Abstract: A method and device for milling a large-diameter aspheric surface by using a splicing method and a polishing method to solve the problems of large time consumption and serious tool wear in the machining of a meter-scale large-diameter aspheric surface are disclosed. where an aspheric surface is discretized into a series of rings with different radii, and the rings are sequentially machined via generating cutting by using an annular grinding wheel tool with an outer diameter less than ¼ of a diameter of the aspheric surface; the rings are equally spaced, there are a total of N rings, and a width of any ring is jointly determined by the Nth ring, the (N?1)th ring, positioning accuracy and a generatrix equation of the aspheric surface; and the aspheric surface is enveloped by a large number of rings. A contact area between the tool and a workpiece surface is rings.

Abstract: The invention discloures a differential deceleration and continuously variable transmission gear box with self-locking functional small tooth number difference planetary gear, comprising a planetary gear mechanism comprising a planetary carrier arranged floatingly, the small tooth number difference planetary gear mechanism comprises small tooth number difference planetary gear and an output disk with self-locking function arranged on the small tooth number difference planetary gear.