Keyang Motor Gear Profile

Does anybody know what the gear profile is on the keyang worm gear motors (the power window motors) in the KOP, or where I can go to look up the profile? We need to buy 2 gears with a 4:1 ratio to the motor for our arm. :frowning:

We used a 12 DP to match the Keyang

They are not standard by any means. We ended up going at them with calipers and making a CAD model of the gear by hand. One of our team mentors was able to get them water-jetted and that’s how we made them.

If you’re interested, I can see if I can hunt down the CAD files. Even those weren’t quite exact though, we pushed it through and arbor press a few times before it gave a nice clean fit.

At those types of speeds 12 DP is a close fit. I believe Dr. Joe once mentioned that they’re a stub tooth profile.

The stub tooth was on the Nippon-Denso window motors. I’m unsure if the Keyang is the same, but you could buy a gear and try it. A stub gear uses one DP for the tooth thickness and number, and a second, smaller DP for the addendum, dedendum, pitch diameter, height, etc. So if a 12DP gear fits, then it might be a 12DP stub. In which case you’d might have a better mesh if you turned down the 12DP gear to the OD of a 14 DP gear. Ish. I think it’s pretty complicated.

Thanks. 12 it is, that’s what I got too. Is the pressure angle 12.5 or 20? Does it matter? How do I tell? Would it matter if it’s a stub gear? How do I tell? Anything else that would make it incompatible with a normal spur gear?

Could someone tell me some good sites to find aluminum or brass gears? I need 2 12 DP gears with about 36 teeth. McMaster, Grainger and RobotCombat only have steel ones that I could find, wich weigh about 2.5 lbs each with 3" pitch diameters, which is way too much. I don’t want to have to drill out a whole lot.

WM Berg
But I hope you have time and money. They list that particular combination as around $40 and the stock is either 2 weeks or “call berg”

EDIT: They appear to have minimal stock of a 12 DP, 3.5" PD gear, if that’s an option