SCOPE
This standard establishes a classification system which may be used to communicate geometrical accuracy specifications of unassembled cylindrical wormgearing with axes at right angles. It also provides information on measuring methods and practices. This standard provides the gear manufacturer and the gear purchaser with a mutually advantageous reference for uniform tolerances and inspection procedures. Tolerance grades 3 through 12 are defined in this standard and are based on the relative effect of geometrical errors on conjugate action for wormgear sets acting as speed reducers.

Tolerances Equations and Tables
Tolerance equations are provided in clause 5 for calculating the maximum values allowed by the specific tolerance grade. Tables are provided in annex A for reference.

Measuring Methods and Practices
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.

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. This standard does not apply to worms with mean diameters larger than 400 mm, nor does it apply to wormgears with mean diameters larger than 2540 mm. This standard does not apply to geometry finer than 0.5 module. This standard does not apply to spiral gears or any type other than cylindrical single enveloping wormgearing.

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 responsibility of the user.

FOREWORD
[The foreword, footnotes and annexes, if any, in this document are provided for informational purposes only and are not to be construed as a part of ANSI/AGMA Standard 2111-A98, Cylindrical Wormgearing Tolerance and Inspection Methods (Metric).]

The purpose of this standard is to establish geometrical accuracy communication between a manufacturer and purchaser of unassembled cylindrical wormgearing with axes at right angles.

AGMA 390.02 September 1964 was a replacement for AGMA 234.01 for fine pitch wormgearing. ANSI/AGMA 2000-A88 is a partial revision of AGMA 390.03, but does not cover wormgearing. AGMA 390.03a of 1988 still only covered fine pitch wormgearing. ANSI/AGMA 2111-A98 then is a replacement for AGMA 390.03a for fine pitch wormgearing. In addition, it also covers coarse pitch wormgearing.

The Cylindrical Wormgearing Committee began working on this standard in August, 1993. At that time, it was determined the International Standards Organization’s (ISO) method for tolerance grades would be used in this standard.

ANSI/AGMA 2111-A98 was approved by the AGMA membership in June, 1998 and approved as an American National standard on October 1, 1998.

Reaffirmed November 2020

ISBN: 1-55589-717-7 

Pages: 43