1. Foil bearings run on a film of oil. 2. Heshmat made an experiment with a turbine engine to check the strength of the shaft. 3. The shaft used in the experiment was made of cast iron. 4. The technology of foil bearings was invented 20 years ago. 5. The smallest foil bearings are less than 1 sentimetre in diameter. 6. Heshmat compares the operation principles of the bearings with tossing a child into the air. 7. Foil coating enables to prevent overheating. 8. The military are going to use the foil bearings in submarines.
Exercise 2. Give synonyms to the following words from the text:
progress, ultimate, ordinary, main, performance, to support, to achieve, stiffness, to toss, innovative, regulation.
10. Wiggle Room
|a take||точка зору, трактовка||a PCB (printed circuit board)||печатна плата|
|a screw||гвинт||a stake||пакет акцій|
|to come up with||знайти||a joint venture||спільне підприємство|
|a shift||зсув||to headquarter||розміщувати штаб|
|a hip||стегно||to purchase||купувати|
|a thread||різь, нарізка||to customize||виробляти на заказ|
|to squiggle||звиватись||to be rated||бути розрахованим|
|a clearance||зазор||to replace||заміняти|
|to advertise||рекламувати||a stepper motor||шаговий мотор|
Here’s a different take on the piezoelectric actuator, the device that takes advantage of the deformation of certain ceramics when an electric field is applied to them. The piezoelectric actuator changes shape and can move something.
A few years ago, David Henderson got the idea of using the shape-changing phenomenon to cause a nut to vibrate and drive a screw. What he came up with is a linear motor that can move about 100 times its own mass and can be manufactured in sizes down to about 1.5 centimeter thick, and perhaps even smaller.
Henderson received a patent for the idea in 2005 and has founded a company, New Scale Technologies Inc., which says it can make as many as 100,000 motors a month at its factory in Victor, N.Y. He is both co-CEO and chief technology officer. The other co-CEO, Ted Franceschi, is chief development officer.
The device consists of a screw inside a nut, with both parts made of stainless steel. The nut is encased in four piezoelectric plates. A voltage is applied to the plates at the frequency of the nut’s first bending resonant frequency, Henderson said. Depending on the size of the nut, that could be anywhere from about 40 to 200 kilohertz. The plates operate in pairs, and the current is applied separately to each pair with a 90-degree phase shift.
The result is an alternating deformation of the plates that causes the nut to vibrate in a circular motion. Henderson compared the action to the movement of the hips of a person spinning a Hula Hoop. Tangential forces from the threads of the nut work on the screw, which will begin to rotate and can move a load.
The company calls it the Squiggle motor. According to Henderson, the system requires an axial load to work properly. When there is no load on the screw, it may move, or it may not, depending on thread clearance and the mass of the screw. The company makes the motors in which the nut is as small as 1.5 × 1.5 × 6 mm. Henderson said it may be possible to manufacture them 33 percent smaller.
One of the applications for which New Scale advertises the motors is for fine control of lenses in tiny cameras, like the ones in cellular phones. New Scale recently expanded a two-year-old license with Tamron Co., a maker of optical equipment in Japan. Tamron is now licensed to make Squiggle motors for its own products at factories in Japan and elsewhere in Asia. It may also serve as a contract manufacturer for New Scale.
The company suggests a range of uses for Squiggle motors, from toys to electronic locks or microfluidic controls in drug pumps.
There are several options for the electronics needed to drive the motors, Henderson said. Among them, he said, are benchtop electronics in housings, separate PCBs using discrete electronic components that are ready for integration in a customer’s product, or a motor drive circuit on a single application-specific integrated circuit.
New Scale has partnered with Austriamicrosystems AG, a manufacturer of integrated circuits in Unterpremstaetten, a suburb of Graz, Austria, to develop a chip that will be able to drive two Squiggle motor simultaneously. The collaboration will also develop a position sensor.
Austriamicrosystems earlier this year invested $6 million to buy a 25 percent stake in New Scale. Austriamicrosystems was formed in 1981 as a joint venture of American Microsystems Inc. and VOEST Alpine AG. It is headquartered in a 12th-century castle, Schloss Premstaetten, that VOEST purchased in 1981.
New Scale makes a range of Squiggle motors in standard sizes and offers to customize, as well. The smallest stock motor that New Scale makes, Model SQL-1.5-6, has a nut that is 1.5 × 1.5 × 6 mm. Its mass is 0.15 grams and it is rated to generate up to 0.2 newton, or 20 grams force. The stock model has a maximum travel of 6 mm and a travel speed of 5 mm per second. Its resolution is listed at 0.5 micrometer.
According to Henderson, a Squiggle motor is applicable “anyplace you want to replace a solenoid or stepper motor and want to go smaller.” They are especially advantageous at widths, or motor diameters, under 6 mm, he said.
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