Device and method for detecting concentricity of gear shaft

The invention belongs to the technical field of gear shaft machining, and particularly relates to a gear shaft concentricity detection device and method, and the device comprises a workbench, a first conveyor belt and a second conveyor belt. The first conveyor belt and the second conveyor belt are respectively used for conveying gear shafts away; a grabbing assembly is arranged on the workbench. The workbench is fixedly connected with a placing table; a fixed seat is fixedly connected to the placing table; a first sharp shaft is rotationally connected to the side wall of the fixed seat, and the first sharp shaft rotates through a power assembly; a first air cylinder is fixedly connected to the containing table through a supporting block and provided with a first piston rod. A pair of first supporting plates is arranged on the placing table, a placing plate is fixedly connected to the top ends of the first supporting plates, and the cross section of the placing plate is an inverted isosceles trapezoid; a detec