b'Engineer Innovation | Industrial Machinery & Heavy Equipment(a) (b) (c)Figure 1: AFPM Topologies: (a) Coreless stator; (b) YASA stator; (c) Single rotor stator (notice the stator yoke located on the right axial surface); (d) PM Rotor.Rotor 1 yoke PM Stator coils Stator teeth PM Rotor 2 yokeFigure 2: Exploded view of the YASA AFPMin figure 1): a coreless machine, aAt these ratings, the single rotor yokeless and segmented armaturemachine required only half the PM (YASA) machine, and a single rotor-singlematerial of the YASA machine (and stator (called the single rotor machine).approximately one-fourth that of the Exploded views of the YASA and singlecoreless machine). Therefore, it is at a rotor machines are shown in figures 2significant advantage in terms of and 3. For the integrated hydraulic- inertia, cost, and power density. electric machine, the rotor moment ofHowever, the single rotor machine can inertia and gravimetric power density areexperience significant axial force critical to achieving fast transientbetween the stator and rotor. While this response and compact form factor. Anmay have tipped the scale in favor of analytic sizing framework wasthe YASA machine, in this application constructed, that compares the threethe expected axial magnetic forces are design variants based on thesewithin the ratings of the bearings for parameters and subject to thethe hydraulic pump. Therefore, the constraints of the hydraulic pump. Wesingle rotor AFPM is a clear favorite.converged to a rated speed of 15,000 RPM, based on a compromise betweenThe multi-objective genetic algorithm the mechanical challenges, hydraulicwas used to search the design space for pump losses and the power density. the single rotor axial flux machine. The 44'