PASCAL'S PRINCIPLE AND HYDRAULICS - Pascal's Principle - Blaise Pascal was a French mathematician, physicist and religious philosopher who lived in the mid-seventeenth century. He made some significant observations about fluid and pressure. He noticed that the shape of a container had no effect on pressure. He also noticed that pressure applied to an enclosed fluid is transmitted undiminished to every part of the fluid, as well as to the walls of the container. When it says "enclosed fluid," that means that in order for Pascal's Law to be true, you have to be looking at a liquid in a closed container. Hydraulic systems use incompressible fluids, such as oil or water, to transmit forces from one location to another within the fluid. Hydraulics are used in most breaking systems. Pascal's law states that when there is an increase in pressure at any point in a confined fluid, there is an equal increase at every other point in the container. Therefore Pascal's law can be interpreted as saying that any change in pressure applied at any given point of the fluid is transmitted undiminished throughout the fluid. Imagine if you have a U-tube filled with water and pistons are placed at each end, pressure exerted against the left piston will be transmitted throughout the liquid and against the bottom of the right piston. The pressure that the left piston exerts against the water will be exactly equal to the pressure the water exerts against the right piston.

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Pascal's Principle and Hydraulics

edinformatics.com

 

 

Pascal's Principle

Blaise Pascal was a French mathematician, physicist and religious philosopher who lived in the mid-seventeenth century.

He made some significant observations about fluid and pressure.

He noticed that the shape of a container had no effect on pressure.

He also noticed that pressure applied to an enclosed fluid is transmitted undiminished to every part of the fluid, as well as to the walls of the container.

When it says "enclosed fluid," that means that in order for Pascal's Law to be true, you have to be looking at a liquid in a closed container.

Pascal's Principle and Hydraulics

Hydraulic systems use incompressible fluids, such as oil or water, to transmit forces from one location to another within the fluid.

Hydraulics are used in most breaking systems.

Pascal's law states that when there is an increase in pressure at any point in a confined fluid, there is an equal increase at every other point in the container.

Therefore Pascal's law can be interpreted as saying that any change in pressure applied at any given point of the fluid is transmitted undiminished throughout the fluid.

How do Hydraulics Work?

Imagine if you have a U-tube filled with water and pistons are placed at each end, pressure exerted against the left piston will be transmitted throughout the liquid and against the bottom of the right piston.

The pressure that the left piston exerts against the water will be exactly equal to the pressure the water exerts against the right piston.

Now suppose the tube on the right side is made wider and a piston of a larger area is used; for example, the piston on the right has 10 times the area of the piston on the left.

If a 1 N load is placed on the left piston, an additional pressure due to the weight of the load is transmitted throughout the liquid and up against the larger piston.

The additional pressure is exerted against the entire area of the larger piston.

While the pressure exerted is the same, since there is 10 times the area, 10 times as much force is exerted on the larger piston.

Thus, the larger piston will support a 10 N load - ten times the load on the smaller piston.

Pascal's Law and Mechanical Advantage ----Pascal's law allows forces to be multiplied.

Generally, the mechanical advantage is calculated as:

MA = (the distance over which force is applied) ÷ (the distance over which the load is moved)

Applied to the system shown below, such as a hydraulic car lift, Pascal's law allows forces to be multiplied.

The cylinder on the left shows a cross-section area of 1 square inch, while the cylinder on the right shows a cross-section area of 10 square inches.

The cylinder on the left has a weight (force) on 1 pound acting downward on the piston, which lowers the fluid 10 inches.

As a result of this force, the piston on the right lifts a 10 pound weight a distance of 1 inch.

The 100 pound load on the 1 square inch area causes an increase in pressure on the fluid in the system.

This pressure is distributed equally throughout and acts on every square inch of the 10 square inch area of the large piston.

As a result, the larger piston lifts up a 1000 pound weight.

The larger the cross-section area of the second piston, the larger the mechanical advantage, and the more weight it lifts.

The formulas that relate to this are shown below:

Area1/Area2= Distance moved 2/Distance moved 1

This system can be thought of as a simple machine (lever), since force is multiplied. The mechanical advantage can be found by rearranging terms in the above equation to

Mechanical Advantage(MA) = D1/D2 = A2/A1

For the sample problem above, the MA would be 10:1 (10 inches/ 1 inch or 10 square inches / 1 square inch).

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https://www.edinformatics.com/math_science/pascals-principle-and-hydraulics.html

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HYDRAULIC HAMMERS - The Hydraulic hammer is a construction equipment that is used for the demolition of a structure and breaking rocks into smaller sizes. It is an attachment on an excavator and works on the principle of hydraulics. It applies high pressure from its small canister which has pressurized hydraulic oil stored in it. They are much more powerful than other hand-held hammers and its force is varied based on the force of piston strokes and its size. The hydraulic hammer is of two types namely – inner valve type and outer valve type. Both types have mostly same components, such as a cylinder which is the most important part of the hydraulic system. A piston is also present in both types of a hydraulic hammer which converts kinetic energy into hammering energy and a front head is featured to support the machine, and one back head which contains the nitrogen gas. Most applications for hydraulic hammers are for mining, rock breaking, concrete breaking and demolition. Many are designed as attachments to mobile equipment such as backhoes and diggers. The hydraulic hammer starts with its main valve in the cylinder. The hydraulic oil is supplied to hammer through this valve. When upward stroke takes place, the pressure in the upper chamber is released by the main valve and through the outlet. Then the high pressure in the lower chamber pushes the piston upwards.

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Hydraulic Hammers

What is Hydraulic Hammer and how does it work?

Ramjatab pandit

engineeringinsider.org

The Hydraulic hammer is a construction equipment that is used for the demolition of a structure and breaking rocks into smaller sizes.

It is an attachment on an excavator and works on the principle of hydraulics.

It applies high pressure from its small canister which has pressurized hydraulic oil stored in it.

They are much more powerful than other hand-held hammers and its force is varied based on the force of piston strokes and its size.

The hydraulic hammer is of two types namely – inner valve type and outer valve type.

Both types have mostly same components, such as a cylinder which is the most important part of the hydraulic system.

A piston is also present in both types of a hydraulic hammer which converts kinetic energy into hammering energy and a front head is featured to support the machine, and one back head which contains the nitrogen gas.

Most applications for hydraulic hammers are for mining, rock breaking, concrete breaking and demolition.

Many are designed as attachments to mobile equipment such as backhoes and diggers.

Working of a Hydraulic Hammer

Hydraulic hammer works on the principle of hydraulics by Blaise Pascal which states that “applying pressure on one part of a fluid transfers that pressure to all areas of the fluid, allowing for a multiplication of force”.

Since the oil used is incompressible, it allows the transfer of power instantly with negligible loss.

The hydraulic hammer starts with its main valve in the cylinder.

The hydraulic oil is supplied to hammer through this valve.

When upward stroke takes place, the pressure in the upper chamber is released by the main valve and through the outlet.

Then the high pressure in the lower chamber pushes the piston upwards.

As the piston reaches the upper end of the stroke, the main valve directs the flow to upper chambers that make it high-pressure chamber.

This causes the piston to move downward because of accumulated energy from the gas chamber, hence creating the impact stroke cycle.

The energy is transferred to the tool that uses it to do various tasks.

At the point of impact, the main valve shifts and the pressure from upper chamber is released, enabling the upper stroke to take place.

Most of the hydraulic hammers come with fully enclosed housing over their parts not only to protect them from other materials but to ensure that they last longer.

To increase the safety of equipment on which the hydraulic hammer is attached, the models comprise of shock absorbers at the top that absorbs all the impact and recoil energies.

Moreover, the shock absorber also helps to protect the parts of the hydraulic hammer.

Some of the hydraulic hammers are equipped with steel bushing in their bottom that isolates them from vibration.

Hydraulic hammers are environment-friendly because they produce less noise and pollutants. They are preferred in the places that are sensitive to vibration and noise, as a vibratory hammer may damage the existing structures. 

https://engineeringinsider.org/hydraulic-hammer-working/