| 摘要 |
646,993. Screw and nut gearing; conveying rotary motion. THOMPSON PRODUCTS, Inc. Nov. 18, 1947, No. 30561. Convention date, May 5. [Classes 80(i) and 80(iii)] In a screw and nut mechanism employing intermediate balls between helical grooves of the screw and nut a secondary nut is provided which is adjustable eccentrically of the main nut to provide a lateral preloading on the balls to take up backlash. As shown applied to a vehicle steering mechanism a steering shaft 10 transmits longitudinal motion to a nut member 20 through balls 14. This motion is resolved into a variable amount of rotary motion by means of an anchor link 24 coupled to a projecting arm 22 of the nut in a manner as described in Specification 619,147, which motion is transmitted to a steering droparm shaft 30 through projecting rollers 48 on the shaft engaging in grooves 20f in an extension 20e of the nut. A secondary nut 40 is provided adjacent the nut 20 having an extension 40b with a slightly eccentric surface engaging a corresponding surface on the nut member 20. Thus, relative rotation of the nuts 40 and 20 imposes a lateral loading on the two sets of balls to take up any play, the two nuts then being secured together by a clamp 44. An axial preloading may also be obtained by the use of shims 46 between the extension 40b of nut 40 and nut 20. The rollers 48 are also made conical and adjustable radially of shaft 30 to eliminate play in the grooves 20f. These grooves 20f may be curved to vary further the relative rotation between shafts 10 and 30. |
