FEM modeling and analysis of a novel rotary-linear isotropic brushless machine

In several applications, ranging from industrial robotics to advanced automotive, a combination of rotary and linear motions along the same axis is ultimately required. Rotary-linear motors, providing both torque and force, may permit to fulfill the related requirements more effectively than conventional solutions using 2 distinct normal actuators. This paper presents the FEM modeling and analysis of a novel rotary-linear permanent magnets synchronous machine, whose structure, analytical modeling and control are presented in companion papers. Such machine was purposely conceived to be manufactured using common affordable technologies or even by assembling standard parts. A 3-D parametric model purposely developed to permit a detailed analysis of the machine operation is described. Several simulation results concerning various operative conditions are reported and commented, confirming the substantial validity of the basic idea and highlighting the secondary effects due to non-ideal aspects of machine behavior.