Kalmar ContChamp DRD S Series, Technical Handbook

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ContChamp DRD-S
Technical Handbook
Brake system
Description
22 S. Grupp 70
9407
04-10
WDB brake system
This system is known as the wet disc brake system, in which each
hub is equipped with a multiple-disc assembly.The disc assembly
comprises stationary discs arranged alternately with a number of
rotating discs. The disc assembly is compressed by hydraulic
pressure to provide effective braking action. The assembly is sub-
merged in a hydraulic oil bath to dissipate the heat generated by
braking. A separate cooling circuit is provided to cool the hydrau-
lic oil.
The advantages of the wet disc brake system include the fact that
no adjustment is needed, and that no fading or wear occur. More-
over, the enclosed oil bath keeps the system completely free from
water and impurities.
The wet disc brake system comprises three separate hydraulic
circuits, i.e. the foot-brake circuit, the cooling circuit and the park-
ing brake circuit. All circuits are supplied with hydraulic fluid under
pressure from a fixed vane-type pump. The brake circuits are
supplied from four hydraulic accumulators and the cooling circuit
is supplied directly from the pump.
The pump feeds a charging valve which ensures that a minimum
pressure will always be maintained in the accumulators. During
the charging process, the charging valve serves as a priority
valve, so that a certain residual flow will be supplied to the cooling
circuit. If the engine runs at no load, the residual flow may be so
small that the flow in the cooling circuit will temporarily stop.
When the accumulator has been charged to full pressure, the
charging valve transfers the entire pump flow to the cooling cir-
cuit.
N.B. Certain machines have a separate tank for the brake
system.