Title: System concepts
1System concepts
- Circuits with flow sources
Only one user can be delivered from one source
Concepts
2System concepts
- Circuits with flow sources
Without restriction valve
The pump delivers under constant conditions. If
the load changes, the rotational speed of the
motor changes. If the load change is under a
certain limit, the rpm change is small.
If it is large (Dp2) then the rpm will go down
drastically and the flow source is transformed
into a pressure source.
3System concepts
- Circuits with flow sources
What happens if we want to change the rpm of the
motor at constant torque?
Constant torque ? constant Dpm Changing rpm ?
changing Q
a) Regulating the rpm or Vg of the pump
4System concepts
- Circuits with flow sources
b) By restriction in series
A1 lt A2 lt A3
?pp ?pr ?pm
- Qp Qr Qm
- Qp Qrv Qr
nm can be continuously adjusted
5System concepts
- Circuits with flow sources
b) By restriction in series (cont.)
If the load changes, how does the motor rpm
change by constant restriction valve opening?
c) Parallel restriction valve
Qp Qr Qm
?pm ?pr
6System concepts
- Circuits with flow sources
c) Parallel restriction valve (cont.)
The rpm can be changed by changing the
restriction area.
Here the load is constant
7System concepts
- Circuits with flow sources
We can use a flow control valve
c) Parallel restriction valve (cont.)
If the load is not constant
The rpm change is much smaller
8Examples
9Examples
10The End