| 摘要 |
<p>A ball-screw rack device for converting rotary motion to linear motion in which a screwholder body (3) is secured to the body or machine (17) to be displaced and is displaceable along a guide element (15) to which a rack (7) is secured. A screw pinion (1, 2) is connected to the screwholder body (3) and is in the form of two longitudinally connected worms (1, 2), a helical groove (8) is formed in each worm (1, 2), having the same pitch and angle as a corresponding helical groove (9) formed in the rack (7). A set of balls (11) is provided for engagement between each worm (1,2) and the rack (7). Each set of balls (11) is arranged to recirculate between the leading and the trailing turns (18, 19) of the helical groove (8) formed in the associated worm (1, 2) by means of a helicoidal groove (120) cut in the body of the associated worm (1, 2) and by openings (20) at the leading and the trailing turns (18, 19) respectively. The transmission of the axial force between the rack and the screw pinion succeeds through the balls.</p> |
