What is the function of a 'spool valve' within a hydraulic system, and how does its internal design contribute to its specific function?

The function of a spool valve within a hydraulic system is to control the direction of hydraulic fluid flow. It acts as a switch, directing fluid to different parts of the system to actuate (control) cylinders, motors, and other components. The spool valve's internal design directly contributes to this function. A spool valve consists of a cylindrical spool that slides within a valve body. The spool has several lands, which are raised sections, and grooves, which are recessed sections. These lands and grooves ar....