Self-damping actuator

A method of controlling actuator velocity, the method comprising:

• urging movement of an output member of an actuator at a first output member velocity;
• urging, by a fluid actuator assembly, based on movement of the output member at the first output member velocity, fluid flow at a first fluid flow velocity through a fluid velocity resistor configured to provide a predetermined resistance to fluid flow;
• urging, by the fluid actuator assembly, based on movement of the output member at the first output member velocity, fluid flow at a second fluid flow velocity through a fluid velocity fuse configured to flow fluid flows having a first predetermined range of fluid velocities and to block fluid flows having second predetermined range of fluid velocities, wherein the second fluid flow velocity is within the first predetermined range of fluid velocities;
• permitting, by the fluid velocity fuse, fluid flow through the fluid velocity fuse based on the second fluid flow velocity being within the first predetermined range of fluid velocities;
• urging movement of the output member at a second output member velocity, different from the first output member velocity;
• urging, by a fluid actuator assembly, based on movement of the output member at the second output member velocity, fluid flow at a third fluid flow velocity through the fluid velocity resistor;
• and
• urging, by the fluid actuator assembly, based on movement of the output member at the second output member velocity, fluid flow at a fourth fluid flow velocity through the fluid velocity fuse, wherein the fourth fluid flow velocity is different from the second fluid flow velocity, and wherein the fourth fluid flow velocity is within the second predetermined range of fluid velocities;
• and
• blocking, by the fluid velocity fuse, fluid flow through the fluid velocity fuse based on the fourth fluid flow velocity being within the second predetermined range of fluid velocities.

A turbofan engine system comprising:

• a turbofan engine;
• a nacelle surrounding the turbofan engine and defining an annular bypass duct through the turbofan engine to define a generally forward-to-aft bypass air flow path;
• a thrust reverser having at least one output member, movable to and from a reversing position where at least a portion of bypass air flow is reversed;
• an actuator coupled to the at least one output member to move the at least one output member into and out of the reversing position;
• a source fluid reservoir;
• a fluid velocity resistor configured to provide a predetermined resistance to fluid flow;
• a fluid velocity fuse configured to flow fluid flows having a first predetermined range of fluid velocities and to block fluid flows having second predetermined range of fluid velocities;
• and
• a fluid actuator assembly configured to urge fluid flow from the source fluid reservoir through the fluid velocity resistor and the fluid velocity fuse based on actuation of the output member.