ABSTRACT
The principle of energy conversion and electromagnetic electromechanical motion devices were first examined and demonstrated by Michael Faraday in 1821. One of the first commutator direct current (DC) electric motors was designed, tested, utilized, and commercialized by Anyos Jedlik in 1828 and William Sturgeon in 1832. Alternating current machines (synchronous and induction) were invented and demonstrated by Nicola Tesla in 1880s. By 1882, Nicola Tesla pioneered and developed the theory of the rotating magnetic field which is a cornerstone principle of electromechanical motion devices. He designed and demonstrated a two-phase induction motor in 1883. The first three-phase squirrel-cage induction motor was invented and demonstrated by Michail Osipovish Dolivo-Dobrovolski in 1890. In this chapter, we study various high-performance translational and rotational DC
electromechanical motion device and actuators which operate utilizing the electromagnetic interactions between windings and permanent magnets. As covered in Section 2.5, the torque tends to align the magnetic moment ~m with ~B, and ~T¼~m~B. Various illustrative examples were reported and visualized in Figure 2.14. One also recalls that the torque is ~T¼~R~F, where for a filamentary closed loop the expression for the electromagnetic force is ~F ¼ i
þ l
~B d~l. This equation is simplified to ~F ¼ i~B þ d~l for a uniform magnetic
flux density distribution. We examined electrostatic and variable-reluctance actuators in Chapter 3 emphasizing that other advanced actuation solutions exist. The device physics can be centered on utilization of the energy stored by permanent magnets which establish a strong stationary magnetic field. The electromagnetic force and torque production is evident from the equations for F and T reported. Various permanent-magnet motion devices were devised, designed, fabricated, and widely utilized. The studied motion device and actuators have been called electric machines and electric
motors. Usually, the windings are placed on the rotor (brushes and commutator are used to supply voltage to windings on the rotational rotor), while permanent magnets are on the
stator (stationary member). From ~F ¼ i~B þ d~l one concludes that the device physics is
based on electromagnetic force or torque developed between windings on the moving (or stationary) member and permanent magnets on the stationary (or moving) member. As examples, permanent-magnet DC motors, limited-angle axial-topology actuators, and
Analysis, and Design with
speakers are documented in Figure 4.1. In general, superior performance, excellent capabilities, and affordability are ensured by permanent-magnet DC and AC electromechanical motion devices. Correspondingly, these devices are the preferred choice and are widely applied in the majority of systems. The power range of permanent-magnet devices is up to 100 kW with the overloading capability (for a relatively short time from seconds to minutes) reaching 10. This chapter covers various permanent-magnet electromechanical motion devices.
