Hydraulics is the technology of production, control and power transmission by pressurized fluid. Generally, a hydraulic system performs four basic works:
- converting mechanical energy to pressurized fluid power by pumps
- transfering fluid by tubes and hoses to the desired points
- controling pressure, direction and flow by valves
- work done by actuators .
Hydraulics basic rules are as follows:
- pressurized fluid always passes the path with the least resistance
- pump makes flow, not pressure
- pressure is created only against the resistance of a barrier
From the useful parameters in hydraulics, flow rate and power can be noted:
- Flow rate: Amount of fluid passing from a section in a second. And is calculated as follow:
Q = (dV/ t) = v’A = Vn
dV: volume difference
v’: speed
A: section area
V: displacement volume
n: rotational speed of the pump
- Power: Amount of consumed energy per second that is calculated from the following equation:
P = p ‘× Q / 600
P: power (kW)
p’: pressure (bar)
Q: flow rate (lit/min)