Patent ID: 8813596

Claim:
A ball screw with a circulating assembly, comprising: a screw shaft including an axis and an outer helical groove in an outer surface thereof around the axis; a nut being mounted on the screw shaft along the axis of the screw shaft and including an inner helical groove in an inner surface thereof around the axis of the screw shaft, the inner helical groove cooperating with the outer helical groove to define a loaded path for receiving a plurality of balls, the nut further including a circulating hole in communication with the inner helical groove, and a recess which is formed in an end surface thereof along the axis of the screw shaft, the recess including a bottom surface opposite the outer helical groove and a side surface which the circulating hole penetrates; the circulating assembly being disposed in the recess of the nut along the axis of the screw shaft and divided into a first circulating block and a second circulating block, along the axis of the screw shaft, the first circulating block including a top surface, a first dividing surface opposite the top surface, a first curved surface connected between the top surface and the first dividing surface, a first circulating channel recessed into the first dividing surface toward the top surface of the first circulating block, and a nail portion disposed in the outer helical groove of the screw shaft and located on the first curved surface, the second circulating block including a second dividing surface which is planar and abuts against the first dividing surface, another bottom surface which is planar and abuts against the bottom surface of the recess, a second curved surface with the same curvature as the first curved surface, a second circulating channel recessed in the second dividing surface toward the another bottom surface, the first and second circulating channels being combined to form a circular circulating channel in communication with the circulating hole and the loaded path, a circular outer profile of the circular circulating channel being connected to the another bottom surface of the second circulating block, between the another bottom surface of the second circulating block and the second dividing surface of the second circulating block being defined an angle of 18 degrees to 25 degrees, a maximum distance between the first dividing surface and the top surface of the first circulating block being denoted as HC1 while another maximum distance between the second dividing surface and the another bottom surface of the second circulating block is denoted as HC2, and they satisfying the relation: HC2>HC1.