Advanced Assembly and Engineering Tools - Inventor 2013 and Inventor LT 2013 Essentials - page 190

The Calculation tab varies based on the tool, but the information that you
can enter or extract is precisely the information you would need in order to use
engineering criteria to evaluate the components you're creating. You won't use
the Calculation tools for all the tools I will review, but keep in mind that they
are available.
Using the Spur Gear Generator
The Design tab of this dialog box is broken down into three major sections. The
top is the Common area where you specify the tooth characteristics of the gear.
The middle is where you set the requirements for size of the gears that support
the teeth, and the bottom is an information area that will offer feedback on the
design and calculations.
1. Make certain that the 2013 Essentials project file is active, and then
open the c08-06.iam file from the Assemblies\Chapter​8 folder.
2. Hold the Ctrl key, and click the Spur Gear tool on the Power
Transmission panel of the Design tab.
The Spur Gears Component Generator dialog box opens and displays
the default values (Figure 8.11).
FIGURE 8.11 The default values for the Gear Generator
3. Beginning in the upper left, change Design Guide to Number Of Teeth.
4. Set the Desired Gear Ratio value to 4.0000 ul from the drop-down.