A novel rotary-linear brushless machine using standard active parts

Rotary-linear motors, able to simultaneously provide torque and force, represent one of the most interesting types of multi-degree-of-freedom machines. In fact, in several applications the combination of a rotary and a linear motion along the same axis is used. This paper presents the basic concepts and the theoretical analysis of a novel rotary-linear machine, purposely conceived to be assembled using common active parts easily found on the market. The machine structure is described and its analytical model is derived and commented, developing considerations concerning several aspects including control strategy, capability and preliminary design.