Product category:
Loadcells, Force Sensors and Torque Sensors
News Release from: Sensor Technology | Subject: TorqSense
Edited by the Engineeringtalk Editorial
Team on 08 April 2008
Torque sensor helps simplify test beds
TorqSense is an in-line digital torque sensor which is easy to use, accurate and low in cost, making it suitable as the core of any motor test bed.
The automotive industry's race to develop a new generation of high-performance, low-emissions power plants has lead to the emergence of high-capability test beds that simultaneously monitor multiple parameters The sector is pinning many of its hopes for the future on the development of electric/petrol and electric/diesel hybrid engines integrated with known performance enhancing technologies such as fuel injectors and superchargers
Other projects are looking at marrying other 'green' options such as regenerative braking and kinetic energy storage with hybrid engines.
The once-humble test bed can now require as much engineering design as the power plants themselves if they are to be able to monitor multiple parameters simultaneously.
However for them to be efficiently usable they have to be, at heart, as simple as possible.
This need has been converted into a market opportunity for a specialist torque sensor firm in Oxfordshire.
Sensor Technology produces TorqSense, an in-line digital torque sensor which is easy to use, accurate and low in cost, making it suitable as the core of any motor test bed.
Tony Ingham, from Sensor Technology, explains: "Measuring an engine's torque is a fundamental business; older sensors often used slip rings which wear over time, thus increasing inaccuracies or had analogue electronics which are difficult to interface with digital equipment".
"TorqSense does away with slip rings as it is noncontact, working through an RF couple and with modern digital RF electronics inside, it allows easy interfacing with digital equipment and its own TorqView software so the development engineers can concentrate on monitoring the key input and output parameters".
In a hybrid power plant electrical power and mechanical torque are essentially the same thing - an energy flow, which has to be used as efficiently as possible with minimum losses.
The two directions of energy flow, to and from the power source, are equally important to optimise so that recharging is as efficient as running.
"There are some really radical thinkers currently employed in advanced engine design", Ingham said.
"To them, electric motors, IC engines, generators and regen units are all essentially the same - torque producers that ultimately drive the road wheels".
TorqSense transducers use two tiny quartz piezoelectric combs, called Surface Acoustic Wave (SAW) devices fixed to the surface of the sensor's shaftt.
As the torque increases the spacing between the combs inside the SAW devices vary , allowing the resonant frequency to change proportionally to the applied torque of the rotating shaft under test.
In effect the SAW devices are frequency-dependent strain gauges that measure changes in resonant frequency of the test shaft as the test program is run.
The noncontact sensor uses a wireless radio frequency (RF) coupling to transfer the data signal to a pick-up head.
The same RF coupling also supplies power to the SAW devices.
This is possible because the devices are based on piezo technology that needs less than 1mW of power.
This arrangement does away completely with the difficulties of fitting slip rings inside the sensor and maintaining their contact quality throughout an extended test run. Request a free brochure from Sensor Technology ...
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