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 rolling bearing mechanism comprising a rod (110), an outer ring (130) surrounding the rod coaxially, and rollers (120) interposed between the rod (110) and the outer ring (130), with the rod, the outer ring, and the rollers each having a respective right-handed thread and a respective left-handed thread, the left-handed threads (122a) of the rollers meshing with the right-handed thread (112a) of the rod and with the left-handed thread of the outer ring, and the right-handed threads (122b) of the rollers (120) meshing with the left-handed thread (112b) of the rod (110) and with the right-handed thread of the outer ring (130).

Abstract: A rolling bearing mechanism comprising a rod (110), an outer ring (130) surrounding the rod coaxially, and rollers (120)interposed between the rod (110) and the outer ring (130), with the rod, the outer ring, and the rollers each having a respective right-handed thread and a respective left-handed thread, the left-handed threads (122a) of the rollers meshing with the right-handed thread (112a) of the rod and with the left-handed thread of the outer ring, and the right-handed threads (122b) of the rollers (120) meshing with the left-handed thread (112b) of the rod (110) and with the right-handed thread of the outer ring (130).

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 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: A valve operator assembly having a tubular housing extending along a central axis, an input member rotatably mounted with the housing, a transmission mechanism arranged in an inner bore of the housing and extending along the central axis, the transmission mechanism providing a rotating element connected to the input member and a translating element, the transmission mechanism adapted to convert applied rotation of the input member to the rotating element into axial translation of the translating element. At least one rolling bearing is radially arranged between an inner bore and rotating element to support in rotation and guide the rotating element within the housing. The valve operator assembly includes a clutch mechanism to permit transmission of driving torque from the input member to the rotating element in both directions around the central axis, and prevent any back-driving torque from the rotating element to the input member in either direction.

Abstract: A roller screw mechanism has a screw provided with an outer thread, a nut surrounding and coaxial with the screw, the nut being provided with an inner thread, a plurality of rollers radially disposed between the screw and the nut and each provided with an outer thread engaging the outer and inner threads and with two outer gear teeth, and two synchronization gear teeth meshing with the gear teeth of the rollers. The mechanism further includes one retaining cage for the rollers including a plurality of pockets spaced apart one with another in the circumferential direction. At least the outer thread of each roller is located inside the associated pocket of the cage.

Abstract: The invention concerns an operator assembly having a tubular housing extending along a central axis (X1) and a transmission mechanism arranged in an inner bore of the housing and extending along the central axis (X1). The transmission mechanism providing a screw with a threaded outer surface and a nut with a threaded inner surface. The nut is radially mounted around the screw and the inner thread is configured to cooperate with outer thread. The operator assembly further provides angular contact bearings that are radially arranged between the inner bore of the housing and an outer surface of the rotating nut to support in rotation and guide the nut within the housing. The angular contact bearings are axially adjacent and are disposed within an angular contact ball bearing and an angular contact roller bearing.

Abstract: A valve operator assembly is provided for a valve and includes a housing, an input member rotatably mounted with respect to the housing, and a transmission mechanism having a rotating screw provided with an outer thread and a translating nut surrounding and coaxial with the screw, the nut being provided with an inner thread, the transmission mechanism being adapted to convert rotation of the screw into axial translation of the nut. The input member is mounted on the rotating screw. The assembly further includes an outer translating sleeve radially disposed between the housing and the translating nut and adapted to be connected to the valve translating member of the valve. The outer translating sleeve is provided with an inner thread and is connected to the translating nut so as to slide relative to the housing when the rotating screw rotates.

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 valve actuated device for a valve having a valve body and a valve translating member; a housing; a rotary and non-translating sleeve mounted in the housing and connected to an input rotary means; an axial shaft means positioned coaxially to the sleeve and adapted to be connected to the valve translating member; screw connecting means provided between the axial shaft means and the sleeve for convert applied rotation of the sleeve into axial translation of the axial shaft means; anti-rotation and axial guidance means installed between the housing and the shaft means; the anti-rotation and axial guidance means providing a linear ball bearing including a sleeve mounted to the housing and at least one rolling element recirculation system, the rolling elements thereof engaging axial groove of the shaft means.

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: The valve operator assembly is provided for a valve and includes a housing, an input member rotatably mounted, and a transmission mechanism including a translating element and a rotating element connected to the input member, said transmission mechanism being adapted to convert applied rotation of the input member into axial translation of said translating element. The assembly further includes at least one locking mechanism radially interposed between the transmission mechanism and the housing, and provided with friction means in radial contact with the housing, and with at least one pre-stressing element acting on said friction means to maintain said radial contact. The pre-stressing element and the friction means cooperate together to lock the transmission mechanism with the housing in a static position of said assembly.

Abstract: A valve operator assembly for a valve includes a valve body and an axially moveable valve translating member, a housing mounted on the valve, an input member rotatably mounted with respect to the housing, and a transmission mechanism. The transmission mechanism including a translating element connected to the valve translating member and a rotating element connected to the input member. The transmission mechanism configured to convert applied rotation of the input member into axial translation of the translating element. The valve operator assembly providing a spacing element having a tubular shape defining an axial bore through which passes the valve translating member and the translating element of the transmission mechanism. The spacing element connected by intermediate fixing means on the valve body on one end and on the housing on the other end to define cooperating mounting surfaces between the spacing element.

Abstract: A roller screw mechanism has a screw provided with an outer thread, a nut surrounding and coaxial with the screw, the nut being provided with an inner thread, a plurality of rollers radially disposed between the screw and the nut and each provided with an outer thread engaging the outer and inner threads and with two outer gear teeth, and two synchronization gear teeth meshing with the gear teeth of the rollers. The mechanism further includes one retaining cage for the rollers including a plurality of pockets spaced apart one with another in the circumferential direction. At least the outer thread of each roller is located inside the associated pocket of the cage.

Abstract: A valve operator assembly is provided for a valve and includes a housing, an input member rotatably mounted with respect to the housing, and a transmission mechanism having a rotating screw provided with an outer thread and a translating nut surrounding and coaxial with the screw, the nut being provided with an inner thread, the transmission mechanism being adapted to convert rotation of the screw into axial translation of the nut. The input member is mounted on the rotating screw. The assembly further includes an outer translating sleeve radially disposed between the housing and the translating nut and adapted to be connected to the valve translating member of the valve. The outer translating sleeve is provided with an inner thread and is connected to the translating nut so as to slide relative to the housing when the rotating screw rotates.

Abstract: A valve operator assembly having a tubular housing extending along a central axis, an input member rotatably mounted with the housing, a transmission mechanism arranged in an inner bore of the housing and extending along the central axis, the transmission mechanism providing a rotating element connected to the input member and a translating element, the transmission mechanism adapted to convert applied rotation of the input member to the rotating element into axial translation of the translating element. At least one rolling bearing is radially arranged between an inner bore and rotating element to support in rotation and guide the rotating element within the housing. The valve operator assembly includes a clutch mechanism to permit transmission of driving torque from the input member to the rotating element in both directions around the central axis, and prevent any back-driving torque from the rotating element to the input member in either direction.

Abstract: The invention concerns an operator assembly having a tubular housing extending along a central axis (X1) and a transmission mechanism arranged in an inner bore of the housing and extending along the central axis (X1). The transmission mechanism providing a screw with a threaded outer surface and a nut with a threaded inner surface. The nut is radially mounted around the screw and the inner thread is configured to cooperate with outer thread. The operator assembly further provides angular contact bearings that are radially arranged between the inner bore of the housing and an outer surface of the rotating nut to support in rotation and guide the nut within the housing. The angular contact bearings are axially adjacent and are disposed within an angular contact ball bearing and an angular contact roller bearing.

Abstract: The valve operator assembly is provided for a valve and comprises a housing 18, an input member 20 rotatably mounted, and a transmission mechanism 22 comprising a translating element 24 and a rotating element 28 connected to the input member, said transmission mechanism being adapted to convert applied rotation of the input member into axial translation of said translating element. The assembly further comprises at least one locking mechanism 23 radially interposed between the transmission mechanism 22 and the housing 18, and provided with friction means 82 freely movable in circumferential direction relative to the transmission mechanism and to the housing and with one freewheel 80 comprising a plurality of locking members mounted in radial contact with a track of said friction means, the freewheel and the friction means cooperating together to lock the transmission mechanism 22 with the housing 18 in a static position of said assembly.

Abstract: A valve operator assembly for a valve includes a valve body and an axially moveable valve translating member, a housing mounted on the valve, an input member rotatably mounted with respect to the housing, and a transmission mechanism. The transmission mechanism including a translating element connected to the valve translating member and a rotating element connected to the input member. The transmission mechanism configured to convert applied rotation of the input member into axial translation of the translating element. The valve operator assembly providing a spacing element having a tubular shape defining an axial bore through which passes the valve translating member and the translating element of the transmission mechanism. The spacing element connected by intermediate fixing means on the valve body on one end and on the housing on the other end to define cooperating mounting surfaces between the spacing element.