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If you’re fairly new to the area of hydraulics or you have an intern working with you then you may find the following information useful to read or share with others.
Before we get started – hydraulic principles are not easy or straightforward until you’ve delved in and learnt a few things. Fluid dynamics, hydraulic mathematics, circuitry and related matters can be downright complicated and that’s why it’s necessary to share information of the type that you find in these blog posts. Goodness knows what any of us did prior to the development of the internet. We would have had to go out of our way to build relationships with others in the industry in order to have free access to their knowledge. But we do have access and thank heavens for that.
With much gusto, let’s look at the basic fundamentals of hydraulics.
It was knowledge founders such as Newton, Pascal and Galileo who first discovered phenomena that was considered interesting, and actually formed the basis of some of what we know today. Way back in 1650 Pascal came across and then formalised the ‘Law of Hydraulics’. It took another 150 years to actually start using and applying that knowledge for practical purposes.
Hydraulic devices operate based on his law which states that confined liquid will carry the power of any external force that is exerted upon it. So much so that it will be carried to every part of the interior of the vessel that liquid is in.
When a hydraulic pump is in use by a mechanic and he is exerting force to confined liquid, then that power will be transmitted through the liquid, whether it’s in a pipe or a hose right up to the piston which will then be forced to move.
Although what you read above is a simplified version, today’s hydraulic machines use the exact same principles, but the mechanics may be replaced by an electric motor or even a gasoline engine. There could be more hoses, some relief and check valves to go through on the way. There could even be a few return lines and a reservoir of fluid to cross. Whatever the case, the action and the result remains the same; movement.
When it comes to how much force is either input or output from devices of hydraulic nature, a pressure measurement is used. This is recorded in the format of pounds per square inch, or psi.
To put this into perspective, 1 psi is equal to one pound of weight put onto an area of 1 square inch.
If 10 pounds of force were put onto 10 square inches, then the result would be the same – 1 psi. If there is a liquid pressure creating a force against a piston then it will be measured either in tons or pounds. A pressure of 100 psi on a piston that has an area of 10 sq inches will be 100 psi x 10 (square inches) or 1000 pounds.
Although there will not be a lot of fluid displacement when a small piston is pushed down in the pump cylinder. Therefore, it will only be enough to move the larger piston a little or short distance. Although a large advantaged is gained in terms of force, there is not much advantage in ‘distance’.
This can be illustrated as follows. Imagine a man pushing his hand against a wall. He can push as much as he likes, but the wall is going to be opposing him with resistance. Without that resistance he would not be able to push, as his hand would just move through the air. This is something that applies to hydraulics too. Without the same resistance, there won’t be the expected result. For example, although a pump might be rated to deliver an output of 10,000 psi if it doesn’t meet with an equal resistance from a cylinder, it won’t output that 10,000 lbs of pressure.
When it comes to hydraulic pumps, there is a variety of different designs including:
· Piston pumps
· Vane pumps
· Gear pumps
When it comes to cylinders, you can expect to come across:
· Spring return
· Gravity return
Valves are also is use, and this is what performs the large variety of functions that hydraulic machines are capable of.
For example, the lowering and raising of a barber’s chair, brakes in cars, the hydraulic raising and lowering of the landing gear in planes and even the jack that is used by many lay persons and mechanics to change the tyre on their car.
Years ago, low pressure is what was popular and in use in hydraulic systems, but these days there are far more high pressure hydraulics being utilised. Strangely enough the safety factors involved are similar, with higher pressure ranking as being slightly safer than lower pressure. The largest benefit of using high pressure equipment is that it is usually smaller compared to a lower pressure device, but will deliver the same amount of force.
This has been a rather eclectic collection of facts about hydraulic systems, but together they should give a deeper insight into how this very clever power delivery system works.
Keep following our blog for more insights into hydraulic systems.
In this article we want to explain the ins and outs of hydraulic powerpacks. A vital piece of equipment that is used with so many machines we see every day.
In a nutshell, hydraulic powerpacks are self contained units that are used instead of a built in power supply for hydraulic machinery. Hydraulic power uses fluid to transmit power from one location to another in order to run a machine. It really is as simple as that.
So what do they look like?
In order to recognise and better understand hydraulic powerpacks, it is a good idea to get to know the key components. Hydraulic powerpacks come in many different shapes and sizes, some are very large and stationary whereas others are much smaller and more compact. In fact, some hydraulic powerpacks are so compact that they can easily be transported in a small van or even an estate car.
The only real way to identify hydraulic powerpacks is through its main components. No matter the size of the unit, all power packs will have the following; a hydraulic reservoir, regulators, a pump, motor, pressure supply lines and relief lines.
What do these components do?
It may be obvious to some but in this post we wanted to explain every component as simply as possible. So here goes.
First up is the hydraulic reservoir which quite simply holds the fluid. Reservoirs will come in different sizes.
Then we have the regulators. Regulators are vital as they control and maintain the amount of pressure that the hydraulic powerpack delivers.
Thirdly we have the pressure supply lines and relief lines. The supply line simply supplies fluid under pressure to the pump and the relief lines relieve pressure between the pump and the valves. The relief lines also control the direction of flow through the system.
Finally we have the pump and a motor. We will begin with the simpler component of the two, the motor. The motor is simply there to power the pump. Easy as that. Now the pump generally performs two actions. Firstly, it operates as a vacuum at the pump inlet and through atmospheric pressure forces fluid from the reservoir into the inlet line and then to the pump. It then delivers the fluid to the pump outlet and pumps it into the hydraulic system. We did warn you that the second part would be slightly more confusing.
So what is the function of hydraulic powerpacks?
Hydraulic powerpacks deliver power through a control valve which in turn runs the machine it is connected to. Hydraulic powerpacks come with a variety of valve connections. This means that you can power a variety of machines by using the appropriate valves.
Hydraulic powerpacks are relied upon by a range of different machines that use hydraulic power to do its work. If a machine is required to carry out heavy or systematic lifting then its likely it would need help from a hydraulic powerpack.
To make it easier for you to understand, we have included a list of trades that regularly rely on our powerpacks. On a building site you will see machines like bulldozers and excavators, which both need hydraulic powerpacks. But, it is not just on building sites that you will find these types of machines. Fishermen and mechanics both need hydraulic powerpacks too. If we did not have them then how would fishermen lift their nets or how would mechanics lift our cars?
When picking a hydraulic powerpack there are a variety of pumps and options to pick from and it is important to pick the right pack to meet your machines needs. It is also important to consider a pack that will help maximise productivity and minimise cost.
Many people will overlook the necessity of hydraulic powerpacks, but they really are vital to ensuring our society runs efficiently.
Do you need to maintain hydraulic powerpacks?
Yes you do and this is hugely important! Hydraulic powerpacks require regular maintenance to ensure they are working properly and safely and to help extend their life. Maintaining hydraulic powerpacks is relatively simple and includes checking the tubing, this can be for any noticeable problems such as dents or cracks. It is also vital to regularly change the hydraulic fluid and look at the reservoir to check for any corrosion or rust.
What hydraulic powerpacks do we provide?
Generally we provide four different types of hydraulic powerpacks. You can pick from a standard powerpack, a mini powerpack, a micro powerpack or a bespoke powerpack.
The standard hydraulic powerpack uses a standard range of modular components and is ideal for the most demanding industrial applications. The mini powerpack is ideal for applications requiring up to 5.5kW. The micro hydraulic powerpacks were originally produced for mobility applications, so are great for when space is limited. Finally, if none of these seem to fit your needs then we offer bespoke hydraulic powerpacks ensuring your application gets the hydraulic powerpack it requires.
Finally, who is the genius behind hydraulic powerpacks?
The man behind hydraulics was Laissez Pascal. A French mathematician, physicist and religious philosopher who lived in the mid seventeenth century. Pascal made observations about fluid and pressure which led to Pascal’s law. 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. Hydraulic powerpacks have been designed based on Pascal's law of physics, drawing their power from ratios of area and pressure.
So, interested in our Power Packs? Come on over to the main website and see what we can do for your Hydraulic Power Pack Needs .
Hydraulics has been around for a very long time. But are you aware of how far it has actually come? You wouldn’t be alone if you responded with no. It is a very technical subject that can be quite difficult to understand, but in this article we want to tell you the story of hydraulics! We want to share with you who discovered hydraulics, what it was originally used for and how hydraulic power got to where it is today.
So why don’t we start at the beginning! Where does the word hydraulic come from?
The word hydraulic originates from the Greek word ‘Hydros’ which means water. Why water? Well, this is because water was the first liquid to be used in the hydraulic system. Today, hydraulics includes the physical behaviour of all liquids, not just water.
What do farmers, firemen and fruit pickers all have in common? Well, firstly they all begin with F, they’re all hard grafters but the most important similarity is that they all work with some pretty cool machines on a daily basis. I mean if they didn’t then how would farmers harvest potatoes, firemen rescue people who are stuck at the top of burning buildings and how would fruit pickers pick fruit from the highest trees? Thanks to the machinery they use (which are all powered by a hydraulic power unit), their jobs are made so much easier.
So what is a hydraulic power unit?
In a nutshell, a hydraulic power unit is a mechanism that transforms one form of energy into a fluid form. The hydraulic power unit is capable of moving the fluid, if the fluid reaches obstacles it pressurises and is then capable of mechanical force. The power transported by the fluid is then used to power machinery and it could easily lift a car or a tree.
What affects a hydraulic power unit’s performance?
Some important elements that impact the performance of a hydraulic power unit are the reservoir volume, power capability and pressure limits. Its physical size and pumping strength also play a part in its performance.
Who relies on hydraulic power units?
As we have already mentioned hydraulic power units are used by a variety of industries across the globe. Commonly they can be seen powering machinery in the construction, automotive, manufacturing and entertainment industry and the power supplies vary depending on the machine it needs to work with.
In everyday life you may be surprised at the amount of machines powered by hydraulic power units, that help society function that little bit better. From bin men and their garbage trucks, to fairground rides that we like to enjoy, hydraulics is a big part of our life and most of us don’t even realise. All the drivers among also use the power of hydraulics whenever we brake.
After this article, I'm sure you would agree with us when we say that hydraulics are pretty impressive.
Hi Everyone, here Hydra Products we have decided to start utilising our Blog more to keep you up to date, informed, and hopefully occasionally amused by our ramblings! There’s lot’s more to come but just to make sure we’re all starting on the right page we thought we’d better just give you a very brief history of Hydraulic power...
Water has played a huge part in the advancement of mankind and has been a powerful source for us to harness for thousands of years, right up to present day. Harnessing the power of water has enabled us to carve out a living using water wheels: to produce our food, tools, wood, clothes, paper, iron, marble, cotton and wool. Today, “fluid power” or hydraulic power relies on pressurized fluid in order to produce power. It’s all around us, in everyday objects, but if we look back in time, it was a while before it was used the way it is today.
In Imperial Rome, water was used to power mills to produce flour, saw stone and timber. In Britain, water was used to extract lead from tin ore in a process known as “hushing”. Many years later this was developed into hydraulic mining which was used during the California Gold Rush.
In 1648, a young French mathematician and physicist, Blaise Pascal, made a discovery that was to become known as Pascal’s Law. Through his works he realised that “pressure exerted anywhere in a confined incompressible fluid is transmitted equally in all directions throughout the fluid such that the pressure variations (initial differences) remain the same”. This laid the groundwork for further insights into how fluids could be harnessed for energy and in 1738, Daniel Bernoulli first formulated what was to become known as Bernoulli’s Principle which describes the behaviour of a fluid under different conditions of flow and height. This was later used in the network of high pressured water pipes between various generating stations which used steam driven pumps and mills that required power, allowing power to be transmitted over larger distances. Unfortunately this particular project did not continue for long as the development of electricity was found to be a far more convenient and, at the time, a much more suitable way of powering devices.
It was towards the end of the eighteenth century (1795) when Joseph Bramah, patented the hydraulic press. It was based on Pascal’s Law which formed the groundwork for the science of hydraulics. Not long after, the Americans developed the technique of producing electricity using hydropower and hydraulic power plants began to be built. Once the industrial revolution had firmly established itself, engineers and industrialists across the world realised they could utilise Bernouilli’s principles but on a much bigger scale. In the late 19th century, the first hydropower scheme was pioneered by William George Armstrong whom many see as the grandfather of Hydraulic Power (along with Joseph Bramah). A keen fisherman, after spending the day fishing and looking at the watermill, Armstrong decided that it wasn’t the most efficient way of harnessing energy. Upon returning home, he set about designing a rotary engine that was to be powered by water. When nobody showed any interest in it, he set about a redesign, and ended up with a piston engine. This led to the development of hydraulic power-pipe networks (with hydraulic power pipes being used to carry pressurised liquid to transmit mechanical power from a main power source) which were used to power cranes throughout Britain’s cities and also in Geneva, Switzerland. As time has gone on we have seen the development of different hydraulic parts including seals, control values and accumulators, all of which have lead to further uses of hydraulic power.
Today there are many different forms of hydraulic power and water power that are currently being used or developed. The majority of them generate electricity but there are a few that are mechanical. We see examples of hydraulic power in use all around us today and probably the best place to see it at work would be on a building site: diggers, cranes, bulldozers and all kinds of heavy equipment vehicles rely on power from hydraulic drives to ensure they have the power to get the job done! A hydraulic drive is a device that uses pressurised fluid in order to drive the machinery and it is made up of many components, of which an important one is the hydraulic pump which can have a power density of up to 10 times that of an electric motor. It’s not surprising that we are still harnessing the power of these incredible pieces of engineering more than 200 years after they were first conceived!
Hydraulic power is currently being developed further year after year. It will be extremely interesting to see what the developments will be in the future.
Having spent over two decades developing a wide range of appropriate hydraulic power units, we have been told by our customers that our hydraulic power units are on point. Not only are they well thought out but they are maintenance friendly, efficient and leak proof. Each one is designed using the most advanced 3D modelling in combination with reliable fluid power analysis tools.
Our hydraulic power units range from micro sized to no-nonsense 375kW systems that are used offshore in the subsea oil and gas industry. Hydraulic power units are often used for serious hard core roles. After all, what else can perform such feats as pulling cars out of canyons, moving massive volumes of earth or lifting giant trees? The only machines that can are hydraulic power units that can convert the movement of liquid into mechanical force.
Power units are actually fairly simple. Their task is to pressurise fluid so that it can perform tasks such as those mentioned above. The fluid is then pushed along through a series of values as it cannot be compressed, so any pressure will cause it to move. At the end of the line, it will go into a piston which will extend as it fills and this is where the magic happens. A giant boulder is lifted up from a river bed or a disabled person’s wheelchair is lifted onto a bus. There are no end to the possible applications of hydraulic power.
Here’s an introduction to our range of hydraulic power units and examples of how they can be used in factories and out in the field:
Standard Hydraulic Power units
The most common requirements are satisfied by these workhorse power units. They offer AC motors up to 30kW and can produce flows up to 100 litres per minute. Holding up to 180 litres in the reservoir and producing hydraulic pressures of up to 250 bar, these machines are used across all manner of industries.
Easy to configure, assemble and maintain, these HPUs are often used for any application that needs a dependable source of power. Industrial machine applications include punching machines, niche areas such as charcoal drying drums and performing any lifting duties.
Mini Hydraulic Power Units
The little brother of the standard isn’t workshy either. Expect AC and DC hydraulic power units that product 30 litres per minute with reservoirs that can hold up to 100 litres and produce 250 bar pressure. These are the machines that can handle up to 5.5 kW.
Our customers find that our mini hydraulic power unit is perfect for a range of applications such as cardboard compacting machines, climbing walls, car park access control equipment and machine tool clamps. They have been designed for easy maintenance and deliver years of trouble free operation. Some of our customers use them on applications that have produced over 1 million operations.
Micro Hydraulic Power units
The smallest of our everyday offerings can still deliver serious power. Although it may have only an 89 mm wide footprint, this little beast is able to handle both reversible and uni-directional work, depending on what you need. DC motors range from 150 to 800 watts and the AC goes from 150 to 275 Watts with flow rates of 5 litres per minute. Hydraulic pressures of 200 bar are the norm.
Perfect for those applications where hydraulic power is needed but the space is limited. For example, our customers have fitted these to step lifts, wheelchair lifts and on through-floor lifts. Although they were originally designed for mobility applications, they have been found to be ideal for wider use including unmanned operations of pipeline control valves to tasks such as lifting glass into place on tall buildings.
Bespoke Hydraulic Products and Systems
Whatever you need, we can design it for you. We have already produced a broad array of hydraulic products that have been used for all manner or purposes across most industries.
Hydraulic power is still something that amazes us. When it comes to transmitting power, hydraulics offer the densest method of it. In the past, we’ve even developed a bespoke hydraulic power unit to flush out gearboxes in the pit garages of F1. You may not know it but next time you watch a movie and you see a full sized ship with rocking hulls on it, it could be one of our products that is creating that rock.
We enjoy solving hydraulic power challenges. If you have one and you don’t know quite how to solve it, contact us today and we’ll work with you to find a solution.
As a manufacturer of high-performance hydraulic equipment, our field may not be something that everybody is familiar with. For the lay person, they’ll find that most domestic power tools are fuelled by electric, with a few pneumatics in the mix, such as nail hammers. It’s uncommon to stumble across hydraulic tools outside of manufacturing or other heavy industrial environments. Although there are some hand held hydraulic tools in circulation, it’s quite rare and they are usually specialised.
In this post, we are going to study the differences between these two types of equipment power.
Overall, both types of tools are based on the same principle. An action is created as a result of a motor compressing a substance whether it is air or liquid. This puts them in the same category in contrast to the rigid transmission that may for example be used in a car.
In addition, what makes these tools more accommodating is the fact that the lines that they use are flexible, so therefore aren’t constrained by needing to be set on a fixed configuration. The gas and liquid can also absorb shock which can result in a longer life of a system compared to those that endure a large amount of vibration and breakages.
The following are areas in which there is a major difference between hydraulic and pneumatic:
· Compression: gas is compressible and liquid isn’t. This means that the pneumatic machine will operate once air pressure drops to a certain level as it can store energy, whereas on a hydraulic system, it’s necessary to continually run a pump.
· Exhaust: as air is a by-product of pneumatic systems, it is not suitable for work such as underwater machinery, whereas hydraulic systems are.
· Lubrication: hydraulic fluid can be its own lubrication, whereas pneumatic air needs to be lubricated with an aerosolised oil. Lubrication is important when it comes to maintaining the longevity of moving parts.
· Filtering: air compressors can capture a huge amount of particles and dust when used in a dirty environment. Hydraulic systems are more likely to produce their own impurities as they are a closed and pressurized system. Quite often anti-corrosion additives need to be added to aid hydraulic systems in protection against erosion.
· Heat: this is why aircraft and other large vehicles depend on air brakes as opposed to brake fluid. Fluids can retain heat, but on the other hand hydraulic systems are less likely to need cooling but when they do they can create vapour pockets and can fail catastrophically. Brake fluid used is more likely to be used on cars when there are not multi-tons involved.
· Smoothness: the incompressible nature of fluid enable hydraulic systems to be far more precise and smooth in control.
· Pressure: There’s a big difference in the amount of pressure that hydraulic and pneumatics operate under. Hydraulics can be in the 1,000s of psi, whereas pneumatic tools are usually more like 90-125 psi.
These are just some of the differences and similarities between hydraulics and pneumatics.
Hydraulic Power Pack
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