Linear actuators
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Rotating piezoelectric motors for high precision positioning & space applications
19 June 2023
Piezo-electric motors have been successfully developed for various applications like autofocus drives in camera lenses and handling equipment for semiconductor production. Their high speed and accurate positioning capability, combined with a favourable holding torque in unpowered condition, make piezomotors also very attractive for actuation purposes in spacecraft mechanisms. The paper introduces a new concept of a versatile ultrasonic piezomotor. The testing campaign carried out on the designed rotating piezomotor has validated the vacuum compatibility and the lifetime of the motor in air.
Ski embbeded piezo system
19 June 2023
Since many years, the field of active control of vibrations has been growing up and many new applications using smart actuators have been developing. In 2003, CEDRAT TECHNOLOGIES in collaboration with SKI ROSSIGNOL initiated a project supported by ESA where these concepts (smart material and active control of vibration) were adapted and applied on a ski structure. The project aim was to damp the large modes of vibrations keeping the robustness of the control and the static loads during the ski ride.
A new amplified piezoelectric actuator for precise positioning and active damping
19 June 2023
Two typical characteristics of direct piezoelectric actuators are displacements of ten micrometers and high stiffnesses. recently, multilayers actuators have been improved, and they now display strains of approximately 1200ppm at low excitation levels (less than two hundred volts). Thus, they are well suited to perform precise positioning of optical devices. But for industrial needs, this performances is still insufficient for positioning devices with larger displacements (in the range of several hundred micrometers).
Active washer for smart mechanical linkage
9 December 2017
Bolted connection is the most common way to assemble mechanism. It is widely used in transport domains, such as aerospace, rail, aircrafts⊠Ensuring that the minimum torque value is always present in the assembly is one of the main maintenance tasks for those components. A possible way to carry out those actions is to implement active component in the bolted assembly. A solution is proposed in this document. Construction, potentialities, performances (based on lap-joint demonstrator) and limitations are identified and confronted to other techniques.
Actuator based on the Thomson effect
1 January 2003
Good limitations of the current in a circuit using an electromechanical breaker suppose a very fast opening of the contacts. Due to the fact that the electrodynamic repulsive forces do not generate enough acceleration, an actuator has to be used to improve the breaker performances. Since a traditional reluctant magnetic device is too slow for the application concerned, a propeller based on the Thomson effect has been chosen. FLUX2D simulations make possible a good understanding of the propellerâs operation and thus the improvement of its design.
Smart actuators for aircraft applications
4 January 2003
Smart actuators and intelligent structures receive a considerable interest in the fields of Air & Space, to realise new functions or more efficient functions than passive structures. In these fields, there are needs for actuation means offering high mechanical energy density (product of stroke and force divided by the mass), a low power consumption, a resistance to severe environment (such as vibrations) as well as other case by case needs : High resolution (embedded active optics for cameras and telescopes), fast response (active control of structures shape, active damping of vibration)âŠ
