Method for making a ball-nut and method for making a ball-screw

A method for making a ball-nut comprising the steps of:

• a) obtaining a ball-nut body including a substantially-cylindrical inner-circumferential wall portion having a longitudinal axis;
• b) obtaining a whirling-type internal-diameter cutting machine;
• and
• c) cutting a plurality N of longitudinally-spaced-apart, 360-degree closed-loop surface grooves in the inner-circumferential wall portion using the cutting machine, wherein each surface groove surrounds the longitudinal axis, is adapted for receiving a plurality of ball bearings, includes a helical-grooved portion substantially coaxially aligned with the longitudinal axis, includes a crossover-grooved portion, and includes a transition-grooved portion disposed between the helical-grooved portion and the crossover-grooved portion, wherein longitudinally-adjacent crossover-grooved portions are circumferentially staggered, and wherein a narrower groove is cut in the helical-grooved portion and the crossover-grooved portion than in the transition-grooved portion.

A method for making a ball-screw comprising the steps of:

• a) obtaining a ball-screw body including a substantially-cylindrical outer-circumferential wall portion having a longitudinal axis;
• b) obtaining a whirling-type external-diameter cutting machine;
• and
• c) cutting at least one 360-degree closed-loop surface groove in the outer-circumferential wall portion using the cutting machine, wherein the at-least-one 360-degree closed-loop surface groove surrounds the longitudinal axis, is adapted for receiving a plurality of ball bearings, includes a helical-grooved portion substantially coaxially aligned with the longitudinal axis, and includes a cross-under-grooved portion.

A method for making a ball-screw comprising the steps of:

• a) obtaining a ball-screw body including a substantially-cylindrical outer-circumferential wall portion having a longitudinal axis;
• b) obtaining a whirling-type external-diameter cutting machine having a cutting tool;
• and
• c) cutting a plurality N of longitudinally-spaced-apart, 360-degree closed-loop surface grooves in the outer-circumferential wall portion using the cutting machine, wherein each surface groove surrounds the longitudinal axis, is adapted for receiving a plurality of ball bearings, includes a helical-grooved portion substantially coaxially aligned with the longitudinal axis, includes a cross-under-grooved portion, and includes a transition-grooved portion disposed between the helical-grooved portion and the cross-under-grooved portion, wherein longitudinally-adjacent cross-under-grooved portions are circumferentially staggered, and wherein the cutting tool is angled to cut a narrower groove in the helical-grooved portion and the cross-under-grooved portion than in the transition-grooved portion.