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US 8,418,574 B2Granted
Linear actuator
AssigneeROLLS-ROYCE plc
InventorsTimothy Mark Stephen Myers, Francis Russell Watson
Life of this patent
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Abstract
A combined linear and rotary actuator has a shaft with a screw thread, a nut engaging the screw thread and engaging means movable between a first location where rotation of the turning mechanism produces substantially linear displacement of the shaft, and a second location where rotation of the turning mechanism produces substantially rotary displacement of the shaft. The linear actuator finds particular use on retractable marine propulsor such as used on submarines and the like.
Claims25
A linear actuator comprising:
- a shaft having a thread;
- a rotatable turning mechanism engaging the thread;
- and
- an engaging means movable between a first position where rotation of the turning mechanism produces substantially linear displacement of the shaft, and a second position where rotation of the turning mechanism produces substantially rotary displacement of the shaft,
- wherein the engaging means further comprises
- a sleeve extending around the shaft and having a slot that extends parallel to the shaft, and having a limit stop outside the slot, and
- a pin mounted to the shaft, and
- wherein when the pin abuts against the limit stop, the engaging means prevents rotation of the shaft in a first direction and permits rotation of the shaft in the opposite direction.
5 more elements
A linear actuator comprising:
- a shaft having a thread;
- a rotatable turning mechanism engaging the thread;
- and
- an engaging means movable between a first position where rotation of the turning mechanism produces substantially linear displacement of the shaft, and a second position where rotation of the turning mechanism produces substantially rotary displacement of the shaft,
- wherein the shaft further comprises a travel limiter, which limits the maximum linear displacement of the shaft,
- wherein the rotatable turning mechanism comprises a nut rotatable by a motor,
- wherein the motor is a rim driven motor and the nut is a rotor in the rim driven motor.
4 more elements
A linear actuator comprising:
- a shaft having a thread;
- a rotatable turning mechanism engaging the thread;
- and
- an engaging means movable between a first position where rotation of the turning mechanism produces substantially linear displacement of the shaft, and a second position where rotation of the turning mechanism produces substantially rotary displacement of the shaft,
- wherein propulsion means are mounted to the shaft,
- wherein the propulsion means is a rim driven azimuthing thruster.
3 more elements
Dependencies are inferred from the claim text.