DATUM ELECTRONICS
M425 TORQUE TRANSDUCER HANDBOOK
5
MECHANICAL
INSTALLATION
OBJECTIVE OF THE MOUNTING
The objective is to align the shaft of the M425
Torque Transducer (sensor) with the torque.
The torque should where possible be driven
through the centre line of the shaft.
Unlike Disk Transducers that require very fine alignment
tolerances when mounting, the M425’s longer shaft allows
a greater degree of flexibility in terms of alignment.
M425 Torque
Transducer
Anti-rotation
point
Securing
post
Load pump
Engine
Bearing
Bearing
Keyway couplings
Plummer blocks
or suported bearings
Data output
cable
Typical installation with bearing block each side
THINGS TO AVOID
Overload
= 150% the rating of the transducer. Loads at this
level should be avoided as they will decrease the fatigue life
of the Transducer. If you are likely to see large overloads at
the same time as wishing to see high resolution data for much
smaller torques please consult our sales team.
Ultimate Load
= at the ultimate loads quoted for the
Transducer shaft (see table 8, page 16) the sensing element
will be damaged and large offsets will occur. At this level
the shaft will be well beyond its design limits and may
mechanically fail. If you have loaded a Transducer above
the Proof Load/Overload level it should be checked before
continued use.
Diagram No. 4
The series M425 Torque Transducers are designed
to withstand a level of overload.
The load levels quoted within tolerances (see table 8 on
page 16) should not have any effect on the calibration or
zero setting of the Transducers. Each Transducer has been
subjected to the proof load level within its testing cycle.
Loading the Transducer above the proof level will offset the
Transducer zero and will damage the Transducer. Regular
loading beyond the proof level will start to show progressive
zero movement and may effect both the gain and the
hysteresis of the Transducer. The shaft absolute load is the
maximum before the shaft will yield.
You should avoid any side loads or bending loads across
the shaft. As the M425 Transducer series have relatively
long shafts they are more tolerant to a small degree of
misalignment than short flange transducers (sensors), however
misalignment can change the loading on the internal bearings
of the device and should be avoided where possible.
Consider large dynamic or transient torques when
designing your test system.
When designing the test rig or test system that will use the
M425 Transducer you should consider the effect of any large
inertial / kinetic loads such as flywheels or brakes. If the
system is to drive to a high level of torque, and then a brake is
applied, the dynamic torque in the test rig can be much higher
than that of the output of the drive motor. The fast deceleration
torque may exceed the limits above causing damage.
Bent shaft
Offset shaft
Centre line shaft alignment
Diagram No. 5
Correct alignment indicated
above with the load running
through the centre of the shaft.
Avoid misalignment and side
loads or bending loads as
indicated on the right.
Where the installation will see a larger degree of misalignment
you should consider the use of flexible couplings in the
drive line. If misalignment is very likely consider the Datum
Electronics RS and FF ranges which are bearing-less
transducers (see page 18). Talk with our sales team who can
advise on this type of installation.
