To provide an electric direct acting actuator having a short axial length.
Between the outer diameter surface of a rotating shaft 14 driven through an electric motor 12 and the inner diameter surface of an outer ring member 13 secured to the outer diameter side of the rotating shaft 14, a plurality of planetary rollers 15 rotating around the rotating shaft 14 while revolving as the rotating shaft 14 rotates are interposed. A spiral groove 24 is formed in the outer diameter surface of each planetary roller 15, a spiral protrusion 23 engaging with the spiral groove 24 is provided on the inner diameter surface of the outer ring member 13, and rotation of the rotating shaft 14 is converted into axial movement of the planetary roller 15. In such an electric direct acting actuator, the stator 19 of the electric motor 12 is arranged to surround the outer circumference of the outer ring member 13, the cylindrical rotor 18 of the electric motor 12 is arranged oppositely to the radial direction of the stator 19, and a portion 22 for coupling the rotor 18 and the rotating shaft 14 is provided.
EGUCHI MASAAKI
MAKINO YUSUKE
Torii Kazuhisa
Takayoshi Tagawa
Higashio Masahiro