5

Power flow during gear shifting and braking

In operating terms, fuel consumption

plays a major role. The overdrive en-

sures that fuel-friendly engine speeds

are achieved both in city and in longdis-

tance trafﬁc. This is also aided by the

torsional vibration damper which pro-

tects the transmission from low speed

engine vibrations.

The oil circulates solely inside the trans-

mission. The Voith DIWA.5 is designed

without external oil hoses or pipes. This

simpliﬁes transmission installation and

improves the overall reliability of the oil

circuit saving service and maintenance

costs.

Filter replacement without having to

change the oil? Oil change intervals up

to 180 000 km? Even that is possible

with the DIWA.5, again helping to re-

duce maintenance costs.

Reliability starts in the detail

Specially developed sensors ensure

that the transmission is extremely reli-

able. However, on those occasions when

a sensor needs to be replaced they are

all accessible from the top of the trans-

mission reducing maintenance times.

Installation space is scarce in buses.

The compact outer dimensions (e. g. by

omitting pipes and tubes) facilitate the

installation of the transmission even in

the most conﬁned of spaces. Last but

not least, transmission installation and

removal times from the vehicle chassis

are also signiﬁcantly reduced – owing to

the straightforward connection of the

torsional vibration damper.

Hydrodynamics are one of the core

competences at Voith: that is why over

100 years of experience have been put

into our converter, the key component

of the DIWA transmission.

Idling/neutral position

input clutch open

Starting

Overdrive

Clutch for the overdrive closes, clutch for

direct gear opens.

Reversing

(R)

Power is transmitted hydro-dynamically/

mechanically just as during starting.

Braking

(Retarder function with the converter)

The turbine wheel acts as axial pump which

delivers oil against the stalled impeller and the

guide wheel. Heat resulting from the conversion

of kinetic energy is dissipated via the heat

exchanger.

n

Active power ﬂow

n

Rotating components

n

Locked rotating components

n

Stationary components

n

Clutch plates closed

ANS – Automatic Neutral Switch

In order to save fuel, the power ﬂow between

the engine and transmission, including the

converter, is automatically interrupted when

the vehicle is at a halt.