ANSI/AGMA 2011-A98 pdf download.Cylindrical Wormgearing Tolerance and Inspection Methods.
Measuring methods and practices are included in order to promote uniform inspection procedures (see clause 4). These methods permit the manufacturer and purchaser to conduct measuring procedures which are accurate and repeatable to a degree compatible with the specified tolerance grade.
1.3 Exceptions
This standard applies to individual worm and gear components. It does not establish a tolerance grade for enclosed drive assemblies. Establishing ratings based on tolerance grade is beyond the scope of this standard. Gear design and backlash are also beyond the scope of this standard. Refer to the latest AGMA Publications Catalog for applicable standards. This standard does not apply to worms with mean diameters larger than 16 inches, nor does it apply to wormgears with mean diameters larger than 100 inches. This standard does not apply to geometry finer than 0.063 axial pitch. This standard does not apply to spiral gears or any type other than cylindrical single enveloping wormgearing.
1.4 Limitations
The American Gear Manufacturers Association makes no representation, warranty or guarantee in connection with the publication of any AGMA Standard and hereby expressly disclaims any liability or responsibility for loss or damage resulting from their use. Similarly, violation of any federal, state or municipal regulation with which an AGMA Standard may conflict, or for the infringement of any patent resulting from the use of an AGMA Standard is the responsibllity of the user.
2 Symbols, terms and definitions
The symbols, terms and definitions used in this standard are, wherever possible, consistent with ANSI/AGMA 1012-F90 and other approved AGMA documents.
2.1 Symbols
Table 1 is a list of the symbols used in this standard, along with the associated terms. The Where first used column gives the clause or equation number where the particular symbol is first used.
2.2 Definition of terms
axial plane: The axial plane is the plane containing the line of axis of the worm. Diameters may be measured in this plane but thread surtaces would require a theoretical knife edge measurement. These measurements may be obtained by indirect means using normal plane measurements. The probe measurement in Method A will give a direct axial measurement, however, since the normal to probe center is repeated at each point.
datum thread: The designated thread used as the starting point for measuring other threads.ANSI/AGMA 2011 pdf download.