jcb 1CX, Service Manual

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10 - 1
Section E Hydraulics
9803/8550
Section E
10 - 1 Descriptions
*
Drive Motor Operation
Note: On the illustration below, the main parts of the motor
are shown slightly separated for purposes of explanation.
Basically, this type of motor comprises a gearwheel set D
which is connected by a valve drive E to a disc valve F.
The gearwheel set consists of a toothed internal gear (the
rotating part) and a fixed external gear rim whose 'teeth' are
formed by rollers. The internal gear is free to rotate in a
circular orbit within the gear rim.
The disc valve is arranged to create a series of inlets and
outlets which, as the gear rotates, always align precisely
with the chambers formed between the internal gear teeth
and the gear rim rollers.
Key
A Output Shaft
B Brake Pack
C Cardan Shaft
D Gearwheel Set
E Valve Drive
F Disc Valve
Oil under pressure passes through the disc valve inlets to
the inter-tooth chambers on one side of the gearwheel set.
These chambers are so shaped that the oil pressure within
them creates an imbalance of forces which causes the
internal gear to rotate. As the gear rotates the oil in the
chambers is progressively connected to the disc valve
outlets, from where it returns to tank.
A cardan shaft C connects the inner gear to the output shaft
A.
Brake pack B comprises a series of alternate friction plates
and brake pads. The brake is normally held 'on' by spring
force and released by hydraulic pressure.
Issue 2*
167740
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