What is a Hydraulic Power Unit?

Hydraulic power units, also referred to as hydraulic power packs , are systems that utilize a multi-stage network to move hydraulic fluid in order to power certain machines. They come in a lot of different shapes and sizes so they can meet the requirements for a variety of machines. The three key factors that influence performance are pressure, capacity, and volume. Additionally, certain physical traits also define the hydraulic power unit including pumping strength, size, and power supply.

Today, we’re going to look closely at the operational principles and components of a hydraulic power unit in order to learn how it works.

Essential Components of a Hydraulic Power Unit

Here’s a look at the essential components of a hydraulic power unit.

• Hydraulic Power Control: This is the interface that’s used by the operator in order to control the machine. It contains power switches and features that allow the user to monitor the system. This system is generally wired directly into the power unit. 
• Motor Pump: Hydraulic power units are built using either a single pump or multiple pumps. Regardless of the number of pumps, only one will be active at any given time. 
• Tank: Used to store hydraulic fluid. The tank must be large enough to accommodate the amount of fluid needed to operate the hydraulic power pump. 
• Accumulators: Containers that are connected to actuators. They supplement the pumping system by collecting water from the pumping components in order to maintain hydraulic fluid pressure. 
• Filters: Most hydraulic power units have a single filter built into the top of the tank that is used to fill or empty the tank. This is done through the operation of a multi-directional valve. Filters are built in a way that allows them to be replaced even while the machine is in operation. 
• Heating and Cooling Systems: Temperature regulation is essential to the function of a hydraulic power unit. Heating systems are designed to elevate the temperature when necessary while cooling fans are designed to keep temperatures under the parameters.

Selecting the Right Hydraulic Power Motor

A hydraulic motor is the device responsible for moving hydraulic fluid through the machine. Its size and capabilities directly impact the overall machine. If the right motor is installed on the device, then it minimizes wasted energy and improves the overall operational cost of the machine.

When choosing the right motor, it’s important that you take the power source into account. For instance, gas-powered motors tend to have even torque-to-speed curves whereas an electric motor has greater initial torque. But that’s not the only consideration.

Motor size is another consideration. A gas-powered motor should be at least two times as powerful as en electric motor for the same system. But the most important consideration is the cost to power the motor. You must get one that’s as close to the requirements as possible so you don’t waste power. Getting a motor that’s too large for the hydraulic power unit will burn up more energy and significantly increases operational cost.

The Operation of a Hydraulic Power Unit 

At the beginning of operation, the pump pulls hydraulic fluid from the tank into the accumulator. Pressure is built up in the accumulator until it meets the predetermined level. When this happens, the pump circulates fluid through the charging valve in order to maintain the required pressure.

The fluid’s temperature is also monitored and is either cooled or heated to maintain a specific temperature. Overheating triggers a complete shutdown of the motor. 

Finally, pressure switches are used by the operator to regulate pressure throughout the machine, which in turn, will dictate the motion of the components, such as hydraulic cylinders .

Final Thoughts

The main factor to keep in mind when choosing the motor for a hydraulic power unit is to make sure the motor closely matches the horsepower of the power unit. When chosen correctly, a hydraulic power unit provides a cost efficient way to operate large machinery.