Abstract: A process for the production of a ball screw, which has at least one element produced powder metallurgically, is suggested, with which the at least one element is produced from a plurality of parts, wherein at least one first precursor body with a first joining area and one second precursor body with a second joining area are produced and the first precursor body and the second precursor body have been or are brought into contact via the first joining area and the second joining area prior to the sintering and/or during the sintering.

Abstract: A direct acting force limiting actuator wherein the actuator output force either directly or indirectly causes significant drag on a rotary input shaft rather than on the translating output member. Consequently, input energy is dissipated before the actuator gear train mechanical advantage amplifies the reaction forces.

Abstract: Ball screw, having a spindle nut (2) which may be provided on a recirculating ball screw (1) and on the inner circumference of which turns (3) of ball grooves (4), helically wound around an axis, are provided in which balls (5) can roll, at least one return element (8), arranged on the outer circumference of the spindle nut (2) and provided with a return duct (9) for the balls (5), at its two ends connecting a start of a turn (3) to an end of a turn (3) in order to permit a continuous recirculation of the balls (5), the return element (8) between its two ends being supported on a support (15, 21), the return element (8) being resiliently supported by means of at least one spring element (14) on the support (15, 21).

Abstract: A ball screw mechanism including a screw having a first axis and at least one screw groove extending along a first helical path about the first axis, and a nut having a first aperture receiving the screw. The nut also includes at least one nut groove extending along a second helical path about the first axis between first and second edges disposed on opposite sides of the screw. The at least one screw groove and the at least one nut groove are aligned and cooperate to form a helical passageway extending at least 180 degrees about the first axis between a first opening at the first edge and a second opening at the second edge. The ball screw mechanism also includes a plurality of balls moving, in part, along the helical passageway.

Abstract: A circulating member for a ball screw is disposed on a nut, the nut is formed with Gothic type threads, and the circulating member of the ball screw is formed with return path for enabling the balls to circulate. The connecting ports at both ends of the return path for connecting the threads of the nut are shaped in Gothic style, thus eliminating the level difference and consequently preventing the balls from being struck and jammed.

Abstract: A ball screw assembly has an axially extending screw with an external helical groove and a nut with a through bore for receipt of the screw. The through bore has an internal helical groove adapted for cooperation with the external helical groove to define a ball raceway. A plurality of load bearing balls is disposed in the raceway for rolling contact with the internal and external grooves. A spacer is disposed between adjacent ones of the load bearing balls to prevent the balls from contacting one another. Each of the spacers has at least three pairs of diametrically opposite concave dimples adapted for contact with the load bearing balls at separate times from one another.

Abstract: In a ball circulating groove structure of a ball nut, a deflector is provided with an inner collar extending along a penetrating direction of a hole of the ball nut and engaging with the ball nut in a side of an inner surface of the ball nut, and an outer collar engaging with the ball nut in a side of an outer surface of the ball nut.

Abstract: Provided is a screw device capable of reducing noise generated therefrom. The screw device has a screw shaft 5 having a rolling-element rolling groove 5a spirally formed on an outer peripheral surface of the screw shaft; a nut 6 having a loaded rolling-element rolling groove 6a spirally formed on an inner peripheral surface of the nut and facing the rolling-element rolling groove 5a of the screw shaft 5 and a rolling-element return path connecting an end of the loaded rolling-element rolling groove 6a with an other end thereof; and a plurality of rolling elements 7 arranged in a rolling-element circulation path. A low-noise plate 12 is mounted on a flange 9 provided at an axial end of the nut 6 so that the low-noise plate 12 covers at least a part of an end surface of the flange 9.

Abstract: Provided is a novel steering device which can be formed to be compact, which is easily applicable to a vehicle with a small engine room such as a front-engine/front-drive car, and which is of neither the ball nut type nor the rack and pinion type. The steering device operates steerable wheels by converting rotation of a steering shaft to axial movement of a relay rod, the steering device including: a gear casing through which the relay rod is passed; a spiral ball rolling groove provided in the relay rod within the gear casing so as to exhibit a lead of a magnitude of 1 or more; a nut member threadedly engaged with the ball rolling groove of the relay rod through an intermediation of a large number of balls and supported rotatably with respect to the gear casing; an input shaft to which rotation of the steering shaft is transmitted and which is in an intersecting or offset relationship with the relay rod; and a first transmission gear for transmitting rotation of the input shaft to the nut member.

Abstract: A ball screw includes a screw shaft 1, a nut 2 screwed to the screw shaft 1 via balls 3 rollably charged to a ball rolling path 5 in a spiral shape, a ball return path 6 for circulating the ball 3 by delivering the ball 3 from an end point to a start point of the ball rolling path 5, and ball guide member 10 for guiding the ball 3 between the ball rolling path 5 and the ball return path 6. The ball guide member 10 is fitted to a recess portion 15 provided at an end face of the nut 2. An outer edge portion 20a of a fixing member 20 is inserted into a groove portion 16 formed at an inner face of the recess portion 15, so that the fixing member 20 fixes the ball guide member 10 to the nut 2.

Abstract: A preload structure for a ball screw in the inner surface of a nut is formed a helical groove whose lead is different from the lead of the adjacent helical groove to produce a lead deviation between the helical groove of the nut and the helical groove of the screw. By such arrangements, the lead deviation can be used to achieve the preload objective, thus reducing the fitting number demanded of the circulation system. Consequently, not only the single circulation system fittings can be used, but also the length of the nut is shorter and without extra machining, and the producer only needs to control the deviation of the interval helical track during rubbing to achieve various preload changes.

Abstract: A housing has a screw shaft passing wall in which a through hole, through which a screw shaft passes, is formed. A spline outer cylinder is held at one end by the screw shaft passing wall, and a disc spring that biases the spline outer cylinder toward the screw shaft passing wall is arranged at the other end of the spline outer cylinder. A tapered recess is formed in one end face of the spline outer cylinder, and a tapered projection that is fitted in the tapered recess is formed in a face of the screw shaft passing wall of the housing, which faces the spline outer cylinder.

Abstract: A ball screw includes a screw shaft, in which a thread groove is formed in an outer peripheral face thereof, that includes a small-diameter portion with a diameter smaller than an outer diameter of the screw shaft formed integrally at one end of the screw shaft; a nut, through which the screw shaft passes, having a thread groove formed in an inner peripheral face thereof; a plurality of balls disposed in a ball passage formed by the thread groove of the screw shaft and the thread groove of the nut; and a ring-shaped stopper, immovably fitted on the small-diameter portion, that prevents the nut from moving.

Abstract: The present invention relates to an error-compensating bearing screw conveying device including: a screw shaft having a screw mounted along the outer circumferential surface thereof; a nut body adapted to fittedly insert the screw shaft thereinto along the inner circumferential surface thereof and having a plurality of mounting holes formed along the outer circumferential surface thereof in such a manner as to conform to a spiral passageway formed on the screw of the screw shaft; and a plurality of radial bearings mounted in the mounting holes of the nut body and adapted to be rotated at the fixed positions thereof in such a manner as to come into contact with the outer circumferential surface of the screw of the screw shaft along the outer races thereof when the screw shaft or the nut body is rotated; and position-adjusting means mounted on the top sides of the radial bearings so as to adjust the positions of the radial bearings in such a manner as to be oriented toward the center of the screw shaft.

Abstract: Method for producing a spindle nut of a ball screw, by provided the circumference of the nut with at least one through-opening for receiving a deflecting piece for balls of the ball screw. A hole punch arranged in the spindle nut and operable to punch out the through-opening from radially inward to radially outward through the casing of the spindle nut.

Abstract: Between two mutually adjoining load balls 5, there is interposed a retaining piece 10 having two concave surfaces 11 which are respectively opposed to the two adjoining load balls 5. The retaining piece 10 has an outside diameter dimension equal to or more than 0.5 times the outside diameter dimension of the load ball 5. Further, the retaining piece 10 has an outside diameter dimension which, when the retaining piece 10 passes through a screw groove circulation passage and a tube circulation passage, prevents the retaining piece 10 from touching the inner walls of these screw groove circulation passage and tube circulation passage, or has an outside diameter dimension which is equal to or less than 0.9 times the outside diameter dimension of the load ball.

Abstract: A ball screw device includes a ball nut having an inner thread formed by a number of helical groove portions and helical ridges, and an opening and a depression communicating with each other, and a channel communicating with the depression of the ball nut, a radially inserted deflecting member has a block engaged into the opening of the ball nut and an extension extended from the block and engaged into the depression of the ball nut for anchoring the deflecting member to the ball nut. A fastener may be engaged through the deflecting member and engaged with the ball nut for securing the deflecting member to the ball nut.

Abstract: A ball screw assembly, wherein the circulate component is positioned in the nut by inserting a protrusion in a notch, so that the circulate component is positioned easily, and the problem of assembly difficulty is solved. The method of fixing the circulate components in the nut is that: the circulate component is formed with an axial hole and the radial hole that are connected to each other, the axial hole of the circulate component is aligned to the axial locking hole of the nut, and then liquid resin is injected into the axial hole of the circulate components, and the liquid resin will form a locking members after curing, thus fixing the circulate component in the nut. Due to the formation of the locking member is determined by the diameter of the hole to be machined, the configuration of locking member will be varied in response to the diameter of the hole to be machined. Whatever the diameter of the hole to be machined changes or not, it will not affect the interchangeability of the locking member.

Abstract: A rotary actuator 10 includes: a housing 40; a first screw shaft 11 fixedly disposed on one end side of the housing 40 and formed with a spiral screw groove 12 in its outer peripheral surface; a second screw shaft 21 disposed on another end side of the housing 40 to be rotatable around an axis in a state of restricting a movement in an axial direction and formed, in an outer peripheral surface thereof, with a spiral screw groove 22; a nut member formed, in an inner peripheral surface thereof, with two kinds of nut grooves 31 and 32 corresponding to the screw grooves 12 and 22 formed to the first and second screw shafts 11 and 21 so as to be engaged therewith. The screw groove 12 formed to the first screw shaft 11 has a lead larger than a lead of the screw groove 22 formed to the second screw shaft 21.

Abstract: A ball screw device includes a number of bearing members received between a ball nut and a screw shaft, and an image device engaged into the bore of the ball nut, and directed toward the screw shaft but spaced from the screw shaft for taking an image of the screw shaft and for viewing a changing of the inner thread of the screw shaft and for allowing the users to change or to replace the worn out ball nut and/or the worn out screw shaft and/or the worn out bearing members right away or at the best time. A processor device may be coupled to the image device for processing the images taken by the image device. A displayer may display the images, and a warning device may generate a warning signal when the screw shaft has been worn out.

Abstract: A ball screw in which surface hardness of balls is higher than both of surface hardness of a ball screw groove of a screw shaft and surface hardness of a ball screw groove of a nut, and a solid lubricant film is formed on a surface of the balls with a thickness of 1 ?m or more and 5 ?m or less. Further, cross-sectional shape of grooves 11 and 21 of a screw shaft 1 and a nut 2 is a Gothic arc. A ratio (R/D) of a radius (R) of the arcuate cross-section of the groove 11 with respect to diameter (D) of balls 2 is set to 51.0% or more and 52.0% or less. The solid lubricant film made of MoS2 is formed on the surface of the balls 3 with a thickness of 0.5 ?m and 3.0 ?m or less.

Abstract: A roller transmission and gearing mechanism with a driving body, roller means and a driven body, wherein the driving body is coupled to the driven body by means of the roller means, the bodies are guided with a single degree of freedom, and define respective roller guide tracks thereon, the tracks contact the roller means and determine the movement of the roller means, which contact the roller guide tracks along rolling curves, the roller guide tracks start and terminate at respective pairs of limit surfaces, and the roles of the driving and driven bodies can be interchanged, furthermore the distances between points of the rolling curve on the driving body and on the driven body are different, the rolling means move with pure rolling motion, and for all contacting point-pairs on the rolling curves the respective tangential planes are parallel to each other, the velocities of the contacting pairs of points are identical but have opposite signs, in the contacting points the action lines of forces intersect the

Abstract: A ball screw device includes a ball nut having an inner thread formed by a number of helical groove portions for forming an endless ball rolling passage in the ball nut and for receiving a number of bearing members, and an endless spacer moving passage formed in the ball nut and communicating with the endless ball rolling passage of the ball nut for receiving a number of bearing spacers which are engaged between the bearing members for spacing the bearing members away from each other and for preventing the bearing members from striking onto each other. The bearing spacers may be spherical bearing spacers, and made of synthetic materials.

Abstract: Since it is configured that an female screw groove 2a of a nut 2 extends round an axis of the nut 2 through 360 degrees or less and a sectional shape thereof taken at right angles to the groove contains a circular arc portion 2c of 90 degrees or less and a rectilinear portion 2d which connects to the circular arc portion at a bottom of the groove and extends in parallel with the axis, after molding, a lower mold LM and an upper mold UM can simply be removed from a barrel mold BM in the axial direction, and consequently, the necessity of provision of a parting plane which passes through the thread groove 2a can be obviated, thereby making it possible to easily form the thread groove 2a which is free from a difference in level or a stepped portion.

Abstract: A linear motion apparatus has a guide shaft including a spiral-shaped or linear-shaped rolling element rolling groove, a movable body including a spiral-shaped or linear-shaped rolling element rolling groove opposed to the rolling element rolling groove of the guide shaft, a large number of rolling elements rollably moving along a rolling element rolling passage formed between the rolling element rolling grooves of the guide shaft and movable body and, a rolling element return passage communicating with the rolling element rolling passage, wherein, in the portion of the rolling element rolling groove of the movable body that is adjacent to an open end of a rolling element return passage, an escape portion is formed by abrasive flow machining in such a manner that the grinding depth thereof increases gradually toward the open end of the rolling element return passage.

Abstract: A device for retaining optical components includes a number of open orifices disposed next to one another in an arrangement. A raceway corresponding to the arrangement is provided, the raceway including a number of detents. A ball bearing follows the raceway and cooperates with the detents so that each of the detents is brought, in a respective following direction, into click-stop engagement with the ball bearing so as to hold the orifices in a selected position. Each of the detents has, in the respective following direction, a profile including a combination of an outer and an inner arc-shaped profile. The outer profile has less curvature than the inner profile and surrounds the inner profile.

Abstract: A ball screw apparatus includes: a screw shaft having a screw groove, a nut having a screw groove and holes, a number of balls rollably provided between the screw grooves, and a ball circulating member having an end portion to be fitted to the holes. The ball circulating member includes aside cap having leg portions to be fitted into the holes. Each of the leg portions contains a scooping up path or a returning path. The scooping up path and the retuning path are inclined with respect to outer peripheral faces of the leg portions. The holes include a slot substantially in parallel with directions of the screw grooves. The scooping up path and the returning path are directed substantially in a tangential direction of the screw shaft and inclined substantially toward a lead angle direction of the screw grooves.

Abstract: The invention relates to a ball screw device in which a screw shaft and a nut member are threadedly engaged with each other through a number of balls. In such a ball screw device, an inner surface of a cover plate contacting an end surface of a nut main body is provided with a projecting return piece adapted to be fit-engaged with a recess cut in an inner peripheral surface of the nut main body, the return piece being provided with a scoop portion for dislodging the balls from the ball rolling groove of the screw shaft and a direction switching passage for guiding the dislodged balls to the entrance of a ball return hole. The projecting return piece is divided into a first piece formed integral with the cover plate and a second piece fixed to the first piece by a curved plane including the center line of the direction switching passage.

Abstract: A recirculating ball screw and nut drive including a spindle, a spindle nut guided on the spindle, balls guided between the spindle and the spindle nut, in a working passage defined by grooves of the spindle and spindle nut, and deflection pieces arranged on both ends of the spindle nut to divert the balls out of the working passage into a return passage accommodated in the spindle nut, and to divert the balls out of the return passage into the working passage accommodated in the spindle nut, where the ball deflection pieces are annular and composed of at least two circular-ring sectors.

Abstract: A linear motion device has: a linear motion body externally fitted onto a shaft and making a relative linear motion along the shaft; a plurality of balls retained in a rolling element groove formed in an inner surface of the linear motion body, and rolling between the rolling element groove and the shaft; separators interposed among the balls; and a circulating path formed in the linear motion body and for circulating the balls from one end side of the rolling element groove to the other end side thereof; wherein the linear motion device is charged with grease containing base oil which is 220-395 in worked penetration defined by JIS K2220 and 50-500 mm2/s in kinematic viscosity at 40° C.

Abstract: A ball screw device comprises a nut having a thread groove in the inner peripheral surface thereof, a screw shaft having a thread groove in the outer peripheral surface thereof and a plurality of balls interposed between the respective thread grooves. In the screw shaft, the thread groove is of at least substantially one turn. In the screw shaft is provided a ball circulation groove for coupling the downstream and upstream sides of the thread groove so that the balls are returned to the upstream side from the downstream side so as to be thereby circulated.

Abstract: The invention provides a ball screw apparatus which suppresses abrasion and damage by competition of balls, controls spaces between retaining pieces and balls, and prevents retaining pieces from falling, thereby enabling to more improve operating ability. The retaining pieces are positioned between the balls running in a ball rolling path, such that a sum total of the spaces between the retaining pieces and the balls is 50% or less of an outer diameter size of the retaining piece, and at the same time a contact angle between the retaining piece and the ball is 25° or above to 40° or below.

Abstract: The present invention relates to a new guide actuator with high radial direction load capability, which has the purpose of providing a directional force bearing way to common loading method to make the actuator can bear load and transmit with higher accuracy. On design, the present invention has grooves bearing load at the center of the bottom of the U-shape guide structure, and a table is set between two inner side walls of the U-shape guide structure, grooves corresponding to the grooves of the U-shape guide structure being set at the bottom of the table, rollers being set between grooves and grooves to make the table and the U-shape guide structure slide respect to each other with very low friction due to rolling motion of the rollers with high radial load capability.

Abstract: An electric power steering apparatus comprises a rack-and-pinion mechanism and a ball screw mechanism. The ball screw mechanism comprises a shaft formed a screw groove and a nut formed a screw groove. A ball-roll path is created spirally by the screw grooves of the shaft and the nut being opposite each other. A plural number of balls are contained into the ball-roll path. A ball-return path is connecting both ends of the ball-roll path so that the balls go through. A circulation path consists of the ball-roll path and the ball-return path, in which the balls move endlessly. A plural number of separators is arranged between the balls respectively in order to prevent balls from contacting each other. A number of the balls is fewer from one ball to three balls than a maximum number of the balls which can be contained into the circulation path.

Abstract: A liner motion device has a liner motion element fitted on a shaft and moving straight along the shaft; a plurality of balls which are retained in a rolling element groove formed on the inner side of the liner motion element and roll over between the rolling element groove and the shaft; a separator interposed between the rolling elements; and, a circulating path formed in the liner motion element through which the rolling elements are circulated from one end of the rolling element groove to the other, wherein the separator is a product of a synthetic resin containing a lubricating oil in an amount of 3 to 25% by volume.

Abstract: A screw feed apparatus has a screw shaft having a screw groove formed on the outer peripheral surface thereof; a nut having a screw groove formed on the inner peripheral surface thereof opposed to the outer peripheral surface of the screw shaft; a large number of rolling elements rollably interposed between the two screw grooves of the screw shaft and nut; a circulation path disposed in the nut for returning the rolling elements to their original positions; and, a deflector piece disposed in the nut for connecting the circulation path to a rolling path formed between the two screw grooves, wherein the deflector piece includes a plurality of divisional pieces respectively formed rolling element guide grooves cooperating together in forming a rolling element guide path for guiding the rolling elements to the circulation path.

Abstract: A linear motion device includes an inner member and an outer member cooperatively forming a ball circulating path therebetween, a plurality of balls rollably disposed in the ball circulating path, and a plurality of retaining pieces interposed between the balls, wherein the ratio of a ball-to-ball direction force applied to the retaining piece by the balls disposed at the both sides thereof to the elastic displacement of the retaining piece by the force is adjusted to a range of from 0.1 to 10 [N/?m] from 0.1 to 10 [N/?m] by predetermining a bore diameter of a through-hole formed at the central portion of the retaining piece to a range of from 35% to 65% of a diameter of the ball.

Abstract: A ball screw has a screw shaft including a spiral-shaped ball rolling groove formed in an outer peripheral surface thereof; a nut including a spiral-shaped ball rolling groove formed in an inner peripheral surface thereof; a plurality of balls disposed in a raceway formed by the two rolling grooves; and, a return path for moving the balls from the terminal point of the raceway to the start point of the raceway, the two end portions of the return path respectively including a rising surface rising from the ball rolling groove of the nut and a stopper portion disposed opposed to the rising surface to form the end portion of the raceway, wherein a boundary portion between the rising surface and the ball rolling groove of the nut is formed a round portion having the radius of curvature 0.05 times the diameter of the ball or more.

Abstract: A higher efficiency roller screw system that includes a nut body designed to engage a threaded shaft. The nut body includes a center bore with closed, partial helical grooves formed therein. Disposed inside the center bore is a shaft with open helical threads formed thereon. A plurality of rollers with non-helical grooves formed thereon are also disposed inside the nut body's center bore and longitudinally aligned with the shaft. The grooves on each roller are designed to engage the grooves on the nut body and the threads on the shaft. The nut body includes a cross-over region where the trajectory of the internal grooves extend radially outward and axially. When the rollers' grooves contact the grooves in the cross-over region, the rollers are forced outward to maintain contact with the grooves on the nut body and are deflected axially. When they move outward, they disengage from the helical threads on the shaft.

Abstract: A circulation member of a ball screw for circulating a ball rolling on a spiral ball rolling groove formed on a screw shaft. The circulation member includes a central portion and a pair of leg portions disposed at both ends of the central portion so as to extend therefrom, the leg portions having inner peripheries having center lines inclined in directions different from each other with respect to a center line of an inner periphery of said central portion. The leg portions also have outer peripheries having center lines being parallel to each other and have thicknesses, different in circumferential directions thereof, at cross sections in directions normal to center lines of the outer peripheries of the respective leg portions.

Abstract: A ball screw which is little subject to deterioration of operating characteristics and occurrence of wear, torque change, noise, vibration, etc. during operation due to stagnation or competition of balls. The ball screw includes a screw shaft having a helical thread groove formed on the outer surface thereof and a nut having a thread groove formed on the inner surface thereof corresponding to the thread groove on the screw shaft which engages with the screw shaft with the interposition of a number of balls rollably provided in a helical ball rolling path formed between the two thread grooves, and spacers between adjacent ones of the number of balls, wherein the variation of the total of the gap between the balls and spacers during the rolling of the balls is smaller than 1/20 of the diameter of the ball.

Abstract: A ball screw mechanism has an opposing thread provided by an integral male thread formed at one end of a nut received on the screw. The male thread is of a smaller form than the female thread on the screw so as to not normally be in contact therewith, but should ay loss of the balls occur with the resultant slight relative axial shift of the screw and nut, the male threads engage to limit such relative axial movement to protect connected equipment. Both the nut male and female threads may be machined from a cylindrical nut blank.

Abstract: The invention is a ball screw, comprising: a shaft having a spiral-shaped shaft; a nut having a spiral-shaped nut ball groove and screwed with the shaft via a plurality of balls; and a ball circulation passage for raking the plurality of balls at one end of the ball rolling, wherein an end part of the ball circulation passage is connected to one end part of the ball rolling passage in such a manner that: a gap ?t formed between a ball contacting part of the nut ball groove contacted with the ball and an inner circumferential surface of the end part of the ball circulation passage is set 0.2 mm or less; and a change of angle in a ball rolling direction is 10° or less, the change caused by raking the ball from the ball rolling passage to the ball circulation passage.

Abstract: A wiper ring to be applied to a nut of a ball screw having a screw shaft comprises a plurality of segments each constituted as independent element having a seal portion to be contacted to the screw shaft, support pins extending in an axial direction of the screw shaft so as to correspond to the segments, respectively, the segments being arranged in a circumferential direction of the screw shaft to be rotatable about the pins, the pins being connected to each other through support members so as to limit the relative movement of the respective pins, and a spring member for urging the segments arranged circumferential direction of the screw shaft so as to be directed towards radially central side of the screw shaft.

Abstract: An electric power steering apparatus (11) includes a reduction mechanism (G) for transmitting the rotation of a rotating shaft (28a) of a motor (28) to a ball screw nut (20) while reducing the speed of the rotation. The reduction mechanism includes a drive gear (29), which is coaxially connected to the rotating shaft of the motor, and a driven gear (16a), which is arranged on the outer surface of the ball screw nut. Due to the reduction mechanism, the motor may be inclined relative to a rack shaft (18).

Abstract: A ball screw apparatus, has a screw shaft including a screw groove; a nut fitted with the screw shaft, the nut including a screw groove and a ball return passage; a circulation piece including a ball circulation passage; and, a large number of balls, wherein, in the inner peripheral surface of the nut, a concave-shaped snap ring groove extending along the peripheral direction of the nut is formed, in the face of the circulation piece that faces the inside diameter side of the nut, a concave-shaped snap ring groove is formed so as to connect to the snap ring groove of the nut, and an outside diameter portion of a snap ring is fitted into the two snap ring grooves to thereby fix the circulation piece to the nut.

Abstract: The ball screw comprises a shaft including a spiral-shaped shaft groove having a semicircular-shaped (Gothic-arch-shaped) section, a nut including a spiral-shaped nut ball groove which corresponds to the shaft groove and has a semicircular-shaped (Gothic-arch-shaped) section, a large number of balls rotatably fitted into between the nut ball groove and shaft groove in such a manner that they are held by and between these two grooves, and a circulation member capable of defining a ball circulation passage for allowing the balls to circulate endlessly therethrough, wherein a portion of the nut ball groove is formed larger in the effective diameter than the remaining portions of the nut.

Abstract: A rolling element interference preventer for a guide device prevents a number of rolling elements rolling at regular intervals in a continuous circulation path of the guide device from interfering with each other. The rolling element interference preventer is formed of a thermoplastic resin elastomer having a physical property in accordance with an expression, (A×B)÷C?18, where A represents a 10% elongation stress, B represents a tensile strength, and C represents a bending modulus of elasticity.

Abstract: A liner motion device has a liner motion element fitted on a shaft and moving straight along the shaft; a plurality of balls which are retained in a rolling element groove formed on the inner side of the liner motion element and roll over between the rolling element groove and the shaft; a separator interposed between the rolling elements; and, a circulating path formed in the liner motion element through which the rolling elements are circulated from one end of the rolling element groove to the other, wherein the separator is a product of a synthetic resin containing a lubricating oil in an amount of 3 to 25% by volume.

Abstract: A coupled circulation tube for a ball screw unit. The tube is formed on a planar surface at one side of the ball screw bearing, each tube joined to two circulation holes. Each circulation tube is formed by coupling two symmetrical rigid metallic half tubes at recessed grooves and flanges interposedly arrayed one after another longitudinally along the wall of each half tube to form a resultant U shaped arcuate elbow tube for ball circulation such that it is firmly constructed with a desired toughness free from loosening, cracking or deforming by constant collision and abrasion of the rolling balls.