| 摘要 |
According to the present invention, a tunnel type ball screw comprises a nut, a screw shaft, and a return element. The nut includes a female thread groove. The screw shaft is inserted into the nut and includes an outer groove, wherein a male thread groove of the screw shaft includes an insertion groove and a first return groove connected to the insertion groove in a radial direction. The return element is installed inside the insertion groove of the screw shaft and includes a rolling groove and a second return groove, wherein the rolling groove is connected to the outer groove to form a male thread groove, the male and female thread grooves form a spiral channel, and the first and second return grooves form a return channel for connecting the spiral channels. Therefore, the tunnel type ball screw allows a plurality of balls to circulate through the spiral channel and the return channel. |
