The damping coefficient of the rotary damper is defined by viscous resistance.
Hydraulic rotary motion dampers use silicon oil as the damping fluid medium to generate different damping torque.
The unit for silicone oil viscous is mm2/s (cSt). Rotary damper manufacturers need to purchase various models of damping oil to meet different torque requests. One damping oil can only correspond to one specification. A bit larger specifications can also be obtained by increasing the amount of damping oil injected and then compressing the volume of oil in the inner cavity by ultrasonic. But in this case, it requires batch sample testing to verify the production yield.
Case Study
Our customer, the manufacturer in the Medical device industry, was looking for three torque requested in the following picture. They were asking for the same model, as well they required Anti-Gama rays. This greatly limits the damping oil options available. Finally, we found two kinds of anti-Gama oil for the customer. Following the test result that shows using one model oil for three different torque values, we can see that while applying the same oil, it is possible to make different torque, but they will be of different production yield ratios.
Reference:
https://en.wikipedia.org/wiki/Viscosity
