Fractional-horsepower motor

Lore & Background

The earliest commercially successful electric motors date to the late 19th century, when Nikola Tesla patented his induction motor in 1888. Fractional-horsepower motors would not have been developed without the push toward urban and later rural electrification using alternating current, which began in cities around 1900. Chester Beach, an employee of Hamilton-Beach, invented a high-speed fractional motor in 1905, which the company used in its Cyclone Drink Mixer introduced in 1910, sold to urban drugstores for soda fountains. Within a few years, it was found in most drugstores.

With electrification came the potential market for washing machines, refrigerators, vacuum cleaners, and other appliances. Major manufacturers like Westinghouse and General Electric, already making large motors, recognized this. By 1920, over 500,000 FHP motors were powering washing machines and other appliances in America. After World War II, demand surged again with consumer goods, and growth continued through the consumerist boom of the 1950s and 1960s. In 2000, the European FHP market was worth an estimated $4.5 billion with some 300 million units in manufacture.

Servo motors and stepper motors are specialist types of fractional-horsepower motors for high-precision or robotics applications, usually running from a DC supply. Combined with a planetary gearbox, they can offer accuracies less than 8 arc-minutes. Due to their specialized nature, these types tend to be expensive compared with standard lower-precision units.

Reader's Guide

Fractional-horsepower motors are used across a wide range of industries and applications for motion and compression needs. The largest portion of sales is attributed to the automotive sector, accounting for some 35% of all FHP motor sales, driving auxiliary applications such as electric windows, windshield wipers, powered seats, wing mirrors, central locking systems, roof openers, and trunk openers. In Europe, the majority of these applications are fulfilled by Brose, Bosch, and Nidec. The second-largest area of consumption is white goods and small domestic appliances, approximately 12% of the European market, including pumps and compressors in refrigerators, coffee machines, and washing machines, as well as suction in vacuum cleaners. Until its recent divestment, Electrolux was believed to be Europe's largest manufacturer of FHP motors for domestic appliances. Industrial applications consume a similar number of units to domestic products, used across conveyance and process applications. Other applications include pumps and compressors, medical devices, portable tools, office machinery, and HVAC. Development increased with the growth of e-bikes. Because of their practicality, they continue to be incredibly popular, with the European FHP market worth around US$4.5 billion in 2017.

Did You Know?

• Fractional-horsepower motors are exempt from the US Energy Policy Act of 2005 and the European directive 2005/32/EC concerning efficiency classes of low-voltage three-phase asynchronous motors.
• Chester Beach invented a high-speed fractional motor in 1905, which was used in the Cyclone Drink Mixer introduced in 1910.
• Servo motors and stepper motors, types of FHP motors, can offer accuracies less than 8 arc-minutes when combined with a planetary gearbox.