Hydraulically actuated camshaft adjusting device for changing the relative angular position of a camshaft in relation to a crankshaft of an internal combustion engine, wherein the camshaft adjusting device has at least two hydraulic chambers (A, B), which are arranged between a stator and a rotor and are separated by a vane, and which are supplied with pressure oil from a pressure oil source by means of a hydraulic oil control assembly, wherein the hydraulic oil control assembly has: - a first supply line, which is arranged between the pressure oil source and a first hydraulic chamber, wherein a check valve is arranged in the first supply line, which permits the flow of hydraulic oil from the pressure oil source into the hydraulic chamber and prevents it in the opposite direction, wherein the first supply line is free of further switchable valve elements, and wherein the first supply line is the single feed line for hydraulic oil from the pressure oil source into the hydraulic chamber, - a second supply line, which is arranged between the pressure oil source and a second hydraulic chamber, wherein a check valve is arranged in the second supply line, which permits the flow of hydraulic oil from the pressure oil source into the hydraulic chamber and prevents it in the opposite direction, wherein the second supply line is free of further switchable valve elements and wherein the second supply line is the single feed line for hydraulic oil from the pressure oil source into the hydraulic chamber, - a valve element, which is arranged to act between the hydraulic chambers (A, B) and a tank and has three valve positions (I, II, III), as follows a) a first valve position, in which the drainage of hydraulic oil from the two hydraulic chambers (A, B) into the tank is interrupted, b) a second valve position, in which the drainage of hydraulic oil from the first hydraulic chamber to the tank is released and the drainage of hydraulic oil from the second hydraulic chamber to the tank is interrupted, and c) a third valve position, in which the drainage of hydraulic oil from the second hydraulic chamber to the tank is released and the drainage of hydraulic oil from the first hydraulic chamber to the tank is interrupted. - a first supply line, which is arranged between the pressure oil source and a first hydraulic chamber, wherein a check valve is arranged in the first supply line, which permits the flow of hydraulic oil from the pressure oil source into the hydraulic chamber and prevents it in the opposite direction, wherein the first supply line is free of further switchable valve elements, and wherein the first supply line is the single feed line for hydraulic oil from the pressure oil source into the hydraulic chamber, - a second supply line, which is arranged between the pressure oil source and a second hydraulic chamber, wherein a check valve is arranged in the second supply line, which permits the flow of hydraulic oil from the pressure oil source into the hydraulic chamber and prevents it in the opposite direction, wherein the second supply line is free of further switchable valve elements and wherein the second supply line is the single feed line for hydraulic oil from the pressure oil source into the hydraulic chamber, - a valve element, which is arranged to act between the hydraulic chambers (A, B) and a tank and has three valve positions (I, II, III), as follows a) a first valve position, in which the drainage of hydraulic oil from the two hydraulic chambers (A, B) into the tank is interrupted, b) a second valve position, in which the drainage of hydraulic oil from the first hydraulic chamber to the tank is released and the drainage of hydraulic oil from the second hydraulic chamber to the tank is interrupted, and c) a third valve position, in which the drainage of hydraulic oil from the second hydraulic chamber to the tank is released and the drainage of hydraulic oil from the first hydraulic chamber to the tank is interrupted. a) a first valve position, in which the drainage of hydraulic oil from the two hydraulic chambers (A, B) into the tank is interrupted, b) a second valve position, in which the drainage of hydraulic oil from the first hydraulic chamber to the tank is released and the drainage of hydraulic oil from the second hydraulic chamber to the tank is interrupted, and c) a third valve position, in which the drainage of hydraulic oil from the second hydraulic chamber to the tank is released and the drainage of hydraulic oil from the first hydraulic chamber to the tank is interrupted.