Worm gear software .

By Dr. Stepan V. Lunin.

3-d CAD model of a worm gear set - output from the program

This software was the only worm gear software in 20-th century that could visualize the motion of the worm gear tooth contact in colors in 3 - d.

First worm gear software with 3-d visual motion of the contact


The program was based on Luninís Direct Digital Simulation Method.Learning the most advanced gear technology from ZAKGEAR. 
3d gear software samples. Gear CAD models. On the picture above you can see that a very small mesh covers the worm gear tooth surface. The program calculated the x,y,z coordinates of each point of the mesh. The contact pattern is visualized by painting each triangle of the mesh in correspondence to the distance from the pinion surface.

ZAKGEAR has developed worm pinion software as well.

The picture below is generated on the program in order to show how would the contact look like if you would make such of extreme enveloping worm wheel.

100% contact. Not localised.


The program helped very much to reduce the development cost of a new worm gear. Because the program simulates the manufacturing process it was much less expensive to do gear cutting iteration on the program using a computer. For example, without the program it was very difficult to predict how much do you need to oversize the hob cutter in order to get a good localized contact pattern. The program was able to show the contact pattern for different misalignments of the hob cutter or misalignments of the pinion.

Simulation of tooth contact stress on a worm gear

Increasing stress on worm gear mesh.

When the center distance changes the tooth contact pattern changes as well:

Deviation of center distance on a worm gear

Sample worm gear data

-2 Cutter-gear swivel angle
53.9095 Cutter-gear center distnce
3 #threads on the cutter
15 Cutter Pressure Angle (rad)
13 Cutter lead
17.4 Cutter lead angle (deg)
18.08 Cutter OD
67 # threads on the gear
3 # threads on the Pinion
53 Gear-Pinion center distance
15 Pinion pressure angle (deg)
13.2 Pinion lead
20 Pinion lead angle (deg)
16 Pinion OD
100 Gear OD
14 Gear width
11 Hob root diameter

Download sample IGES file.

Home page: www.zakgear.com