Hydraulic Cylinder with Cylinder Cushions

This example shows a hydraulic double-acting actuator equipped with cushions on both end stops. The cushions serve as hydraulic brakes when the piston approaches the stops, absorbing some of the kinetic energy of the system before the piston touches the stops. For more information, see Double-Acting Actuator (IL).

Model

This figure shows the schematic diagram of one end of the hydraulic cylinder with snubber passages.

Simulation Results from Scopes

Simulation Results from Simscape Logging

These plots show the pressures in the cylinder and the position of the piston, whose stroke is 0.6 m. The piston smoothly retracts to the hard stop at the end of cylinder casing and smoothly extends back to its full stroke length.

These plots show the flow rates through the fluid passages that model the cushion on side B of the actuator. As the 4-way valve connects the pump to side B, the check valve opens to permit fluid to flow into the main chamber out of the snubber. The piston moves smoothly away from the hard stop, opening a larger passage between the fluid port and the main chamber, with the check valve closing. During the second half of the cycle, a small amount of fluid passes through the cushion orifice, which allows the piston to approach the hard stop more smoothly.