| 摘要 |
PURPOSE:To prevent lowering of thrust during high speed operation by applying a partially cut substantially annular nonmagnetic conducting body around a pole part provided with scale teeth and slider teeth. CONSTITUTION:A partially cut rectangular and annular nonmagnetic conducting body 8 is fixed around a pole part provided with scale teeth 5 of a stator 1 and a pole part provided with slider teeth 6 of a core 3, i.e., side pieces 3a-3d, while covering them. Leakage flux around the pole parts increases as the moving speed of a mover 2 increases and an eddy current is induced in the conductive nonmagnetic body 8 thus forming a reverse field. Consequently, the leakage flux around the pole parts is canceled thus concentrating the flux at the scale teeth 5 and the slider teeth 6. Since horizontal component of flux is also increased, thrust is increased. According to the constitution, lowering of thrust due to degradation of current rising characteristic, caused by the inductance of an exciting coil 4 during high speed rotation, can be compensated for. |
