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Lynn L. Charlson


1909 - 2004) Charlson was a self-taught inventor and designer; a pioneer in the field of hydraulic power, and founder of the Char-Lynn Company. A mechanical genius, entrepreneur and pioneer in the field of hydraulics, he was issued 94 patents. He was a savvy businessman who knew marketing as well as hydraulics.


Charlson became a self-taught inventor and designer through diligent use of the public library. While working as a night clerk in a small Minneapolis hotel, and using books borrowed from the public library, he acquired a solid background in mechanics, hydraulics, and electronics. His opportunity came suddenly from an unexpected source. A manufacturer who stayed at the hotel noticed the books that Charlson laid down when he came to the counter to wait on him, and got into the habit of discussing his manufacturing problems with him. He found the young clerk’s ideas very helpful in solving some difficult problems. He recommended Charlson for a job, saying that although Charlson was not an engineer, he knew more about working out hydraulic and other mechanical problems than any engineer he had ever met.

In 1946, he developed a low cost hydraulic pump. With his design, he was able to use a die casting machine that enabled him to turn out his pumps by the thousands at a handsome profit. He sold them at a cost lower than many of his competitors could manufacture them.

He pursued a career of inventive product design and development culminating in the invention of an inexpensive high torque, low speed hydraulic motor using orbit motor principle. After seven years of effort, he discovered the gerotor orbit motor principle. The word gerotor is derived from "generated rotor." The motor operates on the principle of an internal gear rotating within a fixed external gear. The outer ring is a stationary part of the motor housing. It has internal gear-like teeth which mesh with the corresponding teeth on a smaller gear, or rotor, which rolls inside the ring, turning about an eccentric axis in an orbit. Its great advantage over other hydraulic motors is that is gives high torque at very low speed. In many applications the motor can drive the load without a gearbox. This motor has been characterized as probably the most unique and useful hydraulic device in the field of fluid power in modern times. It brought fluid power to thousands of new applications worldwide, thus expanding the entire industry. Typical applications for these motors are winch drives, mixer drives, elevator drives, small vehicle transmissions and machine tools. Many millions of hydraulic motors utilizing the Charlson’s inventions are today found in thousands of applications all over the world and in many industries, including agriculture, mining, construction, and transportation.

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