In the governor is a spring-loaded valve that opens in proportion to how fast the governor is spinning -- the more rapidly the governor spins, the greater the valve opens. Fluid in the pump is fed on the governor in the output shaft. Modern day automatic transmissions use pace sensors https://elliotktuyw.onzeblog.com/34180086/the-smart-trick-of-gearbox-auto-that-no-one-is-discussing