Perhaps you prefer insert gears from standard parts in internet or other CAD software due to its difficult to design them in CATIA. Aided this application you could parametric design some of common gears ,Sprockets,Bearings (Ball Bearing & Roller Bearing) and convert text to sketch.
This app has 4 tabs
First tab: you can create Spur, Helical, Bevel, Spiral Bevel, internal, rack and worm gear
Second tab: you can create Sprocket from table
Third Tab: you can convert text to Sketch (it support Arabic and Persian text by its converter)
Forth tab: you can create some of common Ball bearings and Roller Bearings from table.