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!