Basic Facts About Gearhead Backlash and Lost Motion

Basic Facts About Gearhead BacklashWhen it comes to gearheads, any lost motion contributes to position error, can complicate control efforts, and can introduce magnified dynamic loading on components. Many reduction technologies try to minimize lost motion and its effects.  When evaluating various reduction technologies it is usually not sufficient to consider just backlash. You must also think about all of the lost motion contributors, which would include the torsional stiffness of the gearhead.

What is backlash?

For a pair of meshed gears, backlash is the amount by which a tooth space exceeds the thickness of an engaging tooth.  For a gearhead, backlash is the amount of motion the meshed gears have when the input is held fixed.  Torsional stiffness on the other hand may include such things as deflection of components, bearing support, etc.

Theoretically, perfect gears do not require backlash to operate satisfactorily.  However, manufacturing tolerances, bearing dimensions, thermal considerations, and other practical considerations result in unavoidable backlash.

How to select your gearhead mounting kit

How to measure backlash

At Parker we measure the backlash of every Stealth gearhead by locking the input and applying to the output a torque of 2% of the gearheads rated torque.  Measurements are taken at 6 points around an output revolution to ensure constant, low backlash throughout the entire cycle.  Torsional stiffness is maximized with our high tooth to tooth contact ratio, and integral ring gear machined directly into the steel housing.  The combination provides a well-balanced product that will minimize the lost motion of any application.

Basic Facts about Gearhead BacklashArticle contributed by Jeff Nazzaro, Gearhead and Motor Product Manager, Electromechanical Automation North America. Originally published on ParkerMotion.com





Learn more about Parker options in Gearheads by downloading our Gearhead CatalogBasic Facts About Gearhead Backlash



Other posts about gearmotors and gearheads include:

What You Should Know About Gearhead Sealing

When to Use Gearing in Motion-Control Designs Part 1 of 2

When to Use Gearing in Motion-Control Designs Part 2 of 2

How Gearheads Reduce Inertial Mismatches Solving Design Challenges



Have a question about Parker products or services? We can help: Contact Us!

Comments for Basic Facts About Gearhead Backlash and Lost Motion

Please note that, in an effort to combat spam, comments with hyperlinks will not be published.

Leave a comment