Hydraulic Power Pack

What is the function of Hydraulic Power?

The function of Hydraulic Power is to simply convert a primary drive source into a hydraulic fluid flow.

The elements required to achieve this are:

  • Primary source: AC or DC Motor or Internal combustion engine
  • Hydraulic Pump: Common types include gear, piston or vane
  • Oil tank or hydraulic reservoir: container for the hydraulic fluid
  • Filtration Pump inlet (suction), Pressure filter (pump outlet) and return filters (back into the reservoir) are the common types.

What are the Main Elements?

Primary drive sources could be direct current from a vehicle battery (DC),alternating current ( AC)  from single or 3 phase motor, internal combustion engine  or an air motor. These dictate the hydraulic power delivered to the oil and therefore control the flow and pressure limits.

Pumps produce flow and are designed to do this at a pressure that the system restrictions demand. Hydraulic pumps are usually selected based on their suitability to produce flow, pressure rating, economy and noise.

Hydraulics reservoirs are the storage vessel for the oil required to operate the hydraulic system components, such as hydraulic actuators or hydraulic motor, and ensure this oil is stored and maintained in the best possible condition. Common ancillary’s filler/breathers and drain ports, level gauge, level switches and inspection covers.

Filtration is a critical part of a hydraulic power pack, ensuring wear is minimised and efficiencies are maintained. Basic suction strainers ensure the very largest of contaminants do not enter the pump. Pressure filters are normally configured at the pump outlet ensuring highly filtered oil enters the hydraulic system. Contamination within the system is filtered out by the return filter before it enters the hydraulic reservoir.

What are Control Elements?

Pressure control valves, these limit or control the hydraulic pressure within the hydraulic system

Directional Control hydraulic valves:  manual , electrical, pneumatic  or hydraulic operated valves direct the oil flow around the system to operate actuators, motors or other functions. Instrumentation, Oil level and temperature protection switch, Pressure switches and filter clogging switches are all common.

Cooling is another other key consideration, where efficiencies within a system or machine will produce heat in the oil, this must be cooled to ensure long life and high efficiency. The simplest hydraulic power pack circuit is termed  a "P&T pack" which is simply the provision of a Pressure outlet port and a Tank return port. Minimum hydraulic valves on this type of powerpack should be a maximum pressure relief valve and a check valve to protect the pump.