There is disclosed an improved "harmonic screw" type actuator wherein rotary motion of the power input component is converted into linear motion of the output component by means of a strain wave imposed upon a flexible sleeve member of the assembly, which is flexed into intermittent screw engagement
There is disclosed an improved "harmonic screw" type actuator wherein rotary motion of the power input component is converted into linear motion of the output component by means of a strain wave imposed upon a flexible sleeve member of the assembly, which is flexed into intermittent screw engagement by a member which is motor-driven to rotate relative to the periphery of the flexible sleeve; thereby causing progressively advancing/retreating inter-engagements of thread-like surfaces formed on the axially stationary and axially movable components of the system. A variety of automatic "fail-safe" provisions are included as well as means for manual operation in power loss situations.
대표청구항▼
1. A harmonic screw actuator comprising in combination a pair of inner and outer members coaxially mounted for relative axial movement, the outer member having an internal thread portion and the inner member having external thread portion, the outer diameter of the inner member being less than the i
1. A harmonic screw actuator comprising in combination a pair of inner and outer members coaxially mounted for relative axial movement, the outer member having an internal thread portion and the inner member having external thread portion, the outer diameter of the inner member being less than the inner diameter of the outer member, the external thread portion of the inner member being resiliently deformable radially outwardly into contact with the internal thread portion of the outer member; a plurality of rollers arranged inwardly of the inner member in engagement with peripherally separate portions of the external thread portion; a drive shaft mounted for axial and rotational movement, said rollers being supported for orbital movement in engagement with the peripherally separate portions of the external thread portion incident to rotation of the drive shaft and for outwardly and inwardly directed radial movement to engage and disengage, respectively, the peripherally separate portions of the external thread portion with the internal thread portion of the outer member incident to axially extending movement of the drive shaft relative to the inner member, whereby when the drive shaft is extended axially of the inner member and rotated, the peripherally separate portions of the external thread portion are resiliently deformed into threaded engagement with the internal thread portion and the points of thread engagement advance axially of the internal thread portion to cause the outer member to move axially of the inner member; and means to rotate the drive shaft. 2. The harmonic screw of claim 1, wherein the rollers are pivotally and rotatably mounted on said drive shaft and pivotally and rotatably engaged with the external thread portion of said inner member, the diameters of said rollers being greater than the radial distance between the points of contact which the rollers make with said drive shaft and inner member, whereby axial movement of the drive shaft imparts a radial outward or inward movement to said rollers, thereby engaging or disengaging the external thread portion of said inner member with the internal thread portion of said outer member. 3. The harmonic screw of claim 1, and further comprising a spring means for effecting relative axial movement of said inner and outer members into a fail-safe position defined by said inner and outer members whenever said external thread portion of the inner member is disengaged from the internal thread portion of said outer member. 4. The harmonic screw of claim 1, wherein said means for extending the drive shaft includes a solenoid having an armature coaxially mounted relative to said inner and outer members, and spring means connecting said armature to said drive shaft. 5. A harmonic screw actuator comprising in combination: (a) a rigid cylindrically shaped outer shell member (10) closed at one end portion (12) and open at its other end portion, said closed end portion (12) terminating in an external connection device (14), said outer shell member (10) having an internally threaded portion (15); (b) a cylindrically shaped inner shell member (20) having an axially extending resiliently deformable end portion (16) having an externally threaded portion (18) and an outer diameter less than the inner diameter of said outer shell member (10), said outer shell member (10) is telescopically disposed about said inner shell member 20 for relative axial movement; said inner shell member (20) being open at one end opposite to the closed end portion (12) of said outer shell member (10) and closed at its other end by an end wall portion (28); (c) an end bell (40) extending rigidly from said end wall portion (28) and terminating in an outwardly extending external support connection device (43); (d) a motor (30) mounted upon said end wall (28); (e) an actuator drive shaft (44, 46) axially slidably and rotatably mounted within bearing means (45) carried by said end wall (28); (f) said end portion (16) of said inner shell member (20) being resiliently peripherally deformable and internally trackway grooved (52), and said drive shaft (44, 46) being externally trackway grooved (48); (g) a plurality of rollers (50) arranged in peripherally spaced apart relation to trackway roll around in said grooves (48, 52) in accord with rotations of said drive shaft (44, 46) while being canted out of normal attitudes relative to said end portion (16); (h) the inner track diameters of said grooved portions (48, 52) and of the outer peripheral diameters of said rollers (50) and of said threaded portion (18) and of said threaded portion (15) being so dimensionally related that, whenever said drive shaft (44, 46) is axially extended relative to said inner shell member (20) so as to cause said rollers (50) to individually extend radially towards normal attitudes relative to said end portion (16), peripherally separate portions of said threaded portion (18) are resiliently deformed into threaded inter-engagement with said threaded portion (15), whereby when said drive shaft (44, 46) is in axially extended position so as to inter-engage said threaded portions (15, 18) and is rotated, the points of thread engagement of thread portion (18) advance axially relative to said thread portion (15) and cause said relative axial movement between said outer shell member (10) and said inner shell member (20); (i) means (84, 97) operable to cause said drive shaft (44, 46) to be axially extended; and (j) means (30, 97) operable to cause said drive shaft (44, 46) to rotate. 6. An actuator as set forth in claim 5 wherein said end wall portion (28) is flexible to permit said motor (30, 31) to readily adjust to alignment variations of said drive shaft (44, 46) relative to said end portion (16). 7. An actuator as set forth in claim 5 wherein said rollers (50) are housed within cage means (54) operating to maintain said rollers in uniformly peripherally spaced apart relation. 8. An actuator as set forth in claim 7 wherein said drive shaft (44, 46) includes radially projecting shoulder means (91, 93) limiting axial translation of said cage (54) and said rollers (50) relative to said drive shaft (44, 46) so as to prevent displacements of said rollers (50) from said grooves (48, 52). 9. An actuator as set forth in claim 5 wherein spring means (90) is provided to return said actuator to its starting position upon disengagement of said threaded portions (15, 18). 10. An actuator as set forth in claim 9 wherein said spring means (90) compactly encompasses said outer shell (10). 11. An actuator as set forth in claim 5 wherein locking control means (84, 98, 118) are provided to be operable to maintain said shaft (44, 46) and rollers (50) and threaded portions (15, 18) in threaded inter-engaged condition. 12. An actuator as set forth in claim 11 wherein the resiliency of said end portion (16) operates to return said drive shaft (44, 46) to non-extended position upon release of said locking control means (84, 98, 118). 13. An actuator as set forth in claim 11 wherein said locking control means (98) is manually controllable. 14. An actuator as set forth in claim 11 wherein said locking control means (118) is operable in response to a change in temperature. 15. An actuator as set forth in claim 11 wherein said locking control means (118) is operable in response to a mechanical shock imposed on said actuator. 16. An actuator as set forth in claim 11 wherein said locking control means (84) is an electrically energized solenoid and is automatically released upon deenergization thereof. 17. An actuator as set forth in claim 16 wherein the major portion of said valve shaft (44) is formed of non-magnetic material and terminates in a driver portion (46) in which said grooves (48) are provided, and which is formed of long-wearing hardened steel. 18. An actuator as set forth in claim 16 wherein said locking control means (84) is controlled by smoke detector means (130). 19. An actuator as set forth in claim 16 wherein said locking control means (84) includes an axially slidable armature (85) arranged to bias said drive shaft (44, 46) to extend axially. 20. An actuator as set forth in claim 19 including a manually adjustable latching device (98) which is automatically unlatched whenever said solenoid (84) operates to cause said drive shaft (44, 46) to shift axially. 21. An actuator as set forth in claim 19 wherein said solenoid armature (85) is arranged to axially thrust against a bearing device (56) carried by said drive shaft (44, 46) for axial displacements thereof. 22. An actuator as set forth in claim 21 wherein said solenoid (84) operates through means in the form of an axially resilient interconnection device (60).
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이 특허에 인용된 특허 (5)
Vergues Jacques (Valence FRX) Rubet Roland (Chabeuil FRX), Disconnectable electromagnetic eccentric actuator.
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