Hi @mammadli.h, welcome to the forum 
These are the most relevant forum threads I was able to find:
- Newton Gripper Cable Extension/Access to Gripper Internals
- Linear bearing information request
- Lead screw / bumper
- Drawings and models
In terms of key functionality, there’s a geared down DC motor which drives a lead screw, which extends and retracts a piston attached to the pivot point of the jaws (which can be replaced with custom ones).
For easy integration with the single-directional servo-style PWM control that some of our other electronics use, there’s an internal ESC that treats ranges of pulse durations as (respectively) close / stop / open commands. Current measurements allow detecting when the resistance suddenly increases, which provides dynamic end-stops (e.g. for when the jaws are fully opened, or closed onto an object).