摘要 |
A screw-nut screw coupling comprises a tubular element provided with an internal helical groove and an elongate member, formed by a preloaded spring having an external helical groove machined thereon. The tubular element is coupled to the elongate member by means of a number of balls mounted for rolling along an helical path defined by said helical grooves and forming a portion of an endless path for said balls to roll therealong. The tubular element is formed by at least two co-axial tubular sleeves rigidly connected to one another, one of said sleeves being arranged outside the other and being provided with groove means defining a portion of said endless path. |