Microfabricación, ensamblaje y ensayo de micropiezas y conjuntos electromagnéticos para integración en motores eléctricos de tamaño reducido

  1. VILLALBA ALUMBREROS, GABRIEL
Supervised by:
  1. Efrén Díez Jiménez Director
  2. Ignacio Valiente Blanco Co-director

Defence university: Universidad de Alcalá

Fecha de defensa: 02 February 2024

Committee:
  1. José Luis Pérez Díaz Chair
  2. Cristina Navío Bernabeu Secretary
  3. Fidel Fernández Bernal Committee member

Type: Thesis

Abstract

This thesis describes the development of a series of novel manufacturing techniques for characteristic components of high-performance electromagnetic microactuators. Such developments have ultimately resulted in the construction of a microactuator for potential use in surgical tools within the European H2020 UWIPOM2 project. Among the microfabrication processes developed, it is worth highlighting the use of fluid-cooled laser cutting and milling for the manufacture of sintered Sm2Co17 micromagnets with high magnetic performance. This new manufacturing process has allowed the manufacture of magnets only 65 µm thick and characteristic lengths between 65 µm and 230 µm. At the same time, it has been possible to maintain the electromagnetic performance of its macroscopic counterparts for the first time, observing a high remanence of 1.19 T of (BR) and 880 kA/m of coercivity (HC). Numerical control micro-milling processes for iron-cobalt-based alloys have also been developed and demonstrated, using milling cutters between 50 µm and 250 µm in diameter in the process. As a result, micromachining has been achieved as housings for magnets, yokes and 2D microcomponents cut from sheets of FeCo-2V ferromagnetic alloys. Finally, microcoils of only 140 µm in length and 4 layers have been made using a 20 µm cable with a final filling factor of 60.6% on ferromagnetic cores of 120 µm in diameter. While these microfabrication techniques have been developed, new configurations and topologies for electromagnetic actuators of various sizes have been explored in search of performance optimization in terms of specific torque and power. Thanks to the development of these techniques and the optimization of the designs, a series of parts and subassemblies characteristic of high-performance electromagnetic actuators have been manufactured and tested. Finally, a fully functional prototype of a brushless synchronous micromotor with permanent magnets of only 0.4 mm in diameter has been built and its operation has been experimentally analyzed.