Abstract: A ball screw assembly for use in an actuator is provided. The ball to screw assembly may include a ball screw supported for rotation by the actuator. A ball nut may be provided around the ball screw and may be held against rotation with the ball screw by said actuator. A primary load path may be provided between the ball screw and the ball nut for operatively coupling the ball nut with the ball screw. A secondary load path may be provided between the ball screw and the ball nut, wherein the secondary load path can be disengaged during a normal operating mode of the ball screw assembly and the secondary load path can be engaged during a second operating mode of the ball screw assembly.

Abstract: Steering actuators for vehicles are described herein. An example actuator includes a rack to be coupled to a knuckle of a vehicle, a ball nut coupled to the rack, a ring gear coupled to the ball nut, and a motor with a pinion engaged with the ring gear. The motor is to rotate the ball nut, via the pinion and the ring gear, to move the rack linearly.

Abstract: An apparatus for preloading a bearing assembly on a shaft includes a first annular threaded member positioned about the shaft and a second annular threaded member positioned about the shaft. The first and second threaded members have intermeshing threads such that rotation of the second threaded member causes axial translation of the first threaded member to apply a first axial force to the bearing assembly to preload the bearing assembly. An actuator is operable to rotate the second threaded member relative to the first threaded member to apply the first axial force to the bearing assembly.

Abstract: A torque monitoring device for a fastener is provided. The torque monitoring device includes a sensing element mounted within the fastener. The sensing element measures a value of fastener elongation. The torque monitoring device also includes a receiving element coupled to a torque machine. The receiving element is communicably coupled with the sensing element. The receiving element is configured to receive the value of fastener elongation from the sensing element. The receiving element is also configured to generate an alert for terminating a torque operation being performed by the torque machine when the value of fastener elongation exceeds a pre-set value of fastener elongation.

Abstract: An actuator having a planetary screw drive (PSD), in particular for the operation of a clutch of a motor vehicle, wherein a plurality of planetary rollers which mesh with a ring gear that encircles the planetary rollers are in contact with a spindle, where the planetary rollers are positioned at both ends in a planetary roller carrier and the planet carriers are supported non-rotatingly in a sleeve that encircles the ring gear and points radially inward at both ends, wherein the sleeve and the planetary carriers supported in it are axially fixed and connected non-rotatingly to a rotor of a drive and are drivable around an axis of rotation, the spindle is supported non-rotatingly and the spindle performs an axial stroke when the rotor and the planetary carriers supported in the sleeve rotate, is provided.

Abstract: An actuator with a planetary screw drive (PSD), in particular to operate a clutch of a vehicle, wherein a centric spindle having a pitch is connected non-rotatingly to a rotor of a drive and is drivable by the drive around an axis of rotation, and a plurality of planetary rollers are engaged with the spindle and mesh with a ring gear encircling the planetary rollers which has grooves in the circumferential direction, wherein both ends of the planetary rollers are positioned in a planetary roller carrier. The planetary roller carriers are supported non-rotatingly on both ends in such a way that a fixed assignment of the pitch of the spindle to an axial travel of a component that is movable axially by the PSD, which is operatively connected to an axially actuatable piston, is realized.

Abstract: A roller screw mechanism comprising a screw having an outer threading; a nut arranged around and coaxially to the screw, the nut having an inner threading; and a plurality of mutually identical rollers interposed between the screw and the nut. Each mutually identical roller having an outer threading engaged with the outer and inner threadings of the screw and of the nut. The threading of each mutually identical roller being prolonged axially at each end by teeth respectively engaged with teeth of two annular crown rings fixed in an unthreaded part of the bore of the nut. Each of the mutually identical rollers comprises an angular visual positioning feature. The nut comprises an angular visual positioning feature making it possible to angularly place the rollers in the crown ring.

Abstract: A vehicular seat slide device, includes: a first rail fixed to one of a vehicular floor and a seat; a second rail fixed to the other one of the floor and the seat, and linked to be movable relative to the first rail; a screw rod supported by the second rail to be rotatable around an axial line which extends in a moving direction; a metal case fixed to the first rail, and through which the screw rod is inserted; a resin nut housed in the metal case in a state of being unmovable in the moving direction with respect to the metal case, and screwed to the screw rod; and a metal nut housed in the metal case in a state of not being in contact with the resin nut in the moving direction, and screwed to the screw rod.

Abstract: Provided is a screw device in which a sudden change in force on or a sudden change in the positions of the rolling members can be suppressed at the boundary between a helical loaded rolling-member rolling path and a return path of the screw device. A curvature radius change section is provided in the return path of the screw device. When viewed in the axial direction of a nut, the curvature radius change section is configured so that the curvature radius of a track centerline of the rolling members in the return path is equal to or larger than the curvature radius of a track centerline of the rolling members in the loaded rolling-member rolling path, and so that the curvature radius of the track centerline of the rolling members in the return path increases gradually or in a stepped manner with increasing distance from the loaded rolling-member rolling path.

Abstract: The invention relates to a ball screw (10) with a threaded spindle (12), a nut (14), rolling bodies (16) and at least one deflecting device (18, 20), wherein the threaded spindle (12) is displaceable by rotation, and wherein the deflecting device comprises an inner first body part (18) and an outer second body part (20), which body parts together form a deflecting channel (22), wherein the deflecting channel (22) has two tubular ends (24, 26) which are connected to each other via a transfer region (28), wherein the tubular ends (24, 26) of the deflecting channel are in each case formed by mutually complementary partial tubular sections (30, 32, 34, 36) of the body parts (18, 20), and wherein a sleeve (40) surrounding the nut (14) is provided, the deflecting device (18, 20) sits in an opening (42) in the nut (14), the deflecting device (18, 20) projects radially beyond the outer lateral surface of the nut (14) in a relaxed state when the sleeve (40) is absent and, in the presence of the sleeve (40), said sleev

Abstract: A vehicle power steering assembly comprises a steering member having a screw portion. The screw portion has an external screw thread convolution with a first lead spacing. A ball nut is operatively connected to the screw portion. A bushing is operatively connected to the screw portion. The bushing has a bushing screw thread convolution with a second lead spacing. The second lead spacing is different than the first lead spacing. The bushing biases the ball nut against the screw portion.

Abstract: In a ball screw (1), comprising a screw shaft (3), a nut (7) threaded onto the screw shaft via a plurality of balls (9) received in a raceway (8) defined between the two parts, an end deflector receiving recess (6) is formed on each axial end thereof to complementarily receive an end deflector (21) which defines a part of the raceway in cooperation with an opposing part of the nut, wherein the end deflector is provided with a pair of engagement claws (31, 32) that engage corresponding parts of the thread (4) formed on the nut. Thereby, the need for a special engagement feature or other arrangement for attachment is eliminated, and still a highly firm and accurate engagement is ensured between the nut and the end deflector.

Abstract: A threaded spindle (11), having a drive part (20), which has a longitudinal axis (A) and is mounted in a first journal (70), and having a threaded part (30), which likewise has a longitudinal axis (B), and having a threaded nut (50), which is mounted in a second journal (80a; 80b) and in which the threaded part (30) is guided. The drive part (20) and the threaded part (30) are formed as separate parts and are each provided with at least one coupling element (25, 55), which are connected to each other in an articulated manner by plugging together. A mutual offset or inclination angle (a) of the longitudinal axes (A, B) of the drive part (20) and of the threaded part (30) can be compensated in this manner. The two-part threaded spindle (11) forms a threaded drive with the threaded nut (50) thereof, which can for example be used in a parking brake of a vehicle braking system.

Abstract: A driving device for an electric lock latch, comprises a housing, a motor having a power output shaft connected to a drive shaft with an external thread on a part thereof, an unequal diameter coil spring having a cylindrical spiral in the middle thereof screwing with the drive shaft, and a first and second conical spiral on both end thereof not screwing with the drive shaft, and a lock latch secured to the second conical spiral. The drive shaft is driven and rotated by a motor to pass the rotation power to the cylindrical spiral, and a rotary motion of the drive shaft is converted into a linear motion of the unequal diameter coil spring for moving the lock latch to change the locked and unlocked state of the lock device. Accordingly, the lock structure and the installation thereof may be simplified and the power-saving effect is achieved.

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 spindle (242; 414; 542; 642) for driving a bung of a cartridge is provided. The spindle includes a generally circular shaft having an outer surface (560). The generally circular shaft extends from a distal end to a proximal end of said circular shaft. A first helical groove (219; 519; 619) is provided along a first portion of the outer surface. The first helical groove having a first pitch. A second helical groove (221; 521; 621) provided along a second portion of the outer surface of the generally circular shaft. The second helical groove overlapping the first helical groove. The second helical groove having a second pitch.

Abstract: An actuator in one embodiment includes a threaded shaft; a shaft engaging portion coupled to the threaded shaft, the shaft engaging portion being moveable in a direction parallel to an axis of the threaded shaft upon a relative rotation between the threaded shaft and the shaft engaging portion; and a ceramic bushing coupled to the shaft engaging portion, the bushing encircling the threaded shaft.

Abstract: A threadform for a gate valve has a set of threads on a stem that engage a threaded receptacle of the gate. When the stem is rotated, the gate moves. The threads have a thread height to thread base thickness ratio that is at least the inverse of 0.7 times e raised to 0.388 divided by a nominal thread diameter of the threads. That ratio is at least 1.1.

Abstract: The present invention provides a roller screw which bears loads in both directions along the axis of the screw shaft and which is also capable of preventing interference between each roller end surface and roller rolling grooves. Between roller rolling surfaces 1a, 1b of the screw shaft 1 and roller rolling surfaces 2a, 2b, respectively, of the nut 2, there are formed two or more roller rolling paths 3a, 3b, respectively. In one roller rolling path 3a, plural rollers 4a are parallel-arranged, and also in another roller rolling path 3b, plural rollers 4b are parallel-arranged. The rollers 4a arranged in the one roller rolling path 3a bear a load in one direction (1) along the axis of the screw shaft 1, while the rollers 4b arranged in the other roller rolling path 3b bear a load in the opposite direction (2) along the axis of the screw shaft 1.

Abstract: Ball screw having a spindle nut (2) arranged on a spindle (1), together with balls (3) which are arranged in a series and are capable of rolling in a helical ball track (4), the helical ball track (4) being defined by a thread groove (5) formed on the spindle (1) and by a thread groove (6) formed on the spindle nut (2), the balls (3) arranged in a series being returned in a return duct (7) from an outlet end to an inlet end of the helical ball track (4), the divided circle end play of the series of balls being less than or equal to 0.3 millimeters or the ratio between the pitch of the helical ball track (4) and the diameter of the balls (3) ranging from 1.02 to 1.2 or the thread grooves (5, 6) of the spindle nut (2) and of the spindle (1) in each case having a gothic profile (8, 9), a pressure angle formed by the balls (3) in contact with the gothic profile (8, 9) ranging from 15 to 35 degrees.

Abstract: A ball screw, which improves its durability under circumstances where a radial load and a moment load are applied to it, has a screw shaft (2) formed with a helical screw groove (2a) on its outer circumferential surface. A nut (3) is adapted to mate with the screw shaft (2). The nut (3) is formed with a helical screw groove (3a) on its inner circumferential surface. The nut helical screw groove (3a) corresponds to the screw shaft screw groove (2a). A number of balls (4) are rollably contained within a ball rolling passage formed by the oppositely arranged screw grooves (2a, 3a). Bridge members (5), each formed with a connecting groove (5a) on its inner circumferential surface, connect the screw grooves (3a) of the nut (3). A contact angle (?) between each ball (4) and one or both the screw grooves (2a, 3a) is set within a range of about 20˜40°.

Abstract: A ball screw apparatus of a screw shaft circulating-type includes a nut having a first groove formed in an inner peripheral surface thereof, a screw shaft having a second groove formed in an outer peripheral surface thereof, and a plurality of rolling elements provided between the first and second grooves. A circulating groove is formed in the screw shaft so as to interconnect opposite ends in a spiral direction of the second groove of the screw shaft to form a closed-loop ball endless circulating passageway. Processing relief portions for preventing a processing tool of a rotary drive-type from interfering with the circulating groove when processing the second groove of the screw shaft by the processing tool are provided respectively at the opposite end portions in the spiral direction of the second groove of the screw shaft.

Abstract: An actuator including a threaded shaft and a carriage having a shaft engaging portion coupled to the threaded shaft. The carriage is moveable in a direction parallel to an axis of the threaded shaft upon a relative rotation between the threaded shaft and the shaft engaging portion. A ceramic bushing is coupled to the shaft engaging portion of the carriage, the bushing surrounding the threaded shaft. The ceramic bushing is much harder than heretofore used materials and results in greatly reduced particulate formation. The carriage or portion thereof can be formed around the bushing, e.g., by injection molding.

Abstract: A ball screw mechanism including a screw shaft with a screw groove formed on an external surface, a nut with a screw groove formed on an internal surface, and plural balls held in the grooves. A ball circulation piece is fit in a window portion in the nut and has a circulation groove for circulating the balls. The screw groove of the nut and the circulation groove are machined by moving a tool of a diameter equal to or larger than the diameter of the balls, along the screw groove of the nut so that a step is eliminated at a joint therebetween. The infeed depth of the tool is gradually changed as the tool is moved toward the joint so that boundary lines between a machined surface and a non-machined surface on flanks of the screw groove of the nut extend at an acute angle to one another.

Abstract: A ball screw mechanism includes a ball screw shaft of a metal material coaxially connected to a rotary driving source, a nut member of a resin material being screwed onto the ball screw shaft, a plate member fixed to an upper surface of the nut member by screw members, and steel balls which are arranged on a passage formed in the nut member closed by the plate member and which are installed into screw grooves of the ball screw shaft and the nut member.

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 ball screw having: a screw shaft having a spiral ball rolling groove; a ball nut having a ball rolling groove corresponding to the ball rolling groove; and a large number of balls interposed between the ball rolling grooves so as to roll freely; wherein the ball rolling groove of at least one of the screw shaft and the ball nut is ground so that a maximum value component of a number of undulation peaks per lead in the ball rolling groove is not in a range of from 0.95 nm to 1.05 nm centered on an integral multiple nm of a number m of load balls per lead calculated by an expression: ( ? ? ? d m ) 2 + L 2 P in which P is a distance between centers of the adjacent load balls disposed at substantially equal intervals in the ball rolling groove, dm is a ball pitch circle diameter, and L is a lead.

Abstract: A lead screw for a linear actuator, which has a metal pipe having a helical projection resin-molded on its outer surface, and a ball for a pivot bearing welded to a distal end of the metal pipe, is disclosed together with a method of manufacturing the same. With the lead screw according to this invention, a slight positional deviation from the origin, which is caused at a high ambient temperature by thermal expansion of a resin material filled up in the metal pipe, can be prevented reliably. Linear movement upon rotation of a stepping motor can take place with high precision.

Abstract: In a ball screw drive comprising a spindle (1), a nut (3) surrounding the spindle (1), and balls (4) arranged between the spindle (1) and the nut (3), which balls (4) are in rolling contact with a screw track (2) formed on the spindle (1) and on corresponding screw tracks (7, 12) formed on rings arranged within the nut (3) comprises a deflecting region for returning the balls (4) from a run-out end of a common turn of the screw tracks (2, 7, 12) to a run-in end of this turn, the screw tracks (7, 12) of the rings arranged in the nut (3, 15) are made on front faces of these rings with the screw tracks (7, 12) of two adjacent rings defining together with the screw track (2) of the spindle (1, 18), an endless circulation channel for the balls (4).

Abstract: An actuator for an automated transmission in a motor vehicle drive train has a central actuating shaft with a shift finger. Two sleeves are supported concentrically on the actuating shaft and can be driven in mutually independent rotation. Two grooves of opposite helical pitch are arranged on the actuating shaft, and each of the sleeves has at least one inward-directed guide pin engaging one of the grooves.

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: 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 rolled ball screw has a screw shaft having a ball screw groove so as to engaging with rolling elements of a ball screw, the screw shaft is formed by rolling while a thread rolling die is pressed against a cylindrical bar-shaped member to thereby roll the ball screw groove, wherein the number of waves per circumference per lead of said ball screw groove is set different from the integer multiples of the number of said rolling elements per lead of said ball screw groove.

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 has: a screw shaft having a spiral ball rolling groove; a ball nut having a ball rolling groove corresponding to said ball rolling groove; and a large number of balls interposed between said ball rolling grooves so as to roll freely; wherein said ball rolling groove of at least one of said screw shaft and said ball nut is ground so that a maximum value component of a number of undulation peaks per lead in said ball rolling groove is out of a range of from 0.95 nm to 1.

Abstract: A rolled ball screw has a screw shaft having a ball screw groove so as to engaging with rolling elements of a ball screw, the screw shaft is formed by rolling while a thread rolling die is pressed against a cylindrical bar-shaped member to thereby roll the ball screw groove, wherein the number of waves per circumference per lead of said ball screw groove is set different from the integer multiples of the number of said rolling elements per lead of said ball screw groove.

Abstract: A ball screw includes a spindle element which has a first groove arrangement on an outer circumferential surface, a nut element which surrounds the spindle element and has a second groove arrangement on an inner circumferential surface, and a plurality of balls, at least some of which engage into the first groove arrangement and the second groove arrangement. The nut element is rotatable about an axis of rotation with respect to the spindle element, and, during the rotation of the nut element about the axis of rotation with respect to the spindle element, the balls which engage into the first groove arrangement and the second groove arrangement roll in the first and the second groove arrangement, while at the same time rotate about respective ball axes of rotation.

Abstract: In a ball groove profile of a ball screw, an outer diameter portion of a screw shaft of the ball screw and a substantially semi-circular ball rolling portion of a ball groove of the ball screw are connected to each other through arcuate portions. The radius of curvature of each arcuate portion ranges from a value half a radius of a rolling ball or more to twice the radius of the ball or less. The arcuate portions are connected at least to the ball rolling portion continuously and smoothly. The outer diameter of the screw shaft is set to a value equal to or slightly smaller than the diameter of the central circle of the ball fitted with the ball groove arranged on the outer diameter of the screw shaft, and the difference between the outer diameter of the screw shaft and the diameter of the central circle of the ball is set to 10% of the diameter of the ball or less.

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: 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 &Dgr;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 drive device for a moveable part, in particular a hinged side window of a vehicle, with an actuating drive and with a threaded piece which is driven by the actuating drive and which meshes with an associated threaded piece, the associated threaded piece moving the part, there being provision, in order to reduce undesirable noises, for individual flights of at least one threaded piece (14) to be designed in such a way that they come to bear under the effective force in the respectively associated flights of the other threaded piece.

Abstract: A lead screw for a linear actuator, which has a metal pipe having a helical projection resin-molded on its outer surface, and a ball for a pivot bearing welded to a distal end of the metal pipe, is disclosed together with a method of manufacturing the same. With the lead screw according to this invention, a slight positional deviation from the origin, which is caused at a high ambient temperature by thermal expansion of a resin material filled up in the metal pipe, can be prevented reliably. Linear movement upon rotation of a stepping motor can take place with high precision.

Abstract: A nut unit (20) for use in a ball screw drive comprises a sleeve-shaped nut body (10) that is made of an essentially rigid material and that has an axis (A) and an inner circumferential surface (14). A one-piece, channel-shaped, ball-guiding strip material helix (18) is arranged on the inner circumferential surface (14) of the nut body (10). The strip material helix (18) is mounted within a concavely-curved support groove (16) formed in the inner circumferential surface (14) of the nut body (10). The helix (18) has an external convexly-curved profile (46), which is embodied with external profile flank regions (46′) and an external profile crown region (46″). The helix (18) defines, by means of a curved internal profile (48) facing the axis (A), a ball channel with an internal profile base region (48″) and two internal profile flank regions (48′). The outer profile flank regions are essentially rigidly supported by the support profile of the support groove (16).

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: A ball screw includes a spindle element which has a first groove arrangement on an outer circumferential surface, a nut element which surrounds the spindle element and has a second groove arrangement on an inner circumferential surface, and a plurality of balls, at least some of which engage into the first groove arrangement and the second groove arrangement. The nut element is rotatable about an axis of rotation with respect to the spindle element, and, during the rotation of the nut element about the axis of rotation with respect to the spindle element, the balls which engage into the first groove arrangement and the second groove arrangement roll in the first and the second groove arrangement, while at the same time rotate about respective ball axes of rotation.

Abstract: A nut unit (20) for use in a ball screw drive comprises a sleeve-shaped nut body (10) that is made of an essentially rigid material and that has an axis (A) and an inner circumferential surface (14). A one-piece, channel-shaped, ball-guiding strip material helix (18) is arranged on the inner circumferential surface (14) of the nut body (10). The strip material helix (18) is mounted within a concavely-curved support groove (16) formed in the inner circumferential surface (14) of the nut body (10). The helix (18) has an external convexly-curved profile (46), which is embodied with external profile flank regions (46′) and an external profile crown region (46″). The helix (18) defines, by means of a curved internal profile (48) facing the axis (A), a ball channel with an internal profile base region (48″) and two internal profile flank regions (48′). The outer profile flank regions are essentially rigidly supported by the support profile of the support groove (16).