@phdthesis{8469,
  author       = {{Hemsel, Tobias}},
  isbn         = {{ISBN 3-935433-10-7}},
  publisher    = {{Verlagsschriftenreihe des Heinz Nixdorf Instituts}},
  title        = {{{Untersuchung und Weiterentwicklung linearer piezoelektrischer Schwingungsantriebe}}},
  volume       = {{101}},
  year         = {{2001}},
}

@article{8914,
  abstract     = {{Piezoelectric ultrasonic motors have been investigated for several years and have already found their first practical applications. Their key feature is that they are able to produce a high thrust force related to their volume. Beside rotary drives like the travelling wave motor, linear drives have also been developed, but only a few are presently commercially available. In the present paper, we first describe the state of the art of linear piezoelectric motors. The motors are characterized with respect to their no-load velocity, maximum thrust force, efficiency and other technical properties. In the second part, we present a new motor, which is judged to be capable of surpassing the characteristics of other piezoelectric motors because of its unique design which allows the piezoelectric drive elements to be pre-stressed in the direction of their polarization. The piezoelectric elements convert energy using the longitudinal d33 effect which allows an improved reliability, large vibration amplitudes and excellent piezoelectric coupling. Energy loss by vibration damping is minimized, and the efficiency can be improved significantly. Experimental results show that the motor characteristics can be optimized for a particular task by choosing the appropriate operating parameters such as exciting voltage, exciting frequency and normal force. }},
  author       = {{Hemsel, Tobias and Wallaschek, Jörg}},
  issn         = {{0041-624X}},
  journal      = {{Ultrasonics}},
  keywords     = {{Linear motor}},
  pages        = {{37 -- 40}},
  title        = {{{Survey of the present state of the art of piezoelectric linear motors}}},
  doi          = {{10.1016/S0041-624X(99)00143-2}},
  volume       = {{38}},
  year         = {{2000}},
}

@inproceedings{8915,
  abstract     = {{Ultrasonic linear motors have now been investigated for several years. Their key features are high thrust forces related to their volume and good position-accuracy. This contribution consists of two main parts. In the first part we describe the state-of-the-art of linear piezoelectric motors. Characteristics like no-load velocity, maximum thrust force and other technical properties of commercially available devices will be reported as well as those of prototypes. In the second part we report an ongoing research and development project aiming at a linear piezoelectric motor, which is capable of surpassing some of the shortcomings of other piezoelectric motors}},
  author       = {{Hemsel, Tobias and Wallaschek, Jörg}},
  booktitle    = {{Ultrasonics Symposium, 2000 IEEE}},
  issn         = {{1051-0117}},
  keywords     = {{linear motors, ultrasonic motors, linear piezoelectric motor, maximum thrust force, no-load velocity, ultrasonic linear motor, Electromagnetic devices, Electromagnetic fields, Frequency, Friction, Gears, Materials science and technology, Piezoelectric materials, Research and development, Vibrations, Wheels}},
  pages        = {{663--666 vol.1}},
  title        = {{{State of the art and development trends of ultrasonic linear motors}}},
  doi          = {{10.1109/ULTSYM.2000.922635}},
  volume       = {{1}},
  year         = {{2000}},
}

@inproceedings{8916,
  author       = {{Hemsel, Tobias and Wallaschek, Jörg}},
  booktitle    = {{Tagungsband der ACTUATOR}},
  pages        = {{250--253}},
  title        = {{{Piezoelectic linear motors}}},
  year         = {{2000}},
}

@inproceedings{8917,
  abstract     = {{Piezoelektrische Schwingungsantriebe sind Kleinmotoren, deren Funktionsprinzip darin besteht, dass elektrische Energie mit Hilfe von Piezokeramiken in mechanische Schwingungsenergie gewandelt und diese dann durch hochfrequente Kontaktvorgänge auf den anzutreibenden Teil übertragen wird. Der Stand der Technik auf dem Gebiet piezoelektrischer Linearantriebe zeigt, dass viele piezoelektrische Linearantriebe bereits zufriedenstellende Leistungsmerkmale aufweisen. Gleichzeitig ist zu erwarten, dass die Leistungen dieser Antriebe noch deutlich verbessert werden können. Ein Ansatz, insbesondere den Wirkungsgrad und die mechanische Leistung zu erhöhen, wird anhand eines Motors aufgezeigt, der am Heinz Nixdorf Institut entwickelt wurde. Eine Übersicht der in ausgewählten Einsatzgebieten geforderten Leistungsdaten führt auf Entwicklungsziele für bestehende und neuartige piezoelektrische Linearantriebe.}},
  author       = {{Hemsel, Tobias and Wallaschek, Jörg}},
  pages        = {{147--166}},
  title        = {{{Stand der Technik und Entwicklungsperspektiven linearer piezoelektrischer Schwingungsantriebe}}},
  volume       = {{1533}},
  year         = {{2000}},
}

@inproceedings{8905,
  author       = {{Hemsel, Tobias and Krome, Jürgen and Littmann, Walter and Wallaschek, Jörg}},
  booktitle    = {{Proceedings 2. Polnisch-Deutscher Workshop "Werkzeuge der Mechatronik"}},
  title        = {{{Modellierung piezoelektrischer Stapel- und Vielschichtaktoren für dynamischen Betrieb}}},
  year         = {{1998}},
}

@inproceedings{8906,
  author       = {{Hemsel, Tobias and Wallaschek, Jörg}},
  booktitle    = {{Proceedings of VIBROENGINEERING}},
  number       = {{1}},
  pages        = {{7--12}},
  title        = {{{A piezoelectric linear vibration drive for high driving forces}}},
  year         = {{1998}},
}

@inproceedings{8898,
  author       = {{Goldschmidt, Stefan and Hemsel, Tobias and Krome, Jürgen and Storck, Heiner and Wallaschek, Jörg}},
  booktitle    = {{Tagungsband zum 4. Laser Vibrometer Seminar der Polytec GmbH}},
  title        = {{{Schwingungsprüfstand zur vollautomatischen Messung von Ultraschallschwingungen in piezoelektrischen Antrieben}}},
  year         = {{1997}},
}

@inproceedings{8900,
  abstract     = {{Piezoelectric ultrasonic motors are a new kind of actuators that produce high driving-forces related to their volume. Beside rotary drives like the travelling wave motor many linear drives have been developed and are already commercially available today. These motors can provide static holding-forces and driving-forces of up to 30 N at velocities of up to 220 mm/s. These operational characteristics, which are expected to be improved continuously, make these devices attractive as direct-drives for sliding roofs or windows in automobiles. In this contribution a short outline of the present state-of-the-art of linear ultrasonic motors is given. Different operating principles are compared with respect to the potential driving-force and power. Finally the working-principle of a newly developed motor, which uses the piezoelectric d33-effect, is explained in detail. Theoretical and experimental results show that this motor is capable of achieving high driving-force and rated output-power}},
  author       = {{Hemsel, Tobias and Wallaschek, Jörg}},
  booktitle    = {{Proceedings of the 30th International Symposium on Automotive Technology \& Automation (ISATA)}},
  pages        = {{631--637}},
  title        = {{{Ultrasonic motors for linear positioning tasks in automobiles}}},
  year         = {{1997}},
}

@inproceedings{8901,
  author       = {{Hemsel, Tobias and Wallaschek, Jörg}},
  booktitle    = {{EUROMECH, European Mechanics Colloquium "Synthesis of Mechatronic Sytems"}},
  number       = {{370}},
  title        = {{{Piezoelectric ultrasonic linear motors}}},
  year         = {{1997}},
}