| 摘要 |
PURPOSE:To restrain vibration in an elastic deformation mode, and thereby suppress noise down by covering a ball circulation member made out of soft material such as synthetic resin and the like which can be formed into a complicated shape, by each metallic reinforcing member and the like from the outside, which are high in stiffness and density. CONSTITUTION:Each end cap 15 is formed by pressing a cylindrical ball circulation member 5 into each reinforcing cap 16 with pressure where the ball circulation member is made of synthetic resin while being formed by injection molding, and each reinforcing cap is made of metal such as stainless steel for covering a cylindrical surface 5a and a circular surface 5b. Each ball 3 is rolled within spiral grooves 1a and 2a as a ball screw nut 2 is advanced, each ball comes to the end cap at one end so as to be led into the curved path 7 of the ball circulation member 5, so that each ball comes in a ball return passage 6 within a nut main body 4. When each ball comes to the end cap 15 at the opposite side, each ball is turned over while being led by the curved path 7, so that each ball is returned to the spiral grooves 1a and 2a. Since the outside of the ball circulation member 5 is covered by each reinforcing cap 16, the-overall strength of each end cap 15 is thereby increased. |
