Patent attributes
A self-pumping hydropneumatic spring strut unit includes a working cylinder filled with oil under pressure and a piston and rod unit displaceable in the cylinder so as to define two working spaces in the cylinder, and high-pressure and low pressure chambers surrounding the cylinder. The strut unit further has a piston pump operable to transport a working medium from the low-pressure chamber into the one working space which is in flow communication with the high-pressure chamber. The piston pump has a cylinder defined by the inner surface of the piston rod unit, and a hollow pump rod coupled to the working cylinder and having a flow channel in communication with the low-pressure chamber. The flow channel has a deregulating opening on the working space and a throttle in flow communication with the deregulating opening. A filter device protects the throttle from impurities carried by the oil during flow from the deregulating opening to the low pressure chamber.
