The invention relates to a device for releasably connecting and adjusting the positions between a crankshaft and a cam shaft of an internal combustion engine, which includes a setting gear (1) configured as a three-shaft gear, which has a drive shaft (4) connected to the crankshaft, an output shaft (5) connected to the camshaft, and an adjusting shaft connected to an electric adjusting motor (2). A stationary transmission ratio i_o, which has a base or emergency running position, is present between the drive and output shafts when the adjusting shaft (6) is idle, the magnitude of the gear transmission ratio determining the gear type (positive or negative) and the direction of adjustment of the camshaft (3). Functional safety of the device is improved due to the fact that the base or emergency running position of the camshaft (3) can be reached and maintained in case of an outage or failure of the adjusting motor (2) and/or the control thereof be a slow-down or arresting of the adjusting shaft (6), simultaneous rotation of the drive shaft (4), and an appropriate gear transmission ratio.