torquemeters limited, founded in 1951, have a · torquemeters limited, founded in 1951, ......
TRANSCRIPT
Torquemeters Limited, founded in 1951, have a
worldwide reputation for torquemeters of very high
accuracyand credibility both for test stand Research
and Development applications and also for
permanent installation on large turbomachines.
The efficiency, reliability and quality of all rotating
machinery, large and small, is of paramount
importance to end users, and to remain competitive
suppliers need to test prototype and production
machines with increasing thoroughness.
The margins for improvement are already so much
reduced that success depends on highly accurate
test stand measurements, particularly torque.
Operators of large turbomachines are also
increasingly interested in their in service
performance and use permanently installed
torquemeters for condition monitoring, maximising
plant output and control purposes.
Their'Torquetronic' phase shift system, originally
licensed from Rolls Royce, is used by many of the
world's leading aero engine and turbomachinery
companies and is available as a 0.1% accuracy
standard model range or custom engineered to suit
specific requirements.
Torquemeters Limited are also the world leaders in
continuous duty torquemeters for the oil, gas and
petrochemical industries, with over 350 units in
service on turbomachines up to 80MW and
20,000rpm with exceptional reliabili~
Applications fall into two categories.
Power Absorption Measurement -of pumps,
fans, compressors, generators, gearboxes, etc using a
torquemeter and any convenient prime mover:
Power Output Measurement -of turbines, I.C
engines, electric and hydraulic motors, etc using a
torquemeter and any convenient load absorption
device.
The mechanical design and interfacing of
torquemeters to the coupled machines can be
critical to their success. and the Company's
reputation is based on their unique capability in high
speed transmission engineering at high powers
speeds up to I 50.000rpm.
Operating from a purpose built factory with
modern production, calibration and design facilities,
the Company are certified to ISO 900 I. Sales,
technical support and after sales service for the
Company's international customer base is handled
by a network of sales offices and agencies covering
20 countries worldwide.
Some practical applications:
Performance measurement -Research and
Development testing of prototype machines to the
highest levels of accurac~ such as aero engine or
industrial compressor development.
Production testing -Pass off testing of production
machines such as helicopter or automotive engines,
pumps, etc.
Acceptance testing -Works or on-site acceptance
of performance guarantees of coupled machines.
Machinery protection -Indication of peak
operating torque to prevent damage to process
machinerr
Process control -Optimisation of process plant
machinery to maximise output, efficiency and product
quality.
Condition monitoring -Continuous indication of
performance deterioration of process machines
guides maintenance and cleaning scheduling.
I
Phase shift principle
This simple form of phase shift torquemeter is well
known. As torque is applied to the rotating shaft, a
change of phase is produced between the signals of
the two pickups. Howeve~ large inaccuracies are
introduced by any relative movements between the
shaft and the pickups. i iI I..
To Phasemeter
Torquetronic system
The 'Torquetronic' system's key feature is the use of
a pair of multipole pickups in the form of internally
toothed rings, which provide compensation for any
relative movement between shaft and stator:
The circumferential pickup / field coils provide a
toroidal flux path such that as the shaft rotates, the
teeth generate sinusoidal signals in stationary coils,
whose phase dispJacement is directly proportionalto shaft twist and hence torque. .
The integrity of the phase measurement electronics can
be conclusively proved by inverting the two signals using
a built in Complement switch. If the sum of the original
and Complement readings add up to exactly 100% the
phase measurement must be correct.
I .I II I
..
Complement ~
switch ~
~
TORQUE
(as % phase displacement)
Rotastat feature
'Torquetronic' test stand models feature a built in
Rotastat system in which the pickup teeth can be
rotated to generate signals with the shaft stationary.
This allows static calibration with lever arms and
weights and zero speed torque measurement.
The calibration constant of the system is simply the
torque to twist the shaft through one tooth pitch which
must clearly correspond to exactly 100% phase
displacement. The stiffness of the high tensile steel shaft
is as stable as Youngs modulus and exceptionally linear:~ ~
To Phasemeter
2
Standard 'ET' models
The ET model range of high
precision transducers covers 1-
75,000Nm, up to 120,000rpm
in 4 frame sizes. Available in
suspended or pedestal versions
and Low, Medium and High Speed
bearing contigurations.The unique
interchangeable shaft facility
typically allows each model to
cover a 40: 1 torque range at full
accuracy.
ET I SOHS -14OONm, JO,OOOrpm
ET9000HS- 75,OOONm, 6,500rpm
Custom designs
For special test rig applications at
high or low speed,Torquemeters
Limited can provide custom
designed solutions, including the
complete transmission. Any rating
considered.
Turbine test rig- 24000kW 13,OOOrpm
3
Continuous Duty
For condition monitoring of large
turbomachines in the oil, gas
petrochemical industries,
Torquetronic is widely regarded as
the most reliable and credible
system available with over 300
installations on virtually every
turbine type from I -80MW.
(Ref Brochure PSL 9.05.65)
Gas pipeline booster 20MW @ 6,500rpm
Tordisc couplings
For exacting test stand applications
Torquemeters Limited offer a range
of standard or custom designed
ultra lightweight low moment
TORDISC diaphragm couplings.
Torques up to 30,OOONm, speeds
up to 80,OOOrpm.
Electronics
All 'Torquetronic' transducers
use common electronics, the
"613" Readout Unit or the
'700" Signal Processor Unit,
available with a wide range of
digital and analog interfaces.
(Ref Brochures PSL 9.05.55 /56)
.00.0 I % RD.
0.02% RD.
0.05% RD.
0.05%
0.05%
Irpm
.9 rSpecifications -ET models
Resolution:Linearity + Hysteresis
Zero Repeatability :t
Temperature Compensation :t
Static Calibration :t
Speed :t
i-i\
The combination of the errors above in relation
to the full scale Phase Displacement (PD.),
typically 75% gives:
w .8
::>--'
~O .7
~::>';:i .6
wL0\! .51/1«>-U .4
~::>UU .3
«
.2
Overall accuracy: @ 95% Confidence level
JTE
RJPEATABltl~ ~ ~
R~PEATABI~ITY I ~
0.13% F.S.D.
0.10% F.S.D.
Absolute
Repeatability
:!:
:!:
Operating temperature -40 + 100°C0
20 30 40 50 60 70
% PHASE DISPlACEMENT
80 90 1000 10
5
Fig2
10 20 30 40 50 60 70 80 90 100OBSERVED READING ~P.D)
The "Torquetronic" principle was
conceived to provide the highest level
of torque measurement accuracy and
credibility for the exacting task of
aero engine development. However;
the practical accuracy of any
Torquemeter is no more than can be
proved to the users own satisfaction.
Unlike most measuring instruments
the transmission Torquemeter cannot
be calibrated against any standard.
The "Torquetronic" system was
designed from the outset so that its
integrity'can be readily proved by the
following indirect tests.
.Static calibration -
Application of torque without
rotation
.Dynamic calibration -
Application of rotation without
torque
Static calibration
The torsional stiffness of the shaft or the
calibration constant is simply determined with
lever arms, normally provided, and weights. The
calibration is thereafter as stable as Youngs
modulus and is strictly linear:Very large shafts are
usually supplied works calibrated on our 140kNm rig. Fig.1 shows the results of a typical calibration model, to
a linearity of 0.0 I %RMS. The minor effect of shaft temperature on stiffness is precisely known and may be
corrected for; using a shaft thermocouple.
Dynamic calibration
The Torquemeter is run with the
driven machine uncoupled to establish
the Zero Torque Datum (Z.TD.) Fig.2
shows the results of a typical
calibration.
Any systematic variation with speed is
compensated electronicallfAll transducers undergo no load
testing and calibration up to their
maximum operating speed on the
company's 120,OOOrpm spinning facilitfReadout integrity is proven by a
Reading + Complement check, Fig.3.
6
Standard ET models
L.$.
M.$,
H.$,
$,
Nominal ratings for standard Torquemeters
Special consideration for each application is advisable
Low Speed, Grease Lubricated
Medium Speed. Grease Lubricated
High Speed. Oil Lubricated
Suspended, Low Speed. Grease Lubricated
105 105
~
~ET5000~
1""'::- IU~ET3000
-ET2000
I
,~ET1000
I~ET12°1!;ET1000r ' I
104 10.
1- ETiiiO ~~
"ET600'""::-
~M.S.~ ET250
rET150 ~I~
103 103~ETio~"-
I. ET60 .L
~1- ET25 .
-ET26-
-ET25'
~ ~
~ T15. ET12!
, -
~ ET10 ~
102 102
~i " ~
~~
~ ~H,S~ET6
rETS
10 10
~
E~w::>OQ:
~
E~w:JOIx:
~
'rque Range
0.74 Ibf ft
)g Interchangeable Shafts
INm
specification.que shaft ratings are made to customel
Easi terchangeable ti N full accuracy t inel ler a very wide je range.
7
~
rrf{
Installation
Pedestal type
The transducer is fixed to a
bedplate. The couplings each side
must have two flexible planes.
Preferred choice for high speeds.
Convenient for calibration
Suspended type
The transducer is supported by the
shafts of the associated machines.
The couplings on each side must
have a single flexible plane. Casing
rotation is restrained by a link
Coupling selection
Whilst the 'T orquetronic' transducers are designed to be insensitive to external shaft loading, T orquemeters
Limited's extensive transmission engineering experience is available to assess or recommend coupling selection.
For higher speeds and powers Torquemeters Limited manufacture the TORDISC, an advanced Low Mass
Moment, profiled membrane coupling for speeds up to 80,OOOrpm and torques up to 30,OOONm.
Lubrication
Low and medium speed models are grease lubricated. High speed models are oil lubricated with air packed
seals pressurised from an external fan.Type K bearing thermocouples are standard on Medium Speed and High
Speed models.
Temperature Compensation
For the highest possible accuracy or for use in high ambient conditions, a shaft thermocouple/RTD can be
supplied for automatic modulus compensation (O.O25%/OC)
Torque helix
This is a useful way of defining the sense oftorque.T ransducers can be specified for unidirectional or
bidirectional use.
LEFT HAND HELIX -
Shaft is twisted as a left hand thread
RIGHT HAND HELIX -
Shaft is twisted as a right hand thread
9
GEC MARCONI
GIRDLESTONE
GKN
GLAENZER SPICER
GODIVA
GODWIN
GRASSO
ABB
AEROsPATIALE
AEROTEsT
AGUsTA
ALLIED SIGNAL
ALLISON
ALVis
ARIEL
AUXILEC
PEUGEOT
PHlLIPS
PIAGGIO
PLESSEY
PRATT & WHITNEY
HAYWARD TYLER
HELIKOPTER SERVICES
HOBOURN
HONDA
HOWDEN
HPI
REM
RENAULT
RICARDO
ROLLS ROYCE
ROVER
RWTH
BHEL ,
BMW-RRBUMBW/IP
IAC
IFP
ILMOR
ITP
SAUER SUNDSTRAND
SNECMA
STORK
SULZER
SUNDSTRAND
SVERDRUP
CAMBRIDGE UNIVERSITYCATERPILLARCEAT
CEGELECCEPR SACLAYCOMPAIR
COSWORTHCRANFIELD
KAWASAKI
KSB
TECHNOFAN
THOMASSEN
TOYOTA
TURBOMECA
DEMAG DELAVALDELPHIDFVLR
DOWNLEROY SOMER
LUCAS AEROSPACE
u s NAVYEDFEGT
MAN GHH
MAWDSLEYS
MHI
MTUVOlVO
FIAT
FISCHERFLEMINGFROUDE
WEIRS
WESTLANDS
NAL
NASA
NIJHUIS
NISSAN
NORMALAIR- GARRETT
NOVENCO
NUOVO PIGNONE
GARRETT
GEGEC ALSTHOM YORK
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