Fluid power system components and their operation

Fluid Power System Components and Their Operation

Reservoir

  • The reservoir is where the hydraulic fluid is stored.
  • It maintains fluid to the pump and cools as well as filters the fluid.
  • The reservoir design is crucial for optimal heat dissipation and minimisation of fluid turbulence.

Pump

  • The pump creates the flow necessary for the development of pressure which is a function of resistance to fluid flow in the system.
  • Two types of pumps used in hydraulic systems are rotary (gear, vane or piston) and reciprocating pumps.
  • Pumps either supply oil under pressure or do not pump at all. They do not generate pressure.

Valves

  • Valves in a hydraulic system regulate the direction, pressure, and flow rate of the fluid.
  • Directional control valves guide fluid into the desired pathway in a circuit.
  • Pressure control valves limit the maximum pressure in a system by diverting excess fluid.
  • Flow control valves regulate the fluid flow rate.

Actuator

  • Actuators convert the energy of the pressurised fluid into useful work.
  • Actuators can either be linear (like cylinders) or rotary (like hydraulic motors).
  • A hydraulic cylinder converts hydraulic energy into linear motion and work.
  • A hydraulic motor converts hydraulic energy into rotary motion and work.

Pressure Relief Valve

  • A pressure relief valve protects a hydraulic system from overpressure situations.
  • It is typically set to actuate at a pressure slightly above the system operating pressure.

Accumulator

  • An accumulator is a storage device that holds a volume of fluid under pressure through an external source like spring, gas or by the weight.
  • Accumulators are used to store energy, supplement pump flow, compensate for leakage, dampen pulsations, or maintain pressure.

Heat Exchanger

  • Heat exchangers in a hydraulic system maintain the fluid temperature within the optimum operating range.
  • They remove excess heat and can be air or water cooled.
  • Heat exchangers often come into play in high-performance systems where heat generation is significant.

Filters

  • Filters keep the hydraulic fluid clean by removing contamination.
  • Filters can be placed in the pump intake line, high-pressure side, return line or offline in a hydraulic system.
  • The cleanliness of hydraulic fluid has an important role in extending the life of the system.

Connections, Lines, and Fittings

  • Hoses, tubes or pipes, and fittings make up the system of connections in a fluid power system.
  • They transport fluid from one place to another within the system.
  • It’s vital to choose the correct type and size for your application to ensure they can handle the pressure and are suitable for the type of fluid being used.