The beam can be made to vibrate from one stable position to the other by alternating the direction of the applied voltage. When an alternating polarity signal is applied to the piezoelectric layers 210 and 214, the beam oscillates between the two stable positions shown in FIGS. In lieu of piezoelectric layers, magnetostrictive or electrostrictive materials may also be employed. 11. Again, the biasing elements 308 serve to increase the amplitude of displacement of the midpoint of the beam 304 over what would be possible without the biasing elements 308. The substrate sections 306 a-306 c may be formed from plastic, aluminum, or any other suitable, flexible material. This can increase the lift and reduce the drag of aerodynamic bodies such as wings, fuselages, cowlings, struts, flaps and tails. Proper application of active flow control can increase the fuel economy, increase the payload and reduce the operating costs of a wide variety of aircraft, both commercial and military.
The various embodiments are expected to find utility in commercial and military aircraft, spacecraft, and other applications. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following description of the various embodiment(s) is merely exemplary in nature and is in no way intended to limit the present disclosure or its application. The apparatus is used for enabling low frequency vibration energy harvesting (VEH) through the use of a piezo flexure 12 which is supported fixedly from a vibrating structure 14. The piezo flexure essentially forms a beam-like structure, and in one preferred form comprises a piezo bimorph flexure. The entire flexure assembly 102 is supported on the base 103 from a pair of upstanding boss portions 115 and 117. Conventional threaded fasteners 118 and 120 extend through openings 122 and 124 in support arms 126 and 128 of the support substrate 108 to thus suspend the entire flexure assembly 102 above the base 103. The support arms 126 and 128 are located at an approximate midpoint of the support substrate 108, but the support arms could also be offset so as to be closer to one or the other of the link arms 110, 112 and thus not disposed at the approximate longitudinal midpoint.
All forms of active flow control require some form of actuator or motor to energize a flow control element, to thus modify or change the airflow within the viscous boundary layer. The apparatus thus forms a means to significantly “soften” a piezo flexure which enables the piezo flexure to be used in low frequency vibration energy harvesting applications where such a flexure would otherwise be too structurally stiff to harvest the vibration energy. 1, at low frequency, will provide very little power from low frequency vibrations. Que tomar para el dolor muscular por ejercicio . Accordingly, a system that is not limited to efficient harvesting of vibration energy at only the resonant beam frequency, but that is able to harvest energy over a relatively wide frequency range, would be much more effective in generating electrical power from a vibrating structure. At low frequency, the tip beam moves very little relative to the vibrating structure. For example, the apparatus 10 is extremely well suited to applications requiring large deflections of the piezo flexure and low force, such as with an aerodynamic flow control synthetic jet actuator or a low frequency audio speaker.
Tipos De Dolor Pdf
A thicker piezoceramic wafer will provide higher energy content, but this energy will be in the form of high voltage and low charge as compared to a thinner material. SUMMARY OF THE INVENTION The present system and method is directed to a piezoelectric device that is well suited for use as an actuator, motor or other form of drive implement.
Dolor Espalda Pecho
7. The biasing element 208 acting on the free end 206 of the beam 204 significantly amplifies the displacement over what would be achieved without the biasing element 208 acting on the free end 206 of the beam 204. When the polarity of the voltage applied to the piezoelectric layers 210 and 214 is changed, this causes the layers 210 and 214 to deflect the beam 204 into the second stable position shown in FIG. Other applications could include use with electronic sights for hand carried weapons, use with control of rotating mechanisms such as latches or levers to open and close doors and latches, use with automatic switches using over-center characteristics to “switch and hold”, any 2-state switch, position sensing and switch state sensing applications. The apparatus 10 has a significantly lower frequency of operation than a conventional energy harvesting device, such as that shown in FIG.
With further specific reference to FIG. The spring force provided by the biasing elements can be tailored to provide the required sensitivity for a specific VEH application. With specific reference to FIG. 12 to denote the various portions of beam 404. The operation of the apparatus 400 is otherwise identical to that described in connection with FIG. The various embodiments of the drive motor described herein provide extremely lightweight mechanisms for implementing active flow control systems.
Tipos De Dolor De Espalda
11, substrate 306 includes separate piezoelectric layers 310 a, 310 b, 310 c and 310 d on one surface, and preferably a plurality of piezoelectric layers 312 a, 312 b, 312 c and 312 d on an opposing surface of the substrate 306. Piezoelectric layers 310 a-310 d and 312 a-312 d are coupled via electrical conductors 313 to the voltage source 216. A push rod 314 forms a connecting implement that couples the center substrate section 306 b of the beam 304 to an independent flow control element (not shown).
The beam includes at least one piezoelectric layer of material on one of its surfaces, and in one embodiment at least one layer of piezoelectric material on each opposing surface of the beam. In one embodiment, the apparatus includes a support structure that a flexible beam is supported from. The apparatus 200 includes a support structure 202 which is used to support the beam 204 at one end 205. A free end (or tip) 206 of the beam 204 is in contact with a biasing element 208, which in this example is illustrated as a coil spring. Dolor interno de rodilla . Put differently, once external vibration energy has caused the piezo flexure 12 to move from one stable position to the other, the piezo flexure 12 will oscillate around the stable location that it has just moved to, allowing the piezo material 16 and 18 of the piezo flexure 12 to harvest the strain energy over many cycles.
Fisioterapia Querétaro Calendarios
7 and 8, when a voltage of a first polarity is applied to the piezoelectric layers 210 and 214, they cause the beam 204 to be deflected into a first stable position represented in FIG. Each of the stable positions of the piezo flexure 12 are laterally offset from a longitudinal mid line 42 extending between the point of attachment of the fixed end 22 of the piezo flexure 12 and the pivot pin 28 supporting the cantilever beam 24. The mid-line 42 can be viewed as a position of equilibrium, albeit an unstable one.
Dolor Espalda Cáncer Pulmón
In one preferred form, the length and width of the piezoelectric wafers 104 and 106 is about 1.8″ (45.72 mm) and about 0.6″ (15.24 mm) respectively. The apparatus 200 has approximately twice the amplitude displacement of the beam of a conventional piezoelectric beam at an energy of 0.002 Joules. A particular advantage of the apparatus is that the amplitude (i.e., displacement) of the beam is significantly increased without requiring additional drive power or substantially increasing the mass of the beam. A significant advantage of the apparatus 200 is that the amplitude displacement of the free end 206 of the beam 204 is significantly greater than with previous piezoelectric actuator configurations, and especially so at frequencies below the natural oscillation frequency of the beam 204. This is in large part due to the effective softening of the beam 204 caused by application of the bias force. The biasing elements 308, which are illustrated as coil springs, exert a compressive force on the beam 304. This increases the amplitude of displacement of the beam 304 when it is moved between its two stable positions, one of which is shown in solid lines and the other being shown in phantom, in FIG.
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FIG. 5 is a side view of the assembly of FIG. “L” represents the length of piezo flexure 12 and “F” represents the force provided by the spring. Such environments often exist in aircraft and automotive applications where the vibration experienced by an aircraft or automotive vehicle represents energy that could be used to power sensors or other remotely located devices, provided such energy can be harvested by a suitable device. The biasing element 208 is coupled to the free end 206 of the beam 204 by a flexible coupling, or hinge, or rigid attachment such as a weld or clamp.
Dolor Muscular Piernas
The beam has two stable positions, one each on opposite sides of a line bisecting the fixed end of the beam and the point where the biasing element is supported from the support structure. Each slot 130, 131 is further disposed along a midpoint of the overall thickness of its respective link arm 110 or 112. Dolor constante de espalda baja . Slot 130 has a height sufficient to receive an end 132 of the support substrate 108 therein. The substrate 108 can be made of spring steel, beryllium copper, brass, glass epoxy composite or graphite epoxy composite, or any other suitable material. However, any suitable biasing member can be used. With a suitable intermediate linkage assembly, the apparatus can also be made to drive a rotary motion implement. Still further uses could be with systems designed for vibration sensing, motion sensing, force sensing, liquid level sensing, etc.