I believed like OP involute gears had true rolling motion with no slide however quoting Wikipedia (https://en.wikipedia.org/wiki/Involute_gear https://en.wikipe

I believed like OP involute gears had true rolling motion with no slide however quoting Wikipedia (https://en.wikipedia.org/wiki/Involute_gear https://en.wikipedia.org/wiki/Involute_gear): "Where the line of action crosses the line between the two centres, it is called the pitch point of the gears, where there is no sliding contact." So I learnt something :) I also believed torque varied slightly because the point of contact between teeth was not at a constant distance of the gears centers. Illustration: https://en.wikipedia.org/wiki/Involute_gear#/media/File:Involute_wheel.gif https://en.wikipedia.org/wiki/Involute_gear#/media/File:Invo... Would you have sources for the affirmation "constant torque transmission during tooth contact"? BR