control valve 21 the chamber 19 is confined to the end wall of the housing 3 and the base plate 11 the pressure side of the pump 1 extends to a chamber 20 which contains the electromotor 2 and communicates with the check valve 7 the connections from the pump 1 to the chambers 19 and 20 are controlled by the pump rotor but are preferably open channels the electomotor 2 comprises a motor armature 23 a collector 24 and a magnetic part 25 the motor armature 23 is supported on a rigid tubular member 28 that telescopes the shaft 12 and is provided at opposite ends thereof with journal bearings 27 as shown this tubular member provides support for the motor armature and its requisite components including the commutator bushing 31 to assemble these elements they are attached partly by pressure and partly by means of plastic filler means which after spraying of the individual elements ensure a good rotation locking axial connection a bushing 32 or sleeve of this invention is disposed on the telescoping tubular member 28 on the side that confronts the pump and engages in the manner of a rotating coupling comprising at least one axially extending tang 33 which is received in a corresponding recess 34 in the rotor 17 the commutator brushes 35 which are disposed in cage elements 36 are arranged to slide on the commutator bush 31 the cage elements 36 are connected with connection clamps not shown that are disposed outside the housing 3 the magnetic parts 25 of the electromotor 2 includes a permanent magnet 38 which is disposed in a tubular sheet 39 made of a magnetically conducting material.