摘要 |
PURPOSE:To obtain a driving device which can freely conduct rectilineal and rotary motion by fitting two rotary driving members having a spiral ball groove and a ball circulating groove to a main shaft having spiral driving grooves. CONSTITUTION:Two kinds of spiral driving shafts are provided on a main shaft 8. Both driving shafts have pitches in the opposite direction to each other, with which rotary driving members 2, 3 are engaged. The rotary members 2, 3 include balls B, ball circulating grooves 2b, 3b and ball grooves engaged with the driving grooves of the main shaft. Accordingly, the rotary and rectilineal motion of the main shaft can be freely obtained by suitably selecting the respective rotating directions of both rotary driving members 2, 3 or the driving condition thereof. |