I designed this couple of helical gears with NURBS. I didn’t use calculations (except a bit) but created them with an intelligence method that I usually use in most of my designations (a part was visually). I drew two intersected circles in an appropriate place so that the teeth of the two gears to be equal. I trimmed the lines of the two circle in the intersection place and then drew the tooth of one of the circles. I replaced the other circle in a straight path and then copied the tooth of the first circle and attached to the second. Then I calculated the root of the tooth and the perimeter of every circle and then used polar array according to each circle perimeter. Thus I created the base sketch of the gears. After these stages, I used rotation ( copy was active) and drew the bottom of those gears with different angles. Then I picked up the first circles and connected with four lines to the lower circles. I used polar array again and reproduced the necessary lines around the teeth of each circle. Then, I used network of curves and made the surfaces around those gears. At the end I used cap and other works such as engravings.
Nice exercise. Although I’m not convinced the teeth are helical - they look like they are twisted straight teeth. And you could also crown the teeth, done to reduce wear and noise.
Looking forward to seeing mk2 of this!
You are right, sir
Crowning the teeth can reduce contact surface and a couple of matched gears can work smoother and more soundless. Also, the two sides of the tooth will be not worn due to having not any contact.
before I design those gears I searched google for helical gears and found this picture at the top of the first page and that ensured me it is a type of helical gear, though such the gears with twisted curvature shapes of teeth are called helical gear, as well. Is it right?
I will try to redesign the gears again based on your recommendations