Double-layer air bearing

A double-layer air bearing comprises a shaft core and a machine body with an air bearing section. The shaft core is provided with a first flying disc and a second flying disc. The air bearing section of the machine body comprises a first air chamber and a second air chamber which are in clearance fit with the first flying disc and the second flying disc. The upper end face of the first air chamber, the lower end face of the first air chamber, the upper end face of the second air chamber and the lower end face of the second air chamber are each provided with a plurality of air spraying holes which are distributed in a circumferential array mode. The air spraying holes are communicated with an external air source through air channels which are arranged in the machine body. The shaft core can be kept not mechanically rubbing the machine body through a generated air film. The double-layer air bearing overcomes the defects that an existing single-layer air bearing is low in bearing capacity and not stable in performance. The bearing capacity of the shaft core is doubled through the double-layer air bearing, and the application range of machining is widened. The double-layer air bearing is simple in structure, easy to implement and beneficial to the large-scale industrial application and popularization.