For Construction Machinery

and Lift Trucks

Torque Converters

ZF Sachs AGErnst-Sachs-Straße 6297424 SchweinfurtGermanyphone: +49 9721 98-0fax: +49 9721 98-2290www.zf.com

Driveline and Chassis Technology © Z

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What applies to commercial vehicles in general is also true for construction machinery in particular: Requirements for vehicles are on the rise. On theone hand, construction machines are supposed to be versatile, economicallyviable, and reliable, while on the other hand of course they should alsobe saving fuel. With its highly efficient and individually adaptable torqueconverters, ZF Sachs AG is masterfully bridging these two sets of requirements for its area of expertise.

With millimeter-precise accuracy for maneuvering, swift loading andunloading, a high and even level of power transfer, quick and smooth shiftprocesses – construction machinery has to be highly versatile and reliable. And all of this more so than ever! In order for lift trucks, telescopic handlers, backhoe loaders, wheel loaders and dump trucks to successfully completethe tasks assigned by their owners or drivers, all components of the driveline have to be optimally harmonized with one another. Today, no one canconceive of working without the valuable assistance of vehicles equippedwith hydrodynamic torque converters.

ZF Sachs offers a broad spectrum of torque converters here in differentmodel versions. Due to its ongoing development work, ZF Sachs isable to provide production-ready solutions today that already meet therequirements of the future.

More Comfort and Less Fuel Consumption – Torque Converters by ZF Sachs

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Application Lift Truck Wheel Loader

Torque Converter

Free-wheel Unit

Torsional Damper

Standard Optional Future Trend

Backhoe Loader/

Telescopic Handler

Dump

Truck

Lock-up Clutch

LUC

With a hydrodynamic diameter of 280 up to 400 millimeters, torque converters by ZF Sachs can easily be usedfor engine torques up to 2,700 Nm. Thus, not only the entire torque converter range of construction machinery iscovered, but also all individual requirements of manufacturers and operators can be fulfilled. The individual matching of performance and model type to the respective application makes torque converters from ZF Sachs extraordinarily effective.

Torque for Every Construction Machinery Application

W280 W280 W300 W400W300 W300 W340 W400

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The task:

Hydrodynamic torque converters are used in construction machinery with automatic transmissions. The engine torque ispassed to the transmission via the torqueconverter using oil as a transfer medium. A high and even level of power transfer as well as quick and smooth shift processesare a must. Because hydrodynamicpower transfer is fuel-intensive, lock-up clutch ensures direct torque flow between engine and transmission after the drive-off process. To protect the transmission,torsional vibrations have to be “filtered out”.

The technology:

Torque converters from ZF Sachs are known for their robust design. Thanks to individual adaptation of engine and convertercharacteristics, they are optimally designed for any given application with respect to both function and service life. After the drive-off process, the optional lock-up clutch enables torque flow to betransferred directly and thus with no loss of power between theengine and the transmission. This contributes substantially lowering fuel consumption levels and enhancing cost-effectiveness for construction machinery. ZF Sachs torque converters arefeaturing new free-wheel designs to cope with the highly dynamic gear-shifting processes which occur in transmissions these days. The vibrational problems that arise in the driveline when engines are optimized for fuel consumption and emissions are being addressed by integrating torsional dampers into the torque converter.

Torque Converters for Every Torque Range

W400 LUC W300 LUC/TD

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The required convertersize depends on the engine torque to be transmitted.

Impeller

Engine connection

Power take-off

Turbine

Lock-up clutchwith torsional damper

Stator

Free-wheel

Oil pump drive

Converter size Ø [mm]

1,000

1,500

2,000

2,500

3,000

W280 W300 W340 W400

500

0

Engi

ne to

rque

[N

m]

Torque for every construction machinery application

Design of W340 LUC/TD for wheel loaders

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Benefits Longer service life thanks ■to protection of driveline componentsReduced fuel consumption because ■required rpm levels can be lowered Reduced noise emission ■

Comparison of vibrational decoupling for converters with and without torsional damper (TD)

Reduced fuel consumption with lock-up clutch

Torque converter efficiency

Converter without TDConverter with TD

Speed [rpm]

Operationalrange

500 1,000 1,500 2,000 2,500

Ang

ular

acc

eler

atio

n [1

/s²]

Like every other hydraulic machine, torque converters do not work without losses. The efficiency of a torque converter in hydrodynamic mode is about 90 %. A torque converter lock-up clutch enables torque flow to be transferred directly between engine andtransmission. As soon as the lock-up clutch is engaged the efficiency of the torque converter is approximately 100 %.

Fuel consumption can be lowered by up to 15 %, depending on the load cycleand service conditions,as well as the gear in whichlock-up clutch is engaged.

Fuel savings of up to 15 %with lock-up clutch

refuel

0

+

Driving time/distance

Fuel

con

sum

ptio

n

with lock-up clutch

withoutlock-up clutch

refuel

Without lock-up clutch

1 max. 90 %

Lock-up clutch engaged in fourth gear

Lock-up clutch engaged as of second gear

Gea

r

max. 90 % max. 90 %

approx. 100 %

approx. 100 %

2

3

4

5

Lock-up clutch disengaged Lock-up clutch engaged

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Details of Lock-up Clutch Systems

Converter with lock-up clutch with 1 friction facing in dual-line system

Lock-up clutch disengaged

Lock-up clutch disengaged

Lock-up clutch disengaged

Lock-up clutch engaged

Lock-up clutch engaged

Lock-up clutch engaged

Converter with lock-up clutch with 1 friction facing in open three-line system

Converter with lock-up clutch with 4 friction facing in closed three-line system

Torque converters with lock-upclutch using a dual-line principle are used primarily in backhoe loaders and telescopic handlers.The lock-up clutch can transmit up to 500 Nm of torque.

Torque converters with lock-up clutch using an open three-line principle are also used primarily in backhoe loaders and telescopic handlers. The three-line system and the enhanced heat transfer mean that the lock-up clutch can be engaged earlier. This optimizes fuel consumption all the more.

Torque converters with lock-up clutch using a closed three-line principle are used primarily in dump trucks and wheel loaders. In addition to the advantages of the open three-line system, here there is a longer service life. This is because the lock-up clutch’s shift function can be better modulated thanks to the closed control line.

Oil flow

Oil flow

Oil flow

Torque flow

Torque flow

Torque flow