GEAR 21 slip 1
Like the single rows-of-teeth gears, the on-line multiple rows-of-teeth gears start slipping when the rotation rate is over 0.1 rpps. The slip is still due to tooth tilting. It can be seen that the teeth interface in a T configuration just before slip rather than the parallel face-to-face configuration evident during working conditions.

GEAR 22
This shows rotation of off-line multiple rows-of-teeth gears (see Fig.6). They work better than the on-line multiple rows-of-teeth gears, as expected. Power is delivered to the driven gear more evenly so the T configuration of gear teeth is less pronounced.

GEAR 22 slip 2
If the gear rotation rate is larger that a critical value of 0.1 rpps, the off-line multiple rows-of-teeth gears slip.

Shaft 1
This animation shows that we can power the gear to drive the shaft, converting rotational motion into translational motion (see Fig.7).

Shaft 2
This animation shows that we can convert translation of the shaft into rotation of the gear by powering a shaft to drive a gear.

Small-Large
It is expected that it is harder for a small gear to drive a large gear. Interestingly, if the small gear is given a large acceleration, it does not drive the large one at all but instead bounces back and forth several times, like elastic collisions of a small ball between two boards.

Large-Small
It should be easier for a large gear to drive a small one. However, their rotation is not always well-controlled since this system requires a more accurate tooth position design than the others do. If the rotation of the large gear is too slow or too fast, this gear system cannot work well.

Large-Small 1
After an initial acceleration period, we operate the gear system at a medium rotation rate.

Large-Small 2
The slip occurs at a certain high rotation rate. Unlike the same-size gears, in this case the large powered gear keeps rotating and the small one stays still while the slip occurs (still due to tooth tilting).

(Feb 2001 NASA Advanced Supercomputing Division
www.nas.nasa.gov )