All the gear design manuals I've seen say that to maintain smooth conjugate action between gear teeth a contact ratio should ideally be 1.4 or higher. A 1.2 ratio for extreme circumstances. You guys keep telling me 1.0. I'm working with fairly small gears with coarse 4-5 d.p. (22-27 gear...
Do you use the angle from the line of action or do you use the pressure angle? I'm pretty sure its angle perpendicular to the line of action since it changes when center distance changes. I put in just the pressure angle and it does not change the contact ratio as much as the line of action...
OK guys. Looking at the contact ratio now. The calc that I found says to use theta which is the pressure angle. But as the gears come apart the angle of attack changes. The gears are not really applying force at the pressure angle. The calc that I have also takes into account a pinion and a...
Many gear manufacturers say not to do this, but here is my problem.
I have 2 rolls in which paper is nipped between. The rolls need to be driven. We are currently using spur gears to drive them. Both rolls are the same diameter. The distance between the rolls is ajustable. How much can the...
Diamondjim, both gears have the same number of teeth,27. The 4140 material would be hardened to 54 Rc. The cast iron I mentioned would be made by Durabar. The cast iron has contact stress limit of 75,000 and is impregnated with graphite. These gears run 858 rpm at top speed. We are expecting...
Hello, I'm new to the forum. I want to design a gear set. One gear is 4140 steel, one will be a grade 2 cast iron. I do not want to lubricate the gears. Lubricating the gearset becomes a hygeine issue with the lubricant attracting dust particles. The bending stress is 1100 psi. The contact...