초록 ▼

In order to offer a linear working unit which is a linear working unit capable of accurately driving two movable members in mutually reverse directions, i.e., leftward and rightward, with a single driving means and yet formed in a construction highly accurate in performance but compact and moderatel

In order to offer a linear working unit which is a linear working unit capable of accurately driving two movable members in mutually reverse directions, i.e., leftward and rightward, with a single driving means and yet formed in a construction highly accurate in performance but compact and moderately priced, according to the present invention, a left-hand thread part and a right-hand thread part are formed on a single feed screw, with a nut block being joined independently with each of the left-hand thread part and the right-hand thread part and with the respective nut blocks being installed on a guide rail, and rolling elements are set in the space between the rolling groove formed for the rolling elements in the guide rail and the rolling grooves formed in the nut blocks, so that the nut blocks are kept free to slide in the axial direction by the effect of the rolling motion of these rolling elements. Thereby, the linear working unit is capable of operating the two nut blocks so as to make their highly accurate movements in the mutually reverse directions, i.e., leftward and rightward, through control of a single feed screw and, as these nut blocks are built into the same guide rail, the linear working unit can offer the additional advantage that it can be formed in a non-bulky structure comprised of a smaller number of items of component parts and can yet be operated in a simple manner.

대표청구항 ▼

A linear working unit driven by an electric motor, comprising: a U-shaped linear movement guiding member including an elongated guide rail portion, two mutually confronting side surfaces, and a rolling groove formed, for receiving a plurality of rolling elements in an axial direction, on each of the

A linear working unit driven by an electric motor, comprising: a U-shaped linear movement guiding member including an elongated guide rail portion, two mutually confronting side surfaces, and a rolling groove formed, for receiving a plurality of rolling elements in an axial direction, on each of the two mutually confronting side surfaces; a ball screw shaft member rotatably supported by said linear movement guiding member at both ends thereof, said ball screw shaft member having a left-hand ball screw part and a right-hand ball screw part; a first screw nut threadedly mounted on said left-hand ball screw part of said ball screw shaft member via balls to move along said ball screw shaft member by rotation thereof, said first screw nut being guided by said guide rail portion via rolling elements in the form of first balls disposed between said first screw nut and said guide rail portion when said first screw nut is moved along said ball screw shaft, said first balls being circulated in a return passage formed in said first screw nut; and a second screw nut threadedly mounted on said right-hand ball screw part of said ball screw shaft member via balls to move along said ball screw shaft member by rotation thereof, said second screw nut being guided by said guide rail portion via rolling elements in the form of second balls disposed between said second screw nut and said guide rail portion when said second screw nut is moved along said ball screw shaft, said second balls being circulated in a return passage formed in said second screw nut.