AGMA 909-A06 pdf free.AMERICAN GEAR MANUFACTURERS ASSOCIATION Specifications for Molded Plastic Gears.
This information sheet is intended to aide the designer to select an appropriate set of specifications that will clearly convey to the producer what is required. Implications and reasons for the design specifications are discussed. Suggested data forms are given in annexes A. B and C.
1.1 Types of gears and processes
These specifications cover the types of plastic gears commonly manufactured by injection molding. Specifications are described for involute external and internal spur and helical gears. Less common bevel and face gears are not covered here because their specifications are significantly different, although they can be injection molded. Gears made by methods other than injection molding may require other specifications or practices.
2 References
The following documents contain provisions, which, through reference in this text, constitute provisions of this information sheet. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on American National Standards are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below.
ANSI/AGMA 11 06-A97, Tooth Proportions for Plastic Gears (Metric Edition)
AGMA 2000-A88, Gear Classification and Inspection Handbook – Tolerances and Measuring Methods for Unassembled Spur and Helical Gears (Including Metric Equivalents)
3 Symbols
The symbols used in this information sheet are shown in table 1.
NOTE: The symbols and terms contained in this document may vary from those used in other AGMA standards. Users of this information sheet should as sure themselves that they are using these symbols and terms in the manner indicated herein.
4 Gear tooth geometry data
The common method of specifying gear tooth geometry is through a complete list of detailed data, which are unique to gear technology. In engineering drawings part geometry is described in a direct manner, usually with a combination of lines, arcs, and special curves described by a series of data point coordinates. In contrast to this, the size and shape of gear outlines are described by indirect means. These indirect data are based on traditional methods of manufacturing and inspecting gears with some changes or additions associated with the injection molding process. Omission of any of the essential data in the gear designer’s specifications may affect performance, cost, and delivery.
Gear tooth geometry data is often supplied on gear drawings in special tables or formats. The data in such formats are often grouped in categories to convey the different functions of the data. The set of categories described in this section, as listed, and the data assigned to each category, represents one type of specification format among others in common use:
– basic gear data:
– tooth proportions data.AGMA 909 pdf free download.