Hi! My name is Phil Ranger and I’d like to show to my teacher
friends a great free tool that allows you to help your students
understand how hydraulic parts work and how hydraulic circuits operate.
For example, here I already put some equipment in the
environment, namely a power unit, as well as a hydraulic
motor, a lever operated directional valve, and a cylinder. So let’s say I connect the pump output of the power unit straight back
into the return port with a flexible hose. What is really happening inside the
power unit? Let’s look at it with the cutaway view. I see that the oil is pumped
by a gear motor and goes out of the port outlet.
It is coming back in the tank inlet, goes through a filter, and is re-pumped again.
Pretty simple, isn’t it? Now what would happen if I removed the
flexible hose? Since the oil cannot flow out anymore, a high pressure would build at the port
outlet, which could cause a failure. A pressure relief valve prevents this. The high pressure will push against
a spring-loaded metal ball and that allows the oil
to return directly into the tank preventing any
overpressure. Let’s now take a look at the hydraulic motor. Please note that except for the power
unit, everything should be on the table. The
software will not allow you to place equipment on the floor. So let’s connect the port
of the power unit to one side of the motor and the other
side of the motor back to the tank. When I turn the power unit on, I can see that the motor turns, but how?
Let’s use the cutaway view again. I can see that it is the oil that is
pushing on the gears. What would happen if I reversed the
connections? Should the motor turn in the other
direction? And yes, it does. Let’s now look at the cylinder.
I am connecting the back of the cylinder to the port of the
power unit, and the front to the return. The cutaway view shows me that the
cylinder has a movable wall attached to the rod. When the oil pushes on the back, the oil
in the front returns to the tank, and the cylinder rod goes out.
How do I get the rod to return in? Let’s reverse the connections. The
pressure now pushes the wall back, so that works. Shouldn’t there be a way
to do that without connecting and disconnecting horses every time? Of course! Let’s use the lever operated
directional control valve. I connect the power unit on one side, and the cylinder to the other side.
With the lever in the center position, both the port and tank, as well as the A and B ports, are blocked by
these three grey blocks. Pushing the lever in one direction moves
the three blocks. Now the port is connected to B and the
tank is connected to A. Moving the lever to the other position
does the opposite: connecting P to A, and T to B.
This is the equivalent of crossing the hoses. I could have explained all of this
using just a regular blackboard, but the live interaction with the
cutaway views makes it a lot easier to understand, for free! They are
lots of other components available in the simulation software, such as pressure
reducing valves, flow valves, solenoid valves, pressure
gauges, flow meter, electrical control devices,
timers, relays, etc. How do you get this free software? Just follow the link in the comment
section. The only limitation is that after 30 days, the measurement
devices will not work anymore without buying a license. But all of the other features, including
the cutaway view, will still work. I hope this will be useful to you.
Don’t hesitate to send me your comments. Thank you very much and have fun!