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What Is A Hydraulic Power Unit?

In a hydraulic system, the hydraulic power unit is the central driving components. This unit is essentially made up of a motor, a reservoir with an hydraulic pump, all these can generate produce a great amount of power to propel almost any type of hydraulic ram.


The hydraulic power unit is fundamentally hinged on Pascal's law of physics, drawing its power from rather ratio of area and pressure.


The hydraulic power units are applied in different ways, which include :


hydraulic power units are used in a wide range of applications, including:

  • Automation
  • Mobile Gadgets
  • Machine Tools
  • Agricultural Machineries and equipments
  • Aerospace Test Equipment
  • Meat Processing Machineries
  • Rolling Mill Equipment
  • Paper Mill Machineries
  • Industrial Machineries
  • Marine equipment
  • Oil field Machineries
  • Government/Military Equipment
  • Construction Equipment


These hydraulic power units are basically utilized in any application that needs heavy and systemized lifting or other specifications where the recurrent use of powerful and directional force is required.


Try to take note of all the mechanized processes going on around you everyday that make use of hydraulic power units. When you pass through a construction site, there is a high probability to see some sort of large construction machinery which is either an excavator or a bulldozer. All these depend on hydraulic power units to function. It is used by fishermen for lifting their pots and nets. Automobile mechanics use it for lifting cars up to enable move and work freely to make repairs under it. A particular device called 'Jaw of life', which has prevented the loss of many lives from auto accidents, makes use of hydraulic power unit for its extraordinary cutting power. Mechanized farmers also make use of machineries which run on hydraulic power unit for tending and cultivation of their crops. When we go to the amusement park, all those amazing rides that picks you up swiftly from the ground right into the sky and still drops you lightly on the ground make good use of hydraulic power unit to perform this fun-filled task. Also, modern braking systems which has saved a lot of lives by a hair's breath, make use of this hydraulic power unit. We all get our household garbage disposed off regularly but we do not know that the garbage trucks make use of hydraulic power unit for compacting the garbage after it picks it up. hydraulic power unit is utilized almost in every mechanism around us which makes life easier but we don't even know.


In a hydraulic system unit, an enclosed fluid is used to transfer or conduct energy from source A to source B and then creates one of linear and rotary motion or force. The units are the part of a system that applies the pressure which is used to drive cylinders, motors and some other integral sections of the unit. Unlike what is present in standard pumps, the hydraulic power unit uses a multi-stage pressurizing network to transport fluid and also makes use of some temperature control mechanisms.


Some of the significant elements that affect the performance of a hydraulic power unit are power capacity, reservoir volume and pressure limits. Also, other physical features like its size, pumping strength and amount of power supplied to it determine its performance.


To gain a better insight into the principles and design by which hydraulic power units operate, you may need to observe the main components of a standard model utilized in hydraulic systems used for industrial purposes.


Design Components

A huge, long-lasting hydraulic power unit that is built to function under a wide plethora of environmental setting would have several design features which is different from an ordinary pumping system.


There are some features which the standard designs have, they include:


1. Accumulators

They are containers which can be coupled with the hydraulic actuators that perform the function of collecting water from the pumping mechanism. They are there to produce and sustain pressure of the fluid to complement the pumping system of the motor.


2. Filters

A filter is normally fitted along the top of the tank. It usually an autonomous bypass unit, having its own pump, motor and filtering system. By activating a multi-directional valve, it may be used for filling or emptying the tank. Due to their autonomy, they can be replaced at a time when the power unit is still running.


3. Motor Pumps

The power unit may be equipped with only one motor-pump, or various devices with each having an accumulator valve. In the case of multiple pump system, it is only that can work at a time.


4. Power Unit Controllers

The hydraulic power unit controller refers to the operator component which encloses the power switches, monitoring features and displays. This component is very important for the installation and integration of a power unit into a hydraulic systems and it can be found installed into the power unit.


5. Hydraulic Oil Tanks

This is a unit for storage which has sufficient volume to keep the fluids being drained into it. Additionally, one may need to drain actuator fluids into this tank.


6. Coolers and Heaters

An air cooler may be fitted close to or at the back of the filter unit for the purpose of making sure that the temperatures do not rise above operational specifications and parameters. Additionally, a heating mechanism, like an oil-based heater may be used for increasing the temperatures as the operational circumstances demand.


Operating Process

How a hydraulic power unit works is somewhat complex and only understood technically.


When the unit starts functioning, the gear pump moves hydraulic fluid out from the tank, and then transfers it into the accumulator. This mechanism is maintained till the pressure inside the accumulator reaches a calculated and fixed level.


At this stage, the pumping action is then initiated by a charging valve to start fluid-circulation. This makes the pump start a fluid-discharge which is through a a charging valve and then redirects back into the tank at a minimal level of pressure. A designated one-way valve prevents fluid from leaving the accumulator but if the pressure reduces substantially, the charging valve is reactivated and then the accumulator is filled with fluid again.


Farther down the line, the flow of oil into the actuators is controlled and balanced by a reduced-pressure valve.


The accumulator can be connected to other accumulators if it is fitted with a fast-stroking device which enable them to charge pressure too. To reduce the increasing temperature, an automatic thermostat or fan is usually included into the system.


In case of an overheating of fluid inside the system, the motor pump can be stopped with a temperature-switch than can also aid refilling of the tank if the level of its fluid is getting abnormally low. In a case where there are multiple motor pumps inside the system, a flow switch may be used to make them alternate when there is low fluid supply.


Accumulator pressure inside the system can be controlled with pressure switches and operators can be signaled automatically by the monitoring system when pressure goes too low, which can increase the danger of the failure of the power unit.

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