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The transverse flux machine (TFM) is a promising driving machine, especially for the low-speed applications, because it has greater power density, torque, and efficiency than the conventional electrical motors. However, the TFM has a complicated structure, a large torque ripple, and, occasionally, an unbalanced magnetic force. This paper investigates the effects of teeth geometry on torque ripple and unbalanced magnetic force in a rotatory two-phase TFM using the 3-D finite element method, and proposes a rotatory two-phase TFM with herringbone teeth to reduce the torque ripple and eliminate the unbalanced magnetic force. Index Terms--Herringbone teeth, torque ripple, transverse flux machine (TFM), unbalanced magnetic force.

The traditional engine valve train in a combustion engine is the mechanically driven camshaft system that provides one-fixed valve timing. The variable valve timing (VVT), however, is highly required to achieve the significant improvement in fuel economy and lower emission. To provide the VVT, the double solenoid type of actuators with steel-made armature have been developed in past years, but it requires electric power in the most engine operating period, the starting is difficult and the efficiency is low. In this paper, a new linear actuator using permanent magnets is proposed and the dynamic performances are analyzed by finite-element analysis. The results show that the designed colenoid system has a fast transition time between valve events suitable for the practical use in combustion engine valve system Index Terms--Colenoid, finite-element analysis, linear actuator, solenoid, variable valve timing (VVT).

In this paper, a transverse flux reluctance motor circuit-field model, based on a variable equivalent air gap permeance concept, is introduced. The core nonlinearity is fully considered through a saturation factor, calculated with the support of the finite-element method (FEM) analysis. A simplified model variant is developed and the calculated values are compared with the ones obtained by the FEM analysis. The model provides simple analytical expressions useful for dynamic analysis as well as for online control. Index Terms--Circuit-field model, saturation coefficient, transverse flux reluctance linear motor (TFRLM).

This paper presents the development of a transverse flux linear motor (TFLM) with permanent-magnet excitation for Stocker system, which is used for transferring glasses in the liquid crystal display industry. Magnetic field is analyzed by three-dimensional equivalent magnetic circuit network method and two-dimensional finite-element analysis is used to determine the influence of the end effect of a mover on the performance of TFLM. The experimental results of a prototyped motor are in good agreement with the analysis ones. Index Terms--Direct drive, equivalent magnetic circuit network, high force density, transverse flux linear motor.