A drive device for an adjustment installation for adjusting a vehicle part, in particular a power window actuator, having - a carrier element; - a cable drum; - a cable exit housing which is disposed on a first side of the carrier element and which has a first bearing element for mounting the cable drum so as to be rotatable about a first rotation axis; - a drive wheel that is drivable by a motor unit; and a drive housing which is disposed on a second side, facing away from the first side, of the carrier element and which has a second bearing element for mounting the drive wheel so as to be rotatable about a second rotation axis. wherein the cable exit housing and the drive housing are fastened to one another by way of a fastening element which acts between the first bearing element and the second bearing element, characterized in that one of the bearing elements (22, 72) has a conical portion, and the other of the bearing elements (72, 22) has centering engagement for interacting with the conical portion in order for the first bearing element and the second bearing element to be mutually centered, wherein - in a first assembly position in which the cable exit housing and the drive housing are disposed on the carrier element but are not yet mutually axially braced by way of the fastening element, the conical portion and the centering engagement have mutual axial play; and - in a second assembly position in which the cable exit housing and the drive housing are mutually axially braced by way of the fastening element, the conical portion and the centering engagement bear on one another, wherein the cable exit housing is elastically deformable in at least one region when bracing the cable exit housing and the drive housing to each other via the fastening element. - a carrier element; - a cable drum; - a cable exit housing which is disposed on a first side of the carrier element and which has a first bearing element for mounting the cable drum so as to be rotatable about a first rotation axis; - a drive wheel that is drivable by a motor unit; and a drive housing which is disposed on a second side, facing away from the first side, of the carrier element and which has a second bearing element for mounting the drive wheel so as to be rotatable about a second rotation axis. wherein the cable exit housing and the drive housing are fastened to one another by way of a fastening element which acts between the first bearing element and the second bearing element, characterized in that one of the bearing elements (22, 72) has a conical portion, and the other of the bearing elements (72, 22) has centering engagement for interacting with the conical portion in order for the first bearing element and the second bearing element to be mutually centered, wherein - in a first assembly position in which the cable exit housing and the drive housing are disposed on the carrier element but are not yet mutually axially braced by way of the fastening element, the conical portion and the centering engagement have mutual axial play; and - in a second assembly position in which the cable exit housing and the drive housing are mutually axially braced by way of the fastening element, the conical portion and the centering engagement bear on one another,