ANSI/AGMA 2003-D19 pdf free.Rating the Pitting Resistance and Bending Strength of Generated Straight Bevel, Zerol Bevel and Spiral Bevel Gear Teeth.
Where applicable AGMA application standards exist, they should be used in preference to this standard. Consult AGMA Headquarters for current list of applicable standards. Where no applicable AGMA application standard exists, numerical values may be estimated for the factors in these general formulas, and approximate pitting resistance and strength ratings calculated.
The use of this standard for specific applications demands a realistic and knowledgeable appraisal of all applicable considerations, particularly of the:
— allowable stress for the material and the number of load repetitions:
— consequences of any percentage of failure (failure rate);
— appropriate safety factor.
3.2 Non-uniform load
When the load is not uniform, a careful analysis of the gear loads should be made. In this analysis, the overload and dynamic factors should be considered. If possible, however, it is preferable to determine all of the different loads that occur during the anticipated life of the gears and the duration of each load. A method based on Miner’s Rule [5] (See Appendix 0) may be used to determine the equivalent life of the gears for the load spectrum.
3.3 Testing
The preferred method to predict overall system performance is to test a specific design. If a full-scale, full- load test is performed to determine the capacity of a gear drive, the test results are a more valid measure of capacity than the calculations outlined in this standard. Verification by full scale full load testing does not require calculation by the methods of this standard.
Where sufficient experience is available from the operation of similar designs, satisfactory guidance can be obtained by the extrapolation of previous test results or of field data, but it is recommended that the calculation methods of this standard be used to compare the designs.
NOTE: When suitable test results or field data are not available, values for the rating factors should be chosen conservatively.
3.4 Manufacturing methods
Bevel gear teeth are formed by cutting, hard-finish cutting or grinding. There are a number of methods for cutting the teeth, dependent upon the volume of parts to be produced, the desired quality and the availability of equipment.
Hard-finish cutting and grinding of the teeth after heat treatment can produce gears of superior quality with good profile finish, root fillet finish, tooth position and concentricity. Properly hard-finished bevel gears will retain their residual compressive stresses introduced during heat treatment (see 3.8.6).
Precision finish, as used in this standard, refers to a secondary machine finish operation which includes grinding, skiving or hard cut finishing. However, the common form of finishing known as lapping is specifically excluded as a form of precision finishing.
3.5 ManufacturIng tolerances
Rating factors should be evaluated on the basis of the expected variation of component parts in the production run.ANSI/AGMA 2003 pdf download.