Abstract: A cylinder device is capable of heightening the feed accuracy of a screw shaft and stably controlling the feed speed of a conveying unit in a wide speed range. A ball screw shaft is inserted through a hollow shaft motor having an end fixed to a housing, and a decelerator that is a planetary reduction gear unit connected to the hollow shaft motor. Each of a pair of ball screw nuts, which are disposed to face each other and between which the hollow shaft motor and the decelerator are placed, meshes with the ball screw shaft. An internal gear is connected to a spacer disposed at an end of an output gear of the decelerator. An external gear connected to the ball screw nut meshes with the internal gear. The output gear of the decelerator meshes with a connection shaft by splines.

Abstract: A cylinder device is capable of heightening the feed accuracy of a screw shaft and stably controlling the feed speed of a conveying unit in a wide speed range. A ball screw shaft is inserted through a hollow shaft motor having an end fixed to a housing, and a decelerator that is a planetary reduction gear unit connected to the hollow shaft motor. Each of a pair of ball screw nuts, which are disposed to face each other and between which the hollow shaft motor and the decelerator are placed, meshes with the ball screw shaft. An internal gear is connected to a spacer disposed at an end of an output gear of the decelerator. An external gear connected to the ball screw nut meshes with the internal gear. The output gear of the decelerator meshes with a connection shaft by splines.