The invention relates to a valve unit for at least one of influencing and controlling a gas flow in an internal combustion engine comprising at least one valve member for modifying a cross-section of a gas flow-carrying channel through which a fluid flows and a drive train for rotatingly driving the at least one valve member. The drive train comprises an input shaft, which is drivingly coupled to a drive device in the mounted state, and at least one valve member shaft which is non-rotationally connected to the valve member. It is especially advantageous if the drive train comprises at least one phase adjuster for drivingly coupling the input shaft and the valve member shaft, a rotational position of the shafts in relation to each other being adjustable by the phase adjuster.