|Budget Amount *help
¥2,000,000 (Direct Cost : ¥2,000,000)
Fiscal Year 1996 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1995 : ¥1,200,000 (Direct Cost : ¥1,200,000)
A test machine of a two-dimensional linear synchronous motor was built, and the stand-still measurements have proved that one can effectively suppress a harmful cogging force in the x-direction, i. e., the thrust-direction by the proposed design. It was, however, impossible to keep the gap short for a sufficient thrust, since the attractive force between stator-and mover-cores was too large. For avoiding the large attractive force, we proposed a new design without stator slots and with ring windings : One may supply possibly large armature current and keep a relatively long gap for the suppressed normal force. A theoretical equation has been derived for optimizing the gap length under the configuration with the ring windings for maximized thrust and the usage of the stored energy in permanent magnets under the constraint of the normal force.
Furthermore, the lateral thrust, inherently significant for the function of a turnout device, should be investigated. Discontinuous allocation of the armature cores in the lateral direction is the substantial problem, which results in cogging force larger than its own thrust, according to the experiences in the first test machine. A theoretical analysis of the lateral cogging force is, however, almost impossible since the force strongly depends on the three-dimensional and geometrical shapes of the cores around the gap. A numerical FEM-field calculation has been, hence, applied to the improvement of the mover-core shape for reducing the cogging force : A minor modification of the mover shape enables the considerable reduction of the cogging force, that is to say, the self-start of the lateral drive. A control board with a digital signal processor has been purchased for a hardware-based investigation of the power source of the motor and numerical controls of the armature current and the speed of the unit synchronous motors have been investigated theoretically too.