Composition of Hydraulic System

The actual hydraulic system is generally composed of hydraulic pumps, hydraulic valves, hydraulic actuators and accessories. You could get Hydraulic pumps, Hydraulic Valves and Hydraulic Motors in Ryan Hydraulics.

1) The hydraulic pump is driven by an electric motor or engine to discharge hydraulic oil.
2) The hydraulic actuator is connected to the working parts and driven by the hydraulic oil to drive the working parts.
Drive, usually refers to moving the working part. The hydraulic actuator also has a task: to make the working parts move from stationary to braking. In this book, the drive and brake are collectively called control, and the working parts that need to be controlled by hydraulic actuators are collectively called load.
Controlling load movement is the basic task of hydraulic technology to survive.
To control the movement of the load, it is necessary to overcome various resistances that affect the movement. Therefore, this book refers to all kinds of resistance overcome by hydraulic actuators as load force.
Hydraulic actuators are divided into hydraulic cylinders and hydraulic motors.
In general, the hydraulic cylinder controls the linear movement of the load and overcomes the load force; the hydraulic motor controls the rotation or swing of the load and overcomes the load torque. For the sake of brevity, the following generally refers to hydraulic actuators with hydraulic cylinders, which generally only increase the load force and omit the load torque.
According to national standards, motors refer to “actuators that provide rotational motion”, including hydraulic motors and pneumatic motors. Because this book does not involve pneumatics, the hydraulic motor is hereinafter referred to as the “motor”.
3) The hydraulic valve is used to restrict the flow of hydraulic oil, thereby controlling the movement of the hydraulic actuator.
4) Accessories include connecting pipes, oil tanks, filters, heater coolers, indicating instruments, etc.
Because the liquid does not have a fixed shape, hydraulic actuators, hydraulic valves, and hydraulic accessories can be arranged wherever needed, as long as the hydraulic pipes are accessible, without restrictions on direction and distance. Therefore, it is very flexible.

—From ‘Hydraulics for Everyone’