Introduction to Hydraulics

Introduction to Hydraulics

​Fluid Power

​-Fluid power is the method of using pressurized fluid to transmit energy.

-Liquid or gas is referred to as fluid.

-Accordingly, there are two branches of fluid power;

Pneumatics, and Hydraulics.

​Pneumatics

​-Pneumatic systems use air to transfer force from one point to another.

-Air is compressible (This describes whether it is possible to force an object into a smaller space than it normally occupies. For example, a sponge is compressible because it can be squeezed into a smaller size)

​Hydraulics

-​Hydraulic systems use liquid to transfer force from one point to another.

​-Liquid is incompressible (The opposite to compressible. When a “squeezing” force is applied to an object, it does not change to a smaller size. Liquid, for example hydraulic fluid, possesses this physical property.)

​

​*It is this difference that makes hydraulic and pneumatic systems behave in different ways.

Open Ended

What are the two branches of fluid power?

Multiple Choice

Air is incompressible while liquid is compressible.

• True

• False

​Uses

​Hydraulic systems are commonly used where mechanisms require large forces and precise control. Examples include vehicle power steering and brakes, hydraulic jacks and heavy earth moving machines.

​Common examples

​1. Vehicle brake hydraulic systems

The function of a vehicle braking system is to stop or slow down a moving vehicle.

​

​YouTube video:

​https://www.youtube.com/watch?v=82qBBJ8iwcc

​

​​Common examples

2. ​Vehicle power steering

​​The vehicle power steering system uses hydraulic oil, the hydraulic pump supplies the oil through the control valves to the power cylinder. The major advantage of using this system is to turn the vehicle’s wheels with less effort.

​​Common examples

​3. Hydraulic Jack

In a hydraulic jack, a small piston (pumping piston) transmits pressure through the oil to a large piston (power piston) through a check valve, resulting in the weight being lifted.

​YT video: https://www.youtube.com/watch?v=Ykgi09b8BiI

​​​Common examples

​4. Aircraft hydraulic systems

All modern aircraft contain hydraulic systems to operate mechanisms, such as:

flaps and landing gears.

Open Ended

Give some uses/examples of hydraulic systems.

​Hydraulic system components

​Although, these components have been discussed already previously, let's try to remember them again.

​

​1. Power input device: The pump and motor together are called the power input device; the pump provides power to the hydraulic system by pumping oil from the reservoir/tank. The pump’s shaft is rotated by an external force which is most often an electric motor.

​​Hydraulic system components

​2. Control device: Valves control the direction, pressure, and flow of the hydraulic fluid from the pump to the actuator/cylinder.

​

3. Power output device: The hydraulic power is converted to mechanical power inside the power output device. The output device can be either a cylinder which produces linear motion or a motor which produces rotary motion.

​​​Hydraulic system components

​4. Liquid: the liquid is the medium used in hydraulic systems to transmit power. The liquid is typically oil, and it is stored in a tank or reservoir.

​

5. Conductors: The conductors are the pipes or hoses needed to transmit the oil between the hydraulic components.

Multiple Choice

The hydraulic power is converted to mechanical power inside the power input device which could be a cylinder or a motor.

• True

• False

Multiple Select

What are the components that constitute the power input device?

• pump

• reservoir

• motor

• liquid

Multiple Choice

The liquid is typically water, and it is stored in a tank or reservoir.

• True

• False

Multiple Choice

These control the direction, pressure, and flow of the hydraulic fluid from the pump to the actuator/cylinder.

• Valves

• Pipes

• Pump

• Hoses

​Thank you for completing this lesson.

​References:

https://maysaaiat.weebly.com/uploads/5/8/8/3/5883161/atm1122_hydraulics_module_1.pdf

https://www.youtube.com/watch?v=82qBBJ8iwcc

​https://www.youtube.com/watch?v=Ykgi09b8BiI

​

​Images:

https://www.nttinc.com/blog/hydraulics-training-system/

​https://i.ytimg.com/vi/_cefdMItILM/maxresdefault.jpg