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Pressure and flow control system SYDFE1 series 2X, 3X
| Product description
Bosch Rexroth AG, Edition 10.2021, RE 30011-B
5 Product description
5.1
PERFORMANCE DESCRIPTION
The SYDFE1 control system is designed and built for the electrohydraulic control
of swivel angle, pressure and power (optional) of an axial piston pump. It is
intended for stationary applications.
Please refer to the data sheet and order confirmation for the technical data,
operating conditions and operating limits of the SYDFE1 control system.
5.2
DEVICE DESCRIPTION
The SYDFE1 control system is based on an axial piston variable displacement
pump of swashplate design for hydrostatic drives in the open circuit. The flow is
proportional to drive speed and displacement. The flow can be steplessly varied
by adjusting the swashplate.
In an open circuit, the hydraulic fluid flows from the tank to the variable
displacement pump and is transported from there to the consumer via a
directional valve. From the consumer, the hydraulic fluid flows via the directional
valve back to the tank.
In the regenerative operating mode (see chapter 5.4.1 “Regenerative operation“ on
page 22) the hydraulic fluid can also flow from the consumer through the pump
to the tank.
5.2.1 Functional description, section of SYDFE1
In the following description, the numbers in brackets refer to Fig. 2 and Fig. 3 on
page 18.
Pressure and swivel angle control of the SYDFE1 control systems is accomplished
using an electrically controlled proportional valve (
2
). The proportional valve
determines the position of the swashplate (
1
) by means of the actuating piston
(
4
). The displaced flow is proportional to the position of the swashplate. The
counter-piston (
3
), which is pre-loaded by a spring (
5
), is permanently pressurized
to pump pressure.
With a non-rotating pump and depressurized actuating system, the swashplate is
held by the spring (
5
) in po100 %. With a driven pump and a de-energized
proportional solenoid (
8
) the system swivels to zero stroke pressure as the valve
spool (
9
) is pushed to the initial position by the spring (
10
) and, therefore, pump
pressure p is applied to the actuating piston (
4
) via valve port “A”. A balance
between the pump pressure on the actuating piston (
4
) and the spring force (
5
) is
achieved at a pressure of 8 to 12 bar. This basic position (= zero stroke operation)
is obtained when the control electronics is inactive (e.g. when the controller is
disabled).
In contrast to this, a pump with external supply swivels to the negative limit
stop (regenerative operation).
The proportional valve is controlled by external control electronics VT 5041-3X,
which is part of the system. This electronics processes all of the control signals
required to operate the SYDFE1 control system.
The external control electronics type VT 5041-3X is designed as plug-in card in
Euro-format. As a standard, it is provided with one command value input each
for pressure and swivel angle (and optional input for power command value). A
pressure transducer senses the actual pressure value. A swivel angle sensor (
7
)
on the pump senses the actual swivel angle value. The acquired actual values
Open circuit
