This is a geared hinge.  Similar to some of the full length geared hinges available on the commercial market but these have the unique feature of holding the vertical weight with the herringbone gear face.  Low friction and very sturdy.

The pictured version was printed in PLA with .2mm layers.  Inserting the pins into the gears takes a firm press to seat.  Unlike in picture, two “top pins” can be used to secure hinge from both sides. 

Print pins with flat side down, pins parallel to build plate (not upright), print hinge_a and hinge_b with gears as vertical upright column.

*added Hinge_A with long tab and Hinge_B with short tab so you can put together a symmetric hinge as needed.  Match either A side (short or long tab) with either B side (short or long tab).