Patent GB-285927-A (GB)
Title: Improvements in or relating to the electrical driving of spindles for spinning or other textile processes
IPC: H02K19/12
Filed: 1926-08-25
Abstract: 285,927. British Celanese, Ltd., and Cope, E. C. Aug. 25, 1926. Alternating-current induction machines; armatures and field magnets, cooling; windings; driving arrangements. - In polyphase motors which have textile spindles directly coupled to or forming part of their rotors, very high speeds are obtained without the possibility of the motors remaining at any critical speed below full speed by providing unbalanced ampere-turns in the motors or in the high-frequency generators supplying them. The unbalance is obtained either by winding the machines asymmetrically so as to give a maximum difference of 15 per cent in ampere-turns between any two phases or by using asymmetrically wound machines and producing asymmetry in the supply network by means of resistances, impedances, asymmetrically wound transformers or any other method for producing different voltages on the separate phases. The Specification describes a 3-phase, 2-pole, 24-slot star-connected stator winding for an induction motor having 100, 97 and 94 turns respectively between its star point and three phase terminals. The induction motor shown in Fig. 2, which has means 3 for driving a bobbin, has a squirrel-cage rotor with bars 10 in partly open slots disposed spirally on the rotor surface to facilitate starting and to pass cooling air from the openings 11<b> at the bottom of the casing through the air gap to the exit 11<c> at the top. The rotor is secured on the spring-supported shaft by a nut 14 and the screwed flywheel 15. The stator 8 may have spirally disposed slots to facilitate starting, in which case the rotor slots may be axial. The upper bearing is lubricated from a well 19 containing a wick and communicating by passages 23, 24 and the bearing with a sump 25. When the spindle is stationary, the oil collects in the sump, and when the motor rotates, the shaft raises the oil to the well 19 through a spiral groove 4a in the bearing. Any oil falling from the sump is caught by the cupped upper surface of the flywheel, thrown agains the feed plate 9 and returned to the well. The lower bearing and footstep bearing are lubricated from a well 27 by a wick and openings 28, 29. Fig. 3 shows a hollow shaft induction motor electrically similar to the machine shown in Fig. 2 and having its rotor fixed to a flywheel member 9 by screws and a clamping ring 10<b>. Forced lubrication is brought to an inlet pipe 19, the oil for the upper bearing passing through channels 20, 22 to a spiral groove 4<a> in the bearing and thence to a channel 20<a>, the sump 26 and outlet pipe 20<b>. The oil for the lower bearings passes through channels 21, 23 and a. spiral groove 24 to the sump. Any oil escaping into the motor casing passes to the sump through passages 20<c>. The textile spindle is driven through a ball-and-socket joint comprising an extension piece 26<a> rounded to enter a cup in the end of the motor shaft, to which it is secured by a pin 27, and surrounded by a sleeve 28 and resilient packing 29. The upper end of the extension piece is cupped to form one element of a clutch the other element of which is a flange 31 on the textile spindle. The clutch is completed by friction discs 30, and a spring retained by a cover 34. The traverse may be imparted either to the caps or other means used for guiding the threads or yarns or to the motor and spindle. The invention is applicable to motors for any high speed textile operation, such as twisting or doubling artificial or natural fibres by cap, ring and traveller, flyer or other methods; winding or twisting artificial filaments continuously in their formation by the dry or evaporative method; or crepe twisting or doubling. Specification 198,023, [Class 120 (ii), Spinning, twisting, &c.], is referred to.