Search

A dual-rotor yokeless and segmented armature (YASA)-type axial-flux permanent magnet (AFPM) motor with a surface-mounted permanent magnet (SPM) array type was developed for urban air mobility (UAM) aircraft in this work. The proposed AFPM motor had rated and peak output powers of 75.5 and 104 kW, respectively, with rated and peak rotational speeds of 1800 rpm. To achieve a high torque, a cobalt–iron alloy core material was used for the stator core. The prototype AFPM motor, developed by KSEP in the Republic of Korea, was successfully manufactured and verified through experimentation. Additionally, the thermal stability of the winding and permanent magnets (PMs) was confirmed with a water-cooling system. A structure analysis of the proposed AFPM motor was conducted due to the detachment of an uneven air-gap length in the prototype AFPM motor. An output performance comparison based on core materials for the stator and rotor was carried out to explore the material cost reduction. Subsequently, the design for performance improvement by applying a Halbach permanent magnet (HPM) array type was investigated for further research. [ABSTRACT FROM AUTHOR]

This paper introduces a rotor with shrink fit and analyzes its rotordynamics by 3-D FEA. An ultra high speed motor prototype is manufactured for fuel cells at the rating of 15 kW, 120 000 r/min. First, the stability of the rotor structure with shrink fit is evaluated in non-loading and loading condition (120 000 r/min, 210[degrees]C). And then the 3-D rotordynamics analysis and Campbell diagram considering shrink fit are examined for the critical speed of rotor. The analysis shows that the critical speed of the rotor is higher when the rotor is shrink fitted than when the rotor is not shrink fitted. The analysis also shows the increase of shaft stiffness when the rotor is shrink fitted. Index Terms--Campbell diagram, critical speed, interference, natural frequency, permanent magnet, rotordynamics, shrink fit, sleeve, ultra high speed.

Permanent magnet (PM)-type transverse flux linear motors (TFLMs) are electromagnetic devices which can develop directly powerful linear motion. The unique configuration makes power of output higher than longitudinal motors, but also it makes characteristic analysis difficulties. This paper deals with an effective analysis of PM-type TFLM by 3-D equivalent magnetic circuit network method (EMCNM). This paper presents optimum design of PM-type TFLM to reduce the weight of the machine with the constraints of thrust and detent force using response surface methodology (RSM). RSM was well adapted to make the analytical model of the minimum weight with constraints of thrust and detent forces and enable the objective function to be easily created and a great deal of the time in computation to be saved. Therefore, it is expected that the proposed optimization procedure using RSM can be easily utilized to solve the optimization problem of electric machines. Index Terms--3.D equivalent magnetic circuit network method (EMCNM), 3-D finite-element method (FEM), design of experiments (DOE), optimum design, permanent magnet (PM) type transverse flux linear motor (TFLM), response surface methodology (RSM), soft magnetic composite (SMC), table of orthogonal array.

This paper presents optimum design of transverse flux linear motor (TFLM) to reduce the weight of the machine with the constraints of thrust and detent force. Employing penalty functions, each constraint is included in the characteristic function, and the response value is determined by three dimensional magnetic field analyses. Finally, the contribution and effect of the each design variable on the characteristic function is evaluated by the analysis of means (ANOM), and optimum design set is determined. With this procedure, the weight of initially designed TFLM can be reduced 10% with small variation of thrust and detent force. Index Terms--Analysis of means (ANOM), characteristic function, design of experiments, optimum design, table of orthogonal array, transverse flux.

This paper is associated with the manufacture of a transverse flux linear motor (TFLM) and the characteristic of the thrust force and the maximum displacement of the mover in linear motor. The thrust force of this calculation is in good agreement with experiments. We utilized a new design for household electric applications that the volume of a linear motor reduced by 3/4. In this paper, we examine the initial displacement of piston for linear actuator and the reaction force of sustained body for a constant spring coefficient and damping coefficient under several current rates in linear motor. Thus, we calculate with FN3D and ANSYS and experiment the thrust force of the linear actuator with applied current, 0, 500, 1000, and 2000 [ampere turns, AT]. We used the experiment with several types of alternating current and the phase difference between the peak value of applied current and the maximum displacement of the mover of the linear actuator is changed with applied current frequency. Index Terms--Linear actuator, linear motor, phase difference, transverse flux linear motor.

This paper presents an optimum design procedure of permanent-magnet-type 60 W transverse flux linear motor to reduce the weight of the machines with the constraints of thrust and detent forces using fractional factorial design and response surface methodology (RSM). RSM is well adapted to make the analytical model of minimum weight with constraints of thrust and detent forces, and it enables objective functions to be easily created, and a great deal of computation time can be saved. Therefore, the usefulness of this method is verified through the comparison of the performances of the optimal model and those of the initial model. [ABSTRACT FROM AUTHOR]