A linear actuator comprising actuator rod 104 extending along stroke axis 102, the rod comprises: first screw thread 108 on the rod outer surface; a sleeve 118 positioned around, and coaxial with, the actuator rod. The sleeve comprises: a second screw thread 120 on the sleeve inner surface engaging the first screw thread, and a third screw thread 128 on the sleeve outer surface. A screw nut 136 engages the third screw thread and is driven by motor 142. In use, the motor applies a torque to the sleeve via the screw nut, when the applied torque is below a threshold value, the sleeve is restricted from rotating about the stroke axis, such that rotation of the screw nut causes linear displacement of the sleeve and actuator rod together along the stroke axis. When the applied torque equals or exceeds the threshold value, the sleeve is able to rotate about the stroke axis, such that rotation of the screw nut causes rotation of the sleeve, and such that rotation of the sleeve causes linear displacement of the actuator rod. This provides a second actuation mode should the first/primary mode jam or fail.
LINEAR ACTUATOR TOLERANT TO JAM FAILURE MODES
LINEARER AKTUATOR MIT STÖRUNGSTOLERANZ GEGENÜBER FEHLERMODI
ACTIONNEUR LINÉAIRE TOLÉRANT DES MODES DE DÉFAILLANCE DE BLOCAGE
2025-07-30
Patent
Electronic Resource
English
Jam-tolerant linear control motor for hydraulic actuator valve
European Patent Office | 2018
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