What Are Hydraulic Power Units & Are They Different To Hydraulic Power Packs?

Almost every hydraulic system is run by a hydraulic power unit (also referred to as a hydraulic power pack). Hydraulic power units are self-contained systems that are generally built for the single task of converting mechanical energy into hydraulic energy. They work by applying the hydraulic flow and pressure required to drive motors, cylinders, and other complementar parts in a hydraulic system.

Hydraulic power units can range in size from 0.2 to 1000s of kW. HPUs can be used in a vast array of industrial sectors, including offshore, oil & gas, commercial vehicles, production lines, and agriculture to name a few. Hydraulic power units can generate huge amounts of power to drive hydraulic machinery.

What Is the Difference Between a Hydraulic Power Unit and a Hydraulic Power Pack?

There is essentially no difference between a hydraulic power unit and a hydraulic power pack. The two terms are interchangeable. Hydraulic power units sometimes describe the larger sized units whereas power packs often describe the smaller more compact design.

Waster management compaction and bailers

How Does a Hydraulic Power Unit Work?

The hydraulic power unit provides the power required for the transfer of fluid in a hydraulic system. However, hydraulic power units are different from standard hydraulic pumps due to a multi-stage pressurisation network used to move fluid. During the operation of a hydraulic power unit, the hydraulic fluid flows out of the tank into the pump and is directed into the system. 

There are many areas that affect a hydraulic power unit’s performance, such as its size, power supply, pressure limits, power capacity, and reservoir volume.

Types of Hydraulic Power Units

Hydraulic Power Units can come in various types to meet specific requirements. Whether you need a diesel or petrol-powered unit or an electric motor-based system, a huge range of power options are available. Some suppliers offer a modular approach, providing a standard range of components that can be easily customised to design systems according to specifications. For more bespoke solutions, companies like Hydrastore can offer a hydraulic power unit system to meet exact needs in a cost-effective way. Whether you require 3 phase ac motors, filtration systems, suction units, or CAD designed components, a reliable supplier should cover all your hydraulic system and component needs. Don't hesitate to contact us to discuss your specific requirements.

Components of a Hydraulic Power Pack

To have a clearer understanding of the operating principles of a hydraulic power unit it makes sense to investigate a standard model’s basic design components. Depending on the size of the hydraulic power unit and its application determines its design. We have listed the most common standard hydraulic power unit components involved below.

Hydraulic Motor Pump Assemblies

Hydraulic motor pumps are attached either singularly or in multiples to the hydraulic power unit. 

Tank Storage

Tanks are designed with adequate hydraulic fluid volume to support the system's total requirements, dissipate adequate heat, and allow air to separate from the fluid. 

Filter Units

Filters provide a means of removing contamination from the hydraulic fluid. The hydraulic systems' reliability, performance, and life expectancy are extended considerably by maintaining a low contaminant level. Filter elements should be changed on a regular basis or in accordance with the clogging indicators or preventative maintenance program.  Some filter elements are more efficient than others and this needs to be carefully considered.

Coolers & Heaters

Hydraulic systems need to have a temperature regulation process. Ideally, the system is designed with optimum efficiency, and cooling is not required however some systems require additional cooling, and air or water coolers can be installed. Heating systems can provide the opposite and increase temperatures when required in cold climates.

Pressure Control Valve

Hydraulic power packs normally have a pressure relief valve that prevents over pressurisation of the hydraulic system. Depending on the application and selected components pressure relief valves limit the maximum pressure by opening and passing fluid to the tank.

Directional Control Valve

Directional control valves are used to switch the direction of oil flow within service lines, allowing this allows a change in the direction of actuators. 

Hydraulic Accumulators

Hydraulic accumulators are energy storage devices that hold hydraulic fluid and a compressible gas (generally nitrogen), separated by a bladder or sealed piston. The stored energy can be released at critical points through machine cycles to provide a burst of flow above that of the pump.

Electronic Controllers

Some hydraulic systems benefit from electronic control providing an element of logic and machine optimisation. Electronic controllers provide an operating interface controlling items such as solenoid coils, and proportional valves, taking control signals from components like switches, displays, and analogue sensors along with monitoring features. 

Hydraulic Power Unit Requirements

The hydraulic power generation is determined by the prime mover. The desired flow multiplied by the maximum pressure equates to the power demand. System design and appropriate product selection determine the efficiency and ultimate performance of the hydraulic system. The better the design the less noise, less heat, and less wasted energy results.

Hydraulic systems are based on Pascal’s Law of Physics, in that they get their power from ratios of areas and pressure. So, in theory, lifting or turning force can be multiplied with relative ease by adjusting the size of the active area. 

Where Can You Find Hydraulic Power Units Being Used?

Our HPUs range in power from 0.5 kW up to 500 kW with a pressure capability of 100s of bars and flows ranging from single digits into thousands of litres per minute. Our HPUs are carefully engineered for high levels of system efficiency, they’re low noise, energy efficient, and highly reliable. We supply hydraulic power units to a vast array of industries for use in a multitude of applications.

Mobile Hydraulics

For use within construction equipment, commercial vehicles, agricultural equipment, military machines, railways, and mining.

Industrial Hydraulics

Our hydraulic power units are used in industrial applications including process machinery, printing, and presses.

Hydraulics in Aviation

You can see our hydraulic components being used to good effect in aircraft support.

Agriculture Environment Hydraulics

Ground care, harvesting, and forestry are just a few of the areas that make use of hydraulic power units.

Hydraulics in Waste Recycling

Our energy-efficient and reliable hydraulic power units are used across many applications within the waste and recycling industry.

Bespoke Hydraulic Power Units From Hydrastore

Are you looking for a reliable source for bespoke hydraulic power packs? Hydrastore Ltd is able to provide a range of high-quality components for use in the most demanding industrial applications. Our HPU solutions can be tailored to meet most industrial requirements, with tank capacities from 5 litres to many thousands of litres and where required very high flows and pressures.

We offer a standard range of modular components for easy application, whether you require petrol or electric prime movers. We have the expertise to design a system to meet most industrial and mobile needs. If you have any questions or would like to learn more, please don’t hesitate to contact us for an efficient solution with a quick turnaround.

Posted by admin in category Hydraulic Systems Advice on Wednesday, 27th July 2022

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