Patent ID: 8146897
Filing Date: 2012-04-03
Classification: B60G,F16F

Abstract:
1. A self-pumping hydropneumatic spring strut with internal level control, the strut comprising: an external tube; a working cylinder filled with hydraulic damping medium and divided into first and second working spaces by a working piston carried on a hollow piston rod; a compensating space located between the external tube and the working cylinder, the compensating space comprising a high pressure chamber and a low pressure chamber partially filled with hydraulic damping medium, the high pressure chamber having a gas cushion and being connected to the second working space; a piston pump which conveys damping medium from the low pressure chamber into the second working space, the piston pump comprising a hollow pump rod fixed to the working cylinder and extending into the hollow piston rod, the hollow pump rod having a bore connected to the low pressure chamber, an end provided with a suction valve inside the hollow piston rod, and a deregulating opening, which is closable as a function of position of the working piston in the working cylinder, connecting the second working space to the bore; an adjustable damping valve located outside the external tube and having a flow connection connected to a first channel connected to the first working space, and a flow connection connected to a second channel connected to the second working space and the high pressure chamber; and an intermediate part pressed into the external tube and sealed in place, the intermediate part separating the high pressure chamber from the low pressure chamber, at least one of the first and second channels being formed in part in the intermediate part, wherein connections between the adjustable damping valve and the working chambers are arranged in the intermediate part, and an inlet port and an outlet port of the damping valve are only connected with the high pressure fluid clamber.