Burster 8661 User manual

OPERATION MANUAL
Torque sensor
model 8661
Manufacturer:
burster präzisionsmesstechnik gmbh & co kg
©2013 burster
präzisionsmesstechnik gmbh & co kg
All rights reserved Talstrasse 1 – 5
DE-76593 Gernsbach,
Germany
[phone]
P.O. 1432
DE-76587 Gernsbach,
Germany
www.burster.com
1352-BA8661EN-5070-081521

Exclusion of warranty liability for operation manuals
All information in the present documentation was prepared and compiled with great care and
reproduced subject to effective control measures. No warranty is provided for freedom from
errors. We reserve the right to make technical changes. The present information as well as the
corresponding technical data can change without notice. Reproduction of any part of this
documentation or its processing or revision using electronic systems is prohibited without the
manufacturer's prior written approval.
Components, devices and measured value sensors made by burster präzisionsmesstechnik
(hereinafter referred to as "product") are the results of targeted development and meticulous
research. As of the date of delivery, burster provides a warranty for the proper condition and
functioning of these products covering material and production defects for the period specified in
the warranty document accompanying the product. However, burster excludes guarantee or
warranty obligations as well as any liability beyond that for consequential damages caused by
improper use of the product, in particular the implied warranty of success in the market as well as
the suitability of the product for a particular purpose. Furthermore, burster assumes no liability for
direct, indirect or incidental damages as well as consequential or other damages arising from the
provision and use of the present documentation.
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Operation Manual
Torque sensor model 8661 Technical inquiries:
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Contents
1.For your safety ............................................................................................... 7
1.1Warnings and Notes............................................................................. 7
1.2General warnings ................................................................................. 8
2.Introduction .................................................................................................. 10
2.1Intended use....................................................................................... 10
2.2Personnel ........................................................................................... 10
2.3Operating environment....................................................................... 11
2.4Conversions and modifications........................................................... 11
2.5Definitions........................................................................................... 11
3.Preparing for use.......................................................................................... 14
3.1Unpacking .......................................................................................... 14
3.2Scope of delivery................................................................................ 14
3.3Storage............................................................................................... 14
4.Principle of operation .................................................................................. 15
4.1Mechanical design.............................................................................. 15
4.2Electrical design ................................................................................. 16
5.Installation .................................................................................................... 18
5.1Preparing for installation..................................................................... 18
5.2Mechanical installation ....................................................................... 19
5.2.1Free-floating installation.......................................................... 19
5.2.2Installation with mounting block.............................................. 22
5.3Electrical connection........................................................................... 24
5.3.1Sensor-supply......................................................................... 24
5.3.2 Connector pin assignments (standard sensor, 1 range) .......... 24
5.3.3Connector pin assignments (2-range-sensor) ........................ 25
5.3.4The connections in detail........................................................ 26
5.3.5Running cables....................................................................... 30
5.3.6Extension cables..................................................................... 31
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Operation Manual
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6.Calibration and adjustment......................................................................... 32
6.1Factory calibration.............................................................................. 32
6.2DAkkS (DKD) / ISO 17025 calibration................................................ 32
6.3Recalibration....................................................................................... 32
6.4Mechanical adjustment....................................................................... 33
7.Measurement................................................................................................ 34
7.1Switching on....................................................................................... 34
7.2Static and quasi-static torques ........................................................... 34
7.3Dynamic torques................................................................................. 34
7.4Switching between ranges (2-range-sensor)...................................... 36
7.4.1Possible range extension of the nominal torque..................... 36
7.4.2Switching at the voltage output............................................... 36
7.4.3Connection diagram (2 range sensor).................................... 37
7.5Status display (sensor, 1 range, standard)......................................... 38
7.6Status display (2-range-sensor) ......................................................... 38
7.7Speed Limits....................................................................................... 39
7.8Interference ........................................................................................ 39
7.9Check function.................................................................................... 39
8.Type 8661 with USB connection................................................................. 40
8.1General information............................................................................ 40
8.1.1Power supply.......................................................................... 40
8.1.2Wiring...................................................................................... 40
8.1.3Ground connection ................................................................. 41
8.1.4USB 2.0 pin assignment......................................................... 42
8.2Preparing for use................................................................................ 43
8.2.1System requirements.............................................................. 43
8.2.2Software installation................................................................ 44
8.2.3Driver installation.................................................................... 50
8.2.4Software licensing for 8661-P100........................................... 60
8.2.5Device detection..................................................................... 62
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Operation Manual
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8.3Measurement mode, sensor with USB connection............................. 64
8.3.1Display.................................................................................... 64
8.3.2Operation................................................................................ 66
8.3.2.1Starting measurement................................................. 66
8.3.2.2Stopping measurement............................................... 67
8.3.2.3Measurement display.................................................. 67
8.3.2.4Options........................................................................ 68
8.3.3Basic configuration ................................................................. 68
8.3.4Channel settings..................................................................... 69
8.3.5Selecting the measurement rate............................................. 70
8.3.6Trigger .................................................................................... 72
8.3.7Documentation........................................................................ 73
8.4Measurement reports ......................................................................... 74
8.4.1Measurement report finder ..................................................... 74
8.4.2Archive viewer ........................................................................ 76
8.4.3Exporting reports to Excel....................................................... 77
8.4.4Print reports............................................................................ 78
9.Cleaning and maintenance.......................................................................... 80
10.Taking out of use.......................................................................................... 80
11.Technical Data.............................................................................................. 81
12.Disposal ........................................................................................................ 82
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Operation Manual
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Operation Manual
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1. For your safety
1.1 Warnings and Notes
The symbol on the instrument denotes that the user should refer to the
operating instructions
DANGER!
in this manual warns of immediate hazards which result in severe
personal injury or death.
WARNING!
in this manual refers to a hazard or unsafe practice which can result in
severe personal injury or death.
CAUTION!
in this manual refers to a hazard or unsafe practice which can result in
personal injury or product or property damage.
Note
This indicates precautions which should be observed to ensure proper
handling of the equipment
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1.2 General warnings
The torque sensor is state of the art, and is safe to operate. However, if the torque
sensor is used or operated incorrectly, it may present a danger.
WARNING
The following instructions must be followed to prevent electric
shock and injuries:
In order to achieve high measuring characteristic value, the
torque sensor is not designed with the usual safety factors
(2…20) for machine designs. For applicable overload factors,
see the technical data (data sheet).
Observe accident prevention regulations, including for
accessories used.
Use torque sensor only in non-safety-critical applications.
Only use torque sensor outside of potentially explosive
areas (Ex protected areas)
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CAUTION!
The following points must be observed to prevent injuries and
damage to property:
The limits for permissible mechanical, thermal and electrical
loads are shown in the data sheet. These limits must not be
exceeded. Take these limits into account when planning the
measuring arrangement, and during installation (preferably
with the display for the torque connected) and operation.
Impacts and shocks may damage the sensor (e.g. if it is
dropped). Exercise the necessary care when transporting
and fitting the sensor.
Torque peaks in excess of the permissible overload may
destroy the torsion shaft. Make sure that such peaks do not
occur, or ensure that they are absorbed.
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2. Introduction
2.1 Intended use
The torque sensor measures static and dynamic torques on rotating or stationary
machine parts in either direction of rotation. You have the option of measuring
rotational speed or angular displacement. The respective upper range value is
shown on the type plate.
Both the low mass of the sensor and its high torsional rigidity are an advantage
when measuring dynamic torques. However, you need to pay attention to the
torsion spring constant and the sensor’s cut-off frequency with such
measurements. You can find both of these in the data sheet. For more information
on estimating the resonant frequency and measuring dynamic torques see section
"0
Dynamic torques“ on page 34.
The torque sensor is maintenance-free thanks to its contactless transmission of the
measurement signal. The electrical measurement signals can be transmitted to
remote measuring stations where they can be displayed, recorded, processed and
used for control and regulation tasks.
Use the type 8661 torque sensor only for measuring torque and rotational speed or
angular displacement.
Only use the torque sensor for non-safety-critical applications.
The torque sensor is not intended for use as a safety device.
2.2 Personnel
Personnel must be familiar with the respectively applicable regulations. They must
follow these regulations.
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2.3 Operating environment
Avoid radiant heat or cooling on one side.
Protect the torque sensor from damp.
The torque sensor is not resistant to chemical agents. Only use it outside
of aggressive environments.
Keep the bearings and connectors free of dust, dirt and other foreign
matter.
2.4 Conversions and modifications
If you open up the torque sensor or dismantle it during the warranty period, the
warranty will be immediately voided.
The torque sensor may only be opened by our technical personnel.
We will not accept liability for any modifications made to the torque sensor without
our written agreement.
2.5 Definitions
Test side
The measurement test is where the torque sensor is mechanically connected.
Apply the torque to be measured to this end of the sensor.
This end normally has the smallest moment of inertia. Torque sensors with
measuring ranges up to 2 Nm have a smaller and therefore lower-friction ball
bearing fitted at this end.
You will see these markings on the measurement end of the sensor:
T
E
S
T
S
I
D
E
R+
fig. 1.: Sensor Test side
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Drive side :
The drive end is the opposite end to the measurement end. The torque sensor is
also mechanically connected at this end.
This end normally has the larger moment of inertia.
You will see these markings on the drive end of the sensor:
D
R
I
V
E
S
I
D
E
fig. 2.: Sensor Drive side
The torque direction
A torque is clockwise (clockwise torque) if the torque is exerted clockwise when
looking at the measurement end. In this case you will get a positive electrical
signal at the sensor output.
fig. 3.: Torque, clockwise (looking at the measurement end)
You can use model 8661 torque sensors to measure both clockwise and
counterclockwise torques. If the torque is exerted in an anticlockwise direction
(looking at the measurement end), you will get a negative signal at the output.
fig. 4.: Torque, anti clockwise (looking at the measurement end)
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Sign convention for measuring angular displacement
If the sensor shaft rotates clockwise (looking at the drive end), channel A leads
channel B by 90°.
If the sensor shaft rotates anticlockwise (looking at the drive end), channel B leads.
Static and quasi-static torques
Static and quasi-static torques change their value only slowly or not at all. As long
as they are below the rated torque, these torques can take any value.
Dynamic torques
A dynamic torque changes very rapidly and can even oscillate. In this case the
frequency of the torque must remain well below the resonant frequency of the
mechanical structure as a whole.
We recommend that you only measure dynamic torques if they reach a maximum
70% of the rated torque.
When measuring dynamic torques, take the characteristics of your measuring
amplifier into account.
For more information on estimating the resonant frequency and measuring
dynamic torques, see the section 7.3 "Dynamic torques" on page 34.
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3. Preparing for use
3.1 Unpacking
Only transport the model 8625 sensors in their original packaging or in
packaging of equivalent quality.
The sensor must not be able to move within the packaging.
Protect the sensor from damp.
Inspect the sensor carefully for damages.
If you suspect that the unit has been damaged during shipping, notify the delivery
company within 72 hours. The packaging should be retained for examination by a
representative of the manufacturer and/or the delivery company.
3.2 Scope of delivery
Torque sensor
Mating connector
Manual
Data sheet
3.3 Storage
Pack the sensor in clean packaging.
Only store the sensor under the following conditions:
dry
no Condensation
Temperatures between 0° C and 60° C
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4. Principle of operation
4.1 Mechanical design
fig. 5.: Design principle of the torque sensor
The torque sensor essentially comprises three subassemblies: the body, the
connection box and the rotor. The latter comprises the torsion bar, the strain
gauges, the measurement amplifier and the power and signal transmission. If the
torque sensor is fitted with the rotational speed or angular displacement option, an
incremental encoder disk is also fitted for measuring rotational speed or angular
displacement.
fig. 6.: Shaft from a sensor with rotational speed and angle measurement
In addition to the plug and the connection for the external power supply, the
connection box also contains the electronics. The standard version supplies an
output voltage that is proportional to the torque.
If the torque sensor is fitted with the “rotational speed” or “angular displacement”
option, the standard version supplies a 5 V TTL signal. However, you can also use
this output as an open collector output.
The body houses the rotor and two grooved ball bearings.
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Speed/angular displacement measurement (option)
An opto encoder scans a rotating encoder disk. This incremental encoder disk is
made from a transparent material with opaque lines on it. This design is basically a
high-resolution and fast light barrier. In operation, it generates a certain number of
electrical pulses with each rotation. The frequency of these pulses is therefore
dependent on the rotational speed of the shaft and the number of lines on the
encoder disk.
Depending on the model, encoder disks with a different number of lines may be
fitted. The maximum pulse frequency is somewhat higher than 100 kHz
fig. 7.: Close-up view of the encoder disk
4.2 Electrical design
Torque measurement
Torque deforms the torsion shaft and, as it does so, also elastically and reversibly
deforms the strain gauges that are fitted. Their electrical resistance changes
proportionally to their deformation.
The torque sensor has a total of four strain gauges. These are arranged as a
Wheatstone bridge circuit and are supplied with DC voltage by the sensor. The
output voltage from the strain gauges is proportional to the measured torque. An
amplifier multiplies this voltage before it is digitized by an analog/digital converter
(16-bit resolution).
A 16-bit microprocessor processes these digital signals, encodes them and relays
them to infrared LEDs, which send the signals to the stator as a serial light signal.
The stator receives this light signal and converts it back into electrical pulses
before sending it to another microprocessor. This microprocessor controls a
digital/analog converter which generates an analog voltage again (16-bit
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resolution). This analog voltage is the sensor’s measurement signal. It is also
proportional to the measured torque.
Rotational speed measurement (option)
An encoder disk generates a certain number of pulses, e.g. 1,024 pulses, for every
revolution of the torsion shaft. To ensure that this signal does not exceed the
output frequency of 100 kHz, the rotational speed should not exceed
100 revolutions per second. This is equivalent to 6,000 revolutions per minute.
Angular displacement measurement (option)
The principle of measuring angular displacement is the same as for measuring
rotational speed. However, in this case the sensor reads two channels. The
electrical pulses from the two channels A and B are offset by 90°, which also
allows the shaft’s direction of rotation to be identified.
fig. 8.: Angular displacement measurement, channel offset 90°
To do this you have to evaluate the rising and falling pulse edges for both
channels. Hence the angular resolution is four times the number of lines on the
encoder disk. An encoder disk with 1,024 lines therefore gives a resolution of
360 / (4 x 1024) = 0.09°.
For more information on the sign convention, see section 2.5 "Definitions" on
page 11.
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5. Installation
5.1 Preparing for installation
Shafts
Use shaft diameters with tolerance j6.
This results in an H7/j6 fit
Couplings and misalignments
Even if you align the sensor exactly, there will always be a small misalignment
between the shafts.
Therefore, when fitting a torque sensor, always use balanced couplings with
misalignment compensation.
Before fitting the coupling, check the speed it will be operating at.
The respective couplings must be designed for these speeds.
We recommend using torsionally rigid lamellar couplings or bellows couplings
which will enable you to compensate for the misalignments. Always use the
coupling’s full clamping length.
You can distinguish three misalignments. :
fig. 9.: Angular misalignment
fig. 10.: Axial misalignment, e.g. due to thermal expansion
fig. 11.: Radial misalignment
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Both angular and axial misalignments can be corrected using “half-couplings”. Full
couplings are needed, however, to correct any radial misalignment To find suitable
couplings refer to the datasheet 8690.
5.2 Mechanical installation
5.2.1 Free-floating installation
WARNING!
Beware of vibrations!
Operating the overall system close to its natural resonance
frequencies will result in permanent damage!
Make sure that NO resonance occurs throughout the entire speed
range.
The sensor is positioned between two balanced half-couplings. Installed in this
way, the torque sensor and the two half-couplings form a full coupling. Hence it
helps to compensate for the inevitable axial offset between the mechanical
connections.
CAUTION
Excessive torques, bending moments or axial forces will damage
the torque sensor!
Make electrical connections to the torque sensor during installation
and monitor the measurement signal. It must stay within the
permitted range.
Support the sensor when fitting it.
Do not drop the sensor.
Do NOT use hammers during installation
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Ensure that the sensor is aligned precisely.
It is usually sufficient, at low rotational speeds (< 2000 min-1), to align the
coupling using a straight edge in two perpendicular planes. However, we
recommend using a dial gauge or laser to align the coupling and shaft ends.
Only use half-couplings for free-floating installation.
(You'll find suitable couplings on datasheet 8690.)
fig. 12.: Schematic measuring arrangement with free-floating installation
Support the torque sensor or hold it still during installation.
Clean and deburr shafts and hubs.
There must be no foreign matter, burrs, oil or grease on the shafts or hubs
when fitted.
Now slide the half-couplings onto the shafts.
Start on the side that is easier to turn. Usually this will be the measurement
side.
The half-couplings must slide easily onto the shaft. Use the full clamping
length of the half-couplings.
Initially fit all parts together loosely.
Precisely align the shaft ends and couplings of the measurement
arrangement.
This avoids any unnecessarily high reaction forces, while also reducing the
load on the coupling and any spurious forces acting on the sensor.
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