US 5,287,700 AGranted

Flexible bellows actuation system

AssigneeMcDonnell Douglas Helicopter Company

InventorsJeffrey M. Hein, Richard Piechowicz

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Abstract

A closed loop fully self-contained actuation system for converting a mechanical input motion into a mechanical output motion, which actuates a device such as a flight control surface on an aircraft, comprises an input actuator including a first fluid pressurizing means responsive to the mechanical input motion, and an output actuator including a second fluid pressurizing means, as well as a flexible fluid line extending between the first and second fluid pressurizing means to provide fluid communication therebetween. The second fluid pressurizing means is responsive to fluid flow through the fluid line, thereby initialing the output motion. The system is advantageous because it requires no hydraulic pumps, no accumulators, no reservoirs, and no dynamic seals or mechanical joints, permitting great reliability. The actuation system may be easily folded in conjunction with the apparatus on which it is employed, for compact storage.

Claims11

Dependent claims

An actuation system for converting a mechanical input motion into a mechanical output motion wherein said mechanical output motion actuates a device, said actuation system comprising:

an input actuator including a first fluid pressurizing means, a housing, an input actuator shaft extending into said housing, and a first guided piston assembly connected to said input actuator shaft, said first fluid pressurizing means comprising a first bellows and a second bellows, each having fluid therein and being arranged generally end-to-end, said input actuator shaft being adapted to move in response to said mechanical input motion and said first guided piston assembly being adapted to travel linearly in response to motion of said shaft, a portion of said first guided piston assembly being positioned between said first and second bellows;
an output actuator including a second fluid pressurizing means;
and
a flexible fluid line extending between said first and second fluid pressurizing means and providing fluid communication therebetween;
wherein the linear travel of said first guided piston assembly compresses one of said two bellows, thereby pressurizing the fluid therein and forcing it through said fluid line into said second fluid pressurizing means, said second fluid pressurizing means being responsive to said pressurized fluid and thereby initiating said mechanical output motion.

2 more elements

An actuation system for converting a linear mechanical input motion into a rotary mechanical output motion wherein said mechanical output motion actuates a device, said actuation system comprising:

an input actuator including a first fluid pressurizing means;
an output actuator including a second fluid pressurizing means, a housing, an output actuator shaft extending into said housing, and a guided piston assembly connected to said output actuator shaft;
a flexible fluid line extending between said first and second fluid pressurizing means and providing fluid communication therebetween, said first fluid pressurizing means being responsive to said mechanical input motion to pressurize fluid therein and force said fluid into said fluid line;
said guided piston assembly being arranged to interact with said second fluid pressurizing means in such a manner as to travel linearly in response to the influx of said pressurized fluid into said second fluid pressurizing means from said fluid line;
said output actuator shaft having first and second opposed spiral grooves extending along its length, said guided piston assembly having a drive connection mechanism mounted thereon, said drive connection mechanism having a first portion thereof which fits into said first groove and a second portion thereof which fits into said second groove, such that when said guided piston assembly travels linearly in response to the influx of said pressurized fluid into said second fluid pressurizing means, said drive connection means first and second portions travel along said spiral grooves, thereby rotating said output actuator shaft and initiating a rotary mechanical output motion.

2 more elements

Dependencies are inferred from the claim text.