Virtually, all-hydraulic circuits are essentially the same regardless of the application. There are six basic components required for setting up a hydraulic system:
1. A reservoir to hold the liquid (usually hydraulic oil)
2. A pump to force the liquid through the system
3. An electric motor or other power source to drive the pump
4. Valves to control the liquid direction, pressure and flow rate
5. An actuator to convert the energy of the liquid into mechanical force or torque,
to do useful work. Actuators can either be cylinders which provide linear
motion or motors which provide rotary motion and
6. Piping to convey the liquid from one location to another.
Figure 9.1 illustrates the essential features of a basic hydraulic system with a linear hydraulic actuator.
The extent of sophistication and complexity of hydraulic systems vary depending on the specific application.
Each unit is a complete packaged power system containing its own electric motor, pump, shaft coupling, reservoir and miscellaneous piping, pressure gages, valves and other components required for operation.