ETH-messtechnik DRBK Bedienungsanleitung
tel. +49 (0)79 72 93 10-0
hagstrasse 10 . D-74417 gschwend
English
messtechnik
Torque Sensor
DRBK / DRBK-n
DRBK-A
Operating Instructions
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© ETH messtechnik gmbh
This operator manual is not a quality agree-
ment or durability guarantee as set out in
Section 443 of the German Civil Code.
Specification changes, typing and
printing errors reserved.
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Inhalt
Important instructions: ...................................................................................................4
1. Introduction................................................................................................................. 5
2. Field of application and application instructions.........................................................5
3. Structure and mode of operation................................................................................ 6
3.1 Torque Shaft.........................................................................................................6
3.2 Case .....................................................................................................................6
3.3 Measurement ......................................................................................................6
3.4 Disturbances and their compensation.................................................................7
4. Conditions on location.................................................................................................8
4.1 Ambient temperature..........................................................................................8
4.2 Moisture and dust................................................................................................8
4.3 Chemical effects................................................................................................... 8
4.4 Deposits ...............................................................................................................8
5. Mechanical installation................................................................................................9
5.1 Precautions when assembling .............................................................................9
5.2 General assembly guidelines ...............................................................................9
6. Structure of the measurement chain ........................................................................10
7. Connection ................................................................................................................11
7.1 Hints for connection ..........................................................................................12
7.2 Connector ..........................................................................................................12
7.3 Pinout of the connector.....................................................................................12
7.4 Extension of cable..............................................................................................12
8. Pinout ........................................................................................................................13
9. Output .......................................................................................................................14
10. Functions of the display (at DRBK-A).......................................................................15
10. Recalibration............................................................................................................16
11. Disposal ...................................................................................................................16
13. Datasheet ................................................................................................................17
13.1 Technical specifications....................................................................................18
13.2 Mechanical dimensions DRBK..........................................................................19
13.3 Sizes DRBK........................................................................................................19
13.4 Mechanical dimensions DRBK-A ......................................................................20
13.5 Sizes DRBK-A ....................................................................................................20
13.6 Mechanical values and load limits DRBK + DRBK-A ........................................21
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Important instructions:
The torque transducers of the DRBK-A series can be used as machine elements
(e.g. test bench). In the case of mass-critical applications, the installation positi-
on of the drive and measurement side must be taken into account.
Please note that the transducers are not designed with the safety factors (2...20)
customary in machine designs in favor of high measurement sensitivity.
Pay particular attention to the specified overload factors.
Where people and property could be injured in the event of breakage, the user
must take appropriate safety measures (e.g. covers, overload protection) (obser-
ve the relevant accident prevention regulations!).
The torque transducer is not approved for use in hazardous areas.
If the transducer is opened or dismantled within the warranty period, the war-
ranty claim becomes void.
The transducer may only be opened by qualified personnel.
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1. Introduction
Torque transducers measure torques in Nm.
2. Field of application and application instructions
The torque transducers measure both right-hand and left-hand loads. With a
right-hand load, the signal direction is positive. The nameplate provides informa-
tion about the final value of the measuring range.
The torque transducers measure dynamic moments just as precisely as static
torques. Here, the low masses and the high torsional rigidity are of particular
advantage.
Note the signal rise of the transducer specified in the data sheet.
The torque transducers are maintenance-free due to their non-contact measure-
ment signal transmission. Your electrical measurement signals can be transmit-
ted to remote measurement stations and displayed, registered, processed and
used for control and regulation tasks.
As a precision measuring device, the torque transducers require careful handling
during transport and assembly, since impacts or falls can damage the transducer.
Torque peaks in excess of the permissible overload can lead to the destruction
of the torsion shaft. Where such peaks cannot be ruled out with certainty, they
must be intercepted.
The limits for the permissible mechanical, thermal and electrical stresses are
listed in the data sheet. It is imperative that they are complied with. Please take
this into account when planning the measuring arrangement, during installation
and finally during operation.
Channel A
(PIN G)
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3. Structure and mode of operation
3.1 Torque Shaft
The torsion shaft is made of hardened steel. The torque-proportional torsion of
the torsion shaft within its elastic range is evaluated with strain gauges (DMS)
applied to it. The strain gauges are arranged in a Wheatstone bridge circuit. The
non-positive connection takes place via suitable couplings on the cylindrical shaft
ends.
Optionally, the torsion shaft of the DRBK can be equipped with a speed measure-
ment (see data sheet).
3.2 Case
The torque transducer housings are made of high-strength aluminum and the
surface is hard-anodized for protection. The torsion shaft is mounted twice in the
housing via deep groove ball bearings. The transducer is mechanically fastened
via threaded holes on the bottom of the housing. An evaluation electronics for
torque and speed is mounted on the housing.
3.3 Measurement
The torsion shaft and thus the DMS are elastically deformed by the torsional
force. The strain gages change their ohmic resistance in proportion to their
change in length. The downstream electronics transmit the measurement signal
optically frequency-modulated to the external electronics.
The conversion in the external electronics into the two output signals voltage/
current takes place in proportion to the change in frequency. These are available
for further evaluation.
A square-wave signal with 60 pulses/revolution is available at the speed output
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3.4 Disturbances and their compensation
Avoid bending, axial and radial forces. When you have problems with this, use
ETH clutches.
To connect the transducer to a measurement unit you need a shielded cable.
The transducers are EMC-tested and are complying with
EN 55011:1998 + A1:1999 + A2:2002
EN 61326-1:2006-05 and
EN 61000-6-2:2005.
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4. Conditions on location
4.1 Ambient temperature
For best results, the device must be operated within the nominal temperature
range. The best operating conditions are constant and, if necessary, slowly
changing temperatures. The specified temperature errors apply if the tempera-
ture does not change faster than 5K/h. One-sided thermal radiation or cooling
should be avoided and appropriate technical preventive measures taken, if
necessary.
4.2 Moisture and dust
The torque transducers comply with protection type rating IP40 as per DIN
40050.
Note: There should be no moisture inside the transducer connector
4.3 Chemical effects
The torque transducers are not protected against chemical effects. They must
not be used in caustic or corrosive environments.
4.4 Deposits
Dirt, dust or other foreign substances should not accumulate so that they can
enter the bearing or the connectors.
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5. Mechanical installation
5.1 Precautions when assembling
• Handle transducer carefully.
• Important note:
When installing the couplings, do not overload the transducer,
not even temporarily.
It is strongly recommended to remove the transducer before
mounting connect electrically and the torque signal with too
monitor in order not to exceed the measuring range!
• Misalignments in the axial and radial directions must be avoided.
The axis offset should be max. 50% of the permissible values of the
coupling used (axial, angular and lateral misalignment) be.
Please refer to the data sheet for your coupling for this data.
• A good electrical connection of the housing to grounded parts
must be observed.
5.2 General assembly guidelines
The drive and transducer sides should not be swapped, otherwise measure-
ments (readings) will be invalidated during accelerations, for example.
When reading the device label, the drive side is on the right and the transducer
side on the left of the transducer. There is a small cavity in the cover on the
measurement side.
Flexural, axial and radial forces are disturbances that cause incorrect
measurements.
Be careful with the thermal expansion of the assembly.
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6. Structure of the measurement chain
In order to be able to measure with the transducer, a complete measurement
chain must be set up.
This consists of:
• torque transducer
• connection cable
We recommend using our ETH cables.
They are optimized in design and shielding.
• Supply and evaluation device (e.g. PLC)
A supply unit is necessary to supply the transducer with the necessary operating
voltage. The transducer includes the complete measuring amplifier, so that no
additional amplifier is necessary. The measuring signal can be further processed
directly (e.g. PC) or displayed and evaluated with supply and evaluation devices.
Dieses Handbuch passt für folgende Modelle
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