Book•
An Introduction to Ultrasonic Motors
27 Jan 1994-
TL;DR: The ultrasonic motor, invented in 1980, utilizes the piezoelectric effect in the ultrasonic frequency range to provide the motive force as mentioned in this paper, which has already found applications in camera autofocus mechanisms, medical equipment subject to high magnetic fields, and motorized car accessories.
Abstract: The ultrasonic motor, invented in 1980, utilizes the piezoelectric effect in the ultrasonic frequency range to provide the motive force. (In conventional electric motors the motive force is electromagnetic.) The result is a motor with unusually good low-speed high-torque and power-to-weight characteristics. It has already found applications in camera autofocus mechanisms, medical equipment subject to high magnetic fields, and motorized car accessories. Its applications will increase as designers become more familiar with its unique characteristics. This book is the result of a collaboration between the inventor and an expert in conventional electric motors: the result is an introduction to the general theory presented in a way that links it to conventional motor theory. It will be invaluable both to motor designers and to those who design with and use electric motors as an introduction to this important new invention.
Citations
More filters
TL;DR: In this review, the performance merits of relaxor-PT crystals in various electroacoustic devices are presented from a piezoelectric material viewpoint and the impacts and challenges are summarized to guide on-going and future research in the development of relaxors for the next generation electroac acoustic transducers.
556 citations
TL;DR: An overview of present smart materials and their sensor/actuator/structure applications can be found in this paper, where fundamental multifield optomagnetopiezoelectric-thermoelastic behaviors and novel transducer technologies applied to complex multifield problems involving elastic, electric, temperature, magnetic, light, and other interactions are emphasized.
Abstract: Many electroactive functional materials have been used in small- and microscale transducers and precision mechatronic control systems for years. It was not until the mid-1980s that scientists started integrating electroactive materials with large-scale structures as in situ sensors and/or actuators, thus introducing the concept of smart materials, smart structures, and structronic systems. This paper provides an overview of present smart materials and their sensor/actuator/structure applications. Fundamental multifield optomagnetopiezoelectric-thermoelastic behaviors and novel transducer technologies applied to complex multifield problems involving elastic, electric, temperature, magnetic, light, and other interactions are emphasized. Material histories, characteristics, material varieties, limitations, sensor/actuator/structure applications, and so forth of piezoelectrics, shape-memory materials, electro- and magnetostrictive materials, electro- and magnetorheological fluids, polyelectrolyte gel...
205 citations
TL;DR: A compact ultrasonic motor with low manufacturing costs, a simpler driving circuit, and scalability is proposed, which was experimentally characterized and a maximum torque of 1.8 mNm was obtained.
Abstract: This paper proposes a compact ultrasonic motor with low manufacturing costs, a simpler driving circuit, and scalability. The stator of the motor presented in this paper consists of a hollow metal cylinder, whose outside surface was flattened on two sides at 90 degrees to each other, on which two rectangular piezoelectric plates were bonded. Because the cylinder has a partially square/partially circular outside surface, the stator has two degenerated bending modes that are orthogonal to each other. A wobbling motion is generated on the cylinder when only one piezoelectric plate is excited at a frequency between the two orthogonal bending modes. A rod through a pair of ferrules was used as the rotor of this motor. The prototype motor, whose stator was 2.4 mm in diameter and 10 mm in length, operated at 69.5 kHz, was experimentally characterized, and a maximum torque of 1.8 mNm was obtained.
154 citations
Patent•
10 Oct 2005
TL;DR: In this paper, an electroactive-material-based actuator is used to adjust the actuator's morphology to adjust a basic pressure profile applied to the body part, and a pressure transition is adapted to redistribute the basic pressure profiles between the first and second segments.
Abstract: The proposed device includes two segments adapted to enclose a body part in a form-fitting manner. Each segment contains an electroactive-material-based actuator, which is adapted to receive an electrical control signal and in response thereto adjust the actuator's morphology, so as to cause the segment to apply a basic pressure profile to the body part. A pressure transition is adapted to redistribute the basic pressure profiles between the first and second segments. A control signal in respect of the first segment causes the pressure transition system to apply a first adjusted pressure profile to at least part of the second portion of the body part, and vice versa, a control signal in respect of the second segment causes the pressure transition system to apply a second adjusted pressure profile to at least a part of the first portion of the body part.
134 citations
TL;DR: A critical overview of the historical development, functional principles, and related terminology of stick-slip motors can be found in this article, where the most relevant aspects regarding their design are discussed, including aspects of control and simulation.
Abstract: Piezoelectric inertia motors—also known as stick-slip motors or (smooth) impact drives—use the inertia of a body to drive it in small steps by means of an uninterrupted friction contact. In addition to the typical advantages of piezoelectric motors, they are especially suited for miniaturisation due to their simple structure and inherent fine-positioning capability. Originally developed for positioning in microscopy in the 1980s, they have nowadays also found application in mass-produced consumer goods. Recent research results are likely to enable more applications of piezoelectric inertia motors in the future. This contribution gives a critical overview of their historical development, functional principles, and related terminology. The most relevant aspects regarding their design—i.e., friction contact, solid state actuator, and electrical excitation—are discussed, including aspects of control and simulation. The article closes with an outlook on possible future developments and research perspectives.
109 citations