Comparison of lateral- and Cylindrical-Stator electrical machines for high-speed direct-drive applications in confined spaces

Lateral-Stator Machine (LSM) topology is presented in earlier works as an unconventional machine that is advantageous for high-speed, direct-drive applications in confined spaces. Owing to its peculiar geometry, LSM makes use of the additional space in a tool head that cannot be utilized by standard Cylindrical-Stator Machines (CSMs). However, a fair and quantitative comparison of LSM and CSM topologies has not been carried out so far. This paper presents a comparative evaluation of the LSM against slotless and slotted permanent magnet CSMs, not only in terms of torque density but also concerning torque ripple and self-sensing control capability.