A rotary disk rotatable around a vertical rotation axis; a bearing supporting the rotary disk so as to be freely rotatable; a slide disk slidable on a top surface of the rotary disk; a position adjustment bracket that displaces the slide disk along the top surface of the rotary disk; a placement disk that is supported by the slide disk; a plurality of air nozzles that are arranged on a top surface of the stator in an annular shape centered on the rotation axis, and form a static pressure air film between the top surface of the stator and a bottom surface of the rotary disk; an aerostatic pocket formed between the top surface of the rotary disk and a bottom surface of the slide disk; and a communication aperture is formed on the rotary disk and introduces pressure of the static pressure air film into the aerostatic pocket.

The present invention discloses an in-place non-contact detection method for a shaft workpiece. The method includes: establishing a detection system, calibrating the detection system and establishing a detection coordinate system; analyzing a pose of a workpiece in the detection system to establish a coordinate system of a workpiece clamping device; controlling the workpiece clamping device of a shaft workpiece processing machine tool to rotate, continuously acquiring data by a linear laser measuring instrument, and calculating and analyzing the acquired data to obtain an ideal reference axis of the shaft workpiece; continuously acquiring data of a detection part, and calculating and analyzing the acquired data to obtain actual machining precision of runout of a shaft neck of a camshaft; and continuously acquiring data of the detection part, and calculating and analyzing the acquired data to obtain machining precision of coaxiality of the shaft workpiece.