| 摘要 |
PURPOSE:To relieve a power burden to a step motor which is operated to rotationally drive the rotary valve of a flow rate control type power steering device. CONSTITUTION:A rotary shaft 13 is divided into an approximately columnar valve shaft part 13a forward and reversely rotatably inserted in the rotor bore 11a of a pressure oil flow passage 11 and a coupling shaft part 13b to couple the valve shaft part 13a to a step motor 14 and have diameter smaller than that of the valve shaft part 13a. The valve shaft part 13a and the coupling shaft part 13b are intercoupled movably only in an axial direction. This constitution equalizes the areas, on which a pressure oil pressure is exerted, of one end part (the bottom) and the other end part (on the coupling shaft part 13b side) in an axial direction of the valve shaft part 13a with each other. |
