RENK-MAAG

SynchronizingClutch Coupling Program

and its applications

Innovative Power Transmission

In 1960 MAAG decided to develop and manufacture synchronizing clutch cou­plings. After extensive research and design work, including the testing of a proto type on a special testbed, the first unit was sold in 1964. Since then, continuous devel­opment of this product has resulted in a prod uct line that now enables us to offer a range of different synchronizing clutch couplings. All types can be supplied with features tailored to the specific require­ments of the synchronizing clutch coupling applications.

Synchronizing clutch couplings are requi­red in a wide range of application.

Marine Applications

• combined propulsion systems such as CODOG, COGOG, CODAG, COGAG, CODAD, etc.

• efficiency booster drives for diesel engine propulsion

Power Generation

• generator drives• peaking power stations• air storage power stations

Energy Recovery, Combined CycleTechnologies, Cogeneration and others

• connecting expander turbines to main drives in petrochemical plants

• blower drives in nuclear power stations for use during starting sequence

• starting device for gas turbines• automatic turning gears

The MAAG Synchronizing Clutch Coupling Programand its Applications

Synchronizing clutch couplings are cou­plings which engage and disengage auto­matically. They are capable of automat­ic engagement at any speed within the operating range as soon as the driving machine overruns the driven machine. Basically the synchronizing clutch coupling is a disengageable coupling equipped with a synchronizing mechanism.

The synchronizing clutch coupling consists of two main elements:

A) The gear coupling part for the pow­er transmission. This is the same as in a standard tooth coupling, i. e. the external coupling teeth are hardened and ground with longitudinal corrections allowing for angular misalignment.

B) The synchronizing mechanism detects synchronism of both shafts and initiates subsequently the engagement. This syn­chronizing mechanism is an assembly con­sisting mainly of a number of pawls and a multiple notched ratchet wheel. Together they act as a free wheel drive.

2

Today, RENK­MAAG offers three mainsychronizing clutch coupling lines.

3

Type MS Type DS Type HS

1 The synchronizing mechanism is designed for unlimited operation of the clutch in disengaged position at any speed difference between the input and output shafts.

2 The synchronizing mechanism is of relatively light but still robust construction. Therefore, high angular accelerations at engagement are permissible.

3 The synchronizing mechanism plays no part whatever in power transmission. It issimple, compact and incorporated into the coupling sleeve, suitable for high speed operation.

4 Torque transmission is the same as in standard toothed couplings, combining torsional rigidity with axial and angular flexibility.

5 Suitable for transmitting practically any torque at any speed for which toothed couplings can be employed.

6 Angular and parallel misalignment of the shafts is easily accommodated by the coupling components.

• The clutch engages automatically when the input shaft overruns the output shaft.

• Positive torque can be transmitted.

• The clutch disen­gages automatically when the torque becomes negative.

• After the «ENGAGE» command is given, the clutch engages automatically when the two shafts over­run each other, irre­spective of direction.

• Positive and negative torque can be trans­mitted.

• After the «FREE WHEEL» command is given, the clutch dis­engages automatic­ally when the torque becomes negative. Once disengaged, the two shafts are free to overrun each other.

• The clutch engages automatically when the input shaft overruns the output shaft.

• Positive and negative torque can be trans­mitted.

• The clutch disen­gages only upon command.

4

Each synchronizing clutch coupling can also be supplied with a variety of distinctive options. The diagram below gives some ex­

amples of possible features combinations for two of the designs, Type MS and Type HS.

DS

Synchronizing Clutch Coupling

J

X

F

Q

E

A

T

MS-R MS-S

MS

MS-H HS-H

HS

HS-N

Basic Design

Additional Features

R: locking mechanismS: rigid when engagedH: integrated fluid coupling

for start­upN: engagement at low speedJ: electrical insulationX: limited end floatF: isolating device (pawl free)Q: quill shaft arrangementE: encasedT: for turning gearsA: for starter drives

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Applications forMAAG Synchronizing Clutch Couplings

In light of the information on page 4, the following information can be ob tained from the type designation of a particular synchronizing clutch coupling:basic design:

M = mechanical automatic disengagement

H = hydraulic disengagement

S = synchronizing clutch coupling

coupling size

M

H

S

S

26

60 / 7

R

H

additional features(see legend on the left)

coupling / synchronizer size

...

...

...

...

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Marine Applications

Installation of a MAAG synchronizing clutch coupling type HS­40­F in a MAAG marine gearbox type DTA­260W CODOG.

The synchronizing clutch coupling is mounted between the gas turbine and the first reduction pinion shaft, whereas the diesel engine is connected to the gearbox through a friction clutch.

At cruising speed, the diesel engine is clutched to the gearbox and the gas tur­bine is stationary with the synchronizing clutch coupling disengaged. If maximum speed is demanded the gas turbine will be started and accelerated. When the tur­bine shaft overruns the primary pinion, the clutch engages. The ship’s propulsion pow­er is now delivered by the gas turbine, the

diesel engine is disconnected and the gas turbine accelerates further up to full speed.

When changing back to cruising speed, the gas turbine will be decelerated, the diesel engine started and clutched to the gearbox as soon as the speed is within the operating range of the diesel engine. After the load has been transferred from the gas turbine to the diesel engine, the disengage signal is given to the synchronizing clutch coupling, the clutch disengages and the gas turbine, disconnected from the main gear, runs down to standstill.

Synchronizingclutch couplingtype HS­40­F

Clutch coupling

Output (pinion shaft) Input (gas turbine)

Isolating device (manually operated)

Gearbox

Dieselengine

Friction clutch

Gas turbine

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Typical arrangement of two synchronizing clutch couplings in CODOG marine gear­box.

The type MS­36­RF which connect/discon­nect the gas turbine from the main gear train is equipped with a locking mech­anism and an isolating device (pawl free posi tion). The other type MS­36­RQ to connect/disconnect the diesel engine from the main drive is of the quill shaft mounted design.

The operating characteristics of this instal­lation are basically the same as the previ­ous application. However, because type MS clutches are installed no disengaging signal is needed to disengage the clutch. After the power transfer has been accom­

plished, the changeover is achieved by re­ducing the speed of the driver to be shut down.

A clutch is required in the diesel engine drive train because the output members of the hydraulic coupling cannot sustain the higher speed in propulsion mode.

In the installation described here, each of the clutches is equipped with a locking mech anism. Prior to a propulsion mode changeover the clutch to be disengaged has to be unlocked. This is initiated by an electric signal.

Synchronizingclutch couplingtype MS­36­RF

Dieselengine

Hydrauliccoupling

Diesel clutch in disengaged (quill shaft mounted) position

Turbine clutch in disengaged position

Output(pinion shaft)

Output(pinion shaft)

Spoolpiece

Couplingsleeve

Input(gas turbine)

Input(diesel engine)

Lubeoil feed

Gearbox

Gas turbine

Synchronizingclutch couplingtype MS­36­RQ

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The diagram below shows an arrangement for a CODAG marine propulsion system. This system requires three synchronizing clutches, 2 MS types and 1 DS type. The ar­rangement combines a gas turbine with a diesel engine.

Normally, a speed change gearset (gear­box A) is required at the cruise diesel en­gine when the booster is added to the drive system to be operated in combined mode (CODAG). This is necessary to prevent the diesel engine overspeeding.

The gas turbine booster drive is clutched to the main gearbox by an MS clutch (B). The + sign indicates that the clutch engages automatically when the turbine input speed overruns the input pinion speed.

The diesel engine cruise drive is clutched to the main gearbox by an MS clutch (C). The + sign again indicates the same functions as above.

For both drivers to operate together, it is ne­cessary to transmit the power of the diesel engine through a ratio matching gearset, (gearbox A) such that the engine can oper­ate in its most efficient operating condition. This requires a DS clutch (A) which is free­wheeling in either gas turbine only mode or diesel engine only mode, and which is en­gaged and locked (both the + and – ends) when operating in CODAG mode. Clutches B and C also have a locking capability in their respective modes to prevent disengage ment if negative torques are encountered during normal propulsion mode operation.

View of DS synchronizing clutch coupling

In cruising mode when the Diesel only is driving clutch C and A (+ end) are engaged and locked, clutch B and A (­ end) are disengaged. Torque is transmitted by clutch C only.In GT only driving mode clutch B and A (­ end) are engaged and locked, clutch C and A (+ end) are disengaged. Torque is transmitted by clutch B only. Gearbox A is at standstill.In CODAG mode, Diesel and GT driving, clutch A (+ and – end) and B are engaged and locked, clutch C is disengaged.

Main Gearbox

Gearbox Abull gear

Synchronizingclutch couplingtype MS

Synchronizingclutch couplingtype MS

Synchronizingclutch couplingtype DS

Gasturbine

Dieselengine

Hydrauliccoupling

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MAAG synchronizing clutch coupling type HS­85 installed in a power plant between the gas turbine and generator.

The generator is on line permanently. If pow er is needed, the gas turbine is started by its starting system and further accelera­ted to full speed. When the gas turbine shaft overruns the generator shaft, the clutch engages and power is transmitted. When pow er is no longer required, the gas turbine power is reduced to approx. zero, and the disengage signal is sent to the clutch, which disengages immediately. The gas turbine is shut down and the generator to rotate, operating as a synchronous condenser.

Power Generation

Synchronizingclutch coupling

type HS­85

Gas turbine Generator

Input(gas turbine)

Spool piece withsynchronizing mechanism

Servo mechanism

Output(generator)

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MAAG synchronizing clutch coupling type HS­85­H installed in a power plant between gas turbine and generator.

As its designation indicates, this type HS­85­H is combined with a fluid coupling. This fluid coupling will be used to start the gas turbine when the generator is working as a synchronous condensor. The gener ator rotates at synchronous speed, i. e. 3000 rpm, in the case of a 50 Hz grid, the clutch coupling is disengaged and the gas turbine is stationary.

If power is required from the gas turbine, the turbine is accelerated by filling the fluid coupling. Above a certain speed, the tur­bine accelerates under its own power, after which the fluid coupling is emptied. The

turbine accelerates further until it overruns the generator. The clutch coupling engages automatically. Power can now be trans­mitted from the turbine to the generator.

This arrangement avoids the need for an ex­pensive separate starting device for the gas turbine.

Gas turbine Integratedfluid

coupling

Generator

Synchronizing clutch couplingtype HS­85

Fluidcoupling H

Special frame(mounted on site)

Synchronizingclutch couplingtype HS­85­H

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This is an example of a synchronizing clutch application in an air storage power plant.

The synchronizing clutch coupling type MS­85­S is mounted between the gas turbine (power turbine only) and the gen­erator. In this case the MS­type coupling has the S­feature which means that the cou pling will behave like a rigid coupling when engaged.

Disgengageablecoupling

Output(generator/motor)

Input(gas turbine)

Synchronizingclutch couplingtype MS­85­S

Exploded view of the typeMS­85­S synchronizing clutch coupling

Centrifugalcompressor

Generator/motor

Gas Turbine(power turbine

only)

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Energy Recovery, Combined Cycle Technology, Cogeneration

This shows a typical energy recovery appli­cation for the type MS­14 synchronizing clutch coupling in a compressor installa­tion where surplus process gases, instead of being released by a valve, are used to drive a gas expander. This gas expander is cou pled to a centrifugal compressor via the type MS­14 clutch. If no surplus process gases are available, the gas expander is automatically disconnected thus avoiding windage losses in the gas expander.

Steamturbine

Synchronizing clutchcoupling type MS­14

Centrifugalcompressor

Gasexpander

Output coupling hubwith synchronizing mechanism(centrifugal compressor)

Input couplinghub (expander)

Coupling sleeve

Spacer

Coupling assembly

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This is a typical example of a synchronizing clutch coupling application in the field of combined cycle technology in a chemical plant. Steam is generated by a convention­al boiler, which can be used for the process technology or power generation. If steam is available, the steam turbine will be started and automatically coupled to the generator.

In the original arrangement, without over­running clutch, cooling steam was required to windmill the steam turbine (no power generation by steam turbine). By installing the clutch coupling the steam turbine can be shut down, no cooling steam is re quired and overall efficiency is considerably in­creased. In this example installation, the MS­36­J is electrically insulated and in­

stalled between the steam turbine and the gener ator. In this particular case the syn­chronizing clutch coupling was installed as a replacement for a gear coupling.

Output couplinghub with synchronizingmechanism (generator)

Inputcoupling sleeve(steam turbine)

Spacer

Clutch assembly with mounting frameGas turbine Generator Steam turbine

Synchronizingclutch couplingtype MS­36­J

Gearbox

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Other Applications

Synchronizing Clutches for Automatic Turning Gears Type MS-…-T

The MAAG synchronizing clutches for turn ing gears are of simple construction, suit able for turbomachinery installations, and combine outstanding reliability with high torque transmitting capacity.The clutch automatically engages at the instant the input speed tends to overtake that of the output shaft. Conversely, the clutch will automatically disengage when the output shaft speed exceeds the speed of the input shaft. A full range of turning gear clutches is available.

Free-Standing SynchronizingClutch Couplings Type MS-…-E

The encased MAAG synchronizing clutch couplings have been developed for in­stallations where the driving machine has to be totally isolated for «on­site» main­tenance while the driven machine contin­ues to rotate. Typical applications for the encased clutches are fan drives with two driving machines.The input and output shaft are each sup­ported by two amply dimensioned bear­ings. The type MS­clutch is mounted inside the casing between the two shafts. The cas ing is of fabricated steel plates. Standard fle xible couplings such as diaphragm cou­plings can be used to connect the clutch unit to the driving and driven machines.

Input shaftMS clutchOutput shaft

Automatic turning gear clutch type MS­8­T installed in gearbox between turning gear and pinion shaft

Design principle of a MAAG free­standing synchronizing clutch couplingfor high power transmission(e. g. 131.5 MW/60 Hz or125.0 MW/50 Hz)

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Typical Examples of Applications

MAAG synchronizing clutchtype MS-76/E

ANZAC frigate

ANZAC CODOG gear systemon testbed

RENK-MAAG GmbHPostfach 3068 • Sulzer-Allee 46 • CH-8404 WinterthurTel. +41 (0) 52 262 89 88 • Fax +41 (0) 52 262 89 89

info@renk-maag.ch • www.renk-maag.ch

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aufl

age

Kü

09.

2010

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Customer Service / Spare Parts / Maintenance / Testbed

RENK-MAAG cares for the customer during and after the sales: Our ef-ficient sales team is prepared to give advice regarding new equipment and original spare parts for cou-plings and gearboxes of MAAG type. On-site support is provided world-wide for all MAAG-turbo and marine gearboxes by our experienced and certified field service engineers. Pe-riodical and/or preventive mainte-nance assure the safe and reliable operation of equipment. Our service field engineers are at your disposal for inspections and maintenance.

In case of need to fully refurbish or revamp a gearbox, coupling or com-ponents at our facility, we provide a full range of support with the deliv-ery of a re-warranted unit.

New gearboxes and components can thoroughly be tested applying the latest technology in diagnostic mon itoring equipment for vibration, temperature and sound.

Test runs of refurbished gearboxes are also concluded where verifica-tion of repair work must be certified.

RENK-MAAGis at your disposal

Production and other activities are monitored by the internal quality

assurance system and in strictcompliance with ISO 9001 : 2008.