Patent GB-1251385-A (GB)
IPC: H02K15/085
Filed: 1968-03-29
Abstract: 1,251,385. Making dynamo-electric machines; coiling helices; angular bending. JOSEPH LUCAS (INDUSTRIES) Ltd. 21 March, 1969 [29 March, 1968], No. 15174/68. Headings B3A and B3E. A method of making a winding for a dynamoelectric machine comprises winding a flat conductive strip to helical form, bending the resulting coil to form a wave wound winding, and dipping the winding in a synthetic resin whilst maintaining adjacent convolutions of the winding out of contact. Coil winding and shaping.-Aluminium or copper strip 10 is fed from an insulating station, where it receives a layer of self adhesive paper 10a on its upper surface, to a winding station 11, wherein the end of the strip is clamped by a finger 24 on to a shoulder 23 of a former 12. Control means is provided for rotating the former 12 through a pre-determined number of revolutions, and during winding the former 12 moves downwardly against an air spring 15. When winding is completed jaw members (31) of a transfer mechanism (26) are positioned on opposite sides of the wound coil, Fig. 2 (not shown). A severing component 25 cuts the coil from the strip, whereupon the coil unwinds slightly until its ends engage the jaw members (31), whereafter the transfer mechanism is operated to cause the jaws to grip the coil and transfer it to a forming station 34. The coil is deposited in slots defined between the tops of a pair of fingers 36 and the limbs of projections on the fingers, so that the projections prevent unwinding. A ram 38 then moves a carriage 37 downwardly so that a pair of fingers 39 pass inside the coil, while limbs of projections on the fingers pass outside the coil, and further downward movement of the carriage 37 bends the coil to form a winding as shown in Fig. 6. As the coil bends, the fingers 36, 39 move towards one another against the action of springs and the pairs of fingers interdigitate to form a solid cylindrical bar at the end of the travel of the carriage 37. Latches lock the fingers in their closed positions. A sizing sleeve 41 is then moved upwardly, over the shaped coil, to form its outside diameter to that required. The sleeve is returned and as it reaches its original position, it operates a micro-switch to initiate return movement of the carriage 37 and fingers 39, which carry the formed winding upwardly. During upward movement of the carriage, a micro-switch is operated, halting the carriage and causing a shoot to be moved between the fingers 36, 39. Upward movement of the carriage is then resumed, a cam on the frame 35 releases an extractor catch and a pair of stops on the frame 35 engage the winding stripping it from the fingers 39. The winding drops into the shoot and rolls down into a storage bin. Coil insulation.-The formed winding is dipped into a molten synthetic resin material, e.g. P.V.C., which forms around and completely covers the winding. In a modification the winding is formed from aluminium strip without the paper layer. Prior to dipping the winding, the convolutions are spaced from one another by the introduction of slips of paper between adjacent convolutions. Dynamo-electric machine assembly.-The coated winding 44 is provided at one end with a screw threaded portion 45 and at the other with a pair of brushes 46. The winding is then inserted into a yoke 48 so that two of its curved portions 44a are engaged with the rounded ends of a pair of polepieces 49 integral with the yoke. A further pair of polepieces 51 are then inserted into the yoke and secured by screws.