Pump action
test facilities with Surface Acoustic Wave (SAW) equipment from
Sensor Technology. Ultrasound waves have been used to model drive
torque and help contain development costs.
The British-based company, which manufactures individually designed pumps, believes that the investment is necessary to maintain the company's reputation. It claims that customer requirements cannot be satisfied by off-the-shelf units. The firm supplies pumps to a number of industry sectors including the food and beverage industries.
Charles Austen Pumps points out that the cyclical nature typical in many pumps' operation tends to induce torsional oscillations in the drive shaft, which can have a significant adverse effect on performance if unchecked. The company has devoted a great deal of time and research in this area, and believes that new test facilities will enable it to manufacture better pumps.
"We have recently built a new test station based on Torqsense, Sensor Technology's SAW sensor, and it is proving its worth time and time again," said technical manager Brian Glover.
"Many years ago we used a simple torque arm and scales when developing prototype, then we moved on to slip ring technologies which were expensive and difficult to use because they induced a frictional load of their own. Techniques based on Surface Acoustic Waves began to emerge about 10 years ago and we embraced these with considerable success."
SAW provides non-contact monitoring of instantaneous rotary torque, allowing accurate modelling of the load changes. Charles Austen Pumps built its own test stand, which has served the firm well for many years.
"The state of the SAW art has now moved onto a higher plane, so last year we decided to tap into Sensor Technology's expertise and develop a new cutting edge test rig," said Glover. "They supplied us with a Torqsense unit and helped with designing and building the rig."
In essence a Torqsense is a frequency-dependent strain gauge that operates at ultrasound frequencies. It consists of a transducer mounted on the shaft, which monitors variations in resonance frequency of a drive shaft as the torsional load varies and transmits a radio frequency signal to an adjacent pick up.
Charles Austen Pumps claims that Torqsense embraces all the advantages of SAW technology, including a broader signal bandwidth than other analogue based technologies and elimination of electronic interference. The technology also provides lower production costs and has proved to be highly reliable.
"Our reputation is based entirely on the quality of our engineering, and our business on the ability to accurately forecast development cost for each job," said Glover. " Sensor Technology has helped us build a new facility that makes our drive engineering accurate, predictable and reliable, or put another way we are moving from a black art to an exact science."
