Self-pumping hydropneumatic vibration damper
AssigneeZF Friedrichshafen AG
InventorNorbert Ackermann
Life of this patent
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Abstract
A self-pumping hydropneumatic vibration damper with internal level control, especially for motor vehicles, has an oil-filled working cylinder under the pressure of at least one gas cushion. The working cylinder is divided into two working spaces by a working piston mounted on a piston rod. A piston pump, which is driven by the sprung movements of the vehicle and thus conveys damping oil from a low-pressure chamber into the working space connected to the high-pressure chamber. The pump cylinder of this piston pump is formed by the hollow piston rod, which connects the working space connected to the high-pressure chamber to the low-pressure chamber. An axially movable stepped pump piston is provided in the pump cylinder.
Claims14
A self pumping hydropneumatic vibration damper with level control comprising:
- a working cylinder filled with damping oil;
- a working piston mounted on a piston rod and dividing the working cylinder into first and second working spaces;
- a first reservoir connected to the second working space and containing a gas spring which creates pressure in the damping oil;
- a second reservoir;
- a piston pump comprising a housing and a stepped piston which is driven by reciprocal movements of the working piston in the working cylinder to pump damping oil from the second reservoir to the second working space, the stepped piston having a first section with a first diameter and a first end surface, and a second section with a second diameter and a second end surface, wherein the second diameter is larger than the first diameter, and the second end surface is exposed to pressure in the second working space;
- and
- a regulating device which is configured to release damping oil from the first reservoir to the second reservoir.
Dependencies are inferred from the claim text.