Piezomotor Uppsala Ab

Piezomotors Uppsala Ab

Nokia Corporation

Nokia Mobile Phones Limited

Minebea Company, Limited

Piezomotor Uppsala Aktiebolag

Stefan Johansson

Ilpo Kalevi Kauhaniemi

Guido Schmid

Christer Mattsson

Helmut Schneider

Mats Bexell

Anders Jansson

Jonas Eriksson

Olov Johansson

Jarkko Rouvinen

Staffan Karlsson

Andreas Danell

Per Oskar Lithell

Johan Abrahamsson

Pentti Ahlgren

Per Benkowski

Jan Söderkvist

Thomas Trietz

Robert Sunnerberg

Pentti Ablgren

Sölve Lindmark

Karl H&aring;kansson

Martin Wilmer

Anders Larson

An ultrasonic electromechanical stator includes two vibration bodies, a link member connecting the two vibration bodies along a connection direction and a stator support. Each of the vibration bodies includes a respective electromechanical element and is configured to perform bending vibrations in a bending direction when an alternating voltage is applied to the electromechanical elements. The link member has a contact portion intended for contacting a surface of a body to be moved. The link member has a respective mechanical link connecting portion to the vibrating bodies. Each of the vibration bodies is mechanically attached to the stator support by at least two attachment tabs on at least one side, in a direction transverse to both the connection direction and the bending direction, of the respective vibration bodies. Also an ultrasonic electromechanical motor having such an ultrasonic electromechanical stator is disclosed.

Ultrasonic resonating motor

An electromechanical motor assembly includes a stator, a body to be moved and a stator support. The stator has a plurality of electromechanical actuators for moving the body by repetition of steps ensuring that at least one of the electromechanical actuators is in non-sliding contact with the body at every time. The assembly further includes a force applying arrangement for supplying a normal force (N) between the stator and the stator support by at least one spring arrangement. The spring arrangement has a spring constant in the direction (Z) normal to the surface of the body that is lower than 5% of the ratio between the normal force and the average height uncertainty of the surface of the body. The force applying arrangement includes a lateral fixing plate attached between the stator and the support parallel to the main motion direction (X) and juxtaposed to the surface of the body.

Provision of a normal force to electromechanical motor

An electromechanical motor includes an actuator assembly and a body to be driven in a driving direction. The actuator assembly has an actuator backing, a first actuator and a second actuator. The actuators are mechanically attached by a respective single attachment to the actuator backing at a first end of the actuators. The actuators have a respective interaction portion constituting a second end opposite to the first end in an actuator direction transverse to the driving direction. The interaction portions are arranged for interaction with an interaction surface of the body by a respective contact area. The actuators include a respective unimorph member arranged for causing a movement of the respective contact area as a response of a respective electrical signal. The respective movements are transverse to the actuator direction, to the driving direction, and to each other.

Electromechanical motor

An electromechanical actuator comprises a bimorph element () of an electromechanical material. The bimorph element () is controllably bendable in a first direction () by application of three voltage potentials to electrodes () of the bimorph element (). The electromechanical actuator further comprises three conductive film areas () provided at a first side () of the bimorph element (), which first side () is parallel to the first direction (). The three conductive film areas () are electrically decoupled from each other. Furthermore, each of the three conductive film areas () is connected to at least one respective one of the electrodes (). A method for manufacturing such an electromechanical actuator is also disclosed.

Electromechanical actuators and manufacturing method thereof

An electromechanical actuator comprises at least two actuating portions of electromechanically active material extending by a generally elongated shape from a back portion. The actuating portions are bimorphs, attached by a first end to a first side of the back portion and positioned parallel to each other one after the other in a first direction. The bimorphs are arranged to provide movements of the second end along the first direction and along the extension of the actuating portion, thereby being able to move relative a body in the first direction. The actuating portions have generally flat internal electrode layers arranged inside the electromechanically active material directed substantially perpendicular to the first direction. The internal electrode layers extend continuously through the actuating portions and into the back portion.

Heat efficient micromotor

An electromechanical motor (), using at least two bimorph, monomorph or multimorph electromechanical actuating elements () interconnected by a common actuator backbone () is disclosed. The actuating elements () are controllable in both a longitudinal direction (L), i.e. in the main extension direction of the actuating element (), and a flexural direction, i.e. bending of the actuating element (), separately. The different actuating elements () can be controlled individually as well. The actuator () dimensions are preferably selected to resonance frequencies in vicinity of a certain frequency. The actuating elements () are provided with interaction portions () at which any contact between the actuator and a body () to be moved is made. In order to operate well both in fine-positioning and resonant motion, the interaction portions () are arranged to partially suppress the transfer of acoustic waves between the actuating elements () and the body () to be moved.

Wide frequency range electromechanical actuator

An electromechanical motor includes a rail to be moved, a dry, non-lubricated, sliding bearing for the rail, and driving members imposing a mechanical driving force on the rail. The bearing has two rail contacting portions. A first portion contacts the rail for obstructing displacements of the rail in a first direction transverse to a main extension of the rail. The first portion also obstructs rotation of the rail around an axis parallel to the main extension. The second portion is arranged for obstructing displacements of the rail in the first direction transverse to the main extension, while allowing at least a minor movement of at least one of rotation of the rail. The motor allows for mechanical flexibility at certain selected positions and ensures immobility at other selected positions, in order to reduce the impact of externally induced displacements, torques and rotations at critical places in the motor.

Robust electromechanical motor

A digital camera is constructed with multiple lenses mounted in a pair of tubular elements which are nested together for relative axial movement. Movement is provided by piezoelectric actuators mounted externally to a support tube on flexible printed circuit board elements. Each lens tube is provided with a drive rail which extends at least partially over the length of the lens tube and projects radially outward from the periphery of each of the tubes. The rails are accessible to the engagement pads of the piezoelectric actuators to allow the transmission of drive forces to each of the tubes.

Digital camera system with piezoelectric actuators

In manufacturing electromechanical drive elements, vibration properties are defined in a test environment. These properties are found to give a good operation when being arranged in a motor. Two flexural vibration modes are defined. One is an s-mode connected to an element being strapped at two supports at respective outer portions. The s-mode have three nodal points. The other vibration mode is an &#x3b5;-mode connected to an element being strapped at the supports and at a drive pad arranged at a middle portion. The &#x3b5;-mode has one nodal point at each side of the middle portion and the middle portion has a stroke amplitude that is smaller than stroke amplitudes at portions between the middle portion and the nodal points. An average of the resonance frequencies of the s-mode strapped at two and three points, respectively, differs from and the &#x3b5;-mode resonance frequency by less than 25%.

Electromechanical drive element

A peristaltic actuating element () is arranged against a body (). The peristaltic actuating element () comprises volumes (A&#x2013;G) of electromechanical material and is arranged for selectively causing a dimension change in a main motion direction () of the peristaltic actuating element () within a limited peristaltic section (). By changing voltage signals activating the volumes (A&#x2013;G), the peristaltic section () is caused to move along the peristaltic actuating element (). The body () interacting with the peristaltic actuating element is thereby displaced relative to the peristaltic actuating element (). Preferably, the length of the peristaltic section () is less than half the length of the entire peristaltic actuating element (), more preferably much less. It is also preferred, if the peristaltic actuating element () is arranged so that the surface () interacting with the body () is removed therefrom within the peristaltic section ().

Peristaltic electromechanical actuator

The present invention combines bending mode mechanical (f) and electrical (f) resonances, whereby a relatively good efficiency can be achieved within a relatively broad frequency range (&#x394;f). An electrical resonance (f) or mechanical resonance is designed to be situated in the same order of magnitude as another mechanical resonance (f), but separated therefrom. Preferably, the separation (&#x394;f) is smaller than 2f/Q, where fis the resonance frequency for the resonance having lowest quality value, and Qis the corresponding quality value of the mechanical resonance. An electromechanical motor comprising a driving element and electrical resonance circuit according to the above ideas may comprise a double bimorph driving element having one single actuating point influencing a body to be moved. The double bimorph driving element is excited in bending vibrations perpendicular to a main displacement direction, whereby both tangential and perpendicular motions are created by bending mode vibrations.

Near-resonance wide-range operating electromechanical motor

An electromechanical actuatoris disclosed, having drive elements () movable in two dimensions and connected to an actuator backing (). The actuator backing () is made of a material being ferromechanically inactive. Furthermore, the joint between the drive element () and the actuator backing () is stiff and highly stable. This is achieved by use of an irreversible joint made e.g. by thermoset plastic glues, diffusion bonding or co-sintering. Co-sintering is to prefer. The actuator backing () material is selected to be stiff, preferably having a stiffness above 70 GPa and more preferably above 100 GPa, and having a high heat conductivity, preferably above 5 W/mK and more preferably above 10 W/mK, Electrodes () are preferably integrated in the actuator backing to increase stiffness as well as improving the heat conductivity. The drive elements () are preferably covered (), at least at the driving surface, by heat-conducting material.

In an electromechanical motor, elongated electromechanical drive elements are mechanically and preferably also electrically attached to a carrier. A spring is arranged to apply a force on the electromechanical drive element by pressing the backside of the carrier at a pivot point. The carrier is allowed to pivot around the pivot point around an axis parallel to a the element elongation. The electromechanical drive element is thereby suspended in a floating manner. The electromechanical drive elements are arranged to present a bending motion having strokes perpendicular to the elongation. The pivot point, the mechanical joint between the carrier and the electromechanical drive element, and preferably also a nodal point of bending motions of the electromechanical element are situated at a common plane perpendicular to the element elongation. In one embodiment, the electromechanical drive element is provided with metallizations to which the carrier is soldered.

Electromechanical motor and assembling method therefore

An electromechanical motor () has a driving element () comprising two electromechanical sections () extended substantially parallel to a driving surface () of a body () to be moved. The electromechanical sections () are rigidly supported by a backbone portion () of a stator () at a first end (). An link member () having a single actuating portion (), which by its interaction with the driving surface () of the body () moves the body (), is attached between respective second ends () of the electromechanical sections (). The electromechanical sections () are excitable in a vibration mode having strokes substantially perpendicular to the direction of motion (). A portion of the link () or the joints () between the link member () and the electromechanical sections () have a bending stiffness in the direction of the strokes that is significantly lower than the bending stiffness of the electromechanical sections () themselves.

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Uppsala, Sweden

Stefan Johansson