In the gear industry, gear noise and misalignment are among the most common problems manufacturers come across. A relatively easy solution that gear manufacturers can utilize to fix these problems is a concept called gear crowning.
What is Gear Crowning?
Gear crowning “involves changing the chordal thickness of the tooth along its axis. This modification eliminates end bearing by offering a contact bearing in the center of the gear.” Source: Design World
Solving Gear Noise and Misalignment
Gears can generate unnecessary amounts of noise and vibration when paired together. The sound of metal on metal, coupled with inconsistencies in some production lines, corrosion and natural wear and tear can make for some harsh and grating sounds. As gearboxes get smaller and smaller with advancing technology, it becomes even more difficult to maintain these gears as they naturally age and keep the quality at a level where noise and misalignment don’t become a problem.
By using a process like gear crowning, you can decrease the amount of sound in a gear pairing as well as decrease vibration, which can lead to the longevity of the parts of your assembly. Another common use for crowning is to counter offset loads commonly found in cantilevered gear shafts. In this case the crown on the lead would be offset to the center of the gear face width. By considering the above uses of crowning, as well as others, you will also increase user loyalty when your parts outlast the competitor’s.
Typical Tooth Alignment (Lead) Crown Chart
The above chart depicts a typical format for specifying the amount of crown to produce on the gear. The lead tolerance is determined by the quality level of the gear the design requires. The minimum and maximum crown tolerances are determined by the amount of misalignment or excessive end loading in the system.
Gear Crowning at Gear Motions
Gear Motions is capable of performing gear crowning as part of our full-service gear manufacturing services. Our extensive range of advanced gear manufacturing services also includes precision gear grinding and gear inspection to ensure your products will meet the most demanding performance requirements.