AGMA 14FTM05-2014 pdf free.AGMA Technical Paper A Different Way to L 0ok at Profile and Helix Inspection Results By J.M. Rinaldo, Atlas Copco Comptec LLC.
The proper specification of design shape is very important for the proper performance of the gear. Design shape modifications may be used to improve the noise, vibration and harshness (NVH) of a gear set, prevent tooth collisions in heavily loaded gears, compensate for changes in tooth shape due to shaft bending and thermal deformation that occur during normal operation, or for other reasons. In many gears, proper tooth shape modifications are essential for both smooth operation and long life [2] The designer specifies what the tooth shape should be, but it is then up to the machine operator or inspector to verifty that the design intent has been met. Unfortunately, for gears with modified profiles, typical gear charts require a high level of expertise to properly evaluate how the gear deviates from the design shape. What is proposed here is that since the design profile is the ideal shape, the deviations from the design profile should be displayed in addition to the deviations from a perfect involute. No additional data collection will be required, it is simply an alternate method to display the data gathered by an inspection machine. Graphical displays of deviations from the design shape are much easier to evaluate, and can be a very useful addition to the inspection processes. These deviations should of course be zero, so the plot of deviations from design profile should be a straight line coinciding with the axis. These new charts are not intended to be a replacement for traditional charts, but rather an additional chart that in combination with traditional gear charts will make understanding of the deviations much easier. Each method of display has its own advantages; used together they can quickly lead to a full understanding of the deviations.
Examples
Figure 1 shows a typical output of gear profile and helix (sometimes called lead) charts. These charts show the measured traces for both left and right flanks of 3 teeth spaced approximately 120° apart.
Figure 2 is a schematic based on ISO 1328-1:2013 [figure 8] showing how a single profile trace is analyzed for a gear with a design profile that has both root and tip relief. Note that the orientation of the chart is not critical as long as it is properly labeled, many charts present the traces vertically as in figure 1 while in ISO 1328-1 :2013 the traces are presented horizontally.AGMA 14FTM05 pdf download.