What’s a Ball Screw?

May 15, 2017

What’s a ball screw you say?  Isn’t that a pitch no longer used by baseball players?  No wait wait, I think I was served some drinks one time by that name.  I recall waking up the next morning with a severe headache.  Actually, those were screwballs, not to be confused with ball screws — as is commonly used on aircraft designs.
 

Ball screws are a type of actuator which are typically used to drive aircraft components like flaps, slats, landing gears, doors and other control surfaces. In fact, ball screw actuators account for some of the deep "wrrrr" noises you hear in the cabin while on approach in many airliners.  Typically those noises are the ball screws driving the flaps sequentially as you get closer to terra ferma.

 

For us techno-geeks, a ball screw is a mechanical linear actuator that translates rotational motion to linear motion with little friction.  When you see one, its characteristics are unmistakable.  The main attribute being a long rod that is threaded with a ‘ball’ that goes up or down, or right or left, depending on the rotation of the ‘screw’.

 

At S3 Repair Services, a common ball screw we process is for a military transport landing gear.  That screw might rotate at 1080 or 775 Revolutions Per Minute depending on whether the landing gear is being retracted or extended.  Due to high design tolerances and special processes, working on these requires a high degree of attention to detail and specialization…found right here at S3 Repair Services!  And not just ball screws — we also do various Hydraulic, Pneumatic and Electro-Mechanical Actuators.  Yes, we got that covered.  Our portfolio of capabilities transcends just Actuators.  How about Electrical, Electronic, Valves, Wheels, Brakes and Landing Gear?  Yes, that's in our wheel house too!  Read more about our capabilities here.

 

Fun Fact: It’s extremely rare today to find screwball pitchers.  It seems there’s a wide spread belief that employing this pitch can easily damage your arm.