Here is the Gears material from Doug
Wright at the ME Dept.
of the Univ. of W. Australia:
http://www-mdp.eng.cam.ac.uk/web/library/enginfo/textbooks_dvd_only/DAN/gears/meshing/meshing.html#animation
Here is an excellent tutorial on
Hertzian contact and journal
bearings:
http://www.tribology-abc.com
The Calculators are especially good and there are
great items in the Glossary - the ABCs. Here is the Contact
Stress material from Doug Wright at the ME Dept.
of the Univ. of W. Australia:
http://www-mdp.eng.cam.ac.uk/web/library/enginfo/textbooks_dvd_only/DAN/MST/contact/contact.html