Observation and Measurement of Hydraulic Components Using Digital Microscopes

Principle of Hydraulic Mechanism

If pressure is exerted on part of a stationary fluid (oil) in an enclosed container, this pressure will be distributed evenly and vertically to all surfaces the fluid contacts, regardless of the shape of the container. This phenomenon is called Pascal's law. Hydraulic systems use oil to amplify force based on this principle.

Advantages and Disadvantages of the Hydraulic Mechanism

The hydraulic mechanism has great advantages but also presents some unique disadvantages.

Advantages of the hydraulic mechanism

• Great power can be transmitted accurately at high speed.
• Power density is high, allowing devices to be smaller and lighter.
• Pressure control valves ensure a high level of safety.
• Service lives are long due to oil lubrication.

Disadvantages of the hydraulic mechanism

• Susceptible to contamination by oil.
• Oil may ignite. (Ignition point is 200 to 250°C.)
• Oil may leak.

Typical Hydraulic Components

Hydraulic pump

Hydraulic pumps use electric motors or engines as a power source to apply pressure to hydraulic oil.

Control valve

Control valves control the pressure, flow rate, and flow direction of hydraulic oil. These valves are respectively called pressure control valves, flow rate control valves, and directional control valves.

Hydraulic actuator

Hydraulic actuators convert fluid power into mechanical power. Hydraulic actuators include hydraulic cylinders which convert fluid power into linear motion, hydraulic motors which convert fluid power into rotary motion, and oscillating actuators which convert fluid power into oscillating motion.