AGMA 2011-A98

This standard establishes a classification system which may be used tocommunicate geometrical accuracy specifications of unassembledcylindrical wormgearing with axes at right angles.It also providesinformation on measuring methods and practices.This standard providesthe gear manufacturer and the gear purchaser with a mutuallyadvantageous reference for uniform tolerances and inspection procedures.Tolerance grades 3 through 12 are defined in this standard and are basedon the relative effect of geometrical errors on conjugate action forwormgear sets acting as speed reducers.

Tolerance equations and tables

Tolerance equations are provided in clause 5 for calculating the maximumvalues allowed by the specific tolerance grade.Tables are provided inannex A for reference.

Measuring methods and practices

Measuring methods and practices are included in order to promote uniforminspection procedures (see clause 4).These methods permit themanufacturer and purchaser to conduct measuring procedures which areaccurate and repeatable to a degree compatible with the specifiedtolerance grade.

Exceptions

This standard applies to individual worm and gear components.It doesnot establish a tolerance grade for enclosed drive assemblies.Establishing ratings based on tolerance grade is beyond the scope ofthis standard.Gear design and backlash are also beyond the scope ofthis standard.Refer to the latest AGMA Publications Catalog forapplicable standards.This standard does not apply to worms with meandiameters larger than 16 inches, nor does it apply to wormgears withmean diameters larger than 100 inches.This standard does not apply togeometry finer than 0.063 axial pitch.This standard does not apply tospiral gears or any type other than cylindrical single envelopingwormgearing.

Limitations

The American Gear Manufacturers Association makes no representation,warranty or guarantee in connection with the publication of any AGMAStandard and hereby expressly disclaims any liability or responsibilityfor loss or damage resulting from their use.Similarly, violation ofany federal, state or municipal regulation with which an AGMA Standardmay conflict, or for the infringement of any patent resulting from theuse of an AGMA Standard is the responsibility of the user.

Edition:

A98

Published:

06/01/1998

ANSI:

ANSI Approved

Number of Pages:

49

File Size:

1 file , 600 KB