Abstract: A leadscrew assembly includes a screw shaft along which is formed a first helical groove and a primary nut along which is form a second helical groove. The first helical groove and the second helical groove cooperate to define a track. The assembly also includes a secondary nut along which is formed a third helical groove. The first helical groove and the third helical groove cooperate to define a track with a nominal running clearance. A preload X is provided wherein when a load applied to the screw exceeds the predetermined preload, the secondary nut engages with the track such that load of the screw above preload X is transferred through the secondary nut and thus protecting the primary nut.

Abstract: A preload detectable screw device is provided which can detect preload with accuracy and can reduce the influence of generated heat on the output of a sensor. A screw device (1) includes a screw shaft (2), a nut member (3), a plurality of rolling elements (7, 8), at least one axial strain sensor (24) (B, D) that is attached to a surface of the nut member (3) and detects strain in an axial direction on the nut member (3), and at least one circumferential strain sensor (24) (A, C) that is attached to the surface of the nut member (3) and detects strain in a circumferential direction on the nut member (3). Preload of the screw device (1) is detected on the basis of outputs of the axial strain sensor (24) (B, D) and the circumferential strain sensor (24) (A, C).

Abstract: A ball screw assembly having a ball nut including a first end, a second end, a central bore, and a ball track defined by the inner surface, a ball screw shaft including an outer surface defining a ball track, the ball screw shaft being disposed in the central bore so that the ball tracks form a ball raceway, a first stopper disposed within the ball raceway, a plurality of main balls forming a ball train, the ball train being disposed in the ball raceway, and a main spring assembly disposed in the ball raceway between a first end of the ball train and the first stopper, wherein a spring constant of the first spring portion is greater than a spring constant of the second spring portion.

Abstract: A failure diagnostic apparatus for use in a ball screw conveyer includes a bearing stopper placed in contact with a bearing supporting a ball screw, a sensor unit equipped with an elastic member and a heat flux sensor, and a malfunction detector. The heat flux sensor works to produce an output as a function of deformation or displacement of the bearing stopper. The malfunction detector works to analyze the output from the heat flux sensor to detect a failure in operation of the ball screw conveyer. This enables a malfunction of the ball screw conveyer to be detected quickly and accurately.

Abstract: To prevent the positional precision of the ball return passage and the tongue of the end deflector relative to the nut main body from being impaired by an axial force applied by a screw used for securing the end deflector to the nut main body, the end deflector includes a flange (32) provided at an axial end of a main part (30) of the end deflector and provided with an axial through hole (50) for receiving a screw which is threaded into the nut main body, and a rib (52) projecting from a radially inner edge of the flange to an inner side of the deflector receiving recess (26).

Abstract: There is provided a ball screw that is used to apply a preload to balls and that has a configuration of achieving a balance between the cooling efficiency and ease of assembly and disassembly. To this end, the ball screw includes a screw shaft, and a plurality of nuts movable relative to the screw shaft in an axial direction. Each of the nuts includes flow channels, which are cooling mechanisms and which respectively serve as independent channels to allow a cooling medium to pass through them. These flow channels are provided symmetrically with respect to a space between the nuts, and are configured so that the cooling medium can independently circulate in each of the nuts.

Abstract: A double-nut cooling ball screw includes two nuts threadedly engaging with a threaded shaft and having connecting end portions facing toward each other and cooling channel assemblies in fluid communication through coupling holes in the connecting end portions, and a spacer interposed between the connecting end portions and having notched recesses for accommodating guiding assemblies. Each guiding assembly is rotatable relative to the nuts between a non-stored position for facilitating fastening thereof, and a stored position to be concealed between the nuts.

Abstract: A ball screw in a steering system has a groove between the inner peripheral surface of a cylindrical ball nut through which a steered shaft extends and the outer peripheral surface of the steered shaft, and balls are accommodated in the groove. The balls rolling and flowing in the groove are returned from downstream to upstream via deflectors and a return passage member disposed in the ball nut. The return passage member has a first connection portion curved to connect one end of a linear portion of the return passage member to the first deflector, and a second connection portion curved to connect the other end of the linear portion to the second deflector. Each connection portion has an opening that opens in the return passage member longitudinal end face and an opening that opens in the return passage member outer periphery of toward the centerline of the ball nut.

Abstract: There is provided a ball screw device capable of allowing interference to be easily elastically deformable and decreasing friction resistance of a seal member with respect to a screw shaft without damaging seal properties of the seal member. A predetermined section of a land sliding-contact portion (46) of a sliding-contact portion (40) and a section of a seal piece (37) of a lip portion (31) corresponding to the predetermined section are bent to protrude in one side in the axial direction of a nut (7) so that a protrusion (55) is formed, the bent section of the land sliding-contact portion (46) and the bent section of the seal piece (37) configure a pair of side surface portions (58, 58) of the protrusion (55) and a bottom portion (61) connecting the one side ends of the pair of side surface portions (58, 58).

Abstract: A ball screw capable of thermal dissipation is formed of a screw rod, a screw nut, and a plurality of balls mounted between the screw rod and the screw nut. The screw nut includes a mounting surface. A thermoelectric cooler is mounted to the screw nut and includes a heat-absorptive surface and a heat-dissipative surface. The heat-absorptive surface is adhered to the mounting surface. Accordingly, the ball screw can cool the heat down and is structurally simple and the whole weight is not increased due to the thermoelectric cooler.

Abstract: A ball screw is formed of a screw rod, two screw nuts, a link, a plurality of balls, and at least two parallelism sensors. The screw nuts are sleeved onto the screw rod and are connected with each other via a link to define a spiral path therebetween. The spiral path is linked with an internal circulatory passage of each screw nut for receiving a plurality of balls. The two parallelism sensors are oppositely mounted between the two screw nuts and surround the screw rod for sensing the preload between the two screw nuts to figure out whether the parallelism of the screw rod after the assembly is deviated or not. In this way, monitoring the voltage value outputted from the parallelism sensors can monitor the parallelism of the screw rod in real time after the assembly.

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 ball screw capable of sensing a preload is formed of a nut having an internal thread surrounding an imaginary central axis, a screw inserted into the nut and having an external thread surrounding the imaginary central axis, and a plurality of balls are mounted between the internal and external threads in a way that the balls roll therebetween. A mounting hole having a mounting surface therein is formed in the nut. The mounting surface corresponds to the internal thread in a way that it is substantially perpendicular to the imaginary central axis. A force sensor is mounted to the mounting surface. The force sensor can directly sense the preload in real time, so it is uneasily adversely affected by any environmental factor to have more accurate sensing result relatively.

Abstract: A ball screw with an oil-storage unit, the oil-storage unit includes an oil tank and a connector. The connector has one end formed in the form of a convex or concave structure, and the connecting end of the oil tank is also in the form of a concave or convex structure for engaging with the connector, so as to achieve quick assembling of the connector onto the oil tank through the engagement of the convex and concave structures. Since the oil-storage unit can be quickly replaced after the oil is used up, which provides an automatic and continuous self-lubricating function to the ball screw, and consequently extending the service life of the ball screw.

Abstract: Planetary roller gear drive with a spindle nut (1) that is arranged on a threaded spindle (2) and with a plurality of planets (3) that are arranged distributed around the periphery and are in rolling engagement with the threaded spindle (2) and the spindle nut (1). The threaded spindle (2) has a plurality of helical windings wound around the spindle axis forming at least one thread groove (8), and a sensor element (15) is arranged so that it cannot move in the axial direction relative to the spindle nut (1) and detects an axial displacement of the threaded spindle (2) and the spindle nut (1) relative to each other. The spindle nut (1) is supported so that it can rotate about the spindle axis on a housing (12) with the sensor element (15).

Abstract: A ballscrew assembly may include a ballnut configured to combat the negative effects of thermal expansion of dissimilar materials used within the ballscrew assembly. Moreover, the ballscrew assembly described herein may have a decreased coefficient of friction as compared with a steel on steel housing and ballnut configuration. A ballscrew assembly may comprise a ballnut made from a first material, a ballnut housing made from a second material, and a sleeve made from a third material. The sleeve may be positioned between the exterior of the ballnut and an interior of the ballnut housing to reduce friction between the exterior surface of the ballnut and an interior surface of the ballnut housing.

Abstract: A ball screw device includes a cylinder that surrounds the outer periphery of a ball nut. Accommodation holes are formed in the ball nut at a rolling start position and a rolling end position in ball rolling paths. An outer periphery turning groove is formed in an outer peripheral face of the ball nut, and the outer periphery turning groove and an inner peripheral face of the cylinder constitute a turning rolling path. The turning rolling path and connection passages formed in deflectors constitute a circulation path through which balls are returned from the rolling end position to the rolling start position.

Abstract: A method for manufacturing a ball screw according to the present invention includes a seal fixing step of fixing a ring shaped seal (4) to an attachment portion (24) disposed in an end portion of a nut (2) of a ball screw in an axis direction using a fixing member (5). The attachment portion has an inner circumferential surface having a diameter larger than that of an inner circumferential surface on which a spiral groove of the nut is formed. A through hole (25a to 25c) is formed in the attachment portion, the through hole (25a to 25c) penetrating the attachment portion in a radial direction from an outer circumferential surface thereof to the inner circumferential surface thereof.

Abstract: A ball screw device is provided in which a dust-proof member can be simply attached to a nut. The ball screw device (1) is a ball screw device (1) in which a concave portion (6) is formed in an inner circumferential end portion of a nut (4) through which a screw shaft (2) passes and the concave portion (6) is provided with a dust-proof member (5), wherein the dust-proof member (5) is formed of a cylindrical elastic member into which the screw shaft (2) is inserted and includes at least one protrusion (8) protruding in an outward diameter direction from an outer circumferential surface of the dust-proof member (5), and the concave portion (6) has a groove shape to which the dust-proof member (5) is fitted and is provided with a locking portion (7) to which the protrusion (8) is locked.

Abstract: There is provided a ball screw apparatus ensuring easy and proper centering between a nut and a stationary member. Therefore, the ball screw apparatus (1) has a threaded shaft (10), a nut (20) that passes through the threaded shaft (10) and is screwed via a rolling body B into the threaded shaft (10) so as to be disposed movable in the axial direction of the threaded shaft (10), and a stationary member (40). The stationary member (40) is secured to an end surface (20a) of the nut (20), and a dustproof member (60) that prevents entry of foreign matter into the nut (20) is secured to the stationary member (40). The end surface (20a) of the nut (20) is provided with a spigot joint portion (20b) fitted to an outer circumferential surface (42a) of a flange part (42) of the stationary member (40).

Abstract: A ball screw includes a screw rod having an external thread; two screw nuts having an internal thread and a circulatory passage each, a spiral path being formed between the internal threads and the external thread and communicating with the circulatory passage, each of the two screw nuts having a keyway located on respective toric surfaces of opposite ends of the two screw nuts, the two keyways facing each other; a link mounted inside the two keyways to traverse the two screw nuts; a force sensor mounted between and squeezed by opposite sides of the two screw nuts; and a plurality of balls located inside the spiral path or the circulatory passage and keeping rolling while moving.

Abstract: To improve workability and sealing performance of a coolant when a plurality of nuts in a ball screw are brought into contact with one another, the plurality of nuts being coupled to one another, assembled to one threaded shaft and cooled by flowing the coolant through through-holes formed in the plurality of nuts in axial directions of the plurality of nuts. The ball screw includes counterbores of the through-holes formed on opposing end faces of both of adjoining nuts, and a ring-shaped sealing member inserted thereto. The counterbores are formed such that a depth of one counterbore is larger than a length of the sealing member, and the a depth of the other counterbore is smaller than the length of the sealing member, and such that circumferential positions of the counterbores of the adjoining nuts face each other when a desired preload is exerted.

Abstract: There are provided a ball screw that makes it possible to prevent a situation where a large load is applied to a part of a plurality of balls, and an electric power steering system including the ball screw. The ball nut is a component that surrounds a part of the male thread groove, and has a nut inner surface and a female thread groove. The female thread groove is formed in the nut inner surface, and forms a part of the rolling path. A female thread diameter varies according to a position in an axial direction of the ball nut. The female thread diameter is larger at each of axially ends of the ball nut than at an axially intermediate portion of the ball nut, and the female thread diameter is larger at one of the axially ends than at the other of the axially ends.

Abstract: A ball screw (7, 24), having a threaded spindle (8, 28) which is mounted in a rolling fashion by balls (9, 27) on a threaded nut (10, 26) and which is supported on an axial bearing (13, 25), wherein the threaded spindle (8, 28) is axially supported with its first bearing surface (18, 23), which is convexly shaped with a radius of curvature (R1), on a preferably conically designed second bearing surface (19, 22), wherein the first bearing surface (18, 23) and the second bearing surface (19, 22) make contact with one another along a contact path (37), wherein a quotient formed from the ratio of the radius of curvature (R1) to the radius (R2) of the contact path (37) assumes values of between 1.2 and 2.4 inclusive.

Abstract: A ball-screw assembly isolator is provided, and includes a housing; a ball-screw, a bearing assembly, a retaining member, a first compressible member and a second compressible member. The bearing assembly is located between the housing and the ball-screw. The bearing assembly includes an outer race. The retaining member is secured by the housing. The first compressible member is positioned between the housing and the outer race. The second compressible member is positioned between the outer race and the retaining member. The retaining member is configured to be preloaded to exert an axial force upon the first compressible member and the second compressible member.

Abstract: A pneumato-mechanical regenerative power source converts mechanical rotational power at an input/output shaft to stored potential energy, and vice versa, by coupling the input/output shaft to a ball screw via a planetary gear system, which translates a ball nut in cooperation therewith, which in turn translates a piston that provides for either compressing or expanding an associated energy storage gas. A first roller-clutch mechanism provides for locking the carrier of the planetary gear system when storing energy, and releasing the carrier when releasing stored energy, wherein upon release, the ball screw is coupled to the input/output shaft via an overrunning clutch, and the carrier may be locked to limit the release of stored energy.

Abstract: Provided are a ball-type speed reducer and a rotary table device that are capable of performing high-speed rotation and high-rigidity rotation and suitable for reduction in size and weight. An index table 10 includes a ball-type speed reducer 20 and a table 50 that is fixed to an upper surface of a worm wheel 30 of the ball-type speed reducer 20. When the worm gear 22 rotates as the input shaft 24 of the ball-type speed reducer 20 rotates, balls 36 made of a magnetic material move along a ball groove 26 having a spiral shape. The worm wheel 30 rotates as the balls 36 move, and the table 50 rotates. The balls 36 are attracted and held by the permanent magnet 34 on the worm wheel 30 side, so that a case for preventing the balls 36 from coming off the worm wheel 30 can be omitted, whereby the total size and weight can be reduced. Backlash is not required, so that high-speed rotation and high-rigidity rotation are possible.

Abstract: A ball screw device or linear motion guide device has a seal member preventing dust and dirt from entering into a movable member of a linear motion guide device and seals out fine dust, dirt or like by surely contacting a seal to a shaft member without providing a large margin to the seal. The seal member includes a body portion mounted to the movable member and a lip portion contacting an outer portion of the shaft member, the lip portion has an oblique surface having an axial section inclining with respect to its axial direction, the body portion has an urging member urging the lip portion in a diameter direction of the shaft member and a reinforcing portion reinforcing the body portion. The urging member is located on the reinforcing portion side than the tip end of the lip portion in the axial sectional shape of the lip portion.

Abstract: In forming an actuator, a large end surface of a tapered roller of a tapered roller bearing is shot with minute particles of silicon carbide having a diameter of 0.5 to 100 ?m and having an angle formed by crushing, and such a surface is scraped concavely at a diameter within a range from 0.5 to 100 ?m to form a large number of concavities having a depth of equal to or greater than 1 ?m at a pitch of equal to or less than 200 ?m. The concavities are non-continuous and isolated from each other, and serve as a lubricant puddle. The concavities are formed by scraping and not by plastic deformation, and thus the surface is not hardened.

Abstract: A ball screw assembly based on heat-pipe thermal dissipation is composed of a ball screw and at least one heat pipe. The ball screw includes a threaded shaft, a nut, and a plurality of balls mounted between the threaded shaft and the nut. The at least one heat pipe defines a main body and an extended part. The main body is mounted to the ball screw. The extended part extends outwardly for a predetermined length from the ball screw for thermal dissipation or connection with a heat-dissipating device.

Abstract: In a ball screw mechanism, a retainer is provided between an outer circumference of a ball screw shaft and an inner circumference of a ball nut and has a plurality of retainer grooves arranged in the circumferential direction for retaining a plurality of rolling balls. Each retainer groove of the retainer takes a form that allows the rolling balls therein to move radially outward but restrains the rolling balls therein from moving radially inward. Therefore, in the ball screw mechanism and an electric power steering device incorporating the same, the movement of the retainer in radial directions can be restricted by the plurality of rolling balls which are rolled along ball rolling grooves spirally formed respectively on the outer circumference of the ball screw shaft and the inner circumference of the ball nut.

Abstract: A ballscrew assembly for an actuator is provided. In an embodiment, the ballscrew assembly includes a ball nut assembly including a view port; a ballscrew provided within at least a portion of the ball nut assembly; an inner rod provided within the ballscrew in the direction of the longitudinal axis, the inner rod including an enlarged end portion; and a compression mechanism, such that at least a portion of the compression mechanism is provided between the enlarged end portion and the ballscrew. In another embodiment the assembly is configured such that when the inner rod is in a failed state, the compression mechanism provides a force that moves the visual indicator toward the view port. In another embodiment, the assembly includes a proximity sensor in addition to, or in lieu, of a view port to detect a failure.

Abstract: A roller screw is provided having a structure suitable for circulating rollers. The roller screw has a screw shaft 5 with a spiral roller rolling groove 5a formed on an outer peripheral surface thereof; a nut 6 with a spiral roller rolling groove 6a opposed to the roller rolling groove of the screw shaft and formed on an inner peripheral surface thereof; and a plurality of rollers 7 arranged in a load roller rolling path 9 between the roller rolling groove 5a of the screw shaft 5 and the roller rolling groove 6a of the nut 6. Inside the nut 6 is provided a roller return path 11 extending linearly in parallel with an axis line of the nut 6. To opposite end faces in an axis line direction of the nut 6 are attached direction change path forming members 13 in which direction change paths 10 to connect the load roller rolling path 9 and the roller return path 11 are formed. The roller return path 11 is twisted to rotate an attitude of each of the rollers 7 while the rollers 7 move in the roller return path 11.

Abstract: The disclosure relates to a threaded shaft for a roller screw drive, for example for an electromechanical brake booster or an electromechanical power steering system. According to the disclosure, a helical coil with a flat, square-threaded annular cross-section is arranged on a thin-walled pipe, the pipe being formed onto a root region of the helical coil by the application of high pressure from the inside of the pipe.

Abstract: Described is a ball screw for a steering device of a motor vehicle, which ball screw has a threaded spindle (2) and a nut (3) having a nut body which runs on the threaded spindle (2) via balls (4) guided in ball channels, wherein the nut body has a first body element (5) and a second body element (6) which interact via at least one elastic damping body (7) arranged between them. Also described is a steering device for a motor vehicle, in which the ball screw according to the invention is used.

Abstract: Proposed is a ball screw for a steering device of a motor vehicle, which ball screw has a threaded spindle (2), a first nut (3) and a second nut (4), wherein the nuts (3, 4) run on the threaded spindle (2) in each case via balls guided in ball channels, and the nuts (3, 4) can be elastically preloaded by means of at least one spring element (6). The nuts (3, 4) can be coupled to one another by means of a sleeve (9) such that a translatory relative movement of the nuts (3, 4) is possible but a rotational relative movement of the nuts (3, 4) is inhibited. Also described is a steering device for a motor vehicle, in which the ball screw according to the invention is used.

Abstract: A motion guide device includes a rolling passage formed between two members, a number of bearing members disposed in the rolling passage and engaged between the members, and a number of spacers disposed in the rolling passage and engaged between the bearing members, the spacers each include a spherical configuration having six sides arranged opposite to each other, and each include a depression formed in each of the six sides and formed by four tilted and planar surfaces for engaging with the bearing members, and for allowing the spacers to be suitably engaged between the bearing members even when the spacers are rotated relative to the bearing members.

Abstract: A ball screw apparatus is provided which is less likely to increase dynamic friction torque even when a nut is contracted by cooling, and in which cooling effect is made as high as possible and which does not invite excessive machining efficiency droop and increase in pressure loss. The ball screw apparatus includes a screw shaft, a nut screwed with the screw shaft via a plurality of balls, and a cooling section cooling the nut. The plurality of balls to which preload is applied in a two-point contact state, with a preload direction as a tensile direction, are disposed between a screw groove of the screw shaft and a screw groove of the nut. Or, a ratio of the axial length L of the through hole axially formed in the nut and the diameter D of the through hole axially formed in the nut is given by an equation “10?L/D?60”.

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

Abstract: A system to provide differential movement between a first surface, a second surface and a fixed surface includes a first surface movable between a first position and a second position; a second surface movable with the first surface and further movable beyond the first surface; a shaft connected to the second surface to move the second surface; and a drive unit connected to the fixed surface to drive the shaft to move the second surface relative to the first surface and to allow the shaft to move through the drive unit when the second surface is being moved by the first surface.

Abstract: A ball screw unit includes a screw shaft that includes a screw groove, a ball screw nut that is screwed to the screw shaft via balls and that rotates to move the screw shaft linearly in an axial direction of the screw shaft, a hollow shaft that rotates together with the ball screw nut, a housing that rotatably supports the hollow shaft via a rolling bearing, and an elastic member that is provided at a position between the rolling bearing and the housing.

Abstract: The invention relates to a ball screw for a motor vehicle brake, in particular for an electromechanically actuable motor vehicle brake, comprising a rotatable spindle; a nut that is axially movable relative to the spindle in accordance with the rotation thereof; and rolling body arrangement that is disposed between, and displaceable relative to, the spindle and the nut. In this ball screw it is provided that the rolling body arrangement is preloaded into a predetermined normal position by means of at least one spring element. The invention further relates to a vehicle brake having such a ball screw.

Abstract: A ball screw (7, 24), having a threaded nut (10, 26) which is arranged on a threaded spindle (8, 28) and having a stop (43) for the circumferential abutment of the threaded nut (10, 26) in its stop position provided on the threaded spindle (8, 28), wherein the stop (43) has a first stop surface (47) assigned to the threaded nut (10, 26) and has a second stop surface (48) which is provided for abutting against the first stop surface (47) and which is assigned to the threaded spindle (8, 28), and, in the stop position, an axial overlap of the first stop surface (47) with the second stop surface (48) is provided, which overlap amounts to between 20% and 85% of the pitch of the threaded spindle (8, 28).

Abstract: First shoulder portions are formed on the outer periphery of the shaft such that the first spline grooves are interposed between the first shoulder portions adjacent to each other in a circumferential direction of the shaft. Second shoulder portions are formed on the inner periphery of the outer tube such that the second spline grooves are interposed between the second shoulder portions adjacent to each other in a circumferential direction of the outer tube. Main passages of spline-purpose ball circulation passages are formed with the first and second shoulder portions. Clearance are formed respectively between the first and second shoulder portions and the spline-purpose balls in a rotational direction of the screw shaft and the spline-purpose outer tube. The spline-purpose balls disposed in the main passages bear a clockwise torque and a counterclockwise torque transmitted between the screw shaft and the spline-purpose outer tube.

Abstract: An actuator has a rotary drive and a threaded element for converting the rotary motion of the rotary drive into a reciprocating motion of a tappet connected to a hinged wastegate and/or to a variable turbine geometry device of an exhaust gas turbocharger. The tappet and/or an axle between the tappet and the threaded element is received in at least one guide comprising at least one web and allowing for at least a slight tilting or pivoting movement of the tappet in at least one direction. At least some play is present between the web and at least one broadened portion on the tappet and/or on the axle. Methods of actuating a wastegate and/or a variable turbine geometry device.

Abstract: Provided is a rolling-element screw device which does not sacrifice a stroke distance of a nut member (2) although carrying a sufficient amount of lubricant, or hinder heat radiation of the nut member (2), and contributes to facilitation of a replacement operation of a lubricant tank (4).

Abstract: The present invention provides a screw device which takes a heavy load in one direction along the axis of the screw shaft and only a light load in the opposite direction, the screw device capable of providing ease of control of preloading. The screw device of the present invention has a screw shaft 1 with an outer surface having a ball rolling groove 1a for rolling balls 7 and a roller rolling groove 1b for rolling rollers 6 both spirally formed thereon; a ball nut 4 with an inner surface having a ball rolling groove 4a spirally formed thereon facing the ball rolling groove 1a of the screw shaft 1; a roller nut 5 with an inner surface having a roller rolling groove 5a spirally formed thereon facing the roller rolling groove 1b of the screw shaft 1; a plurality of balls 7 arranged between the screw shaft 1 and the ball nut 4; and a plurality of rollers 6 arranged between the screw shaft 1 and the roller nut 5. The ball nut 4 and the roller nut 5 are connected along an axis of the screw shaft 1.

Abstract: A thrust reverser drive arrangement for driving a thrust reverser cowl for movement relative to first and second guide tracks is described which comprises a first actuator located, in use, close to the first guide track, a second actuator located, in use, close to the second guide track, and a third actuator, the actuators being arranged to be driven in synchronism and at the same speed by a drive motor to drive the cowl for movement, the third actuator being of smaller size and/or weight than the first and second actuators, and wherein the third actuator is provided with a load limiter to limit the transmission of loads through the third actuator in the event that the third actuator is subject to a compressive loading greater than a predetermined level.

Abstract: A ball screw/nut type linear actuator (1) where a ball nut (32) moves in forward-backward directions by rotation of a ball screw shaft (31) connected to a motor (22), wherein the ball screw shaft (31) is connected and fixed, in a small diameter hollow section (22c) of the motor shaft (22), to the motor shaft so that a part of the locus of the movement of the ball nut (32) also enters into a large diameter hollow section (22a) of the motor shaft (22). The construction eliminates the need of a coupling for connecting the motor shaft (22) and the ball screw shaft (31) and enables the ball screw shaft (31) to be supported together with the motor shaft (22) by bearings (27, 28) of the motor. As a result, a support bearing for supporting the ball screw shaft can be eliminated. Thus, a short and light linear actuator is realized.

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.