Boosting Efficiency Through The Use of Hydrostatics
Boosting Efficiency Through The Use of Hydrostatics
Boosting Efficiency Through The Use of Hydrostatics
RE 00 207/10.00
59
without traction
effort interruption
2-speed power
shift gearbox
i1, i2
i1, i2, i3
3-speed power shift gearbox
i1, i2, i3
Summation gearbox
60
120
250
Drive rating in kW
A6VM
A2FM
Traction effort
A2FM
Overall efficiency
A6VM
Vehicle speed
Fig. 4
60
RE 00 207/10.00
BB-3
BODEM
software
Microcontroller
+
Software
Gear Direction of
travel
selection
Drive
pedal
Inching
pedal
BB-3
CAN-Bus
Diagnostics,
parameterization,
process monitoring
Rpm speed
A6VM
A4VG
RE 00 207/10.00
61
Power class in kW
A4VG
100
150
180
250
71
90
125
180
A6VM
55
80
107
140
Gear ratio
Motor 1
1st gear
2nd gear
3rd gear
(forward/reverse)
Motor 2
(forward/reverse)
3.03 : 1
6.10 : 1
3.03 : 1
1.34 : 1
Traction F in kN
100 %
50 %
Hydrostatic transmission
and switchable
summation gearbox
20
40
Speed v in km/h
62
RE 00 207/10.00
Traction F in kN
100 %
50 %
Hydrostatic system
20
Hydrodynamic system
40
Speed v in km/h
Fig. 8: Comparison, hydrostatic vs. hydrodynamic 50% decline in power due to auxiliary equipment
PM in kW
100%
nM in rpm
nmax
Hydrodynamic transmission
Hydrostatic transmission DA control
Hydrostatic transmission electronic control + CAN Bus
Fig. 9: Comparison, hydrostatic vs. hydrodynamic: engine characteristics
RE 00 207/10.00
63
Traction limitation
The maximum traction of the machine can be
limited in accordance with the type of ground
being travelled on so that the wheels are
prevented from slipping and thus avoiding
unnecessary tyre wear, as well as ensuring
maximum traction.
Speed limitation
The maximum speed can be infinitely varied
so that the maximum working speed can
remain variable while at the same time
specifying a crawling speed. This is particularly
advantageous when working with such
supplementary equipment as a sweeper or
snow plough, etc.
Eco mode
Particularly when travelling on the road, it is
often found that the diesel engine generates
more power than is required by the travel
drive for the momentary speed. Since the load
status is detected by the travel electronics on
the basis of the engine straining speed, the
engine speed can be reduced to the point at
which the permissible straining value is
Microcontroller
External electronics
2+2 gearbox
Actuation
Communication via CAN Bus
64
RE 00 207/10.00
Diagnostics
Automotive driving
Over-speed safety
Selection of direction
of travel
Gearbox management
Constant speed drive
Variable
characteristics
Inching/Braking
Eco mode
CAN Bus
Implement hydraulics
5. Prospects
New drive concepts combined with electronic
control and the new generation of diesel engines
with electronically controlled fuel injection pumps
open up new possibilities for boosting the
efficiency and operating convenience of wheeled
loaders, particularly in the higher power classes.
These concepts provide the basis for extension of
the hydrostatic system, as well as possibilities for
optimization of the construction machines and will
have a growing influence on the overall design of
the machines.
RE 00 207/10.00
65
66
RE 00 207/10.00