Abstract: In the ball screw device, the circulation path that returns balls from the end point to the start point of the load path includes a return path, scooping paths, and connecting paths. The scooping path has an arc-shaped center line that is curved outward in the radial direction as going toward the reference imaginary flat plane including the center axis of the screw shaft and the center line of the return path in the circumferential direction. The connecting path is arranged on the reference imaginary flat plane and includes a straight path having a linear center line extending in a direction orthogonal to the center axis of the screw shaft. When the radius of curvature of the center line of the scooping path is R1, the scooping angle is ?, and the entire length of the straight path is S, R1 cos(90°??)+S is made larger than the diameter of the balls.

Abstract: The present invention relates to a milling machine processing system with an intelligently follow-up cutting fluid nozzle and a working method. The milling machine processing system comprises a workpiece stage, wherein a milling machine box body is arranged above the workpiece stage; a milling cutter mechanism is mounted on the milling machine box body for processing workpieces on the workpiece stage; a rotating mechanism is mounted on an end surface of the milling machine box body located at one side of a milling cutter; the rotating mechanism is connected with a two-axis linkage mechanism and drives the two-axis linkage mechanism to rotate about a center line on which the milling cutter is located; the two-axis linkage system is connected with a nozzle through an angle adjusting mechanism and is used for adjusting a position and an angle of the nozzle.

Abstract: A ball screw device includes: a screw shaft the outer peripheral surface of which has a first thread groove; a nut the inner peripheral surface of which is provided with a second thread groove that matches the first thread groove, and the outer peripheral surface of which is provided with a through hole; a plurality of balls that roll between the first thread groove and the second thread groove; a circulation component including a main body part and a pair of leg parts provided on both ends of the main body part, and that is provided on the nut; and a pin component that fixes the circulation component to the nut. Each of the leg parts is inserted into the through hole, the pin component is provided on the leg part in an overlapping manner, and the leg part is retained in the through hole by the pin component.

Abstract: In a screw device where a shim is disposed between two nuts, a screw device that can detect preload is provided. The preload detectable screw device includes: two nuts; a shim sandwiched and compressed between the two nuts; a coupling portion configured to couple the two nuts in such a manner as to be incapable of relative rotation to each other; and a force sensor for detecting preload. A contact surface of at least one of the two nuts with the shim is provided with a recess, spaced apart from the coupling portion, in such a manner as to reduce the contact area. The force sensor is attached near the recess on an outer surface of the shim.

Abstract: A linear transmission device suitable for mounting of at least one electronic component includes: an elongated shaft member; a movable member sleeved onto the elongated shaft member and having an end surface; a housing unit disposed on the end surface and includes: a base member, at least one accommodating member and a housing member. The base member is disposed on the elongated shaft member, and includes: an assembling surface and a plurality of assembling portions. The accommodating member is disposed on the base member and includes: a first engaging surface, a second engaging surface, and an accommodating groove for accommodating the electronic component. The first engaging surface has plural connecting portions for combining with the assembling portions. The second engaging surface has plural engaging grooves, the housing member is sleeved on the accommodating member, and includes a plurality of engaging protrusions for engaging with the plurality of engaging grooves.

Abstract: A method for determining lubricant consumption by a transmission mechanism disposed on a machine tool includes steps of: a) estimating, based on an operational speed and a predetermined first predictive model, a total operational physical quantity; b) estimating, based on an individual operational physical quantity and the total operational physical quantity, a total operational count; c) receiving actuation information from the machine tool, and calculating a partial operational count based on the actuation information; and d) calculating, based on the partial operational count and the total operational count, a ratio between an amount of lubricant consumption within a time period and a total amount of lubricant.

Abstract: An external circulation ball screw consisting of a screw shaft, a screw nut, a cover, two reflow members and multiple rolling members is disclosed. The screw nut defines a mounting groove on the outer perimeter and two return holes in the mounting groove. A first half-return channel on a first step in the mounting groove of the screw nut and a second half-return channel in a second step inside the cover constitute a return channel. Alternatively, a third step can be formed in the cover, or the screw nut can be configured to provide a mounting groove and a third step with return holes in the mounting groove. Thus, same size of reflow members can be used with different lengths of return channels.

Abstract: A lubricatable ball spline device includes a ball spline shaft, a ball nut slidably sleeved on the ball spline shaft and having oil guide holes, a linear bearing unit mounted between the ball spline shaft and the ball nut, a bearing ring rotatably sleeved on the ball nut and having an oil supplying hole, a positioning portion disposed between the bearing ring and the ball nut, and an oil passage corresponding to the oil supplying hole. The oil supplying hole, the oil passage, an oil storage space of the positioning portion and any one of the oil guide holes cooperatively form a continuous oil path.

Abstract: A ball screw includes a load path and a non-load path defined between the screw shaft and the screw nut with the two ends of the non-load path respectively connected to the load path and a reflow channel of the return tube. The ball screw defines an imaginary horizontal plane and an imaginary sloping surface that are intersected with each other at the center axis of the screw shaft. The imaginary horizontal plane passes through the non-load path. The imaginary sloping surface passes through the junction between the non-load path and the load path. The imaginary sloping surface defines a negative included angle within 1˜3 degrees with respect to the imaginary horizontal plane to reduce the impact force rendered by each rolling member to the return tube, enhancing operational smoothness and reducing operational noise.

Abstract: Provided is a ball screw capable of reducing unevenness of load distribution of balls and extending a service life of the ball screw. In the ball screw, one end part 6 of a nut 2 on a flange 2-2 side is closer to an end 9 of a screw shaft 1 on a fixed side than the other end part 7 of the nut 2 on a side opposite the flange 2-2 is, two or more circulation paths 5a to 5c are arranged in an axial direction of the nut 2, and a diameter of a ball 3a in the circulation path 5a closest to the flange 2-2 of the nut 2 is smaller than a diameter of a ball 3c in the circulation path 5c remotest from the flange 2-2 of the nut 2.

Abstract: An aircraft undercarriage leg having an orientation control for wheels that causes a sliding rod to pivot. The orientation control has a rotating member mounted on the strut assembly having a toothed sector forming a pinion and is rotationally coupled to the sliding rod, and a rack mounted to slide on the strut assembly along a sliding axis perpendicular to the pivot axis to mesh with the pinion, the rack being moved by drive means. The drive include a rotary drive inside the rack adapted to turn about the sliding axis and to cooperate via a helicoidal coupling with the rack, The rotary drive is immobilized axially by two opposite axial thrust bearings allowing angular tilting of the rotary drive. The thrust bearings are carried by at least one elongate support inside the rack having a proximal end fixed to an end of a cylinder in which the rack slides.

Abstract: In a ball screw (1), the positioning of the deflectors to the nut is facilitated, and the deflectors are prevented from being dislodged in the radially outward direction from the nut. The ball screw (1) includes a screw shaft (3), a nut (7), a pair of deflectors (13) inserted in respective receiving holes (14) of the nut and a plurality of balls (8). The nut (7) is provided with a guide portion (42) configured to cooperate with a corresponding guide portion (41) provided on the deflector (13) so that the insertion of the deflector (13) into the respective receiving holes (14) is guided in a direction at an angle to the radial direction of the nut.

Abstract: A ball screw drive with a spindle nut (1) arranged on a screw spindle (2) and a continuous ball channel (7) formed by the screw spindle (2) and the spindle nut (1), in which channel balls arranged along a continuous ball track (8) circulate continuously, wherein the continuous ball channel (7) includes a load channel (9) wound in a spiral shape, with more than one winding, about a spindle axis (S) and a deflecting channel (10) which continuously connects the two ends of the load channel (9) to one another, wherein the spindle nut (1) has a nut part (4), on the inner circumference of which a ball groove (6) is formed being wound in a spiral shape about the spindle axis S, which ball groove, together with a ball groove (3) of the screw spindle (2) being wound in a spiral shape about the spindle axis S, forms the load channel (9), and wherein a deflecting element (5) including the deflecting channel (10) is arranged on the outer periphery of the nut part (4), and the deflecting ends (12) of the deflecting elemen

Abstract: A ball screw device includes a ball circulation part having a ball circulation path. The ball circulation part is formed by combining a first split body and a second split body. The first split body has a fixing section fixed to an outer surface of a nut member. The second split body has a pair of leg sections configured to scoop up balls moving along a ball load rolling path and return the balls to the ball load rolling path, a connecting section configured to connect the pair of leg sections and disposed between the first split body and the nut member, and a pair of shoulder sections facing side surfaces of the first split body in two directions so as to sandwich the first split body between the pair of shoulder sections.

Abstract: A ball screw with maintenance device includes a screw shaft including a helical rolling groove; a nut having an outer circumferential surface in which at least two mounting holes is formed; two recirculation elements, which are mounted to the nut and each having a through hole having an open end set in a spacing distance from the rolling groove; a fixing cover mounted to the outer circumferential surface of the nut and includes a concentration trough formed therein. The through hole has an end communicating with the concentration trough. The concentration trough is connectable to a suction tube or an oil/grease supply tube. The suction tube can remove contamination from the interior of the nut through the through hole, and the part that has been cleaned up with the suction tube can be replenished with fresh oil/grease with the oil/great supply tube to achieve complete maintenance of the ball screw.

Abstract: The invention provides an external circulation type ball screw device comprising screw shaft and nut having first and second screw grooves. A circulation member comprises first leg, second leg and connection portion. The first leg comprises a first end surface having first inner and outer points, and the second leg comprises a second end surface having second inner and outer points; first and second entrances formed on the first and second end surfaces of circulation passage; first and second thickness respectively provided between the first entrance and the first inner and outer points thereof; the second thickness being greater than the first; the third and fourth thickness respectively provided between the second entrance and the second inner and outer points thereof; the fourth thickness being greater than the third. The groove wall of the second screw groove occupied and the occurrence of broken teeth of the nut are reduced.

Abstract: Ball screws are described that may be incorporated into other devices such as a pulley assembly or a differential device. The ball screws include a threaded shaft defining a central longitudinal axis with a threaded nut threadedly coupled thereto to define at least one track in between them. Each track forms a continuous loop around an infield protrusion and is filled with a plurality of rolling elements filling. Each rolling element has the same radius from the central longitudinal axis such that the nut can rotate at higher speeds without the rolling elements locking up as a result of centripetal force.

Abstract: A motion transmission module with a cooling device is aimed at solving the disadvantage of the conventional motion transmission module that the cooling structure of the conventional motion transmission module would increase the length or outer diameter of the nut. The nut is formed with a flat surface for mounting the cooling device, so that the length of the nut won't be increased. Furthermore, the cooling device also serves as a positioning block to fix the return member, it doesn't increase the outer diameter of the nut.

Abstract: Disclosed is a ball screw module including a screw shaft, a nut member, a ball connector, and a circulating device mounted on the nut member. A helical rolling track is formed between the screw shaft and the nut member. The circulating device is in communication with the helical rolling track and has a circulating route. The circulating route includes an intermediate route, two connecting routes connecting the intermediate route, and two guiding sidewalls formed at sides of the circulating route. The guiding sidewalls guide the ball connector to twist in a clockwise direction while the ball connector entering and leaving the intermediate route and guide the ball connector to twist in a counterclockwise direction while the ball connector passing the intermediate route.

Abstract: A method forms a concave constituting a ball return passage directly on an inner circumferential surface of a nut blank by plastic working without damaging a die. Letter S shaped concaves are formed on an inner circumferential surface of a nut blank, by pressing by use of a die having a blank holder, a cam driver, cam sliders, and a cylindrical member. The cam driver has inclined surfaces having the same angle of inclination as the cam sliders. The cam sliders have letter S shaped convexes corresponding to the letter S shaped concaves, and are held by through holes, respectively. When the cam driver is pressed from the top thereof, the cam sliders move outwardly in the radial direction, respectively, and the letter S shaped convexes push the inner circumferential surface of the nut blank for plastic deformation.

Abstract: A ball screw includes a screw, a nut and a plurality of balls. The nut is slidingly disposed on the screw and includes a nut body and at least one end assembly. The end assembly includes an end circulation member, a dust-proof member and a fastening member. The fastening member and the end circulation member are disposed on the opposite sides of the dust-proof member. One side of the fastening member includes a plurality of projections, and the other side of the fastening member includes a plurality of indentations corresponding to the projections.

Abstract: The rolling element screw device includes: a screw shaft having a rolling element raceway groove; a nut member, which has a loaded rolling element raceway groove opposed to the rolling element raceway groove and is threadingly engaged with the screw shaft through intermediation of the rolling elements; and the circulation component, which includes a pair of the first circulating portions passing through a peripheral wall of the nut member, and the second circulating portion coupling the pair of first circulating portions together, to thereby form the endless circulation path for the rolling elements. Each of the first circulating portions includes a first cylindrical portion fitted into a circulation component mounting hole of the nut member, and a second cylindrical portion which has an outer diameter larger than an outer diameter of the first cylindrical portion. The first cylindrical portion includes a rolling element introducing hole.

Abstract: A ball screw assembly has a screw shaft, a nut, a plurality of balls, and two end caps. The screw shaft has a spiral rolling groove formed on an outer surface thereof. The nut has a spiral load rolling groove formed on an inner surface thereof. The screw shaft passes through the nut, and the rolling groove aligns with the load rolling groove, and the rolling groove and the load rolling groove jointly define a raceway. The balls are disposed between the rolling groove of the screw shaft and the load rolling groove of the nut. The end caps respectively arranged on two opposite sides of the nut. The screw shaft passes through the end caps, one end surface of each end cap is exposed from the nut, and each one of the end surfaces has a plurality of dust discharge outlets formed thereon.

Abstract: A ball screw device includes a screw engaged into a nut member for forming an endless ball guiding passage between the nut member and the screw and for receiving a number of ball bearing members, a ball return pipe includes a U-shaped structure having a central tubular member and two ends for engaging into two orifices of the nut member, and the nut member includes a straight fence formed between the orifice and the screw hole of the nut member for guiding the ball bearing members to move through a ball return pathway of the ball return pipe and the endless ball guiding passage of the nut member and for preventing the teeth of the nut member from being broken by the ball bearing members.

Abstract: A return passage that connects two points of a rolling passage to allow each ball that rolls in the rolling passage to endlessly circulate is formed in a ball screw nut by attaching a circulation member to fitting holes. A protrusion is formed on an outer surface of the circulation member at a position offset from a raceway of the balls that circulate in the return passage. The circulation member is fixed to the ball screw nut when the protrusion contacts an inner periphery of an inner ring of a second bearing.

Abstract: Ball screws are described that may be incorporated into other devices such as a pulley assembly or a differential device. The ball screws include a threaded shaft defining a central longitudinal axis with a threaded nut threadedly coupled thereto to define at least one track in between them. Each track forms a continuous loop around an infield protrusion and is filled with a plurality of rolling elements filling. Each rolling element has the same radius from the central longitudinal axis such that the nut can rotate at higher speeds without the rolling elements locking up as a result of centripetal force.

Abstract: A ball screw has a chain received in a circulation path of the ball screw, and the chain comprises a plurality of partition portions and a connecting portion for connecting the partition portions, a plurality of rolling elements are retained in the chain in such a manner that between each two neighboring partition portions is arranged a rolling element, each of the rolling elements is partially in contact with the return passage of each of the return assemblies to define receiving spaces in the return passage for accommodation of the connecting portion, so that the chain can be moved more smoothly in the return passage, and the manufacturing cost of the return assembly is reduced.

Abstract: A ball screw with a circulating assembly is disclosed. The circulating assembly of the ball screw is divided into a first circulating block and a second circulating block and can be assembled on the ball screw in such a method that the first and the second circulating blocks are assembled separately, so that the circulating assembly is applicable to the screw shaft whose helical groove doesn't extend to the shoulder portion thereof. In addition, the circulating assembly is limited in terms of an angle, and the relation between the first circulating block and the second circulating block is especially limited, so that the ball screw is applicable to the nuts with smaller outer diameter. Hence, the ball screw can be applied to both the nuts with smaller diameter and the screw shafts whose helical groove doesn't extend to the shoulder portion thereof.

Abstract: A ball screw comprises a screw, a nut, two return assemblies and a rolling assembly. The two return assemblies are disposed in two ends of the nut, and each of the return assemblies is defined with a return passage provided with two guiding grooves at two sides thereof for guiding the linking portions of the rolling assembly. The guiding grooves twist an angle of about 90 degrees within the return portion of each of the return assemblies to prevent the linking portions from being stretched or extruded improperly to reduce the deformation to the lowest, thus effectively extending the service life of the rolling assembly.

Abstract: A motion guide device includes a ball nut attached onto a shaft and having helical grooves for receiving ball bearing elements, a ball circulating member is engaged with the ball nut and includes a ball circulating channel communicative with the helical groove of the ball nut, and includes an intermediate segment and two end segments, a ball coupler includes two flexible coupling members for engaging with the ball bearing elements, and the ball circulating member includes two opposite helical guide pathways for receiving the flexible coupling members of the ball coupler, and curved relative to the ball circulating member for smoothly guiding the flexible coupling members to move through the ball circulating member.

Abstract: A circulating element for ball screw includes a first surface defining a circulating passage that extends from one lateral side of the first surface to the other lateral side of the first surface and has a coupling mouth located on each of the two opposite ends thereof, and a second surface defining a coupling groove between the two coupling mouths of the circulating passage and two guide blocks respectively protruding out of the coupling mouths of the circulating passage. Thus, the circulating element has the advantages of low processing cost, ease of installation, high alignment accuracy, and excellent running smoothness.

Abstract: A linear motion assembly includes a screw having a helical external groove extending over a plurality of turns with a radially outwardly extending helical land formed between adjacent turns and a ball nut having a through bore configured for receipt of the screw. The ball nut has a helical internal groove extending over a plurality of turns with a radially inwardly extending helical land formed between adjacent turns. The helical land of the ball nut is radially aligned with the external groove of the screw and the helical land of the screw is radially aligned with the internal groove of the ball nut. At least one helical recirculation insert having a circuitous recirculation groove is configured in radial alignment with the radially inwardly extending helical land of the ball nut and the external groove of the screw, wherein a plurality of balls are received in the circuitous recirculation groove.

Abstract: A ball screw device for reducing damage to a circulating part even during a high speed operation is provided. To this end, the circulating part includes a pair of legs having a tang to scoop up a ball in a direction substantially match with a tangential direction of a spiral path, and a body to connect the pair of legs, wherein a center path diameter Rb of the ball, an internal diameter Rn of the nut, and an internal diameter Rt opposite to the tang satisfy a relationship of Rb ?Rt?Rn.

Abstract: A ball screw device includes a screw engaged into a nut member for forming an endless ball guiding passage and for receiving bearing members, the nut member includes a thickness reduced barrel for forming a peripheral surface in the nut member, a tubular member is engaged onto the barrel of the nut member, a number of bearing elements are engaged onto the nut member and the tubular member, a sleeve is engaged onto the nut member and includes an inner peripheral protrusion having two curved side surfaces for engaging with the bearing elements and for solidly and stably anchoring and retaining the bearing elements between the sleeve and the tubular member and the nut member.

Abstract: A ball screw nut of a ball screw device is fastened to a motor shaft by engaging a male thread portion thereof with a female thread portion of the motor shaft. In a case where, in a movement pathway for balls, an area where the balls roll under load from a rack shaft and the ball screw nut is set as a load area, an area that does not receive the load is set as a no-load area, and areas for transition from the load area to the no-load area are set as transition areas, the male thread portion is formed such that the transition area on the nut-side joint portion-side closest to a seating surface does not overlap phase ranges of cut portions in a state where the ball screw nut is fastened to the motor shaft.

Abstract: A motion transmission module with a cooling device is aimed at solving the disadvantage of the conventional motion transmission module that the cooling structure of the conventional motion transmission module would increase the length or outer diameter of the nut. The nut is formed with a flat surface for mounting the cooling device, so that the length of the nut won't be increased. Furthermore, the cooling device also serves as a positioning block to fix the return member, it doesn't increase the outer diameter of the nut.

Abstract: A spindle nut for a ball screw with a nut part on whose inner periphery there is a spiral ball groove that winds around a spindle axis for the rolling of balls and with two deflection elements, the balls are deflectable into the curved deflection channel of each deflection element and the nut part has two recesses that are spaced apart from each other in the axial direction and one of the deflection elements is arranged in each recess. The nut part is provided with a straight return channel for the balls, and the straight return channel is connected to the two deflection channels. The balls are movable along a ball track in the curved deflection channel and in the straight return channel, and the straight return channel is arranged within a wall thickness of the spindle nut and is arranged at an angle relative to the spindle axis.

Abstract: A ball screw device for reducing damage to a circulating part even during a high speed operation is provided. To this end, the circulating part includes a pair of legs having a tang to scoop up a ball in a direction substantially match with a tangential direction of a spiral path, and a body to connect the pair of legs, wherein a center path diameter Rb of the ball, an internal diameter Rn of the nut, and an internal diameter Rt opposite to the tang satisfy a relationship of Rb?Rt?Rn.

Abstract: Ball screw comprising a ball nut (1), which is rotatably mounted on a threaded shaft and on the inner circumference of which at least one ball thread (2) wound around an axis (8) in a coil shape is provided for balls (3) to roll on, wherein at least one recirculating element (5), which is arranged on the outer circumference of the ball nut (1) and which is provided with a recirculating channel for the balls (3), connects a start of a coil to an end of a coil of the ball thread by means of the two ends of the recirculating element in order to enable endless recirculation of the balls (3), wherein the ball nut (1) is provided with a flange (6) for fastening a belt pulley (15) and with a bearing seat (9), and a sleeve (12) pushed onto the ball nut is provided with a perfectly cylindrical outer circumferential surface, which outer circumferential surface secures the recirculating element (5) on the ball nut (1) and surrounds the ball nut (1) in a tubular shape between the flange (6) and the bearing seat (9).

Abstract: A ball screw device even with a small lead angle and a small number of circulation rolls, includes a rotational part, which keeps unequal division of tongue portions and legs connected to the tongue portions to a minimum and ensures the strength of the tongue portions. A recirculating part of the ball screw device includes a pair of legs, each having a tongue portion for scooping up balls in a direction approximately tangential to a spiral raceway, and a main body connecting the pair of legs. First divided faces for dividing the pair of legs along a ball recirculating path, and a second divided face for dividing the main body along the ball recirculating path are also included. The second divided face is formed by an upper divided face and a lower divided face of the ball recirculating path so that the upper divided face and the lower divided face intersect with each other when viewed from a flat surface of the nut.

Abstract: A deflector for use in a ball screw is composed of a main body and a junction member connected with the main body to form a channel having a first guide groove and two second guide grooves formed at two opposite sides of the first guide groove. Each of the second guide grooves has two walls extending outward from the first guide groove. Each two of the walls have a conjunction formed therebetween. The vertical section of the channel can define an extending axis passing through centers of the two conjunctions. At least one of the walls of each second guide groove is not parallel to the extending axis. In light of the above features, the roller chain can avoid wear and tear to prolong its service life thereof. Besides, the mold for forming the deflector can be designed to be structurally subject to mold release, such that the production efficiency can be increased.

Abstract: In a ball screw apparatus according to the present invention, a ball guide path 19 for guiding a ball 15 scooped up in a tangential direction of a ball center track circle to a ball return path 17 is formed between a ball guide face 182 of a ball circulating member 18 and a ball guide path forming face 20 that is provided at a nut 12. Accordingly, it is possible to provide a ball screw apparatus capable of scooping up a ball in a tangential direction of a ball center track circle to circulate without reducing a diameter of the ball even when a groove interval of a ball screw groove is narrow or when the ball screw groove is a multistreak screw groove.

Abstract: The ball screw apparatus includes a returning way L2 by mounting a circulating member 15 in mounted holes 16, 17 formed in the ball screw nut 13. The ball screw nut 13 includes a base portion 51 and an expanding portion 52. In the base portion 50 a distance from an axis center O1 of the rack shaft 3 to a bottom portion 14a of the nut side screw groove 14 is constant, and in the expanding portion 52 the distance is larger than that of the base portion 51. The expanding portion 52 includes a connecting area 34.

Abstract: A ball screw assembly having a bearing ball recirculation arrangement. The ball screw assembly includes a ball screw, a nut, and at least one set of two return plugs and at least one cap. The nut body is in threaded engagement with the ball screw, wherein one of the ball screw and the nut body is rotationally fixed relative the other. Each plug may be seated into a cavity on an outer surface of the nut body. The cap may have a recessed channel at least partially defining a return path for bearing balls from one end of a load bearing path to another end of a load bearing path.

Abstract: A method forms ball recirculation and rolling grooves at an inner circumferential surface of a nut for ball screw use in a state free of deviation in axial, circumferential, and radial nut directions. A flange end face is formed with a concave part, then an inner circumferential surface of a blank and an end face and outer circumferential surface of the flange are continuously ground. Due to this, the coaxiality of the blank inner circumferential surface and the flange outer circumferential surface, and the perpendicularity of the flange end face to the blank inner circumferential surface, are made smaller. The blank is plastically worked to form the ball recirculation groove and is cut to form the ball rolling groove while using the concave part as a phase reference, the end face as an axial direction reference, and the outer circumferential surface as a radial direction reference.

Abstract: The rolling element screw device includes: a screw shaft having a rolling element raceway groove; a nut member, which has a loaded rolling element raceway groove opposed to the rolling element raceway groove and is threadingly engaged with the screw shaft through intermediation of the rolling elements; and the circulation component, which includes a pair of the first circulating portions passing through a peripheral wall of the nut member, and the second circulating portion coupling the pair of first circulating portions together, to thereby form the endless circulation path for the rolling elements. Each of the first circulating portions includes a first cylindrical portion fitted into a circulation component mounting hole of the nut member, and a second cylindrical portion which has an outer diameter larger than an outer diameter of the first cylindrical portion. The first cylindrical portion includes a rolling element introducing hole.

Abstract: An internal circulation ball screw includes a threaded shaft, a nut having a receiving space, a circulation member mounted to the receiving space and having a first circulation groove and a second circulation groove, and a plurality of rolling members running between the threaded shaft and the nut. The first circulation groove defines a first front section, a first rear section, and a first curved section communicating with the first front section and the first rear section separately. The second circulation groove defines a second front section, a second rear section, and a second curved section communicating with the second front section and the second rear section separately. The first and second curved sections define a predetermined included angle with respect to the threaded shaft radially. Therefore, the wall between the circulation channels is uniform to enhance the durability of the ball screw.

Abstract: A motion transmission module with a cooling device is aimed at solving the disadvantage of the conventional motion transmission module that the cooling structure of the conventional motion transmission module would increase the length or outer diameter of the nut. The nut is formed with a flat surface for mounting the cooling device, so that the length of the nut won't be increased. Furthermore, the cooling device also serves as a positioning block to fix the return member, it doesn't increase the outer diameter of the nut.

Abstract: A method forms a concave constituting a ball return passage directly on an inner circumferential surface of a nut blank by plastic working without damaging a die. Letter S shaped concaves are formed on an inner circumferential surface of a nut blank, by pressing by use of a die having a blank holder, a cam driver, cam sliders, and a cylindrical member. The cam driver has inclined surfaces having the same angle of inclination as the cam sliders. The cam sliders have letter S shaped convexes corresponding to the letter S shaped concaves, and are held by through holes, respectively. When the cam driver is pressed from the top thereof, the cam sliders move outwardly in the radial direction, respectively, and the letter S shaped convexes push the inner circumferential surface of the nut blank for plastic deformation.

Abstract: A ball screw is provided in which an outer circumferential formation is formed at a portion facing a ball circulating passage out of outer circumferential surface of a nut. The ball screw includes: a screw shaft having on its outer circumferential surface a screw groove; a nut having on its inner circumferential surface a screw groove facing the screw groove; a plurality of balls rollably loaded in a spiral ball rolling passage formed by both screw grooves; and a ball circulating passage to return the balls from a start point to an end point of the ball rolling passage for recirculation. The ball circulating passage is a concaved groove formed by concaving a groove on a part of the cylindrical inner circumferential surface of the nut by plastic working. Then, a flange is integrally provided at a portion facing the ball circulating passage and the screw groove.