Product Information

RON 905
High-Accuracy
Incremental Angle Encoderwith Integral Bearing

06/2022

RON 905• Integrated stator coupling• Blind hollow shaft• System accuracy: ±0.4”

Incremental
RON 905Measuring standard

DIADUR circular scale with incremental track

Line count

36 000

System accuracy±0.4”

Position error per
signal period

 ±0.3”

Interface» 11 µAPP

Reference markOne

Cutoff frequency –3 dB

 40 kHzElectrical connection

Cable (1 m) with 9-pin M23 connector (male)

Supply voltage

DC 5 V ±0.25 V/ 250 mA (without load)

Cable length1)

 15 mShaft

Blind hollow shaft

Mech. permissible speed

 100 rpm

Starting torque 0.05 Nm at 20 °C

Moment of inertia of rotor

0.345 · 10–3 kgm2Permiss. axial motionof the drive shaft2)

 ±0.2 mm

Natural frequency

 350 Hz

Vibration 55 to 2000 Hz
Shock 6 ms2
 50 m/s (EN 60068-2-6)
 200 m/s2 (EN 60068-2-27)

Operating temperature

10 °C to 30 °C

Protection EN 60529

IP64Mass

 4 kg1)
2)

With HEIDENHAIN cable
Range includes mounting tolerances and thermal expansion; No dynamic motion permitted

Radial cable (can also be used axially)
A = Bearingk = Required mating dimensions
1 = Direction of shaft rotation for the output signals I2 lagging I1

2RON 905 Product Information    06/2022

RON 905 Product Information    06/2022

3

Mechanical design types and mounting• RON 905 shaft coupling
The RON 905 features a blind hollow
shaft. The shaft is connected by an axial
central screw.

The RON 905 angle encoders feature anintegral bearing and a stator-side coupling.
The measured shaft is directly connectedto the shaft of the angle encoder.
Setup
The circular scale is rigidly affixed to thehollow shaft. The scanning unit rides on theshaft on ball bearings and is connected tothe housing with a coupling on the statorside. The stator coupling and the sealing
design greatly compensate for axial andradial mounting errors without restricting
functionality or accuracy. This simplifies
the mounting process. During angularacceleration of the shaft, the stator
coupling must absorb only the torqueresulting from friction within the bearing.
Angle encoders with a stator coupling
therefore provide excellent dynamicperformance.
Mounting
The housing is firmly connected tothe mounting surface of the machinecomponent via a mounting flange anda centering collar.

4

Mounting an RON 905

Materials to be used for mounting
The machine shaft and the fastening
components must be made of steel. Thematerial must exhibit a coefficient ofthermal expansion of Þ = 10 · 10–6 K–1
to 16 · 10–6 K–1.
Additionally, the material must meet thefollowing specifications:• With a hollow shaft connection
Rm  650 N/mm2
Rp0.2  370 N/mm2• With a housing connection
Rp0.2  370 N/mm2

RON 905 Product Information    06/2022

RON 905 Product Information    06/20225DR. JOHANNES HEIDENHAIN GmbH
Dr.-Johannes-Heidenhain-Straße 583301 Traunreut, Germany +49 8669 31-0
 +49 8669 32-5061
info@heidenhain.dewww.heidenhain.com

1382220 · 00 · A · 02 · 06/2022 · PDF

This Product Information document supersedes all previous editions, which thereby
become invalid. The basis for ordering from HEIDENHAIN is always the Product
Information document edition valid when the order is placed.

More information:
Comply with the requirements described in the following documents to ensure correctand intended operation:• Brochure: Angle Encoders with Integral Bearing
591109-xx• Brochure: Interfaces of HEIDENHAIN Encoders
1078628-xx• Brochure: Cables and Connectors
1206103-xx
For brochures and Product Information documents, visit www.heidenhain.com.