VOITH

AutomaticTransmissions forMidibuses and

. Delivery TrucksVoith Midimat BRVoith Midimat T

•

What many have been waiting for:

• Mrs. A. is moving house.She would like to do it all by her-self with a rented truck. To makethings easier, it should have anautomatic.

• Mr. B. is a mobile wholesalegrocer. His business is sellingand he would like to deal with hiscustomers in a friendly andrelaxed wax - not tired and irrita-ble after an exhausting day's driv-ing. He thinks of getting an auto-matic.

• Mr. C. is a works manager.His overheads are getting on topof him: clutches need to berenewed, brakes need relining -wear and tear everywhere!

• Mrs. D. is an art student.She has a part-time job with a par-cel service company. In the even-ing she feels as if she hasbecame part of the gearbox her-self. Start and stop traffic has wonover fine art!

• Mr. E. has a truck hire com-pany. His private saloon has anautomatic. It makes driving easyand provides better availability ofthe car. He often thinks of hisdelivery trucks ...

2

Help is now at hand for thesepeople. There is an automatictransmission for delivery vans,smali trucks and midibuses.

Midimat Transmissions have thefollowing key features:

• Starting off smoothly with no clutchwear, powerful and quick accelerationthanks to the multi-stage, multi-phasetorque converter.

• High efficiency due to lock-up of theconverter.

• Extremely compact design and lowweight.

• Attractive price.

Voith-Midimat transmissions have beenspecially designed for commercial vehi-cles in city traffic. They reduce the stressand strain of dense traffic and reduceoperator costs. Midimat transmissionsare true automatic transmissions with atorque converter for acceleration andthree mechanical gears. Where the ver-sion with Retarder (Midimat BR) is cho-sen, ali braking can be done completelywear-free, independent of the gearengaged. Up to 90% of all braking opera-tions can be performed with the Retar-der.

The transmission can be installed indelivery and distribution trucks as well asin ali midibuses up to 12t.

Technical Dała

Type MidimatT MidimatBR

Input power P1

[kW] 165 165Input torque M1

[NM] 550 550Input speed n1[RPM] 4000 3000Retarder torque MBR[NM] upto 2000Number of gears 3 3

Stall torque ratio/Mechanical ratios

1st driving range 9,6/3 9,6/32nd driving range 3,64/1,58 3,64/1,583rd driving range 1,4/1 1,4/1Reverse driving 8,36/1,42 8,36/142Weight of dry transmission [kg] 102 160Voltage[V] 24 24

3

50

4035

3025

2015

tlO4 t

zO z6

u, O a.

O 20 40 60 80 100v [km/h] --

Design and Mode of operation

Midimat transmissions are fully auto-matic hydrodynamic-mechanicaltransmissions with a multistage,multi-phase torque converter, and athree-gear planetary output gearstage. The BR version has an inte-grated hydrodynamic retarder.

The torque converter consists of animpeller, a turbine, a reactor and aguide wheel. Reactor and guidewheel are operated automatically viafree wheeling devices.

A modified Ravigneaux-type set ofplanet gears is employed which pro-vides three forward gears and areverse gear.

The wear-free hydrodynamic retar-der is on the output side of the plane-tary gear and therefore independentof the gear engaged. Gearchangingand retarder operation are electro-hydraulic, under command of anelectronic control unit. The transmis-sion design ensures the optimumtransmission of power in all drivingranges.

Tractive effort curvesTransmission Midimat BRVehicle MidibusAxleratio 4,630Tyrerdyn 0,407CwxA[m2j 3,39Weight[t] 10,5Engine power [kW] 110

Options

A power take-off can be included onthe primary side on request.

4

F = Tractive effortv = Oriving speedp = Gradient in %

The hydra ulic and mechanicalcomponents are switched in sucha way that they ensure minimumloss ot tractive effort and efficiencyA significant teature is the automa-tic engagement ot the reactor andguide wheel in the torque conver-ter.

Ok = Lock-up clutchP = ImpellerT = TurbineRl = ReactorR2 = Guide wheel1 G = brake, 1st driving range2 G = brake, 2nd driving range3 G = brake, 3rd driving rangeR = brake, reverse driving

fJ II II El II BmlJ

10 Frietion-dise brake,1st driving range

11 Planetary gear stage12 Output

Retarder13 Rotor14 Stator15 Oilsump16 Heat exehanger

Braking eftort curvesF6 = Braking eftortv = Oriving speedp = Gradient in %

Automatic transmission1 Loek-up eluteh with torsional

vibration damper2 Turbine3 Reaetor4 Guide wheel5 Impeller6 Power take-oft7 Frietion-dise brake,

2nd driving range8 Frietion-dise ciuteh,

3rd driving range9 Frietion-dise brake,

reverse driving

mm lEI

10 Friclion-disc brake,1st driving range

11 Planetary gear stage120utput

Retarder13 Rotor14 Stator150ilsump16 Heatexchanger

- •••••• -~10

1210 ---'-----:.JIj~---Braking eftort curvesFB = Braking effortv = Oriving speedp = Gradient in %

15O 20v [km/h] __

40 60

Braking withthe retarder

The integrated secondary retarder is ahydrodynamic permanent brake whichfully complies with ECE 13. Ali brakingoperations are wear-free. There is nomechanical friction.

During braking, the kinetic energy of thevehicle is converted into heat. This heatis dissipated through the vehicle coolingsystem.

The retarder is controlled trom a 3-notchmanual brake switch at the steering col-umn or in the idle patch of the brakepedal.

Design

The main components of the retarder arethe two bladed wheels, the stator and therotor. For braking the vehicle, oil isinjected between the rotor and the fixedstator. The oil flow is accelerated by thecentrifugal force in the rotor compart-ment and pressed into the stationarycompartments of the stator, where it isdecelerated.

This oil stream is arrested in the station-ary compartments of the stator anddecelerates the vehicle by its retardingon the rotor.

80

5

Economic Driving is Guaranłeedby Elecłronic Conłrol

The micro-computer control system ena-bies the driver to select between threeprogrammes. This ensures that enginesand transmission are always optimallymatched to the driving conditions:

"Normal":Driving with loaded or partly loaded vehi-cle

"Empty":Driving with unloaded vehicle

"Uphill":Driving in hilly terrain

Additional Function:

"Snow":Driving on snow-covered roads.

Dependent on the position of theaccelerator (16 stages), the micro-com-puter control always adjusts the switchpoints to guarantee the most economicalfuel consumption.

The driving program mes can beselected via a push button switch or acontrollever.

The retarder can be controlled throughthe pedal brake valve or a manualswitch.

Cooling circuit diagram at the right:1 Transmission2 Retarder3 Heat exchanger4 Engine5 Radiator

6

----_ .....• --

iii

••

P E H •

1. Gearbox with induction transmitterand control block

2. Push button switch3. Push button switch,

additional function4. Selector lever5. Pedal brake valve6. Accelerator pedal7. Electranic contral unit

---

Installation in the Vehicle

The Midimat transmission is mounteddirectly to the engine and supported bythe engine suspension.

The transmission has its own oil supplywhich is cooled by a heat exchanger eon-nected to the vehicle cooling system.

Heat generated by the retarder duringbraking is also dissipated to the vehiclecooling system via a heat exchanger.

The transmission is contralled electro-hydraulically receiving signals tram anelectranic control unit.

Installation Examples:

Midibuses, delivery vans and distributiontrucks.

Transaxle(Neonplan)

Transverse installation(Menarini)

In-linecentral(MA N)

- In-linesideways(Van Hool)

In-lineTruck

Standard arrangementlorry

Standard arrangementIn-line rear Bus

Oimensions:Top: Transmission type T

Bottom: Transmission type BR

7

Installation in the Vehicle

The Midimat transmission is mounteddirectly to the engine and supported bythe engine suspension.

The transmission has its own oil supplywhich is cooled by a heat exchanger con-nected to the vehicle cooling system.

Heat generated by the retarder duringbraking is also dissipated to the vehiclecooling system via a heat exchanger.

The transmission is controlled electro-hydraulically receiving signals trom anelectronic control unit.

Installation Examples:

Midibuses, delivery vans and distributiontrucks.

Transax/e(Neonp/an)

Transverse installation(Menarini)

In-linecentral(MAN)

- /n-linesideways(Van Hool)

ln-IineTruck

Standard arrangementlorry

Standard arrangement/n-line rear Bus

Oimensions:Top: Transmission type T

Bottom: Transmission type BR

7

VOITH125YEARS~SUPERIOR TECHNOLOGYESPRIT· EXCELLENCE· EFFIZIENZ

Additional brochures are availableonrequest:Technical Manual G 1257Lubrication List G607

J. M. Voith GmbHAntriebstechnik Nutzfahrzeuge0-7920 HeidenheimPostfach 1940Telephone: (07321) 37-0Telefax: (07321) 37-71 04Telex 71 79980 VH O

8o

VOITHGROUP OF COMPANIES