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:

“The 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.”

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?

AGMA’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?

AGMA’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?

AGMA’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:

“Pnd is normal diametral pitch (in-1), where 0.5 ≤ Pnd ≤ 20;”

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?

AGMA’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 ≤ mn ≤ 50
  • 5 ≤ z ≤ 1000 or 10 000/mn, whichever is less
  • 5 ≤ dT ≤10 000 mm