SUPPORT ARM DRIVING DEVICE OF TREATMENT APPARATUS FOR INNER SURFACE OF STEEL PIPE STRUCTURE

摘要

A support arm driving device for an apparatus for treating the inner surface of a steel pipe structure is provided to lift up an arm without damaging the arm by allowing a driving screw member to be withdrawn by external force even when the arm is lifted up due to malfunction. A support arm driving device for an apparatus for treating the inner surface of a steel pipe structure comprises a frame(10) supporting a body and an electromotor(20) installed at the frame. A driving screw member(30) is connected with a driving shaft(21) of the electromotor through a coupling(22). A reciprocating member(40) has a nut section(41) screw-coupled with the driving screw member and a chamber section(42) connected with the nut section. A rack member(50) has a rounded rack section(51) at the front end, a connection rod section(52) at the intermediate portion and a head section(53) at the rear portion. A compression coil spring(60) is mounted on the outer peripheral portion of the connection rod section.