Linear actuators
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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 propeller’s 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)…
A new Rotating Voice Coil Motor for Meteosat Third Generation satellites
19 June 2023
In the frame of the Meteosat Third Generation project (MTG), the future European Operational Geostationary Meteorological Satellites system, Cedrat Technologies has developed a dedicated actuator for the Scan Assembly mechanism (SCA) made by SENER. Such motors are needed to actuate the SCA on the north/south (N/S) and east/west (E/W) axes. The requirement of precise pointing of the SCA induces very specific characteristics for the motorisation. The motor needed characteristics are: to be free from any cogging, high constant motor [N.m/vW] to have a constant torque over full stroke range, to have a very low hysteresis and to have redundant coils. To meet these stringent requirements, the choice was made to develop a specific Rotating Voice Coil Motor.
ACTUATOR2008 Moving Iron Controllable Actuators
6 January 2008
To meet the demand of controllable millimeter-stroke actuators, there are two possible starting points. One is to consider improvement of moving coil actuators, the other is to consider improvement of moving iron actuators. Following this approach and using its experience on the different types of magnetic actuators, Cedrat Technologies has developed new specific Moving Iron Controllable Actuators, called MICA. This actuator circumvents previous controllability limitations of standard Moving Iron actuators while keeping their high forces capabilities. Compared with moving coils of the same force, the MICA are twice less in mass while requiring 3 times less electric power. Another significant advantage of the MICA is a much better heat dissipation and reliability as the MICA coil is fixed into the iron stator.
Rotating step by step piezomotor for nanopositioning and space applications
19 June 2023
Piezomotors are well known in various applications where high precision actuation is required like AFM or handling equipment for semiconductor production. Their specific low speed in direct drive and high torque characteristics combined with high holding torque in off power conditions make them very attractive for any positioning application and especially space mechanisms where low electrical consumption is always sought. A new concept of rotating stepping piezomotor has been developed in the frame of the LISA space project where the mechanism of the telescope orientation was addressed.
