Piston pump having a hollow piston
AssigneeRobert Bosch GmbH
InventorsGerhard Wetzel, Wolfgang Schuller
Life of this patent
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Abstract
The invention relates to a piston pump (10) for a hydraulic slip-controlled vehicle brake system. In order to reduce a structural length of the piston pump (10), the invention proposes embodying the piston (16) of the piston pump (10) as a hollow piston whose inner chamber constitutes a displacement chamber (40) of the piston pump (10) and inserting an inlet valve (20) of the piston pump (10) into the inner chamber of the piston (16).
Claims13
A piston pump with a piston that can be driven to execute a reciprocating stroke motion, characterized in that the piston (16) is hollow, having an inner chamber which constitutes a displacement chamber (40) of the piston pump (10), and that a valve (20) is accommodated inside the piston (16) and controls the flow direction of fluid to be supplied by the piston pump (10), wherein a valve seat part (22) of the valve (20) is accommodated inside the piston (16), the piston is formed with an end wall (18) and a side cylindrical wall, and the side cylindrical wall of the piston has a fluid opening (48), and that between the valve seat part (22) and the hollow piston (16), an intermediary space (24) is formed, which intermediary space communicates with the fluid opening (48) in the side cylindrical wall of the piston and also communicates with the displacement chamber (40) via the valve (20).
The piston pump of claim 9, wherein the valve seat part (22) has a portion that is smaller in diameter than the internal diameter of the hollow piston (16) so that an annular chamber is formed between the smaller portion of the valve seat part (22) and the inside of the hollow piston (16).
A piston pump with a piston that can be driven to execute a reciprocating stroke motion, characterized in that the piston (16) is hollow, having an inner chamber which constitutes a displacement chamber (40) of the piston pump (10), and that a valve (20) is accommodated inside the piston (16) and controls the flow direction of fluid to be supplied by the piston pump (10), wherein a valve seat part (22) of the valve (20) is accommodated inside the piston (16), wherein the piston (16) is stepped so as to have two different external diameters, one portion of the piston thus having an external diameter which is smaller that the other portion, and the piston (16) is placed within a bore (14) of a pump housing (12), and the external diameter of the smaller portion is smaller than the diameter of the bore (12) so as to form a second annular chamber between the bore and the smaller portion, and wherein as the piston (16) makes a stroke that forces fluid out of the displacement chamber (40), the second annular chamber aspirates fluid into itself.
Dependencies are inferred from the claim text.