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A piezoelectric motor or piezo motor is a type of electric motor based upon the change in shape of a piezoelectric material when an electric field is applied. Piezoelectric motors make use of the converse piezoelectric effect whereby the material produces acoustic or ultrasonic vibrations in order to produce a linear or rotary motion. In one mechanism, the elongation in a single plane is used to make a series stretches and position holds, similar to the way a caterpillar moves. Rotating magnetic field as a sum of magnetic vectors from 3 phase coils An electric motor converts electrical energy into mechanical energy. ...
Piezoelectricity is the ability of crystals, certain ceramic materials, (and to some degree, all materials) to generate a voltage in response to applied mechanical stress. ...
It has been suggested that optical field be merged into this article or section. ...
The electronic (gold-plated) contacts of an EF mount lens. ...
Caterpillar of the Emperor Gum Moth A caterpillar is the larval form of a member of the Order Lepidoptera (the insect order comprising butterflies and moths). ...
Current designs Piezoelectric motors are made in both linear and rotary types. The word linear comes from the Latin word linearis, which means created by lines. ...
A sphere rotating around its axis. ...
Commonly known under the trademark names of Inchworm or PiezoWalk motors, the most common type of piezoelectric motor uses three groups of crystals: two of which are Locking and one Motive, permanently connected to either the motor's casing or stator (not both) and sandwiched between the other two, which provides the motion. A trademark or trade mark[1] is a distinctive sign of some kind which is used by an individual, business organization or other legal entity to uniquely identify the source of its products and/or services to consumers, and to distinguish its products or services from those of other entities. ...
Current piezoelectric motors are fundamentally stepping motors, with each step comprising either two or three actions, based on the locking type. The top electromagnet (1) is charged, attracting the topmost four teeth of a sprocket. ...
Another mechanism employs the use of surface acoustic waves (SAW) to generate linear or rotational motion. A surface acoustic wave (SAW) is a kind of wave used in piezoelectric devices called SAW devices in electronics circuits. ...
Locking mechanisms The non-powered behaviour of a piezoelectric motor is one of two options: Normally Locked or Normally Free. When no power is being applied to a Normally Locked motor, the spindle or carriage (for rotary or linear types, repectively) will not move under external force. For a Normally Free motor, the spindle or carriage will move freely under external force; However, if both locking groups are powered at rest, a Normally Free motor will resist external force without providing any motive force. The word spindle might (or might not) have several meanings: A spindle (shrub), a poisonous shrub or small tree of the genus Euonymus. ...
Catherine IIs carved, painted and gilded Coronation Coach (Hermitage Museum) George VI and Queen Elizabeth in a landau with footmen and an outrider, Canada 1939 The classic definition of a carriage is a four-wheeled horse drawn private passenger vehicle with leaf springs (elliptical springs in the 19th century...
In physics, force is an influence that may cause an object to accelerate. ...
A combination of mechanical latches and crystals could be used, but this would restrict the maximum stepping rate of the motor. Look up Rate in Wiktionary, the free dictionary. ...
Stepping actions
 Fig. 1: Stepping stages of Normally Free motor Regardless of locking type, piezoelectric motors — both linear and rotary — use the same mechanism to provide movement. Image File history File links No higher resolution available. ...
Image File history File links No higher resolution available. ...
First, one group of locking crystals is activated — this gives one locked side and one unlocked side of the 'sandwich'.
Next, the motive crystal group is triggered and held — the expansion of this group moves the unlocked locking group along the motor path. This is the only stage where motor movement takes place.
Then the locking group triggered in stage one is released (in Normally Locking motors, the other is triggered). Then the motive group is released, retracting the 'trailing' locking group. Finally, both locking groups are returned to their default states.
Speed and precision The growth and forming of piezoelectric crystals is a well developed industry, yielding very uniform and consistent distortion for a given applied potential difference. This, combined with the minute scale of the distortions, gives the piezoelectric motor the ability to make very fine steps — manufacturers claim precision to the nanometer scale. Potential difference is a quantity in physics related to the amount of energy that would be required to move an object from one place to another against various types of force. ...
A nanometre (American spelling: nanometer) is 1. ...
The high response rate and fast distortion of the crystals also allows the steps to be made at very high frequencies — upwards of 5 MHz. This gives a maximum linear speed of approximately 800 mm per second, or nearly 2.9 km/h. A response is the following: Often a response is the result of a stimulus. ...
A megahertz (MHz) is one million (106) hertz, a measure of frequency. ...
A millimetre (American spelling: millimeter), symbol mm is an SI unit of length that is equal to one thousandth of a metre. ...
Kilometre per hour (American spelling: kilometer per hour) is a unit of both speed (scalar) and velocity (vector). ...
Other designs
Single action
 Fig. 2: Piezo ratchet stepping motor. Very simple single-action stepping motors can be made with piezoelectric crystals. For example, with a hard and rigid rotor-spindle coated with a thin layer of a softer material (like a polyurethane rubber), a series of angled piezoelectric transducers can be arranged. (see Fig. 2). When one group of transducers is triggered, the rotor will be pushed around one step. This design is not capable of such small or precise steps as more complex designs, but can reach higher speeds and are cheaper to manufacture. Image File history File links No higher resolution available. ...
Image File history File links No higher resolution available. ...
A polyurethane is any polymer consisting of a chain of organic units joined by urethane links. ...
A transducer is a device, usually electrical or electronic, that converts one type of energy to another. ...
Patents The first U.S. patent to disclose a vibrationally-driven motor may be "Method and Apparatus for Delivering Vibratory Energy" (U.S. Pat. No. 3,184,842, Maropis, 1965). The Maropis patent describes a "vibratory apparatus wherein longitudinal vibrations in a resonant coupling element are converted to torsional vibrations in a toroid type resonant terminal element." Other important patents in the early development of this technology include: - "Piezoelectric motor structures" (U.S. Pat. No. 4,019,073, Vishnevsky, et al., 1977)
- "Piezoelectrically driven torsional vibration motor" (U.S. Pat. No. 4,210,837, Vasiliev, et al., 1980)
See also The electronic (gold-plated) contacts of an EF mount lens. ...
The electronic (gold-plated) contacts of an EF mount lens. ...
Rotating magnetic field as a sum of magnetic vectors from 3 phase coils An electric motor converts electrical energy into mechanical energy. ...
A ball bearing motor is an unusual electric motor that is constructed as follows: Take a short hollow copper pipe and fit 2 ball bearings on either end. ...
A brushless DC motor (BLDC) is an AC synchronous electric motor that from a modeling perspective looks very similar to a DC motor. ...
The inchworm motor is a device using piezoelectric actuators to move a shaft with nanometer precision. ...
A linear motor is essentially an electric motor that has had its stator unrolled so that instead of producing a torque (rotation), it produces a linear force along its length. ...
The Mendocino motor is a solar powered magnetically levitated motor. ...
A Repulsion motor is a type of electric motor for use on alternating current. ...
The top electromagnet (1) is charged, attracting the topmost four teeth of a sprocket. ...
Traction motor typically refers to those motors that are used to power the driving wheels of a railroad locomotive, electrical multi-unit train (such as a subway or light rail vehicle train), or a tram. ...
The electronic (gold-plated) contacts of an EF mount lens. ...
There are very few or no other articles that link to this one. ...
Image File history File links Download high resolution version (707x768, 49 KB) Summary Largest motor: 1 Hp (750 W) Next largest: 25 W Small motors: CD player motor, toy motor, CD drive head traverse motor Licensing I, the creator of this work, hereby grant the permission to copy, distribute and...
A motor controller is a device or group of devices that serves to govern in some predetermined manner the performance of an electric motor. ...
Adjustable speed drive (ASD) is one of the most general terms applied to equipment used to control the speed of machinery. ...
Direct torque control is one method used in variable frequency drives to control the torque (and thus finally the speed) of the three-phase AC electric motors. ...
A direct on line starter is often abbreviated DOL starter and is a widely-used starting method of electric motors. ...
An electronic speed control or ESC is a device mounted onboard an electrically-powered R/C model in order to vary its drive motors speed, its direction and even to act as a dynamic brake in certain controllers. ...
Small Variable Frequency Drive (VFD) A variable-frequency drive (VFD) is a system for controlling the rotational speed of an alternating current (AC) electric motor by controlling the frequency of the electrical power supplied to the motor. ...
Barlows Wheel is the name given to an early demonstration of an electric motor, designed and built by English mathematician and physicist, Peter Barlow in 1822. ...
In electrical engineering, brushes conduct current between stationary wires and moving parts, most commonly in a rotating shaft. ...
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