Tesla is widely known today for its electric vehicles, but the company has its roots in innovative electric motor design researched by Nikola Tesla in the late 19th century. As one of the pioneers of electric power distribution and polyphase induction motors that helped enable the modern world, Tesla’s early work laid the foundation for the electric vehicles produced by the company today named in his honor.
In the 1880s, Tesla moved to the United States from his native Croatia and started working in Thomas Edison’s New York laboratory. While working for Edison, Tesla began developing AC dynamos and motors that could run on AC power. At the time, Edison was focused on developing and promoting DC power over the newer AC technique being championed by Tesla and George Westinghouse. After a falling out with Edison over unpaid bonuses, Tesla struck out on his own in 1886.
That same year, Tesla filed U.S. Patent 447,920 which described a rotating magnetic field principle for producing an AC motor later credited as establishing the basis for most electric motors in use today. This early induction motor design eliminated the need for mechanical commutators used in DC motors and instead produced a rotating magnetic field from alternating currents. It was a groundbreaking invention that demonstrated the advantages of using AC power over the limiting DC method.
Building on this work, Tesla filed several additional patents in the late 1880s further developing his induction motor concepts. He demonstrated a working prototype induction motor to the American Institute of Electrical Engineers in 1888. Seeing the potential, George Westinghouse licensed Tesla’s AC power patents, allowing Westinghouse Electric to commercialize an entire AC power system and compete against Edison’s DC method. This helped cement AC as the dominant power transmission standard worldwide and aided the expansion of electrification across America and beyond.
In 1891, Tesla began research at his Colorado Springs laboratory on high-voltage, high-frequency alternating currents and wireless transmission of electrical energy. Here, he made many discoveries about wireless communication and developed improved induction motors running on high frequencies as a way to study AC phenomena. A lack of funds cut his experimental work in Colorado Springs short after just over a year.
Nonetheless, Tesla patented several improved induction motor variants in the 1890s based on multi-phase winding configurations and magnetic designs. His three-phase motor designs allowed for rotating magnetic fields that produced smoother, more efficient operation compared to two-phase motors of the era. These polyphase induction motors became a mainstay of industrial applications and helped boost productivity. Some of Tesla’s motor patents from this period included U.S. Patent 511,560 for an improved motor winding configuration and U.S. Patent 568,179 detailing an efficient multiphase motor design.
Through the 1890s, Tesla focused on wireless power innovations while continuing research on improved motors at his New York laboratory. In 1897, he unveiled an immense 186-foot tall transmission tower at Wardenclyffe to conduct wireless power experiments, receiving backing from investors like J.P. Morgan. The projected wireless power business faced difficulties and never fully materialized. By the early 1900s, Tesla’s research funds dried up due to various setbacks and controversies.
Nonetheless, Tesla’s foundational work on AC power transmission and induction motor designs had already made a massive impact. During the Progressive Era, industries widely adopted Tesla’s motors to power assembly lines, manufacturing equipment, industrial machinery, and more. This helped enable mass production and allowed factories to scale up operations. At Niagara Falls, huge alternating current generators supplied hydroelectric power for Tesla’s induction motors to streamline all manner of work.
After losing his laboratory in a 1917 fire, Tesla spent his later life continuing motor and wireless inventions in relative obscurity. Induction motor refinements from other inventors built directly upon his original work. Key developments included closed slots in the stator sheet pack to reduce eddy currents and improve efficiency in the 1920s. Squirrel cage rotor designs also boosted starting torque capabilities.
By the 1940s, roughly 90% of all motors produced were based on Tesla’s induction motor concept as efficiency and low cost made it a standard across industries. Modern variations include standard NEMA frame induction motors for commercial and industrial use along with inverter-controlled induction motors found in variable speed AC drives. Super-efficiency premium efficiency, and energy saving induction motors appeared in the late 20th century due to NEMA standards changes.
As researchers continued optimizing Tesla’s induction motor, it cemented its role as one of history’s most impactful and widely used electrical machines. With over 100 years of refinement, the induction motor design serves as the basis for motor controls still used today – including those powering the electric cars produced by Tesla Motors. Given his brilliant early work inventing the platform, Nikola Tesla can truly be called the father of the modern electric motor. The impact of his induction motor patents shaped the development of mass electrification and industry worldwide. Tesla’s legacy lives on through the electric vehicles that now bear his name.
Andrew Stroud