Roller screw and roller screw roller arranging method
AssigneeThk Co., Ltd.
InventorsKentarow Nishimura, Shino Kimura
Life of this patent
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Abstract
In a roller screw, a plurality of rollers 16 interposed between a nut member 14 and a screw shaft 12 are composed of a forward-motion load roller group 17, the rollers 16 of which are arranged in such a manner that the center lines thereof are set at a given angle α with respect to the center line of the screw shaft 12, and backward-motion load roller group 18, the rollers 16 of which are arranged in such a manner that the center lines thereof are set at an angle β, which is different from the angle α, with respect to the center line of the screw shaft 12; and, the forward-motion load roller group 17 and backward-motion load roller group 18 are disposed such that they are separated from each other.
Claims1
A roller screw comprising:
- a screw shaft having a spiral-shaped roller rolling groove formed in an outer peripheral surface thereof;
- a nut member having a spiral shaped load rolling groove formed in an inner peripheral surface thereof so as to correspond to said roller rolling groove;
- and
- a plurality of rollers to be arranged and stored between said roller rolling groove and said load rolling groove;
- wherein as said screw shaft is rotated with respect to said nut member, said nut member is allowed to reciprocate with respect to said screw shaft;
- wherein said plurality of roller$ includes a forward-motion load roller group the rollers of which are arranged in such a manner that the center lines thereof are set at a given angle with respect to the center line of said screw shaft, and a backward-motion load roller group the rollers of which are arranged in such a manner that the center lines thereof are set at an angle, which is different from said angle, with respect to the center line of said screw shaft;
- and
- wherein said forward-motion load roller group and said backward-motion load roller group are separated from each other within the nut, and
- wherein the winding numbers of said forward-motion load roller group and said backward-motion load roller group are set to be different from each other according to the ratio of axial-direction loads applied to said roller screw during the reciprocating motion thereof.
Dependencies are inferred from the claim text.