Publications related to Efficiency Optimisation of Slotless Magnetic Bearing Machines

Torque Computation With the Isogeometric Mortar Method for the Simulation of Electric Machines

Rafael Vazquez Hernandez, Bernard Kapidani

In this work, isogeometric mortaring is used for the simulation of a six-pole permanent magnet synchronous machine. Isogeometric mortaring is especially well suited for the efficient computation of rotating electric machines, as it allows for an exact geom ...

Institute of Electrical and Electronics Engineers2022

Lifetime of dielectric elastomer actuators under DC electric fields

Fabio Beco Albuquerque

Dielectric elastomer actuators (DEAs) are interesting soft actuators compared to other actuation technologies owing to large achievable actuation strains, high energy density and fast actuation. However, because DEAs need to be operated under high electric ...

EPFL2022

Numerical and experimental investigation of spiral-grooved gas journal bearings

Elia Iseli

Small-scale turbomachinery is increasingly used in carbon-free energy conversion systems, such as commercial or domestic scale heat pumps, fuels cells for transportation and waste heat recovery. The usage of aerodynamic bearings allows the design of compac ...

EPFL2022

Scale effects on efficiency and profitability in the Swiss banking sector

Andreas Fuster

This paper analyzes efficiency and profitability in the Swiss banking sector over the period 1997–2019. We find strong evidence for scale economies: for most banks in the sample, efficiency and profitability increase with bank size. Using an instrumental v ...

2022

Experimental Investigation of Enhanced Grooves for Herringbone Grooved Journal Bearings

Jürg Alexander Schiffmann, Patrick Hubert Wagner, Philipp Kaspar Bättig

This paper presents the results of a theoretical and experimental investigation of the potential of enhanced groove geometries to increase the bearing clearance of a Herringbone Grooved Journal Bearing (HGJB) supported rotor. The theoretical study investig ...

2022

Principle and Analysis of Radial-Force-Based Swirling Actuator for Low-Speed High-Torque Applications

Adrien Jean-Michel Thabuis

This article proposes a swirling actuator that uses the electromagnetic radial force and mechanical gears to generate rotational torque. The proposed actuator generates a rotating radial force between an inner stator and a swirler. The gears on the swirler ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2022

Long Spin Lifetime in Rare-Earth Single-Atom Magnets at Surfaces

Boris Sorokin

Further miniaturisation of magnetic storage devices requires an advent of new types of magnets, since classical ferromagnetic materials show lack of remanence at nano- and subnanoscale. A single atom can represent the smallest possible bit of information. ...

EPFL2022

Ferroelectric Effects Probed by in situ Transmission Electron Microscopy

Reinis Ignatans

Ferroelectric perovskite oxides are widely used in sensors, actuators and optical modulators and, at the same time, they show promise for implementation in future applications such as energy storage, memory and cooling devices. At the infancy of the discov ...

EPFL2022

Performance and Micro-Vibrations in Magnetic Bearings for Space Actuators

Guzmán Borque Gallego

The development of new space missions with novel high-performance and very sensitive payloads for Earth observation or scientific missions has imposed considerably tougher requirements in terms of the satellite's pointing accuracy and stability, and thus o ...

EPFL2021

Effect of electrode composition and patterning method on the lifetime of silicone-based dielectric elastomer actuators (DEA) under different environmental conditions

Herbert Shea, Fabio Beco Albuquerque

We report an experimental investigation of the lifetime of dielectric elastomer actuators (DEAs) under constant DC actuation, with a characterization setup which allows the monitoring of strain and resistance over time for 6 DEAs in parallel. We show how t ...

SPIE-INT SOC OPTICAL ENGINEERING2021