A DRUM MOTOR

Abstract: In a drum motor having a driving electric motor and a gear transmission (16, 17, 18) between the motor armature (14) and an internal toothing (22) in an end cover (2) connected to the shell (1), the gear transmission (16, 17, 18) is offset with respect to the shaft (6) on which the end cover (2) is journalled, and this shaft (6) has an axial bore (8) through which the necessary wires (9) for supplying power to the electric motor are introduced. This enables stocking of a plurality of drum motors of different lengths and motor outputs merely by changing the length of the shell (1) and the length of the shaft (7) opposite the gear transmission (16, 17, 18), it being unnecessary to change the structure around the wire lead-in mount. The wires (9) may be run from the internal mouth (24) of the bore (8) to the stator winding (25) of the motor through a pipe section (23).

Description: A drum motor The invention relates to a drum motor which contains a driving electric motor and is journalled at both ends on shafts extending through the end covers of the drum and adapted to be fixed in an outer frame, said drum motor also containing a gear transmission disposed between the electric motor and one end cover and forming a mechanical drive connection between the armature of the electric motor and an internal toothing in said end cover. In known drum motors of the present type, as described e.g. in the Swedish Published Application 382 538, the current-carrying wires were passed through a bore in the shaft disposed at the drum motor end located opposite the gear transmission. This was quite natural since the wire would then not have to pass the gear transmission, which in most of the known constructions occupies the entire cross-section and thus does not leave any space for the passage of a wire. In the stocking of parts for a plurality of drum motors of various motor outputs and with different lengths of the shell of the drum itself, it is of course endeavoured to keep the number of parts which cannot be incorporated in all drum motor types in the stocked program as low as possible. Consequently, the natural choise is to incorporate the same gear transmission in drum motors having different motor outputs and lengths so that these relatively complicated motor parts can be included in the stocked program. On receipt of the drum motor order, the shell length and the length of the shaft at the end opposite " the gear transmission therefore have to be adapted to the order received. It has been found to be a drawback that when the shaft at the end opposite the gear transmission is manufactured, this shaft must also be provided with an axial bore - generally in connection with a radial hole - owing to the passage of the wire. In addition, the length of the wire has to be adapted to the length of the bore provided in the shaft. The object of the invention is to eliminate these drawbacks so that the drum motors stocked as semi¬ manufactures can be finished in accordance with the orders received in considerably fewer and simpler operations than before. Accordingly, the invention provides a drum motor which contains a driving electric motor and is journalled at both ends on shafts extending through the end covers of the drum and adapted to be fixed in an outer frame, said drum motor also containing a gear transmission disposed between the electric motor and one end cover and forming a mechanical drive connection between the armature of the electric motor and an internal toothing in said end cover, characterized in that the shaft on which said end cover at the end of the gear transmission is journalled has an axial bore, through which the necessary wires for supplyring power to the electric motor are introduced, and that the gear transmission is axially offset with respect to this bore. This structure involves the advantage that the shaft at the end opposite the gear transmission just has to be cut to the required length, whereas it is un¬ necessary to provide an axial bore of a variable OMPI length in connection with a radial hole. Moreover, the entire wire lead-in mount is manufactured as standard on the semi-manufactured drum motors, thus obviating the necessity of splicing and fitting the wire on receipt of every order. This enables rapid finishing of the semi-manufactured drum motors in accordance with the orders received, which in turns results in great advantages in terms of production and economy. A safe running of the wires from the internal mouth of the bore to the stator of the electric motor is obtained with simple means by passing them through a pipe section. The invention will be explained in greater detail below with reference to the drawing, which shows an axial longitudinal section of a drum motor according to the invention. The drum motor shown in the drawing has a shell 1 which has a substantially circularly cylindrical con¬ figuration. The shell 1 has end covers 2 and 3 which are secured to the shell 1 and journalled on shafts 6 and 7, respectively, by means of ball bearings 4 and 5, respectively. The shaft 6 has an axial bore 8 extending through it, and wires 9 are run through this bore from a mains connection box 10 to the interior of the drum motor. The inner end of the shaft 6 mounts a stator housing, composed of two parts 11 and 12, for a stator 13 of an electric motor, whose rotor 14 has a gear wheel 15 driving a gear transmission 16, 17, 18, the gear wheels 16 and 17 of which are secured to a common layshaft 19, and driving through the gear wheel 17 the gear wheel 18 and thus an output shaft 20 on which an output wheel 21 is secured. The output gear wheel 21 meshes with an internal OMPI , - ΪPO~ Λ toothing 22 on the end cover 2 to' complete the drive connection between the rotor 14 and the shell 1 of the drum motor. The gear transmission 16, 17, 18 with the layshaft 19 and the output shaft 20 is axially offset with respect to the bore 8 so as to accommodate a pipe section 23, which is secured in the stator housing 11, 12 between the internal mouth 24 of the bore 8 and the most adjacent and of a stator winding 25. To additionally secure the stator housing, its part 12 is attached to the shaft 7 by means of a pipe pin 26. The stator segments are clamped together between the two parts 11, 12 of the stator housing by means of bolts 27. If a less powerful motor than the one shown in the drawing is to be used, in other words a motor with a shorter stator length, the parts 11, 12 are just clamped more tightl together than shown, and the rotor bearing 28 is moved deeper into the stator housing part 12 to engage the end of the shaft 7 or a spring washer 29 optionally interposed between the bearing 28 and the shaft 7. A drum motor of a different length can be obtained merely by selecting a shell 1 of a suitable different length and adapting the length of the shaft 7 to it, so that the shaft 7 extends from the spring washer 29 and protrudes a predetermined distance exteriorly of the end cover 3. When the drum motor length has been determined in accordance with the order received, the shaft length can e.g. be stated as the drum motor length less a predetermined length.

Claims: P a t e n t C l a i m s 1. A drum motor, which contains a driving electric motor and is journalled at both ends on shafts extending through the end covers of the drum and adapted to be fixed in an outer frame, said drum motor also containing a gear transmission disposed between the electric motor and one end cover and forming a mechanical drive connection between the armature of the electric motor and an internal toothing in said end cover, c h a r a c t e r i z e d in that the shaft on which said end cover at the end of the gear transmission is journalled has an axial bore, through which the necessary wires for supplying power to the electric motor are introduced, and that the gear trans¬ mission is axially offset with respect to this bore. 2. A drum motor according to claim 1, c h a r a c¬ t e r i z e d in that the wires are run from the . internal mouth of the bore to the stator of the electric motor through a pipe section. OMPI '

Inventors: SCHWARZER HANS CHRISTIAN, SCHWARZER, HANS, CHRISTIAN
Applicants: INTERROLL A S, INTERROLL A/S
Application year: 1982
Main classification: H02K7
IPC codes: B65G23, B65G39, H02K5, H02K7