ELECTROMAGNETIC ACTUATOR

PROBLEM TO BE SOLVED: To provide an electromagnetic actuator of novel structure accurately and stably holding axial positions of a stator and a movable element and being capable of obtaining drive power in an axial direction that is generated between the stator and the movable element by electrification to a coil, with high energy efficiency.SOLUTION: The present invention relates to an electromagnetic actuator 10 in which a movable element 14 is arranged in a hollow hole 22 of a stator 12 in such a manner that the movable element can be relatively displaced in an axial direction, and drive power in the axial direction is applied between the movable element 14 and the stator 12 by electrification to a coil 16 of the stator 12. On magnetic gap formation faces 44 and 44 that are positioned at both sides in the axial direction holding a magnetic gap 24 therebetween in an outer yoke 18 arranged around the coil 16, protrusions 46 that protrude in the axial direction are formed, and a tip of each of the protrusions 46 is made eccentric from a center of the magnetic gap formation face 44 in a yoke thickness direction to an inner peripheral side.SELECTED DRAWING: Figure 1 【課題】固定子と可動子の軸方向位置が精度よく且つ安定して保持されると共に、コイルへの通電によって固定子と可動子の間に生じる軸方向の駆動力を高いエネルギー効率で得ることができる、新規な構造の電磁式アクチュエータを提供すること。【解決手段】固定子１２の中空孔２２において軸方向へ相対変位可能に可動子１４が配されており、固定子１２のコイル１６への通電によって可動子１４と固定子１２の間に軸方向の駆動力が及ぼされる電磁式アクチュエータ１０であって、コイル１６の周りに配されるアウタヨーク１８において磁気ギャップ２４を挟んだ軸方向両側に位置する磁気ギャップ形成面４４，４４には、軸方向に突出する突出部４６がそれぞれ形成されており、突出部４６の先端が磁気ギャップ形成面４４におけるヨーク厚さ方向の中央よりも内周側に偏倚せしめられている。【選択図】図１