Abstract
A linear dc motor (LDM) is useful in a high-speed and high-accuracy positioning system with a feedback controller. Because of these advantages, LDMs have already been used as motors of pen recorders and magnetic disk storage devices. Few papers were published on how to design an LDM to gain a maximum thrust constant with thin and long strokes. We therefore propose a method for designing the magnetic circuit of an LDM within the unit‘s limited dimensions. The thrust of an LDM is proportional to the flux density and the number of coil-turns. Our approach to gaining a maximum thrust constant is to use the following two methods: (1) increasing the flux density, and (2) increasing the number of coil-turns. We designed two thin LDMs for a pen recorder. The LDM with a thrust constant of 1.66 [N/A] was obtained by the first method. Similarly, the LDM with a thrust constant of 2.79 [N/A] was obtained by the second method.
