How Aircraft Systems Rely on Acme Thread Actuators

Christopher Nook by Christopher Nook

Even though the acme thread form was originally developed more than 100 years ago, it has proven to be such a reliable and effective design that actuators driven by screws using this thread have become a staple for providing linear actuation and motion control in today’s modern aircraft for non flight critical applications, as well as in the docking and maintenance equipment used to service airline fleets.

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How Aircraft Rely on Acme Thread Actuators

Even though the acme thread form was originally developed more than 100 years ago, it has proven to be such a reliable and effective design that  actuators driven by screws using this thread have become a staple for providing linear actuation and motion control in today’s modern aircraft for non flight critical applications, as well as in the docking and maintenance equipment used to service airline fleets.

The acme thread form is the original trapezoidal screw thread that was developed back in the late 1800s.  It has a 29° thread angle with a thread height that is half of the pitch, the distance between a point on one thread and a corresponding point on the next thread that is parallel to the axis.  The apex and valley of the thread are flat.  Because the tooth shape of an acme thread has a wider base, it is stronger than a similarly sized square thread.  Thus, a linear actuator using this thread is capable of carrying larger loads, such as those required for aircraft and airplane maintenance actuation systems.

Aircraft Actuator Applications

The acme thread form is utilized in some of the electro-mechanical actuators that are qualified for use in many types of non flight critical linear motion control applications.  The design’s high reliability, ability to move large loads, and history of dependable performance make this thread form ideally suited for aircraft-related actuation systems.  When paired with high quality, aerospace-specific motors, actuators based on this thread form can be configured and weight-optimized to drive a variety of aircraft-related linear motion control systems, including:

  • Auxiliary Power Unit (APU) Inlet Door Actuators
  • Ram Air Door Actuators (which include variable geometry inlet doors, turbofans, and variable exhaust louvers on some aircraft for controlling ram air flow)
  • Utility Door Actuators
  • Landing Gear Uplock Actuators
  • Air Bypass Door Actuators
  • Seat Adjustment Actuators
  • Canopy Actuators
  • Silencer Actuators
  • Airflow Control Actuators
  • Nozzle Actuators
  • Cargo Door Actuators
  • Crew Escape and Emergency Door Actuators

Actuators in Aircraft Docking and Maintenance Systems

To keep passenger jets functioning safely, commercial airline companies perform regular maintenance and annual overhauls of every plane in their fleet.  While regular maintenance is often performed in a hangar or on the tarmac, yearly overhauls require sophisticated equipment to provide maintenance workers with safe, ready access to every part of the plane, from the nose, fuselage, and tail to the landing gear, stabilizers, and wing tips.

This access is typically provided through the use of docking systems and maintenance platforms that require a range of linear motion control systems.  Actuators utilizing acme screws can lift and lower maintenance technicians, aircraft components, and supplies through the use of adjustable stands, sliding decks, and push boards.  Because the loads created by aircraft maintenance docking systems can exceed100,000 pounds, linear actuators must be strong and reliable for safe operation, making acme screws an excellent option.

Use Helix Actuators for Your Aircraft Application

Contact Helix Linear Technologies for your aircraft-related linear actuator needs.  Helix supplies a complete line of acme lead screws that have become proven, vital components in aircraft and aircraft docking and maintenance systems.  With Helix acme lead screws, you will find the combination of reliability and performance that are critical to safe air travel and aircraft maintenance activities.

To learn more about how Helix acme lead screws can dependably meet your aircraft, docking, and maintenance actuator needs, download a copy of our latest Helix catalog.

To learn more about how to choose the best screw thread for your actuator, download our FREE Screw Comparison Matrix Presentation:

Free PDF Presentation: Screw Comparison Matrix