Design and manufacturing of a precision cryogenic actuator
Notice bibliographique
Résumé
The CEA CryoMechanism (CM35) was created in the late nineties from the association of basic industrial components. At this stage, the goal was to design a very robust and highly repeatable rotating actuator that could operate from room temperature, down to cryogenic temperatures (20K) with a very low power dissipation. This first model was designed according rules of thumb for ground instruments. Manufactured in 12 units series in 2004 (including two spare units), ten CM are operating once every hour in the mid-infrared imager/spectrometer VISIR, on the Very Large Telescope in Chile, without any major failure reported. From 2010 to 2012, within the framework of the Mid InfraRed Instrument (MIRI) on the James Webb Space Telescope (JWST), a significant evolution of the CM35 was done in order to become a space mechanism. The new CM35 was designed, manufactured and tested according to the flight qualification test program. For this test campaign, thermal cycles (293K-20K), vibrations and life-test (150,000 actuations) were carried out. This test phases allowed to highlight some upgrades to be implemented such as the vibrations behavior improvement. From 2008 to 2012, a smaller CM, called CM21, was developed with a major evolution in the mechanical architecture that reduced the number of part, so minimize the manufacturing cost and time to integration. This model was implanted in CAMISTIC instrument in Antarctic. Today, within the framework of EUCLID mission (launch expected by 2021), the CM35 development, based on the same basic industrial components from the beginning but with the optimized CM21 design, is complete and reaches the status of a flight model mechanism. This is one of the first flight components delivered in the Euclid space mission. The story of CM is not finished yet as this actuator is going to be dispatched into the ELT-METIS instrument by 2021 (Extremely Large Telescope, Mid Infrared ELT Imager and Spectrograph) to rotate around 20 optical wheels. To achieve this goal, the CM design has been reconsidered with a goal of cost optimization. This paper explains the system constraints that had an impact on the conception of the CryoMechanism keeping in mind the links with the cryogenic environment constraints. A focus is done on the mechanical simulations developed for the modeling of the bearing and the correlation from dynamic analysis and vibration test measures. The paper will highlight the manufacturing challenges that have led to a highly repeatable actuator, capable of operations in the range from 300K down to 10K.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».