Patent ID: 8210140

Claim:
The hydraulic unit for a cylinder head of an internal combustion engine with a hydraulically variable gas-exchange valve train, comprising at least one drive-side master unit, at least one driven-side slave unit, at least one controllable hydraulic valve, at least one medium-pressure chamber, at least one high-pressure chamber that is arranged in a transmission sense between the associated master unit and the associated slave unit and that can be connected by the associated hydraulic valve to the associated medium-pressure chamber, at least one low-pressure chamber that is used as a hydraulic medium reservoir and that is connected via a throttle opening to the associated medium-pressure chamber, a hydraulic housing with a bottom part of the housing, a middle part of the housing, and a top part of the housing, wherein the master unit, the slave unit, the high-pressure chamber, the hydraulic valve, the medium-pressure chamber extends in the bottom part of the housing, the low-pressure chamber is constructed in the top part of the housing, and the throttle opening is part of a hydraulic medium channel passing through the middle part of the housing, and the throttle opening extends in a housing seal that is arranged as a separate component either between the bottom part of the housing or the top part of the housing on one side and the middle part of the housing on the other side, and the section of the hydraulic medium channel passing through the middle part of the housing has a low-throttle construction.