초록 ▼

In varying embodiments, the fault tolerant linear actuator of the present invention is a new and improved linear actuator with fault tolerance and positional control that may incorporate velocity summing, force summing, or a combination of the two. In one embodiment, the invention offers a velocity

In varying embodiments, the fault tolerant linear actuator of the present invention is a new and improved linear actuator with fault tolerance and positional control that may incorporate velocity summing, force summing, or a combination of the two. In one embodiment, the invention offers a velocity summing arrangement with a differential gear between two prime movers driving a cage, which then drives a linear spindle screw transmission. Other embodiments feature two prime movers driving separate linear spindle screw transmissions, one internal and one external, in a totally concentric and compact integrated module.

대표청구항 ▼

1. A linear actuator comprising:a substantially-cylindrical actuator frame having a principal axis, an electromagnetic field therein, and an internal surface having a thread disposed thereon;a linear output screw having threads disposed thereon, the linear output screw disposed at least partly withi

1. A linear actuator comprising:a substantially-cylindrical actuator frame having a principal axis, an electromagnetic field therein, and an internal surface having a thread disposed thereon;a linear output screw having threads disposed thereon, the linear output screw disposed at least partly within the actuator frame along the principal axis;a first armature disposed within the actuator frame about the principal axis;a first planetary spindle screw set, having threads mated to the threads of the linear output screw, disposed in a first carrier radially-fixed to the first armature about the linear output screw;a second armature disposed within the actuator frame about the principal axis; anda second planetary spindle screw set, having threads mated to the internal threads of the actuator frame, disposed in a second carrier radially-fixed to the second armature. 2. The actuator of claim 1 further comprising a first field coil cylinder axially aligned with the first armature and a second field coil cylinder axially aligned with the second armature. 3. The actuator of claim 2 wherein the first and second field coil cylinders are disposed in an inner motion frame. 4. The actuator of claim 3 wherein the inner motion frame is axially-movable with respect to the actuator frame, but is radially-fixed with respect to the actuator frame. 5. The actuator of claim 1 wherein the first set of planetary spindle screws is disposed in a first carrier and the second set of planetary spindle screws is disposed in a second carrier. 6. The actuator of claim 5 further comprising an inner motion frame axially-movable with respect to the actuator frame, but radially-fixed with respect to the actuator frame. 7. The actuator of claim 6 wherein each planetary spindle screw set is axially-fixed within the inner motion frame but radially-movable, and wherein the first and second carriers are held in the inner motion frame by a set of thrust bearings. 8. The actuator of claim 1 further comprising a set of sensors for constantly monitoring the torque output of each armature. 9. The actuator of claim 1 wherein the first set of planetary spindle screws are disposed at a first axial location along the linear output screw and the second set of planetary spindle screws are disposed at a second axial location along the linear output screw. 10. The actuator of claim 1 further comprising a first brake to lock the radial position of the first armature with respect to the inner motion frame and a second brake to lock the radial position of the second armature with respect to the inner motion frame. 11. A linear actuator comprising:a substantially-cylindrical actuator frame having a principal axis, an electromagnetic field therein, and an internal surface having a thread disposed thereon;a screw shaft having threads disposed thereon, the screw shaft disposed at least partly within the actuator frame along the principal axis and radially-fixed to a clutch plate;an output cylinder;an inner clutch having a first portion radially-fixed to the clutch plate and a second portion radially-fixed to the output cylinder;an outer clutch having a first portion radially-fixed to the output cylinder and a second portion radially-fixed to the actuator frame;a first armature disposed within the actuator frame about the principal axis;a first spindle screw set, having threads mated to the threads of the screw shaft, disposed in a carrier rotatably fixed to the first armature about the screw shaft;a second armature disposed within the actuator frame about the principal axis; anda second spindle screw set, having threads mated to the internal threads of the actuator frame, disposed in a carrier rotatably fixed to the second armature. 12. The actuator of claim 11 further comprising a first field coil cylinder axially aligned with the first armature and a second field coil cylinder axially aligned with the second armature. 13. The actuator of claim 12 wherein the first and second field c oil cylinders are disposed in an inner motion frame. 14. The actuator of claim 13 wherein the inner motion frame is axially-movable with respect to the actuator frame, but is radially-fixed with respect to the actuator frame. 15. The actuator of claim 11 wherein the first set of planetary spindle screws is disposed in a first carrier and the second set of planetary spindle screws is disposed in a second carrier. 16. The actuator of claim 15 further comprising an inner motion frame axially-movable with respect to the actuator frame, but radially-fixed with respect to the actuator frame. 17. The actuator of claim 16 wherein each planetary spindle screw set is axially-fixed within the inner motion frame but radially-movable, and wherein the first and second carriers are held in the inner motion frame by a set of thrust bearings. 18. The actuator of claim 11 further comprising a set of sensors for constantly monitoring the torque output of each armature. 19. The actuator of claim 11 wherein the first set of planetary spindle screws are disposed at a first axial location along the linear output screw and the second set of planetary spindle screws are disposed at a second axial location along the linear output screw. 20. The actuator of claim 11 further comprising a first brake to lock the radial position of the first armature with respect to the inner motion frame and a second brake to lock the radial position of the second armature with respect to the inner motion frame.