Geared Variable Speed Couplings

Voith Turbo
Geared Variable-Speed Couplings

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Geared variable-speed couplings
Precise control of maximum powers page 2
How will you benefit? page 3
Geared variable-speed couplings page 4
with modular design
Geared variable-speed couplings page 5
for high-speed driven machines
How to select the right coupling page 6
Product range page 9
for high-speed driven machines
Geared variable-speed couplings page 10
for low-speed driven machines

Precise control
of maximum powers
Voith Turbo is the largest manufacturer of geared variable-speed
couplings worldwide. Over 4,000 drives have been supplied so far
and are operating successfully. Powers up to 60,000 kW and speeds
up to 20,000 rpm are possible. Drives with geared variable-speed
couplings are renowned all over the world for their outstanding
features and customer benefits in a wide range of applications,
i.e. in power plants, in the petrochemical industry, the chemical
industry, the iron and steel industry as well as many others.
Economical operation with excellent
reliability is a priority in modern
power plants. Whether they are
installed in boiler feed pump or fan
drives, in thermal power stations, in
combined cycle power plants or
nuclear power plants, Voith geared
variable-speed couplings meet
these requirements, both in the
feed water and in the cooling water
circuit of the power plant.
Controlling the speed of the driven
machine provides accurate and
energy-saving adaptation of power
to the operating point of the plant.
In pump and compressor drives in
chemical and petrochemical industry,
the geared variable-speed
couplings ensure that driven
machines operate more economically.
Voith Turbo has the perfect
geared variable-speed coupling for
virtually all requirements – be it the
smooth acceleration of motor and
driven machine or the precise and
dynamic adaptation of the speed of
driven machine.
Offshore or onshore, in extremely
hot or cold temperatures, on platforms,
pipeline stations or in the
desert – Voith geared variablespeed
couplings have been designed
and built to withstand
rough and extreme conditions,
year after year, with a minimum
of maintenance and maximum
reliability and availability. Designs
to API specifications are available
also.

How will you benefit?
Applications:
How will you benefit?
Power plants
Petrochemical industry
Chemical industry
Power savings and extension of driven machine life
compared to throttle control; lower operating costs
Boiler feed pumps
Pipeline pumps
Compressors
Precise load adaptation of driven machines due to
the high control accuracy and fast reaction times
Boiler fans
Crude-oil pumps
Fans
Reliability > 99.9%
(Evaluation based on units in operation)
Circulating pumps
Injection pumps
Centrifugal pumps
Vibration damping
Coal mills
Pipeline compressors
Relieved motor start-up and smooth acceleration
of heavy masses
Robust and compact design
Process compressors
Easy maintenance, low maintenance costs
Long service life
Combined with a robust squirrelcage
motor, geared variable-speed
couplings have proven themselves
as the preferred choice when competing
against alternative drive
systems.
2
3

Geared variable-speed couplings
with modular design
The modular geared variable-speed
coupling is a further development of
the proven geared variable-speed
coupling design. The gear stage
and the hydrodynamic variablespeed
coupling are provided in a
range of separate modules but with
a common interface so that they
can be combined to provide the
optimum solution for a particular
driven machine power and speed.
The advantages of this design
are obvious:
Increased technical flexibility
Optimum adaptation by combining
gearbox and coupling
Integrated rapid-start device
Compact design, short delivery
times
Easy maintenance
Scoop tube with electrohydraulic
actuator and
mechanically operated
oil circulation control valve
– improved dynamics
– increased precision
– low auxiliary power
– compact design
– no electro-mechanical
connecting members.
4

Geared variable-speed couplings
for high-speed driven machines
Design and function
Type R..KM
Voith geared variable-speed couplings
combine mechanical gears
and a hydrodynamic variable-speed
turbo coupling in one common
housing. The oil tank is bolted to the
bottom of the housing. Depending
on the application or the design,
the gear stage is either arranged
on the input or on the output side of
the coupling.
The coupling fill can be varied as
needed during operation by means
of the scoop tube. As a result, the
speed and power transmitted to the
driven machine can be controlled
steplessly.
Voith geared variable-speed
coupling type R..KM
Oil supply
Both working and lube oil are
supplied from the integrated oil
tank, but have separate circuits.
The oil system can also be used
to supply both the motor and the
driven machine with lube oil.
Design
The design of a geared variablespeed
coupling is essentially
determined by the power and the
speed of the driven machine.
1 Gear stage
2 Hydrodynamic variable
speed coupling
3 Scoop tube
4 Scoop tube controller
(VEHS)
5 Working oil cooler
6 Lube oil cooler
7 Main lube oil pump
8 Oil circulation control
valve
9 Working oil pump
10 Auxiliary lube oil pump
11 Duplex filter
12 Oil tank
5

How to select
the right coupling
The power diagrams show the
powers transmitted in relation to
the input and output speed for the
various coupling types and sizes.
Power [kW x 1000]
Input speed = 1800 rpm (60 Hz countries)
60
50
40
30
20
10
5
4
3
2
1
R 120
R 119
R 118
R 117
R 120/119 GS
R 119/118 GS
R 118/117 GS
600
550
500
450
400
R 110/111 KGS
R 18/19 KGS-14
R 16/17 KGS
0,3
R 111 K 630
R 110 K630
R 19 K...M
R 18 K...M
R 17 K...M
R 16 K...M
R 15 K...M
R 14 K...M
R 12 K...M
R 10 K...M
R 8 K...M
1 2 3 4 5 6 7 8 9 10 15 2
Speed [rpm x 1000]
Input speed = 1500 rpm (50 Hz countries)
Power [kW x 1000]
60
50
40
30
20
10
5
4
3
2
R 120
R 119
R 118
R 117
R 120/119 GS
R 119/118 GS
R 118/117 GS
600
550
500
450
400
R 110/111 KGS
R 18/19 KGS-14
R 16/17 KGS
1
0,3
R 111 K 630
R 110 K630
R 19 K...M
R 18 K...M
R 17 K...M
R 16 K...M
R 15 K...M
R 14 K...M
R 12 K...M
R 10 K...M
R 8 K...M
1 2 3 4 5 6 7 8 9 10 15 2
Speed [rpm x 1000]

Design to API standard are also
available. The size of the machine
then depends on the specified API
service factor.
Power [kW x 1000]
Input speed = 3600 rpm (60 Hz countries)
60
50
40
30
20
10
5
4
3
2
R 115
R 114
R 113
R 115 GS
R 115 GS
R 114 GS
550
R 114 GS
R 113 GS
500/450
400
R 110/111 KGS
R 18/19 KGS-14
R 16/17 KGS
R 19 GS...M
R 18 GS...M
R 17 GS...M
1
0,3
R 111 K 630
R 110 K630
R 19 K...M
R 18 K...M
R 17 K...M
R 16 K...M
R 15 K...M
R 16 GS...M
R 14 K...M
R 12 K...M
R 10 K...M
R 8 K...M
R 15 GS...M
1 2 3 4 5 6 7 8 9 10 15 2
Speed [rpm x 1000]
Input speed = 3000 rpm (50 Hz countries)
Power [kW x 1000]
60
50
40
30
20
10
5
4
3
2
R 115
R 114
R 113
R 115 GS
R 115 GS
R 114 GS
550
R 114 GS
R 113 GS
500/450
400
R 110/111 KGS
R 18/19 KGS-14
R 16/17 KGS
R 19 GS...M
R 18 GS...M
R 17 GS...M
1
0,3
R 111 K 630
R 110 K630
R 19 K...M
R 18 K...M
R 17 K...M
R 16 K...M
R 15 K...M
R 16 GS...M
R 14 K...M
R 12 K...M
R 10 K...M
R 8 K...M
R 15 GS...M
1 2 3 4 5 6 7 8 9 10 15 2
Speed [rpm x 1000]
6
7

How to operate
the coupling
The performance diagram shows
the transmittable coupling torques
M K at different scoop tube positions
as a function of the output speed.
The desired output speed becomes
a stable intersection between coupling
torque M K and load torque
(load curve).
Performance diagram
MK [%]
125
100
75
30%
50
20%
I
III
40% 50% 60% 70% 80%
1
2
II
3
4
100%
S min
25
0
10%
0%
IV
50 100
output speed [% of input speed]
Operating Ranges
I, IV Starting Range
II Control Range
III Overload Range
The shape of the coupling characteristic
curves is given for information
only, since there may be minor
deviations if coupling sizes, circulation
oil flows, oil viscosity, etc. vary.
Parameters
Scoop tube position in % of the full
scoop-tube stroke.
M K
S min
Transmitted coupling torque
Minimum slip required
for torque transmission
S = (1 - ) • 100 [%]
n 1 =
n
input 2
speed
n 1
n 2 = output speed
Typical load characteristics
1 constant torque
(e.g. positive displacement
pumps and compressors).
2 decreasing torque
(e.g. boiler feed pumps
operating at varying pressures).
3 parabolic torque
(e.g. resistance parabolae,
pumps with back pressure,
blowers).
4 decreasing torque
(e.g. boiler feed pumps
operating at fixed pressure).

Product range
for high-speed driven machines
Coupling types for specific applications depend on the respective
arrangement of gearbox and coupling and the power and the speed
of the motor and the driven machine.
Type R..KM
Type R..GS
A combination of step-up gear and
variable speed coupling with high
power density, step-up gearing.
Special advantages due to modular
design.
Type R..KGS
A step-up gear is integrated both
at the input and the output side for
particularly high output speeds,
e.g. for high-speed compressors.
Type R..KGS
Type R..GS
The coupling is direct-driven by the
motor and adapted to the required
speed of driven machine by the
step-up gear located at the output
side of the coupling; ideal for high
powers and extremely high speeds.
8
9

Geared variable-speed couplings
for low-speed driven machines
Design and function
Type R..A
For low-speed driven machines, the
turbo coupling is fitted with a reduction
gear on the output. Coupling
and gear stage are situated in a
common housing, the lower part
of which serves as an oil tank.
By adding a Voith hydrodynamic
brake (optional), with an appropriate
breaking torque characteristic,
heavy masses of the driven machine
can be rapidly decelerated.
8
6
2
1
4
3
7
5
Oil supply
Both working and lube oil are supplied
from the integrated oil tank.
The oil system can also be used
to supply both the motor and the
driven machine with oil.
1 Gear stage
2 Hydrodynamic variable
speed coupling
3 Scoop tube (adjustable)
4 Hydrodynamic brake
(optional)
5 Oil supply
6 Working oil cooler
7 Duplex filter
8 Oil pump
Voith geared variable-speed
coupling type R..A

The control requirements of low-speed driven machines such
as coal mills, I.D. fans or crude oil pumps, vary greatly.
Depending on the application and for optimum adaptation to
the existing space conditions, the gear stage is designed as
a helical gear or bevel gear.
Type R..A
The variable-speed coupling is
fitted with a helical reduction gear
on the output side. Typical driven
machines are coal mills, crushers,
low-speed pumps and fans.
Type R..B
Type R..KGL
A step gear at the input side and
a reduction gear at the output side
make this type into a fast reacting
and compact coupling used e.g. for
fast respones times, loading pumps
and high powers.
Type R..KGL
This type of turbo coupling is fitted
with a bevel gear on the output
side. Geared variable-speed couplings
for low-speed driven
machines with high inertia, e.g. coal
mills.
Type R..B
Geared variable-speed
coupling type R..B
10
11

Voith Turbo GmbH & Co. KG
Variable speed drives
Voithstraße 1
74564 Crailsheim/Germany
Tel. +49795132-0
Fax +49 7951 32-650
vs.drives@voith.com
www.variable-speed.com
www.voithturbo.com
cr 269 e 09.03 3000 MSW Printed in Germany. Technical data and illustrations subject to change.