Abstract: The ball screw device includes: a screw shaft having an N number (N is an integer equal to or larger than 2) of rolling grooves having the same lead; balls configured to roll in the rolling grooves; and a nut member, which is assembled to the screw shaft through intermediation of the balls, and includes one or a plurality of endless circulation paths configured to circulate the balls around the screw shaft. Each of the endless circulation paths of the nut member includes: an N number of load portions, which are configured to allow the balls to roll thereon while bearing a load, and correspond to the N number of rolling grooves, respectively; and an N number of no-load portions, which each couple adjacent ones of the load portions, and are configured to allow the balls to move between the N number of rolling grooves.

Abstract: A ball returning circulator of a ball screw having a nut, a screw and a plurality of balls and a circulation device assembled in a ball rolling duct defined by a nut and a screw are provided. The ball returning circulator includes: at least one ball access port, each of the at least one ball access port at one end of the circulator for releasing balls to come into or out from the circulator; and at least one curved section having at least one opening distanced from the ball access port and at least one cover plate for closing the at least one opening.

Abstract: A ball screw device is provided for which quality can be easily evaluated. The ball screw device includes a threaded shaft with a groove formed on an outer peripheral surface of the shaft, and a cylindrical nut whose screw-thread mates with the groove on the threaded shaft via a plurality of balls. The nut has a pair of mounting holes in each of which a deflector is installed and a communication groove that allows the mounting holes to communicate with each other and is open on the outer peripheral surface of the nut and through which the balls can roll. The width W of an opening of the communication groove is smaller than the diameter of the ball.

Abstract: A linear motion guide device includes a movable member attached onto an elongated member for forming an endless multiple-turn, helical raceway between the elongated member and the movable member and for receiving ball bearing members, and a detecting device includes a magnetic member and an integrated circuit disposed in the movable member and arranged close to the endless multiple-turn, helical raceway for detecting a moving frequency or a movement of the ball bearing members through the endless multiple-turn, helical raceway of the linear motion guide device and for detecting a wear or failure of the ball bearing members and for generating a warning signal.

Abstract: A ball screw device includes a screw engaged into two nut members for forming a ball guiding passage between the nut members and the screw member and for receiving and engaging with bearing members, and a load applying device is disposed on the screw member and disposed between the nut members and applies a load onto the nut members in order to force and move the nut members away from each other and so as to apply a force onto the ball bearing members and in order to stably anchor and retain the ball bearing members between the nut members and the screw member and in order to facilitate a movement between the nut members and the screw member.

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 ball screw device has a plurality of spiral raceways. One end and the other end of each raceway is connected via a bridge. An annular flange of a ball nut has a plurality of mounting portions at equal intervals in a circumferential direction. A fixing screw is fitted to each mounting portion. The bridges arranged so as to overlap with the annular flange in position in an axial direction are arranged at positions different in the circumferential direction from positions at which the mounting portions are arranged, and are arranged at unequal intervals in the circumferential direction.

Abstract: A motion guide device includes a ball nut attached onto a shaft and having helical grooves for forming a ball guiding raceway between the ball nut and the elongated shaft and for receiving ball bearing elements, a circulating device attached to the ball nut and having a pathway communicative with the raceway for forming an endless ball guiding passage between the ball nut and the elongated shaft and the circulating device and for engaging with bearing elements, and a retaining device includes a shorter chain for engaging into the helical grooves or raceway of the screw shaft and the ball nut, and a longer chain for engaging into the pathway of the circulating device.

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: 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 includes a screw shaft formed with two helical raceways that have the same lead and the same thread angle, a ball nut rotatably sleeved on the screw shaft and formed with two ball grooves that correspond to and complement with the helical raceways, a scraper has two contact parts to contact the two helical raceways, a plurality of bearing balls rollably and selectively disposable between one of the ball grooves and the corresponding helical raceway, and a return unit including two return tubes each having two ends respectively and spatially connected to two ends of the corresponding ball groove.

Abstract: A ball return channel of a ball screw is formed within a nut and a ring-shaped non-contact seal is arranged at the axial both ends of the nut. A suction hole radially penetrating the nut is formed within the range of a raceway (a rolling channel formed by a spiral groove of the nut and a spiral groove of the screw shaft). This guarantees not to emit dust produced inside the nut, and attains dust reduction effect higher than that of the conventional ball screw.

Abstract: An electrically driven linear actuator with a smooth motion of a ball screw provides an even load distribution as well as a stable motion of the balls and has an electric motor (5) mounted on a housing (4). A nut (8 or 16), adapted to mate with the screw shaft (7), has a pair of supporting portions (14) at an axially central position on the outer circumferential surface of the nut (8 or 16) to engage one end of a link (2). The nut (8, 16) is formed with a screw groove (8a). Oval bridge windows (10) are formed in the nut (8 or 16) through a wall with a portion of the screw groove (8a) cut out over a distance of at least two pitches of the screw grooves (8a). A bridge member (11), forming the circulating member, is fitted in each of the bridge windows (10).

Abstract: A ball screw device includes a screw engaged into a nut member for forming an endless ball guiding passage and for receiving a number of ball bearing members, a ball return device includes a U-shaped structure having a central carrying member and a protrusion extended out from each end for engaging into the nut member and for increasing the curvature of the ball return pathway of the ball return device, and a return device holder engaged with the protrusions of the ball return device for retaining the ball return device to the nut member and for preventing the ball return device from moving laterally relative to the nut member and for suitably guiding the ball bearing members to smoothly move through the endless ball guiding passages of the ball screw device.

Abstract: A linear actuator includes a ball screw, the ball screw configured to rotate; a nut engaged with the ball screw, the nut configured to translate linearly in response to the rotation of the ball screw; and a ball bearing spline integrated into the nut, the ball bearing spline comprising a plurality of ball bearings, wherein the ball bearing spline is configured to react a torque from the rotation of the ball screw. A ball bearing spline is integrated into a translating nut of a linear actuator, the ball bearing spline comprising a plurality of ball bearings, wherein the ball bearing spline is configured to react a torque from a rotation of a ball screw engaged with the translating nut.

Abstract: An assembly apparatus for assembling a ball screw device includes a support block, a nut arranged in a longitudinal direction, a nut reception base that arranges the nut so that its axial direction towards vertical direction of the assembly apparatus and that supports the nut so as to elevate the nut with respect to the support block, a temporary shaft inserted into an inner diameter side of the nut arranged on the nut reception base and rotatably supported by the support block, an inclined face provided at a forward end portion of the temporary shaft, for guiding balls into the nut raceway groove and a pushing mechanism that has elasticity in the radial direction of the temporary shaft and that pushes balls which are fed into the nut raceway groove by a forward end portion protruding from the outer circumferential face of the temporary shaft.

Abstract: Provided is a rolling-element screw device in which a recess can be easily formed in an outer diameter portion of a nut main body for receiving a circulation member. At both ends of a straight passage 5 of the nut main body 2, a pair of circulation members 8 is provided respectively, in each of which a direction change passage 6 is formed for connecting the straight passage 5 to a loaded rolling-element rolling passage 3. The circulation members 8 in a pair are fit in a pair of recesses 15, respectively, formed in the outer diameter portion of the nut main body 2. The direction change passage 6 of each circulation member 8 has a curve passage 22 which is connected to the loaded rolling-element rolling passage 3. The curve passage 22 is formed in such a way that, when seen in the axial direction of the nut main body 2, the track of the center of each rolling element 7 moving in the curve passage takes the shape of an arc.

Abstract: There is provided a new rolling body screw device manufactured with cheap cost without degrading quality in comparison with a conventional device even for a device having any large dimension in an end-cap type rolling body screw device. The rolling body screw device includes the direction changing passages 42 each including: a scoop-up portion 43 scooping a ball rolling in a loaded rolling body passage as a loaded area of the endless track so as to hand over the balls to the direction changing passage 42 as a non-loaded area of the endless track; and a route path 44 forming a circulation path of the ball scooped by the scoop-up portion. Each of the return pieces is composed, in combination, of a metal part 41a formed of a metal material including the scoop-up portion 43, and non-metal parts 41b, 41c formed of a non-metal material including the route path 44.

Abstract: A ball screw device includes a screw engaged into a nut member for forming an endless ball guiding passage and for receiving a number of ball bearing members, a ball return device includes a U-shaped structure having a central carrying member and a protrusion extended out from each end for engaging into the nut member and for increasing the curvature of the ball return pathway of the ball return device, and a return device holder engaged with the protrusions of the ball return device for retaining the ball return device to the nut member and for preventing the ball return device from moving laterally relative to the nut member and for suitably guiding the ball bearing members to smoothly move through the endless ball guiding passages of the ball screw device.

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 tubular member is engaged with the ball nut and includes a ball circulating pathway communicative with the helical groove of the ball nut, and includes an intermediate segment, two curved segments, and two end coupling segments each having a ball guiding channel which includes a wider inner section for guiding and circulating the flexible coupling member of a ball coupler to smoothly move through the ball guiding channel of each end coupling segment and for preventing the flexible coupling member from being twisted. The tubular member is preferably formed by two half members.

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 lead screw device including a lead screw shaft extending along a longitudinal axis having a lead screw thread portion, and a coupling structure at a proximal end of the lead screw shaft. The coupling structure can have a male securement thread and a female securement thread positioned along the longitudinal axis. The female securement thread can extend within the coupling structure at the proximal end of the lead screw shaft. The coupling structure can provide opposed axial threaded securement to a rotatable shaft along the longitudinal axis from opposing axial directions.

Abstract: A ball screw device includes a screw shaft threaded with a ball nut which has two channels and an opening, a guide member is engaged into the opening of the ball nut and has two curved pathways communicating with the channels to form two separated endless ball rolling passages in the ball nut, and two groups of bearing members are engaged in the two separated endless ball rolling passages for facilitating a movement of the ball nut relative to the screw shaft. The guide member includes two bars for enclosing the curved pathways of the guide member, and the bars each have a curved recess for forming the curved pathways of the guide member and for allowing the guide member to be easily manufactured.

Abstract: An external circulation type ball screw comprises a screw, a nut, rolling elements and a return member. The nut is a hollow structure mounted on the screw. The rolling elements are received in the helical groove of the screw and the rolling groove of the nut. The return member is disposed on the nut and includes a guiding member and a cover. The guiding member is defined with two guiding portions and a first half pipe, and each guiding portion is fixed in the fixing hole of the nut. The cover includes a fixing portion for covering the guiding portion and a second half pipe for covering the first half pipe. The return member is installed in the fixing hole through the guiding portion, and then the cover is used to cover the guiding member, thus finishing the assembly of the return member. In addition, the return device can be produced by molding process, and it solves the problem that the conventional return device is difficult to assemble.

Abstract: A ball screw device includes a screw shaft threaded with a ball nut which has two channels and an opening, a guide member is engaged into the opening of the ball nut and has two curved pathways communicating with the channels to form two separated endless ball rolling passages in the ball nut, and two groups of bearing members are engaged in the two separated endless ball rolling passages for facilitating a movement of the ball nut relative to the screw shaft. The guide member includes two bars for enclosing the curved pathways of the guide member, and the bars each has a curved recess for forming the curved pathways of the guide member and for allowing the guide member to be easily manufactured.

Abstract: A ball screw drive comprising a spindle nut (2) that can be disposed on a spindle (1), said spindle nut (2) comprising on an inner periphery, a ball groove (3) that is arranged along a helix and defines a load-bearing channel (8) for balls (5), an external deflector (6, 24) arranged outside of the spindle nut (2) connecting the two ends of the load-bearing channel (8) endlessly to each other for deflecting the balls (5) from one of the two ends of the load-bearing channel (8) to the other of the two ends of the load-bearing channel (8), a drive pinion for driving the spindle nut (2) being arranged on the spindle nut (2), wherein the external deflector (6, 24) is arranged at least substantially within an axial length of the drive pinion.

Abstract: A first ball circulating hole and a second ball circulating hole for connecting a circulator are bored midway at a screw groove formed on an inner circumference of a ball nut, an intermediate groove path between the first and second ball circulating holes becomes the range of a ball screw track for circulating balls, and other ranges become a first outer track and a second outer track which are not the ball screw track. By making the groove depth of the intermediate groove path deeper than the groove depth of a first groove path of the first outer track and the groove depth of a second groove path of the second outer track, steps are formed between the ball screw track and the two outer tracks. These steps prevent an outflow of the balls from the intermediate groove path to the respective groove paths of the outer tracks.

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: A ball screw device includes a ball nut having an inner thread formed by a number of helical groove portions, a screw shaft having an outer thread formed by a number of helical groove portions, for threading with the inner thread of the ball nut, and a number of rolling members engaged in the helical groove portions of the ball nut and the screw shaft, for facilitating a movement of the ball nut relative to the screw shaft. One or more guide members are engaged in the helical groove portions of the screw shaft, and each has an oil retaining member for suitably absorbing oil and for continuously applying the oil onto the screw shaft. A tube may couple two of the helical groove portions of the ball nut together, to form an endless ball rolling passage and to receive the rolling members.

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: In a ball screw, a nut is fitted with the outer periphery of a screw shaft, ball rolling grooves opposed to each other are formed in the screw shaft and the nut The ball rolling grooves cooperate in forming a ball rolling path therebetween. A tube as a return path disposed on the nut for connecting one end portion of the ball rolling path to the other end portion thereof, the ball rolling path and tube cooperate in forming an endless circulation path. A plurality of load balls are disposed within the endless circulation path. The position of the tube cannot be limited to a single specific position. In the ball screw, retaining pieces are respectively inserted between the mutually adjacent ones of the load balls disposed within the endless circulation path.

Abstract: An internal recirculating ball screw and nut system that is easier to manufacture and more reliant by virtue of a particular configuration of the grooves on the interior of the nut or the follower. Crossback portions of select nut grooves are arranged in a manner that allows the bearing balls to recirculate by slipping over the top of adjacent thread lands of the screw, advancing and recirculating within a single 360 degree rotation within said nut. Said recirculation is accomplished solely through the design of the path of a unitary nut, without use of any ancillary devices.

Abstract: In an actuator device which comprises a screw shaft, a nut member, and balls, the nut member moves relatively to the screw shaft in a first axial direction and a second axial direction opposite thereto in a manner such that it is continually subjected to a load in the first axial direction. A ball screw groove of the screw shaft is formed having a loaded surface which is pressed against the balls, on the side of a groove base in the first axial direction. A ball screw groove of the nut member is having a loaded surface which is pressed against the balls, on the side of its groove base in the second axial direction. These loaded surfaces are finished so that their surface roughness is lower than that of the unloaded surfaces.

Abstract: A ball screw device comprises a screw shaft, a nut externally mounted on the screw shaft, and a multiplicity of balls interposed between thread grooves of the screw shaft and the nut. The screw shaft has a ball circulation groove for coupling downstream and upstream sides of the thread groove so that the balls are returned from the downstream side to the upstream side and thereby circulated in the thread groove of the screw shaft. The ball circulation groove has such a curved shape as to sink radially inward in an intermediate region in a rolling direction of the balls and has a curved shape protruding radially outward in both end regions, and is configured in the manner that the centrodes of the balls rolling in the both end regions and the balls rolling in the thread groove of the screw shaft satisfy predetermined conditions with respect to circulation of the balls.

Abstract: A ball nut and return liner assembly includes a ball nut having a tubular body having a longitudinal axis, the tubular body having an inner surface and an outer surface, a plurality of arcuate grooves defined on the inner surface. A longitudinal slot is defined on the inner surface parallel to the longitudinal axis, interrupting the plurality of arcuate grooves, and forming a pocket for receiving the return liner, the longitudinal slot having first curved walls. The return liner is provided with a first surface having a plurality of S-shaped return grooves extending from the first side to the second side to cooperate with the plurality of arcuate grooves in the ball nut. The return liner is further provided with a second surface for fitting within the longitudinal slot within the ball nut, the second surface having second curved walls.

Abstract: A ball screw apparatus has: a screw shaft including a screw groove; a nut movably fitted with the screw shaft and including a screw groove; a large number of balls rollably disposed in a loaded raceway; and a side cap mounted on the outer peripheral portion of the nut and including a ball circulation passage for scooping up the balls rolling along the loaded raceway in a direction coincident with the lead angle of the two screw grooves and returning the balls to the loaded raceway, wherein, the two screw grooves are respectively formed as multiple thread screws and the side cap is disposed on each of the multiple threads.

Abstract: A portion of a steering shaft 2 capable of being advanced and retracted defines a ball screw shaft 2a of a ball screw mechanism 13. A motor rotor 10 of an electrically driven motor 8 for providing a steering assist force is externally mounted on a rotary nut 14. Mounting of the motor rotor 10 onto the rotary nut 14 is carried out so that the both can be adjustably aligned. By way of example, the rotary nut 14 has an outer peripheral surface formed with an annular protrusion 33 of a arcuate longitudinal sectional shape, having a surface thereof formed with a plurality of axially extending surface indentations 33a arranged side by side in a direction circumferentially of the rotary nut 14.

Abstract: A ball-nut assembly includes a ball nut and a crossover member. The ball nut incudes a radial through slot and an outer surface. The outer surface has a first portion, has a ledge radially recessed from the first portion and at least partially bounding the through slot, and has an undercut wall connecting the ledge and the first portion. The crossover member has a flange and a crossover-grooved portion. A method for making a ball-nut assembly positions the crossover member from outside the ball nut to have the flange supported by the ledge and the crossover-grooved portion located in the through slot. The method also deforms the flange creating a staked portion of the flange which contacts the undercut wall of the outer surface of the ball nut.

Abstract: A fail-safe ball screw assembly has a double-start screw and a corresponding nut. The screw has a first helix with a truncated, smaller diameter flat and an intertwined second helix with an extended, larger diameter flat. Similarly, the corresponding nut has a first helix with an extended, larger diameter flat and an intertwined second helix with a truncated, smaller diameter flat. When the screw is inserted with the nut, the screw's truncated first helix is paired with the nut's extended first helix, and the screw's extended second helix is paired with the nut's truncated second helix. The nut and screw helixes combine to form channels in which bearings balls travel. The bearings allow the fail-safe ball screw assembly to operate with high efficiency and precision, while the overlapping structure of the helixes prevents catastrophic failure caused by the removal or loss of the bearing balls.

Abstract: In a roller screw, a plurality of rollers 16 interposed between a nut member 14 and a screw shaft 12 are composed of a forward-motion load roller group 17, the rollers 16 of which are arranged in such a manner that the center lines thereof are set at a given angle &agr; with respect to the center line of the screw shaft 12, and backward-motion load roller group 18, the rollers 16 of which are arranged in such a manner that the center lines thereof are set at an angle &bgr;, which is different from the angle &agr;, with respect to the center line of the screw shaft 12; and, the forward-motion load roller group 17 and backward-motion load roller group 18 are disposed such that they are separated from each other.

Abstract: A linear actuator comprises a ball screw carrying an axially restrained rotatable ball nut driven by an electrically energized motor. An enclosing motor housing has front and rear walls with axially aligned openings for passing the ball screw. The motor has a radially inner hollow stator assembly and a generally concentric radially outer rotor assembly. A can member is integrated with the rotor assembly to rotate therewith and has a radial end wall connected to the nut.

Abstract: A ball screw (20) includes a bridge member (24) fitted to a rotary nut (22) and provided with a plurality of connecting grooves (28). Each connecting groove (28) connects neighboring convolutions of an inner spiral groove (26) of the rotary nut (22). The ball screw (20) is used as a mechanism for transmitting rotation of a rotor (10) of a motor (8) to a steering shaft (2)in an electrically powered steering device.

Abstract: A ball screw mechanism (20) compact in size, employing a minimized number of component parts and having a high load capacity includes a rotary nut (22) having an internally threaded helical groove (26) and a mounting hole (30) both defined therein, and a simplified bridge member (24) mounted in the rotary nut (22). The bridge member (24) has a plurality of connecting grooves (28) defined on an inner surface thereof each operable to communicate neighboring convolutions of the internally threaded helical groove (26). The bridge member (24) has its opposite side edges formed with respective guide walls (36) protruding in a direction radially outwardly of the rotary nut (22) that are crimped to allow the bridge member (24) to be fixedly retained within the mounting hole (30).

Abstract: In a ball screw according to the present invention, four circulation passages forming a circulation route are respectively arranged in the axial direction of the ball screw. The mounting positions of the second and third circulation passages A2 and A3 are set at positions which are reversed 180 degrees in the circumferential direction thereof with respect to the mounting positions of the first and fourth circulation passages A1 and A4. Accordingly, it is possible to provide a ball screw which can reduce variations in a load distribution along the axial direction of the ball screw caused by moments around a surface perpendicular to the axis of the ball screw that are generated by shifting circumferential-direction phases between circulation passages forming a circulation route from one another.

Abstract: A lubricant supply device comprises application members, a casing and control members. The casing forms a lubricant storage member, which is divided into compartments arranged in the circumferential direction of the lubricant storage member. The number of the compartments is equal to or larger than the number of thread grooves of the screw shaft. The application members are placed in correspondence to the compartments. Each of the application members has the single tongue portion.