Electric Motors – Single Phase, Shaded Pole
A heavy duty, mid 20th century, 60 cycle, 1/20 HP, shaded pole, induction fan motor, custom designed for GE window air conditioner, evaporator and condenser application. Equipped with rubber, torsion 2 point mounting and inherent, automatic overload protection, it helped to make possible a new generation of affordable, larger capacity, quieter more efficient “through-the-wall” [window] air conditioners which changed for ever the expectations of Canadians about what to do about the summer’s heat, GE, Circa 1964. [1 of a set of 3, demonstrating the variations and application of the technology, see also ID#320 and 321]
Technical Significance:
– 1 of a set of 3, shaded pole, custom designed motors, demonstrating the variations and application of the technology, in order to fit the specialized requirements of different air conditioner manufacturers, models, and model years, for example in matters of horsepower, starting torque, rotation, inherent automatic thermal protection, etc [see also ID#320 and 321].
– Equipped with torsion, rubber vibration mountings, and automatic, recycling, inherent overload protection, It would be representative of an 1960’s, generation of heavy, fan-duty, customized shaded pole motor technology, for the now rapidly maturing through-the-wall [window] air conditioner market.
– With a totally sealed body and bearings, it was a marker of the now rapidly emerging body of engineering and manufacturing practice, moving to a “parts replacement” culture, from the traditional “parts repair” mode of operation.
– The single phase alternating current induction motor has a public face of great simplicity – no commutator, brushes, governor nor switching mechanism to get it started, simply a field winding and solid state [squirrel cage] rotor mounted between two bearings. Its “shading pole(s)” consisting of single turn of wire strategically placed around its pole face(s), is all that is required to start rotation. Yet the shaded pole induction motor is a marvel of early 20th century electrical design engineering. [See Reference No. Chapter XIII, P. 297]
Industrial Significance:
– Its low cost and unique speed-torque characteristics made the shaded pole induction motor ideal for small fan applications of 1/20th HP or less. A “one-of-a-kind”, “just-in-time” technology, it quickly found a special place in 20th century appliances and electrical equipment, where air circulation, air conditioning and ventilation where imperatives.
– By the mid 1960’s the through-the-wall [window] air conditioner market was rapidly maturing, providing the Canadian public an affordable solution to spikes in summer heat that her-to-for could not have been imagined. The innovative, unitary engineering concept with cooling and heat rejection equipment all in the same cabinet made it readily installed by the do-it-yourself’s, without special tools and equipment. Air conditioners had become the newest home appliance.
