GB1446162A - Method of making an armature - Google Patents

Abstract

1446162 Welding by pressure FORD MOTOR CO Ltd 21 Feb 1975 [15 March 1974] 7451/75 Heading B3R In making an armature for a dynamoelectric machine the uninsulated ends 30, 31 of insulated conductors forming the armature winding are arranged in pairs in slots 28 in risers 26 of the commutator, one above the other, a welding tip 92e is applied to the upper conductor end 30 in a slot, the tip is ultrasonically energized to weld the conductor ends in the slot, the tip is radially withdrawn and the armature is indexed to align another slot with the tip and the welding of the conductor ends therein are similarly welded, the steps being repeated for all the slots. The armature assembly is arranged, in an embodiment, in an apparatus for welding the conductor ends and for indexing the armature assembly. The non commutator end of the armature shaft 12 is arranged in a sleeve 36 in a V block 34 and the V block is received in a V notch 40 of an indexing device 38, the commutator end being arranged in a shield 46 which receives the ultrasonic welding head. The armature is supported on rollers 42 and the shield is provided with air flow means and a motor 44 is provided to rotate the armature step by step. The welding head 60 which has a number of radially exextending tips is secured to a horn 50 by a bolt so that when a tip is worn, the head may be rotated and a fresh tip brought into position. The horn 50 is coupled to a transducer 51 and reed-like support arms 62, 63 attached to the welding assembly are coupled to fixed supports 68 to allow vibrational movements of the assembly in the direction of arrow 69, Fig. 4. To provide for vertical displacement of the armature assembly relative to the welding head the indexing device 38 is arranged on a table 72 pivotally supported at 74 and resiliently biased towards the welding head by means 76. A drive motor 78 is coupled to a cam 80 which raises and lowers the indexing means 38. In operation the armature assembly 11 is placed in the indexing device 38 with one riser slot aligned with a welding tip and automatically the device 38 is raised to bring the conductor ends in the slot into contact with the welding tip and ultrasonic welding is effected. The device 38 is lowered, the motor 44 rotates the armature to bring another slot beneath the welding tip and welding is effected. All the slots are brought beneath the head before the end of the operation. The initially round conductor ends are deformed to the shapes shown in Fig. 7. The conductor ends may be of copper or aluminium as may be the risers.