Physik Instŕumente (pi) Gmbh & Co. Kg

Physik Instrumente Gmbh & Co. Kg

Burhanettin Koc

Bülent Delibas

Thomas Polzer

An actuator in the form of a stack is described, wherein the stack includes multiple first pairs of layers of a polarized electromechanical material and multiple second pairs of layers of a polarized electromechanical material, and the first and second pairs of layers are disposed, one behind the other, wherein at each pair of layers on each of its terminal surfaces electrically conductive layers are disposed, and, between the layers of each pair of layers, an electrically conductive layer for connection to at least one connection electrode of a second polarity is disposed, and the polarization directions of the electromechanical material of the layers of each pair are aligned opposite to one another, and the directions of polarization of the material of the layers of each pair of layers are aligned perpendicular to the directions of polarization of the material of the layers of each adjacent pair of layers.

Stacked actuator comprising longitudinal and shear actuator sections

A method for operating an electromechanical element, comprising the following steps: by controlling a first control section which is deformable by an electrical voltage by a first voltage signal generation of adjusting movements of a friction element which is arranged on the electromechanical element and which is provided for frictional contact with an element to be driven, controlling of a second control section which is deformable by an electrical voltage by a second voltage signal, which comprises a signal section, the frequency of which compared to the first voltage signal is by a factor, an actuator, a drive device with an actuator and a motor with a drive device and an element to be driven.

Method for operating an electromechanical element, actuator, drive device and motor

The invention relates to an annular or hollow cylindrical ultrasonic actuator, on the end faces of which are arranged n&#x2265;2 friction elements, and on the outer peripheral surface of which are arranged 2n excitation electrodes, spaced apart from one another in each case by a separating gap, each of the friction elements being arranged in the region of a separating gap, wherein, between friction elements that are adjacent with respect to the periphery of the ultrasonic actuator and are located on different end faces, two excitation electrodes are arranged such that, when the ultrasonic actuator is electrically excited, the friction elements of both end faces simultaneously perform a movement which is suitable for driving an element to be driven to rotate in the same direction. The invention further relates to an ultrasonic motor having an ultrasonic actuator of this kind and having a holding device in which the ultrasonic actuator is inserted.

Ultrasonic actuator for a rotary drive

The present disclosure relates to a linear drive, including: an actuator unit with at least one actuator; two guide elements and a movement element, wherein the movement element is displaceable along both guide elements by a movement generated by the actuator unit as a result of a stick-slip effect. In order to allow a more accurate displacement of the movement element in a compact design of the linear drive, the movement element can be brought into engagement with each of the two guide elements by static friction in order to be displaced along the two guide elements as a result of the stick-slip effect.

Linear drive for precision positioning

Disclosed is electromechanical actuator for ultrasonic motor in the shape of an n-sided regular polygon plate with n being equal to or greater than five. The polygon plate has two larger main surfaces and at least five smaller side surfaces connecting the main surfaces with each other. Two electrodes are arranged on one of the main surfaces and are electrically isolated from each other by a linear isolation area. One electrode is arranged on the other of the main surfaces. The polygon plate comprises an electromechanical material that undergoes a deformation when electric voltage is applied to the electrodes. The material of the electromechanical actuator comprises a single or polycrystalline piezoelectric ceramic with piezoelectric charge constant ddiffering from piezoelectric charge constant dboth in sign and in value. The piezoelectric charge constants dand ddefine a first and second main deformation direction of the actuator perpendicular to each other. The orientation of the linear isolation area is parallel to either deformation direction.

Electromechanical actuator, method for electrical excitation of an electromechanical actuator and ultrasonic motor

A method is disclosed for closed-loop motion control of an ultrasonic motor having at least one actuator with an excitation electrode and at least one common electrode, an element to be driven, a controller and at least one electrical generator for generating at least first and second excitation voltages Uand Uto be applied to the electrodes of the actuator for vibration of the actuator. A friction element of the actuator, due to its vibration, intermittently contacts the element to be driven with a driving force. The method includes providing the at least two excitation voltages Uand Uwith different resemblance frequencies, a frequency difference deviating from a servo sampling frequency of the controller by 5 kHz at the most, and simultaneously applying the excitation voltages to the electrodes of the actuator.

Method for closed-loop motion control for an ultrasonic motor

An actuator with a rectangular shape] is made of polarized electromechanical material having two large main surfaces and at least four side surfaces, two of which being longer than the other two side surfaces. At least one friction element is arranged on at least one of the shorter side surfaces. At least two active electrodes are arranged on one of the main surfaces, with one common electrode arranged on the other of the main surfaces The electromechanical material of the actuator is excitable to perform standing wave deformations due to an electric field generated therein for moving the friction element to drive an element. The actuator aspect ratio for its length to its thickness is between 3.9 and 4.1 and an aspect ratio for the length relative to width is between 2 and 5.

Actuator

A rotary ultrasonic motor includes an ultrasonic actuator, a driven element, an inner casing member and an outer casing member. A piezoelectric or electrostrictive or magnetostrictive material is arranged between an excitation electrode and at least one general electrode. The ultrasonic actuator is between the inner and outer casing members of a casing, and is directly or indirectly in contact with the element to be driven, so that periodic deformations generated in the ultrasonic actuator by electrical excitation are transferable to the drive element. The ultrasonic actuator is mounted by a retaining device arranged on the casing with at least one retaining section which engages in a recess associated with a respective retaining section.

Rotary motor with ultrasonic actuator

A piezoelectric motor includes at least two piezoelectric actuators. Each actuator includes two piezoelectric elements on opposite sides of a coupling element, the sides being main sides of the piezoelectric actuators and having a larger area than other surfaces or sides of the piezoelectric actuators. The main surfaces of each of the piezoelectric actuators connect with at least four side surfaces of the piezoelectric actuator. The motor includes an elastic element coupled to and spacing the first and second piezoelectric actuators from each other and there is also a frictional element that couples the first and second piezoelectric actuators for frictional contact for driving an object. The first and the second piezoelectric actuators are adapted to deform in a direction that is substantially perpendicular to a plane defined by the side surface to which the elastic element is attached using a longitudinal piezoelectric effect of the piezoelectric elements.

Piezoelectric motor

An actuator, which can include piezoelectric material, is provided in the form of a single-layer or multi-layer flat plate. At least one layer has two electrodes spaced from each other by means of a separating area and arranged opposite each other both on the upper face of the at least one layer and on the lower face of the at least one layer. The electrodes of the upper face are arranged at an offset from the electrodes of the lower face. A motor is also provided to include the actuator and a movable element to be driven by means of the actuator.

Growing community of inventors

Ettlingen, Germany

Burhanettin Koc