Investigation of Axial-Flux Limited-Angle Torque Motor with Tooth-Tip Structure for Torque Performance Improvement

Limited angle torque motors (LATMs) offer widespread application in positioning first-stage valves within electrohydraulic servo systems, where system compactness and torque quality are of paramount importance. In comparison to their radial-flux (RF) counterparts, the Axial-Flux LATM (AFLATM) offers distinct advantages in these key aspects. This study focuses on the design and performance investigation of a 4-pole-4-slot double-stator AF-LATM. Initially, a superior topology with a tooth-tip structure is selected based on an in-depth analysis of the operation principle. Subsequently, through a comprehensive investigation, this paper reveals the relationship between the key torque performance and the main geometric parameters. Finally, the electromagnetic performances of the optimized proposed AF-LATM with a tooth-tip structure is evaluated. The results demonstrate the proposed motor can offer a 50% wider compact torque range and 31% higher torque density as compared to a conventional RF-LATM, validating the superiority of the proposed AFLATM for electrohydraulic servo applications.