ISO 53:1998 pdf download.Cylindrical gears for general and heavy engineering一Standard basic rack tooth profile
1 Scope
This International Standard specifies the characteristics of the standard basic rack tooth profile for cylindrical involute gears (external or internal) for general and heavy engineering.
This International Standard applies to the standardized modules specified in ISO 54.
The defined profile does not take into account the possible cut-off of the height of internal teeth. This height is to be calculated for each case.
The standard basic rack tooth profile defined in this International Standard constitutes a geometrical reference for a system of involute gears in order to fix the sizes of their teeth. It does not constitute a definition of a cutter, but a cutter may be defined from this standard basic rack tooth profile in order to realize a conforming profile.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.
ISO 54:1996, Cylindrical gears for genera! and for heavy engineering — Modules.
ISO 1122-1:1998, Vocabulary of gear terms — Part 1: Definitions related to geometry.
3 Terms and definitions
For the purposes of this International Standard, the terms and definitions given in ISO 1122-1 and the following apply.
A.1 Application of basic rack forms
Alternative basic rack tooth profiles may be used based on application requirements
-Standard basic rack tooth profile type A is recommended for gears transmitting high torques.
- Basic rack tooth profile types B and C are recommended for normal service. Type C may be applied for manufacturing with some standard hobs.
- Basic rack tooth profile type D is equivalent to a full radius form for the fillet. The enlarged dedendum,h= 1,4 m, with the associated fllet radi, Pp = 0,39 m, permits the finishing tool to work without interference,while maintaining the maximum fllet radius. This profile is recommended for high-precision gears transmitting high torques and consequently with tooth flanks finished by grinding or shaving. Care should be taken to avoid creating notches in the fllet during finishing, which would create stress concentrations.
Characteristics of the basic rack tooth profile types are given in table A.1.ISO 53 pdf download.