Sinumerik 840D/Simodrive 611 Digital; Hydraulic Power Unit - Siemens Sinumerik 840D Series Function Manual

1 General
1.3 Structure of an electro-hydraulically-controlled drive axis
Function
1.3.7

SINUMERIK 840D/SIMODRIVE 611 digital

1.3.8

Hydraulic power unit

1-20
The speed is acquired by continuous differentiation of the distance over time.
Various systems are available depending on the level of accuracy required.
The highest accuracy requirements are fulfilled by digital systems (glass scale
with photoelectric evaluation circuit) mounted directly on the machine.
The most widely used digital incremental systems require a reference point ap-
proach at the beginning of a machining operation.
SINUMERIK controls and SIMODRIVE drive systems are specially designed for
machine tools, manipulators and special-purpose machines.
The numerical control processes the machine program and converts it into con-
trol commands. It also monitors command execution continuously.
The control structures for the electrohydraulic control loop and the interfaces to
S
the shutoff valve,
S
the servo solenoid valve,
S
the position measuring system and
S
the central arithmetic logic unit
are all provided by the HLA module.
The HLA module is an integral component of the SINUMERIK 840D and
SIMODRIVE 611 digital systems.
A range of different NCU modules with graded scope of functions is provided to
allow the SINUMERIK 840D system to be tailored to the varying functional re-
quirements of machines. The control can therefore be optimally adapted to indi-
vidual machines and machining applications and is suitable for equipping stan-
dardized machine series.
This unit supplies hydraulic energy.
It is installed at a distance from the drive axis. Accumulators are employed to
compensate for strongly fluctuating hydraulic energy requirements and to mini-
mize the installed power.
SINUMERIK 840D/SIMODRIVE 611 digital, HLA Module (FBHLA) - 10.03 Edition
 Siemens AG, 2003. All rights reserved
02.99
10.03
J