How do washers create damping effect for a two‑stage hinge joint?

How do washers create damping effect for a two‑stage hinge joint?

① Integrate the flat position of the T‑shaft with the fixed part and flat Washer to form one assembly.

② Assemble the friction hook washer with the moving part into another assembly.

③ Combine the two assemblies above. Tighten the lock lock nut onto the T‑shaft to compress the spring washer and generate mutual pre‑tension force.

④ When the two assemblies rotate around the center of the T‑shaft, friction occurs between the flat oil‑retaining washer and friction hook washer, which delivers damping effect during rotation.