Fail-free actuator assembly
AssigneeGEC-Marconi Aerospace Inc.
InventorsDavid J. C. Crook, Eugene E. Shube
Life of this patent
Estimating the term…
Abstract
An electro-mechanical actuator has two motors which normally operate at the same speed and combine (sum) to move a load via a rotary actuator output member. If the motors begin to operate at different speeds, this indicates that the system has failed, and the output member is automatically decoupled from the remainder of the actuator. This leaves the output member free to rotate relative to the remainder of the actuator. The speeds of the motors are monitored by a differential mechanism which produces a rotary output proportional to the average of the two motor speeds. This average is normally the same as the speed of the output member. Decoupling of the output member occurs when this average deviates from the output member speed.
Claims10
An actuator assembly for selectively moving a load comprising:
- first and second drive motors for normally respectively producing first and second rotary outputs;
- first and second transmissions for normally respectively applying said first and second rotary outputs in parallel to a first rotary member in order to normally rotate said first rotary member at a speed proportional to a normally common speed of said first and second rotary outputs;
- third and fourth transmissions for respectively applying said first and second rotary outputs in parallel to a differential mechanism which rotates a second rotary member at a speed proportional to an average of the speeds of said first and second rotary outputs, said speed of said second rotary member being normally the same as the speed of said first rotary member;
- a rotary actuator output member operatively coupled to said load;
- and
- a coupling mechanism responsive to the speeds of said first and second rotary members for transmitting rotary motion of said first rotary member to said rotary actuator output member as long as the speeds of said first and second rotary members are substantially the same, and for freeing said rotary actuator output member for rotation relative to said first rotary member when the speeds of said first and second rotary members begin to deviate from one another.
Dependencies are inferred from the claim text.