Patent ID: 6561054
Filing Date: 2003-05-13
Classification: F16C,F16H,Y10T

Abstract:
A ball screw with spaces comprising at least a screw bolt, a nut body unit and a plurality of balls and spacers circulating between said screw bolt and said nut body unit, wherein:the outer surface of said screw bolt is formed into screw grooves having semicircular-liked cross section; said nut body unit including at least a nut body and accessories for circulation of said balls, said nut body is hollow while its inner surface is formed into similar screw grooves of semi-circular-liked cross section corresponding to those formed around said screw bolt; a plurality of balls and spacers are accommodated in said screw grooves of said screw bolt and said nut body, and each of said spacers is interposed between adjacent ones of said balls, said balls and spacers are adapted to be located in a circulation passage; said balls are spherically shaped and made of metallic material; each of said spacers comprises a concave contour that is substantially cylindrical in shape and inwardly curved, the radius of the concave contour is less than any radius of said circulation passage, the largest diameter of each of said spacers is smaller than that of said balls, each of said spacers includes two end surfaces that are formed into two substantially concaved curved surfaces that are inwardly curved towards the other, each of the substantially concaved curved surfaces are in contact with an adjacent one of said balls; and wherein each of said inwardly concaved surface of said spacer is formed into sinuate shaped stripes.