To avoid chattering when using a spool in a hydraulic valve, it is often necessary to hold the spool in a locked position until the external force exceeds a certain threshold value. In this example, we will explore the interaction between such a force and the spool’s position in a spool with a preload.
The image shows a schematic drawing of a spool that can easily be transferred to a model using SystemModeler
and the ElastoGap elements found in the Modelica.Mechanics
In the PreLoad model in the Mechanics library, a sinusoidal force acts on a spool of a certain mass. In order for the spool to move in either direction, this force has to cross a certain threshold value where it overcomes friction. The model also contains a spring that ensures the return of the spool into a neutral position if the force is removed.
Simulation Results and custom animation
Create interactive custom animations of the simulation result to your liking using built-in Mathematica functions.
This custom animation shows the interaction between the spool’s position and the applied force in an interactive environment with a 3D graphical depiction of the system itself. Download the notebook and manipulate the "Time" handle to see how the spool’s movement is affected by the force. Use the "Opacity" control to change the transparency of the outer red cylinders.