A door actuator for opening and/or closing a door leaf includes a housing, an output shaft rotatably supported in the housing and with a cam disc, wherein the output shaft is formed for transferring torque onto the door leaf. A first element of motion is linearly movably guided in the housing with a first contact surface. A second element of motion is linearly movably guided in the housing with a second contact surface. A distancing arrangement is disposed in the housing. The cam disc is disposed between the two contact surfaces and for rolling on the two contact surfaces. In at least one delimiting range of angles of rotation of the output shaft, the distancing arrangement delimits the minimum distance between the elements of motion, and, in at least one free range of angles of rotation, does not delimit the linear mobility of the two elements of motion in relation to each other.