How Roller Gear Cam Drive Rotary Table?

Lineup and Specification of TJR Roller-Drive series:
www.tjr-world.com/images/pdf/...
Nowadays, CNC Rotary Table are usually driven by servo motors. There are many transmission mechanisms with different characteristics. One of the newest and best methods is to drive by a Roller Gear Cam. Due to the low reduction ratio, its speed is faster than the traditional transmission mechanism. Rollers and Cams are made of alloy steel. So there is no abrasion even after long-term use. Minimizing the rolling friction at the contact of Cam/Roller, roller and cam feature high accuracy. No backlash occurs during the clockwise/anti-clockwise rotation. High speed, wear-free, and Zero backlash are the three strengths driven by Roller Gear Cam.

[@detamak111]

Congratulations TJR..

[@beachboardfan9544]

How does that mechanism permit zero backlash?