Myron F. Hill, who might be called the father of the gerotor, in his booklet "Kinematics of Ge-rotors", lists efforts by Galloway in 1787, by Nash and Tilden in 1879, by Cooley in 1900, by Professor Lilly of Dublin University in 1915, and by Feuerheerd in 1918.
These men were all working to perfect an internal gear mechanism by a one-tooth difference to provide displacement.
Myron Hill made his first efforts in 1906, then in 1921, gave his entire time to developing the gerotor.
He developed a great deal of geometric theory bearing upon these rotors, coined the word GE-ROTOR (meaning generated rotor), and secured basic patents on GE-ROTOR.
Gerotors are widely used today throughout industry, and are produced in a variety of shapes and sizes by a number of different methods.