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US 9,068,580 B2Granted
Breather of a hydraulic or electrohydraulic control device
AssigneeZF Friedrichshafen AG
InventorNorbert Haaser
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AssigneeZF Friedrichshafen AG
InventorNorbert Haaser
Estimating the term…
A venting device for a hydraulic control unit, designed as a diaphragm in a bore in the control unit, so that collected air can escape, via the diaphragm, to outside the housing. A membrane, which is permeable to air and oil when under pressure, closes the diaphragm bore with respect to the outside. The housing bore and the diaphragm form an inside space that can be vented, via the membrane. The inside space being delimited, during operation, by the diaphragm and an oil column which passes from the control unit into the housing bore and is continually maintained at a defined pressure at which oil, in the housing bore, either does not pass through the membrane or only a minute amount passes therethrough. The oil column remains in the housing bore so that only air, contained in the oil, is vented to the outside without any air being drawn into the control unit from outside.
A venting device for either a hydraulic or an electro-hydraulic control unit, the venting device comprising a diaphragm (1) which is inset in a housing bore (5) of a housing (4) of the control unit, via a diaphragm bore (2) so that air, which collects in an interior of the housing of the control unit, can escape to an outer space (6) located outside the housing (4),
A venting device of either a hydraulic or an electro-hydraulic control unit, the venting device comprising a diaphragm (1) which is inset in a housing bore (5) of a housing (4) of the control unit, the diaphragm has a diaphragm bore (2) through which aft, which collects in an interior of the housing of the control unit, can escape to an outer space (6) outside the housing (4),
A venting device of a hydraulic control unit having a housing with a bore therein, the bore of the housing receives a diaphragm that has a hole, the hole in the diaphragm has a diameter in a range between approximately 0.25 mm and 3.00 mm and is enclosed by a membrane which separates an exterior of the housing from an interior of the housing, the membrane comprises a PTFE fabric having a pore size of approximately 12 μm and an air permeability of approximately 7 l/m2/sec and having a smoothed surface which faces the interior of the housing, a column of oil is maintained in the interior of the housing by the hydraulic control unit at a pressure exceeding a pressure threshold of approximately 0.5 bar such that air collected in the interior of the housing between the column of oil and the membrane passes through the membrane to the exterior of the housing, a height of the column of oil decreases when the pressure on the column of oil falls below the pressure threshold to prevent air from passing from the exterior of the housing to the interior of the housing.
Dependencies are inferred from the claim text.