AGMA 927-A01 pdf free.American Gear Manufacturers Association – Load Distribution Factors – Analytical Methods for Cylindrical Gears.
The terms used, wherever applicable, conform to
ANSI/AGMA 101 2-F90.
NOTE: The symbols and definitions used in this standard may differ from other AGMA standards. The user should not assume that familiar symbols can be used without a careful study of their definitions.
The symbols and terms, along with the clause numbers where they are first discussed, are listed in alphabetical order by symbol in table 1.
3.1 Load distribution factor
The load distribution factor, KH, modifies the rating equations to reflect the non-uniform distribution of load along the gear tooth lines of contact as they rotate through mesh. In past AGMA standards, the variables Cm and Km have been associated with this factor. In ISO standards, the variables KHp. KH(L, KF and KF1, have been associated with the factor. In current AGMA standards the load distribution factor, KH, is used for both pitting resistance and bending strength calculations. There is no separate value, KB for bending strength as found in ISO standards.
The magnitude Of KH is affected by two components, transverse load distribution factor and face load distribution factor.
The transverse load distribution factor pertains to the plane of rotation and is affected primarily by the correctness of the profiles and indexing of the mating teeth. Standard procedures to evaluate it have not been established and it is assumed to be unity in this information sheet.
The face load distribution factor is the focus of this information sheet.
3.2 Target mesh
The target mesh is that mesh for which load distribution is being analyzed. The target mesh includes a target pinion and a target gear.
This information sheet presents an iterative analytical method for determining a value of load distribution factor. The iterative method combines the calculated elastic deflection of the pinion and the gear with other misalignments. The result defines a “mesh gap” in the base tangent plane which is the net mismatch between the gear and the pinion. The teeth in mesh are modeled by an equally spaced series of independent parallel compression springs which represent the mesh stiffness. The mesh gap is then mathematically closed by compressing the springs until the sum of the spring forces equals the total tooth force.
The method has the ability to consider the following influences:
– tooth alignment deviations of pinion and gear;
– tooth alignment and crowning modification;
– alignment of the axes of rotation of the pinion and gear, including bearing clearances and housing bore alignment;
– mesh elastic deflections due to Hertzian contact and tooth bending;
– shaft elastic deflections due to twisting and bending, resulting from the target mesh loads and loads external to the mesh.
Influences that may be accounted for by estimating values and including them as equivalent misalignments of the target shaft axes are:
– elastic deflection of a gear body if it is not a solid disk (such as a spoke gear).AGMA 927 pdf free download.