ANSI/AGMA 2001-D04 (1), Fundamental Rating Factors and Calculation Methods for Involute Spur and Helical Gear Teeth

Comment restated:

Section 8 on dynamic factor seems to have been updated to include the new ANSI/AGMA 2015-1-A01 tolerance standard. The following paragraph comes from page 14 of that standard:

โ€œThe transmission accuracy level number, Av, can be estimated as the appropriate accuracy grade for the expected pitch and profile deviations in accordance with ANSI/AGMA 2015-1-A01. See annex A for use with AGMA 2000-A88.โ€

ANSI/AGMA 2015-1-A01. p.14

Question 1:

Does this standard (ANSI/AGMA 2001-D04) numerically correlate theAGMA 2015-1 accuracy class number with the value of Av? That is, if one has an AGMA quality class A9 product, we are to select curve Av = 9 from figure 1?

AGMAโ€™s response:

The value of pitch and profile accuracy class as defined by AGMA2015-1 may be used as the value for Av in absence of an evaluation of transmission error as discussed in the standard.


Question 2:

If this is the case, why is there a curve for Av = 12, when AGMA2015-1 only covers quality classes A2 to A11?

AGMAโ€™s response:

The figure was constructed by re-labeling the curves in ANSI/AGMA2001-C95. Although accuracy grade A12 is not directly addressed by ANSI/AGMA 2015-1-A01, there is no evidence that the use of the Av = 12 curve is not proper for lower accuracy gear sets (i.e., Av > 11).


Question 3:

Since AGMA 2015-1 has an applicable range of normal module 0.5 to 50 (i.e., normal diametral pitch 0.508 to 50.8), is the same module range represented by the graph in figure 1?

AGMAโ€™s response:

Figure 1 is not limited as a function of module.


Question 4:

Section 8.3.3 shows an alternate method to estimate a value for Av in equations 25 and 26. Below equation 26 the following is stated:

โ€œPnd is normal diametral pitch (in-1), where 0.5 โ‰ค Pnd โ‰ค 20;โ€

Does this mean that the method is only valid if the diametral pitch is not finer than 20? What can one do if you have a fine pitch gear not specified according to AGMA 2015-1?

AGMAโ€™s response:

Equations 25 and 26 are derived from ANSI/AGMA 2015-1-A01 equations 3 and 4. They have the same range of application as ANSI/AGMA 2015-1-A01 equations 3 and 4, i.e.:

  • Accuracy grades A2 through A11
  • 0.5 โ‰ค mn โ‰ค 50
  • 5 โ‰ค z โ‰ค 1000 or 10 000/mn, whichever is less
  • 5 โ‰ค dT โ‰ค10 000 mm