Which of the following components is NOT a major part of a hydraulic system?

In a hydraulic system, the key components are designed to work together to transmit power through hydraulic fluid. The major parts typically include a tank, which holds the hydraulic fluid; a piston, which utilizes the hydraulic pressure to create mechanical force; and a pump, which moves the hydraulic fluid through the system and generates the necessary pressure.

A gear system, while potentially useful in some hydraulic applications for different functions (such as in hydraulically powered gearboxes), is not considered a major or essential part of a hydraulic system itself. It does not play a necessary role in the fundamental operation of hydraulic systems, which rely primarily on the principles of fluid dynamics and the interaction between the tank, piston, and pump. Thus, identifying the gear system as not being a major part of a hydraulic system is accurate and underscores the specific roles each component plays in hydraulic operations.