• double Halbach array
• analytical models
• induction motors
• permanent magnet generators
• finite element models
• linear tubular electromagnetic devices

This thesis focuses on the analysis, modelling and design of electromagnetic tubular devices characterized by a relative movement of translation between the fixed and the moving parts of the machine. Linear motion characterizes a great number of industrial and civil applications: using linear devices instead of the classical rotating ones allows us to avoid the conversion from rotational to linear motion. Hence, mechanical frictional losses are significantly reduced, the total efficiency of the system can be increased, and the probability of a failure can be reduced. Tubular geometry allows us to build compact devices, to reach a high force to moving mass ratio, and to reduce leakage electromagnetic fluxes. This work presents the main analytical methods used to realize accurate models of tubular linear devices with different operating principles. Using these methods, it is possible to obtain accurate results for the preliminary design of a machine with short computational time. This thesis also discusses various kinds of tubular linear devices, whose design has been based on the methods mentioned above. The purpose of the thesis is to demonstrate how their geometry and their features can be properly leveraged for different applications, both as motors and as generators. The results of this work show how specific configurations of tubular devices can grant advantages not only during the operating time of the machine, but also during the other phases of its life.