Hydraulic system for pitch angle adjustment of a rotor blade of a wind turbine and wind turbine with such a hydraulic system

A hydraulic system for adjusting the pitch angle of a rotor blade of a wind turbine, the hydraulic system comprising a variable displacement pump, a hydraulic accumulator, a dynamic valve, a preferably proportional control valve, a tank and a pitch cylinder,

• wherein the variable displacement pump is connected to the control valve via a first connecting line without rotary feedthrough and the control valve is connected to the tank via a second connecting line without rotary feedthrough and the control valve is connected to a piston side of the pitch cylinder via a third connecting line without rotary feedthrough and the control valve is connected to a rod side of the pitch cylinder via a fourth connecting line without rotary feedthrough,
• so that in a first switching position of the control valve the first connecting line is connected to the third connecting line, and
• so that in a second switching position of the control valve, the first connecting line is connected to the fourth connecting line and the second connecting line is connected to the third connecting line,
• wherein the hydraulic accumulator is connected to the first connecting line via a fifth connecting line, in that the fifth connecting line opens into the first connecting line at a junction, wherein the dynamic valve is disposed in the fifth connecting line, and
• wherein the dynamic valve blocks the fifth connecting line in the direction of flow from the hydraulic accumulator to the first connecting line in a first switching position and releases the fifth connecting line in a second switching position.