Abstract: The present disclosure relates to an electrically activatable actuating unit (106) for a motor vehicle brake system (1000), having a housing body (122) and an actuating member (124) arranged in a recess (150) of the housing body (122), wherein the actuating member (124) is coupleable to a brake pedal at a first end and coupleable to a motor vehicle brake (400) at a second, opposite end. The housing body (122) and the actuating member (124) are arranged to be displaceable in a braking direction to actuate the motor vehicle brake (400).

Abstract: A linear actuator includes a roller screw nut, a roller screw shaft and a plurality of planetary rollers forming an inverted roller screw mechanism. A bearing supports a rotating part of the linear actuator. The bearing includes a mounting member and a plurality of bearing rollers engaging a first bearing portion of the mounting member and a second bearing portion of the rotating part. The plurality of bearing rollers is axially fixed relative to the rotating part and the mounting member. A manufacturing method for the linear actuator is also provided.

Abstract: Planetary roller screw having a threaded spindle, and having a nut element arranged on the threaded spindle, and having planets arranged distributed around the periphery of the threaded spindle, which mesh on one side with the threaded spindle and on the other side with the nut element, which is rotatably mounted in both axial directions in each case by means of a first bearing on a rotationally driven planet carrier which receives the planets and is rotatably mounted on a housing by means of a second bearing. The planet carrier has a sleeve encompassing the nut element, at the axial ends of which a flange respectively having a first bearing seat of the first bearing and a second bearing seat of the second bearing is arranged, the flanges being connected with play to one another by means of the sleeve in a rotationally fixed manner and axially with actuating play.

Abstract: The disclosure relates to a planetary roller screw having: a nut arranged on a threaded spindle and divided crosswise to a spindle axis into two nut parts; planetary rollers arranged between the threaded spindle and the nut distributed over the circumference, the planetary rollers intermeshing with the nut parts and with the threaded spindle; a rotatingly driven planetary roller carrier arranged on the threaded spindle, in pockets of which, arranged distributed over the circumference, the planetary rollers are mounted, held at a distance in the circumferential direction, so as to be rotatable about the planetary roller axis; and a housing in which the planetary roller carrier is rotatably mounted. A pre-loading device is provided in order to adjust an axial pre-load between the housing and the planetary rollers.

Abstract: The present invention relates to a linear actuator comprising a console, an outer tube connected to the console, an electric motor, a transmission, and a spindle in connection with the transmission. The linear actuator comprises a spindle nut on the spindle and an inner tube connected to the spindle nut. The spindle nut and the inner tube are guided inside the outer tube. The linear actuator comprises a control box which is connected to the console by means of a snap connection. The linear actuator further comprises an end stop arrangement having an end switch for each direction of movement of the spindle nut. An object underlying the invention is to provide a simpler connection of the control box to the linear actuator. A further object is to provide a less complex construction of the end stop arrangement of a linear actuator. To this end, the control box is connected to the console by means of a snap connection.

Abstract: A screw-pump type electro-hydraulic actuator preferably includes an electric motor device, a hydraulic tube, a pump piston, a spline rod, an actuator rod and a hydraulic control circuit. The electric motor device preferably includes an electric motor and a gearbox. One end of the spline rod is engaged with an output of the gearbox. The pump piston preferably includes a piston base, three sets of screw pump rollers, a spline drive gear, a first piston end plate and a second piston end plate. The hydraulic flow circuit includes a first relief valve, a first check valve, a second relief valve, a second check valve and an accumulator. The screw pump rollers are rotatably retained in the piston base between the first and second piston end plates. The spline gear drives the pump driven gears of the three drive screw pump rollers through the spline drive gear to pump hydraulic oil.

Abstract: An actuating mechanism has a main rotational drive and a roller screw mechanism coupled to the main rotational drive. The roller screw mechanism has a screw, a nut, and a plurality of rollers. One of the screw and the nut is coupled to the main rotational drive, while the other is movable relative to the rollers both translationally and rotationally. The roller screw mechanism also has an annular guide for circumferential and axial retention of the rollers. The annular guide contains a cylindrical sleeve that extends axially outward from one of the annular heels beyond the nut. The screw extends into a bore of the sleeve, and the sleeve is coupled to a secondary rotational drive.

Abstract: A ball screw drive comprises a spindle that includes a torque input portion and a body portion having a ball-screw drive inner raceway, wherein the body portion and torque input portion are met by a support bearing portion of the spindle that includes a support-bearing inner raceway grooved into a surface of the spindle, an outer ring including a support-bearing outer raceway and forming a channel with the support-bearing inner raceway of the spindle, and one or more support-bearing rolling elements arranged in the channel to contact the support-bearing inner raceway grooved into the surface the spindle.

Abstract: A roller screw system includes a spindle defining a longitudinal axis about which the spindle rotates. A nut at least partially radially surrounds the spindle. The nut is configured for longitudinal motion with respect to the spindle. At least one non-helically grooved roller is interposed radially between the spindle and the nut. A cage maintains the at least one roller in position radially between the spindle and the nut and supports the at least one roller for rotational motion. The nut is moved in longitudinally in a duty cycle responsive to transmission of rotational motion from the spindle to the at least one roller, and transformation of rotational motion of the at least one roller to longitudinal motion of the nut. A home position of the nut and a home position of the cage both move longitudinally after a predetermined number of duty cycles.

Abstract: A valve assembly for use with an unmanned aerial vehicle is provided and includes an inlet tube, a shuttle, a base plate, a screw assembly, and a spacer block. The shuttle is partially disposed within the inlet tube and is configured to be placed in a first position where the shuttle abuts the inlet tube and a second position where the outer surface is disposed in spaced relation to the inlet tube. The base plate extends between a first end portion that defines a cavity therein and a second end portion. The screw assembly is disposed within the cavity of the base plate and is coupled to a portion of the shuttle. The spacer block is interposed between the second end portion of the inlet tube and the first end portion of the base plate and is configured to maintain the inlet tube and the base plate in spaced relation.

Abstract: The invention relates to a roller screw mechanism comprising a screw (110) provided with an external thread; a nut (130) coaxially surrounding the screw (130) and provided with an internal thread; and rollers (120), each of which is provided with an external thread, each roller (120) being interposed between the screw (110) and the nut (130) so that the threads of the rollers mesh with the threads of the screw and of the nut; said roller screw mechanism being characterized in that the threads of the rollers are complementary to the threads of the screw and of the nut so that, at zero load, the threads of the rollers co-operate on both of their flanks with the threads of the screw and of the nut in a contact geometry having curvilinear segments.

Abstract: A bearing screw transfer device which converts a rotational motion of a screw shaft into a linear motion by the medium of a bearing is disclosed. The bearing screw transfer device has a first driving bearing and a second bearing which run along a screw groove of a rotating screw shaft, thereby converting a rotational force of the screw shaft into a translational force of an operating plate disposed on an upper portion of the screw shaft, wherein a two-surface screw groove is formed on the screw shaft, and an outer ring of the first driving bearing runs in contact with one surface of the two-surface screw groove, and an outer ring of the second driving bearing runs in contact with the other surface of the screw groove.

Abstract: The present disclosure relates to a separable roller screw assembly comprising: a first screw shaft having a first external thread and being axially separated from a second screw shaft having a second external thread; a planetary roller arrangement comprising multiple rotatable rollers radially arrayed about the first and second screw shafts, whilst being encapsulated by a rotatable nut module; the rotatable nut module being coaxially arranged about the first and second screw shafts and configured for maintaining the planetary roller arrangement, the first and second screw shafts in an axially fixed configuration to permit the assembly to carry a load in an axial direction corresponding to an axial tensile force, whilst enabling displacement of the first screw shaft relative to the second screw shaft when said assembly is released from said axially fixed configuration; and wherein each one of the multiple rollers comprises first and second roller external thread regions adapted to engage said first external t

Abstract: A semi-active anti-roll stabilizer bar capable of controlling the stiffness thereof by virtue of the elastic force of a spring is disclosed. When the stabilizer bar is rotated during general travelling, the stabilizer bar has roll stiffness attributable to the repulsive force due to the spring constant thereof. When the stabilizer bar is greatly rotated during turning of the vehicle, the springs are closely compressed, with the result that the stabilizer bar has the same high stiffness as that of a general stabilizer bar.

Abstract: The present disclosure relates to a cage reset planetary roller screw device comprising a male thread member provided with a male thread and a female thread member provided with a female thread, a number of planetary rollers disposed between the male thread and the female thread. The planetary rollers are disposed between the male thread and the female thread through a cage, and the planetary rollers are disposed in roller retaining pockets of the cage. The side surfaces of the cage are provided with convex ends. The male thread member and/or the female thread member are provided with limit blocks that are in contact with the convex ends of the cage in the circumferential direction of the cage.

Abstract: A mechatronic device, such as a rod-style linear actuator, is disclosed having a shock absorber. In embodiments, the device includes a threaded screw that, when rotated, is also forced to move linearly. A drive nut assembly is disposed about the screw and includes a planetary roller assembly with planetary rollers with threading that engage the threaded screw. The shock absorber is disposed linearly adjacent to the planetary roller assembly and is configured to absorb and/or dissipate a static shock load transmitted through the device so as to protect the screw. The shock absorber may be a polymeric cylindrical member disposed about the screw and contacting the planetary roller assembly via springs.

Abstract: A planetary roller screw mechanism includes a screw shaft provided with at least one external thread, a nut provided with at least three internal threads and at least three rollers arranged, radially with respect to a central axis of the screw shaft, between the screw shaft and the nut. Each roller is provided with at least two external threads. The number of external threads of the screw shaft is a multiple of the number of external threads of a roller. The number of internal threads of the nut is a multiple of the number of external threads of a roller.

Abstract: An electric actuator includes a threaded rod turned by a motor, the threaded rod having a drive zone extended on each side by threaded zones, one of the threaded zones collaborating with a stationary nut and the other of the threaded zones collaborating with a nut secured to a control member capable of translational movement along an axis parallel to the axis of the threaded zone, the threaded rod being moved with a helical motion.

Abstract: An actuating device having a longitudinal shaft, an internal sleeve, an external sleeve, internal screw connecting means provided between the longitudinal shaft and the intermediate sleeve, external screw connecting means provided between the intermediate sleeve and the external sleeve. The direct efficiency of the internal screw connecting means is higher than the direct efficiency of the external screw connecting means. The self-releasable coupling means are provided between the longitudinal shaft and the internal sleeve.

Abstract: A linear actuator comprises a roller screw mechanism guided in rotation with respect to a structure by two angular-contact ball bearings, the roller screw mechanism comprising rollers interposed between an endless screw and two tapped rings which are joined together in rotation and free in translation. Each tapped ring is secured to an inner ring of a ball bearing. The linear actuator further comprises a single preloading device capable of applying load between two outer rings of the angular-contact ball bearings respectively, thereby simultaneously allowing the loading of the roller screw mechanism and the rotational guidance of the roller screw mechanism with respect to the structure.

Abstract: A reciprocating linear pushrod includes a base, a transmission mechanism and a moving mechanism. The transmission mechanism includes a motor and a rotary shaft, and the rotary shaft has a threaded portion including a left-handed thread groove and a right-handed thread groove crossed with each other, and both ends of the left-handed thread groove are communicated to both ends of the right-handed thread groove respectively. The moving mechanism includes a moving rod and a crescent member, and the moving rod has an axial hole and a radial hole and is sheathed on the rotary shaft by the axial hole, and the crescent member is accommodated in the radial hole and embedded into the threaded portion, so that the moving mechanism can be moved reciprocally according to the rotation of the rotary shaft, and this disclosure has the effects of reducing the total volume and simplifying the structure significantly.

Abstract: A motion conversion mechanism includes: a cylindrical body having an internal screw and third gear teeth in an inner periphery thereof, the internal screw being provided in a screw region that is an intermediate region in an axial direction of the cylindrical body; a shaft body disposed coaxially with the cylindrical body inside the cylindrical body and having first gear teeth and a first external screw in an outer periphery thereof; and a plurality of planetary rollers. First planetary rollers among the planetary rollers mesh with the gear teeth formed in a first gear region and do not mesh with the gear teeth formed in a second gear region, and second planetary rollers among the planetary rollers mesh with the gear teeth formed in the second gear region and do not mesh with the gear teeth formed in the first gear region.

Abstract: A high load capacity bearing that includes a cylindrical outer sleeve that fits around a separable cylindrical outer race assembly. The outer race assembly includes a set of non-helical grooves formed on its inside surface that mesh and engage teeth formed on the outside surface of a plurality of rotating rollers that are longitudinally and axially aligned inside the outer race assembly. The rollers are longitudinally aligned and evenly space apart and rotated as a unit inside the outer race assembly. Located inside the rollers is an inner race with non-helical grooves formed on its outside surface that mesh and engage the teeth on the rollers. The inner race includes a smooth inside bore that fits around the support surface on a shaft. During use, the inner race is becomes fixed on a support surface on a shaft and the outer sleeve and outer race assembly are mounted on a part.

Abstract: A hand tool with a mechanical linear drive mechanism coupled to a linear activated working implement. The drive mechanism includes a geared planetary roller screw that includes a torque tube connected to a roller screw's nut body. The planetary roller screw includes a fixed outer race, a rotating set of grooved rollers axially aligned inside the outer race, a cylindrical nut body located inside the set of grooved roller, a plurality of inner rollers axially aligned and inside the nut body, a threaded shaft axially aligned and inside the inner rollers, and a torque tube axially aligned inside the inner rollers. The torque tube is connected at one end to a gear box which is coupled to an electric motor. When the electric motor is activated, the torque tube is rotated which causes a threaded shaft in the tool to move axially. A working implement is coupled to the distal end of the threaded shaft.

Abstract: A roller screw mechanism comprising a screw, provided with an outer thread, a nut positioned around and coaxially to the screw, the nut being provided with an inner thread, and a plurality of rollers inserted between the screw and the nut, each comprising an outer thread engaged with the outer thread of the screw and with the inner thread of the nut. Each of the threads of the screw, rollers and nut comprise first and second axially opposite flanks, respectively forming a first and second angle with a plane perpendicular to the central axis of the screw, the first and second flanks of each thread of the rollers respectively being in contact with the first and second flanks of the nut's thread and with the first and second flanks of the screw's thread. The value of the first angle is different from the value of the second angle.

Abstract: A transmission device for controlling the translational movement of an element includes: an exterior planetary gear equipped interiorly with teeth; an interior planetary gear connected to the controlled element and bearing a rack in the direction of translation; a satellite carrier having satellites with helical teeth engaged with the interior teeth; and a stationary housing accommodating the exterior planetary gear, the interior planetary gear, the satellite carrier. The rack is used to control the translational movement of the interior planetary gear. The transmission device is driven by a motor with a transmission acting either on the exterior planetary gear or the satellite carrier.

Abstract: The roller screw mechanism is provided with a screw including an external thread, with a nut arranged about and coaxial with said screw, the nut including an internal thread, and with a plurality of rollers inserted between the screw and the nut and each including an external thread engaging the external and internal threads of said screw and of said nut. The screw is axially moveable in relation to the rollers. The flanks of the thread of the screw have a concave profile in cross section.

Abstract: A nut (1, 13, 21, 25) for a planetary roller screw drive is provided. A sleeve (14) which is produced by metal forming is provided, and two rings (16) that lie at a fixed distance with respect to each other in the axial direction are provided in this sleeve. In order to engage planets (3), the one ring (16) has the one groove profile (18), and the other ring (16) has the other groove profile (18).

Abstract: An electronic coolant valve mechanism with an integral actuator mechanism. The coolant valve mechanism utilizes an electric motor and a planetary roller mechanism integrated into a valve body to translate and operate a valve member in a linear direction. A manifold can include a plurality of coolant valve mechanism operating independently by a control system.

Abstract: A planetary roller gear drive with a spindle nut (1) that is arranged on a threaded spindle (2) and with planets (3) that are arranged distributed around the periphery and are in rolling engagement with the spindle nut (1) and the threaded spindle (2). The planets (3) revolve on planetary orbits (P) that are arranged perpendicular to the spindle axis and the planets (3) are each divided into multiple planet parts arranged one behind the other in the axial direction.

Abstract: The roller screw mechanism is provided with a screw comprising an external thread, with a nut arranged around and coaxial with the said screw, the nut comprising an internal thread, and with a plurality of rollers interposed between the screw and the nut and comprising flanks interacting with the said threads. The value of the opening angle ? of the flanks of the external thread of the screw is greater than the value of the opening angle of the flanks of the rollers.

Abstract: An actuator has planetary rollers disposed between a rotor shaft of an electric motor and an outer ring member fixed around the rotor shaft. The planetary rollers are rotated about the axis of the rotor shaft and about their own axes, thereby converting rotary motion of the rotor shaft to linear motion of the planetary rollers A helical groove is formed in the radially outer surface of each planetary roller in which a helical rib formed on the radially inner surface of the outer ring member is received. The helical groove has a pitch equal to that of the helical rib and a lead angle different from that of the helical rib. The amount of the linear motion of the planetary rollers relative to the amount of the rotary motion of the rotor shaft is determined by the difference in lead angle between the helical groove and the helical rib.

Abstract: In an electric linear motion actuator, it is proposed to uniformly distribute external thrust loads to respective planetary rollers while the planetary rollers are revolving around a rotary shaft while rotating about their respective axes with a helical rib of an outer ring member in engagement with circumferential grooves of the respective planetary rollers. The planetary rollers have bearing support surfaces on which thrust bearings are supported, respectively. The distance from the bearing support surface of each planetary roller to a predetermined reference position of each circumferential groove (6a) of the planetary roller is different from the corresponding distances for the other planetary rollers, whereby with the planetary rollers supported by the respective thrust bearings, the axial position of each circumferential groove coincides with the axial position of the portion of the helical rib of the outer ring member that is engaged in the circumferential groove.

Abstract: The invention relates to a rotolinear actuator that comprises: a central rod having an outer thread and surrounded by a ring with an inner thread, and threaded satellite rollers distributed between the central rod and the outer ring engaged with the threaded faces thereof. The actuator includes means for dispensing by capillarity a liquid lubricant at least one contact area of at least one satellite roller with the central rod and with the outer ring, wherein the lubricant is economically dispensed by capillarity in an amount that is just sufficient and precisely at the contact locations of the interacting members, from a tank that may be sufficient for the lifetime of the actuator.

Abstract: In an electric linear motion actuator for transmitting torque of a rotary shaft (4) to planetary rollers (7) and thus to a linearly driven output member constituted by an outer race member (5), axial movement of a carrier (6) supporting the planetary rollers (7) is restricted, and the outer race member (5) is axially slidably fitted in a radially inner surface of a cylindrical portion (1a) of a housing (1) and is rotationally fixedly coupled to an object to be driven via keys (25) The planetary rollers (7) have their radially inner surfaces rotatably supported on respective support pins (6c) of the carrier (6), and are radially inwardly biased by radial compression ring springs (21) wound around the support pins (6c) so as to envelop the support pins. The planetary rollers (7) are thus pressed against the radially outer surface of the rotary shaft (4).

Abstract: A rotational-to-linear conversion mechanism inhibits interference from occurring in places except for an engagement site to increase the efficiency of conversion mechanism and reliability, which has: a rack rod 1 including thread on its outer peripheral face; a holder member 3 provided on the outer periphery of the rack rod, rotating about the rack rod and moving in the axis direction; and revolving rollers 21 rotatably supported in the holder member, each having ring-shaped grooves formed in its outer peripheral face to be engaged with the thread, and placed at an axis angle with respect to a center axis of the rack rod to allow the ring-shaped grooves to be engaged with the thread on the rack rod. A contact face of the thread with each ring-shaped groove in an engagement site of the thread and the ring-shaped groove is formed as a convex face having different curvatures in a radial direction.

Abstract: A mechanism for converting rotary motion into linear motion includes a rod having a thread or threaded part at its outer peripheral surface, and a holder member on the outer peripheral surface of the rod, rotatable relative to the rod, and axially movable relative to the rod. Rollers are supported rotatably by the holder member and have annular grooves at their outer peripheral surfaces. Each roller is torsionally disposed at an axial angle greater than or equal to a lead angle of the thread with respect to a central axis of the rod. Both ends of the roller shaft are secured to the holder member, and the mechanism has a structure in which a hole having a diameter greater than that of the roller shaft is provided at one end of the holder member and the roller shaft is secured by a roller mounting member.

Abstract: A differential roller screw comprises an outer nut, and rolling elements comprising a first set of rollers equipped with first grooves, the first set being arranged in a first cylindrical ring around the screw. The screw comprises a second set of rollers equipped with second grooves. The second set is arranged in a second cylindrical ring. The two cylindrical rings are coaxial. An intermediate cylindrical element is arranged between the two sets of rollers, the intermediate element comprising a first internal thread formed with a first pitch and having a first direction and a second external thread formed with a second pitch and having a second direction opposite the first direction.

Abstract: The roller screw mechanism is provided with a screw including an external thread, with a nut arranged about and coaxial with said screw, the nut including an internal thread, and with a plurality of rollers inserted between the screw and the nut and each including an external thread engaging the external and internal threads of said screw and of said nut. The screw is axially moveable in relation to the rollers. The flanks of the thread of the screw have a concave profile in cross section.

Abstract: A nut (1, 13, 21, 25) for a planetary roller screw drive is provided. A sleeve (14) which is produced by metal forming is provided, and two rings (16) that lie at a fixed distance with respect to each other in the axial direction are provided in this sleeve. In order to engage planets (3), the one ring (16) has the one groove profile (18), and the other ring (16) has the other groove profile (18).

Abstract: An electromechanical linear-motion actuator includes a rotary shaft, a stationary outer race member, and planetary rollers between the rotary shaft and the outer race member to rotate about their own axes and revolve around the rotary shaft axis. A helical rib is on the radially inner surface of the outer race member or the radially outer surface of the rotary shaft. A helical groove or circumferential grooves are formed in a radially outer surface of each of the planetary rollers in which the helical rib is engaged. A planetary carrier axially faces the planetary rollers, and thrust ball bearings are between the planetary carrier and the respective planetary rollers 16 for preventing rotation of the respective planetary rollers 16 from being transmitted to the planetary carrier 17. Each of the thrust ball bearings comprises a raceway formed on an axial end surface of the corresponding planetary roller.

Abstract: Direct drive electromechanical rotary-to-linear actuators include one or more electric motors mounted in a housing. Each motor includes a stator and a rotor. The motor drives a planetary drive mechanism that includes an elongated central shaft having one or more helical threads on an external surface coupled to the rotor for conjoint rotation. A planetary nut having helical threads on an internal surface is disposed concentric to the shaft, and a plurality of planetary rollers are disposed concentrically between the shaft and the planetary nut. Each of the rollers has a helical thread on an external surface that is complementary to and in engagement with a thread of the shaft and a thread of the nut. Rotation of the rotor is converted with mechanical advantage into linear movement of the planetary nut. The actuators provide backlash-free operation, higher stiffnesses, slew rates and frequency responses, and better overall efficiency.

Abstract: A differential roller screw comprises an outer nut, and rolling elements comprising a first set of rollers equipped with first grooves, the first set being arranged in a first cylindrical ring around the screw. The screw comprises a second set of rollers equipped with second grooves. The second set is arranged in a second cylindrical ring. The two cylindrical rings are coaxial. An intermediate cylindrical element is arranged between the two sets of rollers, the intermediate element comprising a first internal thread formed with a first pitch and having a first direction and a second external thread formed with a second pitch and having a second direction opposite the first direction.

Abstract: A motion guide device or ball screw 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 a number of roller bearing elements received and engaged with the roller guiding raceway of the ball nut and the elongated shaft, and the roller bearing elements each include two or more bearing members disposed side by side relative to each other, one of the bearing members includes a coupling member or shaft for engaging with the other bearing member and for pivotally coupling the bearing members together, the bearing members include one or more depressions for receiving a lubricating oil or the like.

Abstract: An actuator has planetary rollers disposed between a rotor shaft of an electric motor and an outer ring member fixed around the rotor shaft. The planetary rollers are rotated about the axis of the rotor shaft and about their own axes, thereby converting rotary motion of the rotor shaft to linear motion of the planetary rollers A helical groove is formed in the radially outer surface of each planetary roller in which a helical rib formed on the radially inner surface of the outer ring member is received. The helical groove has a pitch equal to that of the helical rib and a lead angle different from that of the helical rib. The amount of the linear motion of the planetary rollers relative to the amount of the rotary motion of the rotor shaft is determined by the difference in lead angle between the helical groove and the helical rib.

Abstract: A sun shaft, planetary shafts, and a ring shaft having respective axes of rotation in parallel with one another are provided. A helical sun gear, helical planetary gears, and a helical ring gear are provided on the sun shaft, the planetary shafts, and the ring shaft, respectively, and cooperatively constitute a first planetary gear mechanism. A screw sun gear, screw planetary gears, and a screw ring gear 44 are provided on the sun shaft, the planetary shafts, and the ring shaft, respectively, and cooperatively constitute a second planetary gear mechanism. Either of the gear ratio of the screw sun gear to the screw planetary gears and the gear ratio of the screw ring gear to the screw planetary gears differs from the gear ratio of the helical sun gear to the helical planetary gears and from the gear ratio of the helical ring gear to the helical planetary gears.

Abstract: A rotation/linear motion converting mechanism includes a shaft 1 having an external thread 1a on an outer circumferential surface, a nut 2 having an internal thread 2a on an inner circumferential surface, and a roller 3 arranged between the outer circumferential surface of the shaft 1 and the inner circumferential surface of the nut 2. The roller has a thread 3a threaded to the external thread 1a and the internal thread 2a. A spur gear 3b and a spur gear 3c are provided in portions of the roller 3. A spur gear 1b is provided in a portion of the shaft 1. The spur gear 1b is meshed with the spur gear 3b of the roller 3. Internal teeth 4a are provided in a portion of the nut 2. The internal teeth 4a are meshed with the spur gear 3 of the roller 3. This improves the lead accuracy of the shaft 1 when the nut 2 is rotated.

Abstract: Upon assembly of a mechanism for converting rotary motion into linear motion, since a plurality of rollers are different from one another in the tilt direction with respect to a holder, a difficulty occurs in fixing one end sides thereof to the holder and thereafter making fixation for the other end sides.

Abstract: The invention relates to a rotolinear actuator that comprises: a central rod having an outer thread and surrounded by a ring with an inner thread, and threaded satellite rollers distributed between the central rod and the outer ring engaged with the threaded faces thereof. The actuator includes means for dispensing by capillarity a liquid lubricant at at least one contact area of at least one satellite roller with the central rod and with the outer ring, wherein the lubricant is economically dispensed by capillarity in an amount that is just sufficient and precisely at the contact locations of the interacting members, from a tank that may be sufficient for the lifetime of the actuator.

Abstract: A linear electromechanical actuator, for a steering system of the ‘center take-off’ type in a motor vehicle comprises: two electric motors each having a stator, and a rotor, a screw mechanism having an axially stationary innerscrew coupled to the rotors of the motor for rotating about an axis, and an outer nut rotationally fixed and axially translatable along the axis, a connection block, axially translatable with the nut, for connecting the nut to two tie rods of the steering system.