bearing and stator coupling, the graduated disk of the encoder is connected directly to the shaft to be measured. The scanning unit is guided on the shaft via ball bearings, supported by the stator coupling.

During angular acceleration of the shaft, the stator coupling must absorb only that torque resulting from friction in the bearing, thereby minimizing both static and dynamic measuring error. Moreover, the coupling mounted on the stator compensates axial motion of the measured shaft. Other benefits of the stator coupling are:

• Simple mounting
• Short overall length
• High natural frequency of coupling
• Hollow-through shaft possible

Rotary encoders with integral bearing that are conceived for separate shaft coupling are designed with a solid shaft. The recommended coupling to the measured shaft compensates radial and axial tolerances. Angle encoders for separate shaft couplings permit higher shaft speeds.

Rotary encoders without integral bearing operate without friction. The two components - the scanning head and the scale disk, drum, or tape - are adjusted to each other during assembly. The benefits are large diameter of hollow shaft; for high shaft speeds; no additional starting torque.

In addition to the system accuracy, the mounting and adjustment of the scanning head normally have a significant effect on the accuracy that can be achieved with rotary encoders without integral bearings. Of particular importance are the mounting eccentricity and radial runout of the measured shaft.

The inductive rotary encoders ECI/EQI 1300 are mechanically compatible with the photoelectric encoders ExN 1300: the shaft is fastened with a central screw. The stator of the encoder is clamped by an axially tightened screw in the location hole.

The photoelectric ERO modular rotary encoders from Heidenhain consists of a graduated disk with hub and a scanning unit. They are particularly well suited for limited installation space or for applications for which there must be no friction.

Heidenhain angle encoders are characterized by high accuracy values in the arc second range and better. Examples for application are rotary tables on machine tools, swivel heads on machine tools, C axes on lathes, gear-testing machines, printing units of printing machines, spectrometers and telescopes.

Angle encoders with integral bearing, hollow shaft and integrated stator coupling:

Because of the design and mounting of the stator coupling, it must only absorb that torque caused by friction in the bearing during angular acceleration of the shaft. RON, RPN and RCN angle encoders therefore provide excellent dynamic performance. With an integrated stator coupling, the stated system accuracy also includes the deviations from the shaft coupling. Further advantages:

• Compact size for limited installation space
• Hollow shaft diameters up to 100 mm for leading power cables, etc.
• C axes on lathes
• Simple mounting

Angle encoders with integral bearing, for separate shaft coupling:

ROD angle encoders with solid shaft are particularly suited to applications where higher shaft speeds and larger mounting tolerances are required. The shaft couplings allow axial tolerances of ± 1 mm

Heidenhain angle encoders are characterized by high accuracy values in the arc second range and better. Examples for application are rotary tables on machine tools, swivel heads on machine tools, C axes on lathes, gear-testing machines, printing units of printing machines, spectrometers and telescopes.

The ERA and ERO angle encoders without integral bearing (modular angle encoders) are intended for integration in machine elements or apparatuses. They are suited for the following requirements:

• Large hollow shaft diameter (up to 10 m with a scale tape)
• High shaft speeds up to 40000 rpm
• No additional starting torque from shaft seals
• Segment solutions

The robust ERM modular magnetic encoders are especially suited for use in production machines. Their large available inside diameters, their small dimensions and the compact design predestine them for the C axis of lathes, rotary and tilting axes (e.g. for speed measurement on direct drives or for integration in gear stages) and spindle orientation on milling machines, or for auxiliary axes.

Position display units serve to visualize the values measured with linear encoders, length gauges, rotary encoders or angle encoders.  Areas of application include measuring and inspection equipment, dividing apparatuses, monitoring of measuring equipment, manual machine tools, measuring machines.

Position displays from Heidenhain are designed to be highly user-friendly.

The interface electronics from Heidenhain adapt the encoder signals to the interface of the subsequent electronics. They are used when the subsequent electronics cannot directly process the output signals from Heidenhain encoders, or if additional interpolation of the signals is necessary.

Input signals of the interface electronics

Interface electronics from Heidenhain can be connected to incremental encoders with sinusoidal signals of 1 VPP (voltage signals) or 11 µAPP (current signals). The IK 220 PC expansion board can also process EnDat and SSI.

Interpolation of the sinusoidal input signals In addition to being converted, the sinusoidal encoder signals are also interpolated in the interface electronics. This results in finer measuring steps, leading to an increased positioning accuracy and higher control quality.

Formation of a position value

Some interface electronics have an integrated counting function. Starting from the last reference point set, an absolute position value is formed when the reference mark is traversed, and is output to the subsequent electronics.