A ball screw device includes a screw shaft that has a first helical groove on an outer circumference, a nut that has a second helical groove on an inner circumference, a plurality of balls, a stopper provided at an end portion of the second helical groove, and a spring body that is placed between an end portion ball closest to the stopper and the stopper. The spring body is configured of a plurality of coil springs arrayed along the first helical groove and the second helical groove. The coil springs that are adjacent each have a spring end portion of which rigidity is higher than rigidity of a spring middle portion.

Leadscrew and nut actuators are described. The leadscrew and nut actuators include a leadscrew having an external thread and formed from a first material, a nut configured to receive the leadscrew, the nut having an internal thread and formed from a second material, and an insert arranged between the internal thread of the nut and the external thread of the leadscrew, the insert configured to transfer force between the external thread and the internal thread and prevent material contact between the leadscrew and the nut. The insert is formed of a third material different from the first material and the second material.

A ball screw, including: a spindle supported for rotation around an axis of rotation; a ball nut radially disposed around the spindle, axially displaceable with respect to the spindle, and including a helical protrusion, the helical protrusion defining a helical groove; a plurality of balls disposed in the helical groove and in contact with the spindle; a reset spring including a portion located in the helical groove and an end portion extending past the helical groove in a circumferential direction around the axis of rotation; and a retaining device directly connected to the ball nut and arranged to limit displacement of the end portion of the reset spring in a first axial direction parallel to the axis of rotation. For a first circumferential position of the spindle around the axis of rotation, the reset spring urges the plurality of balls in a second axial direction, opposite the first axial direction.

A ball screw device includes a screw shaft that has a first helical groove on an outer circumference, a nut that has a second helical groove on an inner circumference, a plurality of balls, a stopper provided at an end portion of the second helical groove, and a spring body that is placed between an end portion ball closest to the stopper and the stopper. The spring body is configured of a plurality of coil springs arrayed along the first helical groove and the second helical groove. The coil springs that are adjacent each have a spring end portion of which rigidity is higher than rigidity of a spring middle portion.

A ball screw, including: a spindle supported for rotation around an axis of rotation; a ball nut radially disposed around the spindle, axially displaceable with respect to the spindle, and including a helical protrusion, the helical protrusion defining a helical groove; a plurality of balls disposed in the helical groove and in contact with the spindle; a reset spring including a portion located in the helical groove and an end portion extending past the helical groove in a circumferential direction around the axis of rotation; and a retaining device directly connected to the ball nut and arranged to limit displacement of the end portion of the reset spring in a first axial direction parallel to the axis of rotation. For a first circumferential position of the spindle around the axis of rotation, the reset spring urges the plurality of balls in a second axial direction, opposite the first axial direction.

Ball screw drives are disclosed. The ball screw may include a spindle having a threaded portion; a nut having a threaded portion, the threaded portions of the spindle and the nut together forming a ball channel; and a plurality of balls disposed in the ball channel to form a ball chain. Two or more intermediate springs may be disposed within the ball chain, each intermediate spring disposed between two balls in the ball chain. At least two of the two or more intermediate springs may have a different spring stiffness.

Provided is a screw shaft in a ball screw device. At least a part of the screw shaft includes a cylindrical body which is manufactured by a filament winding method or a sheet winding method, and a spiral member or a partitioned spiral member which is fixed to an outer circumferential surface of the cylindrical body and forms a thread groove.

The present invention is related to a fixing and actuating mechanism with a spiral ball channel which is designed as the square and trapezoidal screws or rectangular or particularly coiled springs in different shapes which are produced in the sensitivity that can work in the system to perform the function of converting rotational movement into linear movement similar to the relationship of a screw and square nut and is performing while eliminating the friction between the surfaces to add new functions that the like cannot perform.

A secondary drive coupling may comprise at least one coupling member having a first mating portion and a second mating portion. The first mating portion is configured to engage a first section of a shaft on one side of a region of weakness of the shaft, whereas the second mating portion is configured to engage a second section of the shaft on an axially opposite side of the region of weakness. Both the first mating portion and the second mating portion are each configured to prevent rotation of the at least one coupling member about the shaft. In another embodiment, the at least one coupling member comprises a first coupling member comprising the first mating portion and a first contact surface and a separate, second coupling member comprising a second mating portion and a second contact surface that is configured to engage the first contact surface.

Provided is a screw shaft in a ball screw device. At least a part of the screw shaft includes a cylindrical body which is manufactured by a filament winding method or a sheet winding method, and a spiral member or a partitioned spiral member which is fixed to an outer circumferential surface of the cylindrical body and forms a thread groove.