MATLAB Examples

Hydraulic Cylinder with Two-Chamber Snubbers

This example shows a hydraulic cylinder equipped with a custom model of snubbers (cushions) on both sides of the cylinder. The snubbers are implemented as two-chamber cushions separated by the cushioning bush as the piston comes close to the end of the stroke. The cushioning provides hydraulic braking as the cylinder reaches the end of its stroke, absorbing some of the kinetic energy of the system before the piston reaches the end stop.

Contents

Model

Cylinder with Snubbers Subsystem

The following figure shows the schematic diagram of one end of the hydraulic cylinder with the snubber passages:

Simulation Results from Simscape Logging

The plots below show the pressures in the cylinder and the position of the piston.

The plots below show the flow rate in the fluid passages that make up the snubber on side B of the cylinder. As the four-way valve connects the pump to side B, the check valve opens to permit the hydraulic fluid to flow out of the snubber and into the main chamber. The piston moves smoothly away from the hard stop, opening a larger passage between the fluid port and the chamber and the check valve closes. During the second half of the cycle, a very small amount of fluid flow passes through the cushion valve, allowing the piston to coast more smoothly into the hard stop.