Siemens Sinumerik 840D Series Function Manual

10.03
1.2 Comparison of electric and hydraulic drive systems
1-17
 Siemens AG, 2003. All rights reserved
SINUMERIK 840D/SIMODRIVE 611 digital, HLA Module (FBHLA) - 10.03 Edition
Table 1-1 Comparison of electric and hydraulic drive systems
Criterion Hydraulic driveElectric drive with
leadscrew
Electric direct drive
Noise Noise produced by
linear guides
Noise produced by servo-
motor and leadscrew
S Flow through valve may
produce noise.
S Pump noise on
hydraulic power unit.
Acceleration
characteristics
max. 45 g max. 1 g max. 2 g
Drive cooling Absolutely essential Required only at high
speeds
Required in some cases, in
power unit only
Sensitivity to
ferromagnetic
swarf
High Low Low
Table 1-2 Analogy of characteristic data
Electric Hydraulic
Spindle speed -
Velocity Velocity
Current flowrate
DC link voltage System pressure
Power Flow rate @ Valve pressure differential
Transistor/power section Valve
Motor Drive cylinder
1 General
02.99

Siemens Sinumerik 840D Series Specifications

General

Axes	Up to 31 axes
Power Supply	24 V DC
Control Type	CNC
Interface	Ethernet, PROFIBUS
Display	TFT color display
PLC	Integrated PLC (programmable logic controller)
Operating Temperature	0°C to 45°C
Relative Humidity	Up to 95% (non-condensing)
Max. Number of Channels	Up to 10 channels