How to Specify (AGMA) Face Gear Quality 1

[badpeanut]

What is the proper way to specify quality of a face gear?

AGMA 203.03 (withdrawn specification for face gear design) references AGMA 390.03 for quality. However AGMA 390.03 has been replaced by AGMA 2000-A88 and AGMA 390.03a, and further AGMA 390.03a has been replaced by AGMA 2009-B01 and AGMA 2011-A98. AGMA 2000-A88 definitely does not apply to face gears since "It provides a designation system for quality, materials, and heat treatment of spur, helical (single or double), and herringbone gears." AGMA 2009-B01 appears to apply only to bevel gears and AGMA 2011-A98 appears to apply only to worm gears.

Am I correct in assuming there are no active AGMA specifications for design or quality of face gears?

Should a person reference AGMA 390.03 for quality of a newly designed face gear?

 

[TVP]

I believe you are correct, that there is no active AGMA specification related to face gears. NASA and Boeing have been doing some recent work on face gears for helicopter transmissions, so you may want to review their work. Here is a Google keyword search, narrowed to .pdfs:

http://www.google.com/search?hl=en&...=&as_occt=any&cr=&as_nlo=&as_nhi=&safe=images

 

[TVP]

I meant to include this Gear Technology article from KISSsoft as well:

http://www.kisssoft.ch/english/downloads/pdf/Facegears.pdf

 

[israelkk]

AGMA 390.03 gives accuracy tolerances for individual gears. I do not see any reason why not to adopt and use AGMA 390.03 or AGMA 2000-A88 (same as 390.03 with added metric system). Basically you can use any version of AGMA as long as it is clearly appears in the drawing and agreed with the manufacturer. For face gears the best measuring system will be the use of master gears. You will need a measuring machine that can mesh a face gear with a spur master gear.

 

[tbuelna]

badpeanut,

If your face gear set is conventional, then the pinion is likely a spur gear. So establishing the pinion tolerances for index errors, runout, profile, lead, etc. is generally based on the AGMA standard.

As for the face gear, you must specify the various tolerance requirements yourself and validate them using a CMM or a master gear as israelkk suggests. The CMM will require an accurate surface model of the tooth topology.

Face gears are notorious for heel/toe movement of the tooth contacts under load. So if your face gear mesh is highly loaded or has a high pitch line velocity, you'll likely want perform a TCA to establish that your gears are performing properly. And if not, to help establish any face or profile mods to correct the contact condition. A proper TCA naturally requires a very accurate, refined tooth surface FEM, so once you have that modeled it can also be used for a CMM validation.

AGMA is currently working on a standard (AGMA 916-AXX) for face gears with perpendicular and intersecting axes.

Good luck.
Terry