Complete Product News for March/April 2002.

For high-quality carburized, case hardened gears, close case carbon control is essential. While tight carbon control is possible, vies on what optimum carbon level to target can be wider than the tolerance.

Welcome to our Software Bits page. Here we feature new software products for gear design, manufacturing and testing.

The goal of gear drive design is to transit power and motion with constant angular velocity. Current trends in gear drive design require greater load carrying capacity and increased service life in smaller, quieter, more efficient gearboxes. Generally, these goals are met by specifying more accurate gears. This, combined with the availability of user-friendly CNC gear grinding equipment, has increased the use of ground gears.

Q&A is your interactive gear forum.

Complete Technical Calendar for July/August 2000.

Until recently, there was a void in the quality control of gear manufacturing in this country (Ref. 1). Gear measurements were not traceable to the international standard of length through the National Institute of Standards and Technology (NIST). The U.S. military requirement for traceability was clearly specified in the military standard MIL-STD-45662A (Ref. 2). This standard has now been replaced by commercial sector standards including ISO 9001:1994 (Ref. 3), ISO/IEC Guide 25 (Ref, 4), and the U.S. equivalent of ISO/IEC Guide 25 - ANSI/NCSL Z540-2-1997 (Ref. 5). The draft replacement to ISO/IEC Guide 25 - ISO 17025 states that measurements must either be traceable to SI units or reference to a natural constant. The implications of traceability to the U.S. gear industry are significant. In order to meet the standards, gear manufacturers must either have calibrated artifacts or establish their own traceability to SI units.

This is the third article in a series exploring the new ISO 6336 gear rating standard and its methods of calculation. The opinions expressed herein are htose of the author as an individual. They do not represent the opinions of any organization of which he is a member.

One of the best ways to learn the ISO 6336 gear rating system is to recalculate the capacity of a few existing designs and to compare the ISO 6336 calculated capacity to your experience with those designs and to other rating methods. For these articles, I'll assume that you have a copy of ISO 6336, you have chosen a design for which you have manufacturing drawings and an existing gear capacity calculation according to AGMA 2001 or another method. I'll also assume that you have converted dimensions, loads, etc. into the SI system of measurement.

ISO 6336 Calculation of Load Capacity of Spur and Helical Gears was published in 1997 after 50 years of effort by an international committee of experts whose work spanned three generations of gear technology development. It was a difficult compromise between the existing national standards to get a single standard published which will be the basis for future work. Many of the compromises added complication to the 1987 edition of DIN 3990, which was the basic document.