240 likes | 587 Views
Actuators. Linear movement and vibration. Linear movement. In some (many) industries the most common movement. Realised from rotating via tooth belts or screws. Translation (linear) motor. ”Stationary”. Airgap. ”Moving (Rotor)”. Hydraulics.
E N D
Actuators Linear movement and vibration
Linear movement • In some (many) industries the most common movement. • Realised from rotating via tooth belts or screws.
Translation (linear) motor ”Stationary” Airgap ”Moving (Rotor)”
Hydraulics • PositiveHigh force and power densityEstablished technic • NegativePump Oil storage(fire risk) FilterMaintenance
Pressure air • PositiveNo storageEstablished technic • NegativeCompressor FilterMaintenance
Piezoelectric • Lead Zirconate Titanate • d33 is on the order of 450 to 650 x 10-12 m/V, d31 is on the order of -200 to -300 x 10-12 m/V.
Properties • Unlimited ResolutionA piezoelectric actuator (PZT) can produce extremely fine position changes down to the subnanometer range. The smallest changes in operating voltage are converted into smooth movements. Motion is not influenced by stiction/friction or threshold voltages. • Large Force GenerationPZTs can generate a force of several 10,000 N. PI offers units that can bear loads up to several tons and position within a range of more than 100 µm with subnanometer resolution (see "PZT Actuators" section). • Fast ExpansionPiezo actuators offer the fastest response time available (microsecond time constants). Acceleration rates of more than 10,000 g's can be obtained. • No Magnetic FieldsThe piezo effect is related to electrical fields. PZT actuators don't produce magnetic fields nor are they affected by magnetic fields. They are specially well suited for applications where magnetic fields cannot be tolerated. • Low Power ConsumptionThe piezo effect directly converts electrical energy into motion only absorbing electrical energy during movement. Static operation, even holding heavy loads, does not consume power. • No Wear and TearA piezo actuator has neither gears nor rotating shafts. Its displacement is based on solid state dynamics and shows no wear and tear. PI has conducted endurance tests on PZTs in which no change in performance was observed after several billion cycles. • Vacuum and Clean Room CompatiblePiezo actuators are ceramic elements that do not need any lubricants and show no wear and abrasion. This makes them clean room compatible and ideally suited for Ultra High Vacuum applications. • Operation at Cryogenic TemperaturesThe piezo effect is based on electric fields and functions down to almost zero Kelvin (with reduced specifications).
Laminar design DL » d31*L * U/d D31 = - 250e-12 m/V d=thickness Dd » d33 * U D33 = + 500e-12 m/V
Tube design DL » d31*L * U/d d31 = - 250e-12 m/V
Stack design DL » d33 * U d33 = + 500e-12 m/V
Applications • Precision Mechanics and Mechanical Engineering • Vibration cancellation • Structural deformation • Out-of-roundness grinding, drilling, turning • Tool adjustment • Wear correction • Needle valve actuation • Micro pumps • Linear drives • Piezo hammers • Knife edge control in extrusion tools • Micro engraving systems • Shock wave generation • Life Science, Medicine, Biology • Patch-clamp drives • Gene technology • Micro manipulation • Cell penetration • Micro dispensing devices • Audiophysiological stimulation • Shock wave generation • Optics, Photonics and Measuring Technology • Image stabilization • Scanning microscopy • Auto focus systems • Interferometry • Fiber optic alignment & switching • Fast mirror scanners • Adaptive and active optics • Laser tuning • Mirror positioning • Holography • Stimulation of vibrations • Disk Drive • MR head testing • Pole tip recession • Disk spin stands • Vibration cancellation • Microelectronics • Nano-metrology • Wafer and mask positioning • Critical Dimensions measurement • Microlithography • Inspection systems • Vibration cancellation
TERFENOL-D ACTUATOR ADVANTAGES • HIGHEST DISPLACEMENT OF ANY SOLID STATE ACTUATOR • HIGH FORCE • RELATIVELY FLAT FREQUENCY RESPONSE • MICROSECOND RESPONSE • PRECISE CONTROL • OPERATES OVER A WIDE RANGE OF TEMPERATURES • LOW VOLTAGE OPERATION
Applications • MACHINE TOOLS POSITIONING AND CONTROL INTERNAL COMBUSTION ENGINES FUEL INJECTORS HYDRAULICS PUMPS AND VALVES AEROSPACE PRECISE POSITIONING
Link • http://www.physikinstrumente.com/tutorial/index.html