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Document 34: The History of the Induction Motor in America

More than any other factor, the fractional-horsepower electric motor generated an enthusiasm for woodworking as a leisure-time activity by amateurs. Fractional horse-power motors, themselves, would not have been developed without the push toward urban -- and later rural -- electrification, using alternating current.  Electrification began in the cites around 1915. With electrification, the potential market for clothes washing machines, refrigerators, vacuum cleaners, and a host of related appliances, was recognized by major manufacturers -- like Westinghouse and General Electric -- who already were in the business of selling large motors of industrial settings. By 1920, over 500,000 fractional horse-power motors were powering clothes washers and other appliances in America.  For amateur woodworking, progress occurred as a series of stages: -- rather than foot-power -- it was a major gain, first, to get an electrical power source  to drive major tools, like tablesaws, bandsaws, lathes, i.e., direct drive electric motors (before 1915), second, to move to motors powered by alternatinging current, but third, where a line of machine tools were driven by a single motor, using shafts and pulleys -- see illustration from Delta's set-up below --, and  finally, to where each tool had its own motor. (See Warren D. Devine, "From Shafts to Wires: Historical Perspective on Electrification", The Journal of  Economic History, Vol. 43, No. 2 (Jun., 1983), pages 347-372.  There seems not be an equivalent article to G Leslie Oliver, "Fractional Horse Power Motor and Its Impact on Canadian Society and Culture," Material History Review 43 spring 1996, pages: 55-67. Oliver's point: much less evident in the literature are the results of research into the implications of specific, small and unobtrusive technologies, especially those that enter the home (often by the back door). Oliver argues that the appearance fractional horse power electric motor set in motion a series of changes in living that had a major impact upon behavior, values, and the like, but these shifts occurred without much awareness.Further, Oliver adds, There is little to help us to understand better what the[se technologies] are, what they do, how they work and their intended, unintended, as well as their unanticipated and unplanned for consequences - those now increasingly evident as the twentieth century draws to a close.                                Beginning around 1920, the application of fractional horsepower motors was no longer confined to the driving of electric fans or to the operation of toys. (Docu- ment 30: George A Schock: Early History of the Baldor Electric Co., 1920-1976 1992 .) According to the electrical engineer, Edward L Owen, “The induction motor enables us to refrigerate our food, climatize our living space, and perform many other tasks that we take for granted”. True, the development of these smaller motors was partly stimulated by the growing popularity of the individual-drive systems in small workshops -- which replaced the shaft-drive system (below, see Delta recommended set-up in the Motor Driven Shop, 1930)  --  copied from nineteenth century industrial applications -- and the growing availability of portable electric tools, especially the introduction of greater torque capability.  However, the real driver for developing a market for these motors was their  application in domestic settings. It was the housewife demanding  motor-driven washing machines, ironing machines, vacuum cleaners, dish-washing machines, sewing machines, refrigerators, piano players, and a host of similar appliances, for which motors are required. Examples: Important in this advance in technology  was the development of capacitor motors in 1925. [need sentence noting what the significance of this innovation was] Electric motors, which are, basically, copper wire wound around a magnet, are either multi-phase or single-phase.  Multi-phase motors, on the one hand, generate starting torque along the various windings by applying out of phase voltages to each winding in a pattern that generates a torque force in the desired direction.  Single-phase motors, on the other hand, must generate the same starting torque. However, because  they have only one phase to work from, single phase motors need the  means generate and send a shifted version of the single phase voltage to one of their windings.   There are three common methods of creating single-phase electric motors:  (1) capacitor start, (2) split-phase, and (3) shaded pole.  Each other these motors has some method to provide starting torque to the motor by shifting the voltage given to one of the windings on the motor by some angle.  This phase shift corresponds to one winding of the motor having a voltage before another coil.  The difference in time between when one coil has a voltage and when a second coil has a voltage causes the torque force and begins the movement of the motor. In short, and  without  getting unnecessarily more technical,  the capacitor provides a delay in the energy given to one of the windings.  This delay causes the forces of the motor to be unbalanced and the motor then starts. Economically, capacitor start motors are often more costly due to the inclusion of the capacitor however they have the most starting torque This means that you probably have one in your refridgerator, washer, dryer, or other application, like woodworking tools,  where you may need a lot of starting force but you won't find them in your electric fan. Improved CONSTRUCTION FEATURES Because they replaced steam engine drive with long shafts and belts. early motors featured sleeve bearings in pillow blocks. As a result, these motors could only be horizontally mounted and used indoors, in dry atmo­spheres. Any exposed electrical parts also made them unsafe. Later [when?] end brackets, with sleeve bearings and double-end ventilation,  were adopted, making these motors both safer and widened the range of application, including to amateur woodworking settings. However, it was the development of totally enclosed motors with fan cooling which en­abled these motors to be used outdoors, in say, uninsulatd garages, or even outdoors. For a very good example of an electric motor operating outdoors, see article by J R Koontz, “Driving the Farm Pump Electrically,” Shop Notes v 21 (1925), pp 1-2.   E T Painton Small Electric Motors DC and AC London: Pitman, 1923 PREFACE THE application of fractional horse-power motors is no longer confined to the driving of electric fans or to the operation of toys. The growing popularity of the individual drive system in small workshops, and the increasing use of portable electric tools, has stimulated development of motors, which, though of very small size, are of excellent electrical and mechanical design, and form miniature power units of great reliability and good performance. An even more modern application is found in the domestic sphere, where there is a steadily increasing demand for motor-driven washing machines, ironing machines, vacuum cleaners, dish-washing machines, sewing machines, refrigerators, piano players, and a host of similar appliances, for which motors are required, sufficiently robust to withstand rough handling by a non-technical user, but at the same time light in weight and capable of enduring severe service conditions. Motors for such purposes operate upon the same principles as larger machines, but their operating characteristics often differ widely, and it is the object of this book to indicate the general characteristics of small motors, pointing out departures from the well-known characteristics of large machines, and setting out the general principles governing their performance. For this reason some importance is placed on test results obtained in typical small motors, and at the same time considerable space, in illustration and text, is devoted to the constructional features of motors of various types. ... EDGAR T. PAINTON.       Herbert Vickers, Induction Motor: The Theory, Design, And Application Of Alternating-Current Machines Including Fractional HP Motors Second Edition London: Longman & Sons, 1958 Introductory [This book is an ] ... account of the fascinating history of the induction motor.  The discovery by Gambey, the instrument-maker of Paris, that a compass needle, when disturbed and set oscillating, comes to rest more quickly when it is in the vicinity of copper, than when wood is near it, was made in 1824. At that time also Barlow and Marsh, at Woolwich, had observed the effect on a magnetic needle of rotating it near a sphere of iron. Arago published, in 1824, an account of an experiment with a compass needle within rings of different materials. In this experiment he pushed the needle aside to about 450 and counted the number of oscillations made by the needle before the swing decreased to 0°. With a ring of wood the number of oscilla-tions was 145; with a copper ring 66; and with a stout copper ring only 33. In 1825 he suspended a compass needle over a rotating copper disc and found that, by turning the disc slowly, the needle is dev110ated out of the magnetic meridian. By rotating the disc fast enough he found that continuous rotation of the needle could be produced. The brilliant discovery by Faraday, in 1831, of electro-magnetic induction provided the solution to the question of the origin of the forces present in the above experiments of Gambey, Barlow and Marsh, and Arago. Faraday showed that the rotation of the Arago disc was due to induced currents, set up in the disc by relative motion of disc and compass needle. From 1831 to 1879 this valuable discovery produced no further results. In June, 1879, Mr. Walter Baily read a paper, before the Physical Society of London, on "A Mode of Producing Arago's Rotations." Baily used a fixed electromagnet with four magnet cores joined to a yoke. The four magnet cores were about 4 in. long and each was wound with about 150 turns of insulated copper wire of 2.5 mm diameter. The coils were connected two and two in series, similar to two independent horse-shoe magnets and were set diagonally across one to another. The two circuits were connected separately to a revolving com-mutator, built up of a simple arrangement of springs and contact strips mounted on a piece of wood, with a wire handle by which it was turned. By rotation, the currents from two batteries were caused to be reversed alternately in the two circuits, and this gave rise to the following changes in polarity of the four poles. In this rotating magnetic field a copper disc was suspended. He stated : "The rotation of the disc is due to that of the magnetic field in which it is suspended, and we should. expect that, if a similar motion of the field could be produced by any other means the result would be a similar motion of the disc." He also suggested that if a whole circle of poles were arranged under the disc, successively excited in opposite pairs, the series of impulses all tend to make the disc revolve in one direction around the axis, and added: "In one extreme case, when the number of electromagnets is infinite, we have the case of a uniform rotation of the magnetic field, such as we obtain by rotating permanent magnets." It is clear that Mr. Baily had grasped the fundamental principle of action of the induction motor, and the motor he exhibited before the Physical Society, in 1879, was the first induction motor, but it needed later important discoveries of methods for producing the revolving field by means of alternating currents to make it the useful machine that it is to-day. The next discovery was made by Marcel Deprez in 1883. Deprez fed alternating current to a coil, which produced an alternating or oscillating field along the OX axis. He supplied another coil, whose magnetic axis made an angle of 900 with the OX axis, with alternating current, whose phase difference was 900 in time from the current in the first coil, and showed that a revolving field of constant amplitude could be produced. The frequency of the two currents was the same. He also showed that if the two currents were of equal period, but not of equal amplitude, an elliptically rotating field was produced. The number of turns in each coil was the same. Professor Ferraris arrived at the same conclusions as Baily and Deprez in 1885, and apparently without knowing of the work of either. His paper on "Electrodynamic Rotations Produced by Means of Alternating Currents" was published in 1888. He sug-gested the method of obtaining currents, differing in phase by nearly 90°, by inserting a resistance in one winding and inductance in the reactance other, thus making the ratio of resistance small in one winding and large in the other. This method, it may be noted, is largely used for starting p single-phase motors. Then followed the great work of Nikola Tesla between 1887 and 1891. His researches placed the induction motor on a sound founda-tion. His patents were sold to the Westinghouse Co. of America, whose pioneer efforts in this field must be recognized. In that period, however, the only a.c. supply circuits were single phase, and the frequencies were 133 and 125 c/s. These supply circuits were obviously unsuitable for the development of the motor. In 1891 the Electrotechnical Exhibition at Frankfort was held, and three-phase transmission of power was demonstrated.... Sources: the section draws on Edgar T. Painton Small Electric Motors DC and AC London: Pitman, 1923; Harry Jerome, Mechanization in Industry. NY: National Bureau of Economic Research, 1934, pp 174-175; Herbert Vickers, Induction Motor: The Theory, Design, And Application Of Alternating-Current Machines Including Fractional HP Motors Second Edition London: Longman & Sons, 1958;  Philip Alger and Robert Arnold “History of Induction Motors in America,” Proceedings of the IEEE, V 64: 1976, pages 1380-1383; Warren D. Devine, "From Shafts to Wires: Historical Perspective on Electrification", The Journal of Economic History, Vol. 43, No. 2 (Jun., 1983), pages 347-372; Edward L. Owen,  “The induction Motor's Historical Past”, IEEE Potentials 7 (October 1988), pp. 27-30; G Leslie Oliver, "Fractional Horse Power Motor and Its Impact on Canadian Society and Culture," Material History Review 43 spring 1996 Pages: 55-67. Also . A search of the Reader’s Guide To Periodical Literature ( begins 1895), digitized database fails to unearth article of any substance on inductive fractional horse power motors, even though these motors are widely distributed in domestic appliances, such as washers, refrigerators, and the like. Likewise a search the pages of Popular Mechanic’s Shop Notes, published between 1904 and 1930,  shows only a few article dedicated to electric motors, e.g., the Koontz article cited above. However, significantly, right on the cusp of the 1920s (dated 1930, but necessarily written in the late 1920s), is the Tautz and Fruits’ chapter xviii, “Power, current and motors”, subtitled “power to operate woodworking machinery”, in their Delta manual, the 1930 Modern Motor-Driven Woodworking Shop. SMALL-TYPE MACHINES FOR HOBBIES AND BENCHWORK The induction motor drives amateur woodworking! Without he induction motor, only hand tools and/or foot powered tools would be available to the amateur woodworker. About 1923, the first woodworking machines were built in small sizes for hobbyists by a company in Milwaukee. Today these small-type machines are manufactured in several sizes in almost unlimited quantities at prices such that many people equip basement shops as a hobby. They have proved so valuable that many manufacturers use them for making small parts. Following along this development, portable electric-motor­-driven tools for many of the operations formerly performed by hand in the building trades have been developed. All of these are equipped with ball bearings, light in weight, and very practical. Baldor Motors began manufacturing electric motors in 1920 List of fractional hp induction motor manufacturers in U.S. A.O. Smith 531 N. Fourth Tipp City, OH 45371 Phone: (513) 667-6800 Fax: (513) 667-5873   Baldor P.O. Box 2400 Fort Smith, AR 72902 Phone: (501) 646-4711 Fax: (501) 648-5792 Document 30: George A Schock: Early History of the Baldor Electric Co., 1920-1976 1992    Brook Crompton 3186 Kennicott Ave. Arlington Heights, IL 60004 Phone: (708) 253-5577 Fax: (708) 253-9880   Dayton/Grainger 333 Knightsbridge Pky. Lincolnshire, IL 60069 Phone: (800) 323-0620 Phone: (708) 913-8333 Fax: (800) 722-3291     Emerson Electric/U.S. Motors 8100 West Florissant Ave. P.O. Box 3946 St. Louis, MO 63136 Phone: (314) 553-2000 Fax: (314) 553-1196   General Electric P.O. Box 2222 Fort Wayne, IN 46801 Phone: (800) 626-2004 Phone: (219) 439-2000 Fax: (219) 439-4644   Leeson 2100 Washington Ave. Grafton, WI 53024 Phone: (414) 377-8810 Fax: (414) 377-9025 Lincoln 22801 St. Clair Avenue Cleveland, OH 44117-1199 Phone: (216) 481-8100 Fax: (216) 383-4730   MagneTek 1881 Pine Street St. Louis, MO 63103 Phone: (800) 325-7344 Fax: (800) 468-2045   Marathon P.O. Box 8003 Wausau, WI 54402 Phone: (715) 675-3311 Fax: (715) 675-6361   Reliance 24701 Euclid Ave. Cleveland, OH 44117 Phone: (800) 245-4501 Phone: (216) 266-7000 Fax: (216) 266-7536   Siemens 4620 Forest Ave. Norwood, OH 45212 Phone: (513) 841-3100 Fax: (513) 841-3290   Sterling 16752 Armstrong Ave. Irvine, CA 92714 Phone: (800) 654-6220 Fax: (714) 474-0543   Tatung 14381 Chambers Rd. Tustin, CA 92680 Phone: (800) 828-8641 Fax: (714) 838-3295   Teco 6877 Wynnwood Houston, TX 77008 Phone: (713) 864-5980 Fax: (713) 864-9502   Toshiba 13131 W. Little York Rd. Houston, TX 77041 Phone: (800) 231-1412 Phone: (713) 466-0277 Fax: (713) 466-8773   Westinghouse Motors IH-35 Westinghouse Road P.O. Box 277 Round Rock, TX 78680 Phone: (512) 255-4141 Fax: (512) 244-5500

An account of the course of the development of the fractional horse-power motor is given by Philip Alger and Robert Arnold, in  "The History of Induction Motors in America" Proceedings of the IEEE  64 1976, pages 1380-1383. Other  articles that focus on the this same motor are listed below, in the cream-colored box. 

Philip Alger and Robert Arnold "The History of Induction Motors in America" Proceedings of the IEEE  64 1976 Pages: 1380-1383     Abstract: Reviews the history of the induction motor from its invention by Nicola Tesla in 1888 through the various stages of its development: --the invention of the cast aluminum squirrel-cage winding, -- improvements in magnetic steel and insulation, and -- the progressive reduction of the dimensions for a given horsepower rating, so that today a 100-hp motor has the same mounting dimensions as the 7.5-hp motor of 1897.