90 - 3
Section E
Hydraulics
9803/6410
Section E
90 - 3
Issue 1
Slew Motor
Operation (cont’d)
Relief Valve Working Principles
1
On starting
Due to the superstructure’s inertia there is a build-up of
pressure in the motor when it begins to slew. To prevent
damage, excess pressure is diverted between ports
A
and
B
via poppet valves
43
(part of cross-line relief
valve
J
).
2
When the brake is applied (cushioning)
When the slew control valve is returned to neutral the oil
retur n path from the motor is closed. While the
superstructure is coming to a halt it is, in effect, ‘driving’
the motor as a pump. This results in a pressure build-up
at the outlet port (
A
or
B
depending on slew direction).
This increased pressure opens poppet valve
43
, which
allows oil to flow via paths
g
and
h
, opening check valve
29
and relieving the pressure into cavity
C
.
At the same time, oil flows between the two ports via
the cross-line relief valve
J
, which has already been
partially opened by poppet valve
43
.
The result is a 2-stage relief action which momentarily
delays the pressure build-up as the superstructure
comes to a halt. This reduces the shocks arising due to
sudden braking.
3
Anti-Pendulum Feature
While the superstructure is coming to a halt, as
described in
2
, it drives the motor as a pump. The initial
result is a braking effect on the superstructure. However,
the resulting pressure build-up in port
A
(or
B
,
depending on direction) tends to cause the
superstructure to ‘bounce back’ a little. The process
repeats itself to create what is known as a ‘pendulum
effect’.
To prevent this happening, check valves
50
and flow
control valves
48
work together to divert oil pressure
between ports
A
and
B
until the superstructure has
come to a halt.
Reduction Gear Structure and Working
Principles
(illustration reference page 83 - 2)
Power transmitted by the hydraulic motor output shaft is
transmitted to second sun gear
77
via first sun gear
66
,
planetary gear
69
and holder
65
. Power is then transmitted
to output shaft
53
via second sun gear
77
, planetary gear
72
and holder
76
. The output shaft is constructed with an
integral pinion and is supported in gear case
58
by bearings
57
and
62
.
Due to the severe conditions under which the output shaft
operates, an oil seal
61
is provided in the centre of gear case
58
to protect the bearings from metal waste worn from the
gears. The bearing in chamber
A
is lubricated with gear oil
and the bearing in chamber
B
with grease.
Содержание JS130
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Страница 119: ...3 1 Section C Electrics 9803 6410 Section C 3 1 Issue 1 Layout Operator s Cab...
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Страница 145: ...5 6 Section C Electrics 9803 6410 Section C 5 6 Issue 1 Pump Control Cushioned Boom Starting continued Flow Chart...
Страница 148: ...5 9 Section C Electrics 9803 6410 Section C 5 9 Issue 1 Pump Control Pressure Increasing System continued Flow Chart...
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Страница 159: ...5 20 Section C Electrics 9803 6410 Section C 5 20 Issue 1 Pump Control Swing brake Swing lock continued Flow Chart...
Страница 160: ...5 21 Section C Electrics 9803 6410 Section C 5 21 Issue 1 Pump Control Lever Lock Circuit Diagram Time Chart...
Страница 161: ...5 22 Section C Electrics 9803 6410 Section C 5 22 Issue 1 Pump Control Lever Lock continued Flow Chart...
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Страница 210: ...3 4 Section E Hydraulics 9803 6410 Section E 3 4 Issue 2 Schematics Shuttle Block...
Страница 211: ...Section E Section E Hydraulics 9803 6410 Issue 2 3 5 3 5 Schematics Pilot Control Line Hose Connection Diagram JS03540...
Страница 212: ...Section E Section E Hydraulics 9803 6410 Issue 1 3 6 3 6 Schematics Pilot Control Line Hose Connection Diagram JS03540...
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Страница 278: ...32 2 Hydraulic Circuit Diagram Section E Hydraulics 9803 6410 Section E 32 2 Issue 1 Control Valve JS01700...
Страница 279: ...33 1 Neutral Circuit Section E Hydraulics 9803 6410 Section E 33 1 Issue 1 Control Valve JS01610...
Страница 284: ...33 6 Boom Raise BM Operation Section E Hydraulics 9803 6410 Section E 33 6 Issue 1 Control Valve L...
Страница 287: ...33 9 Slew Operation SW Priority Circuit Section E Hydraulics 9803 6410 Section E 33 9 Issue 1 Control Valve JS01770...
Страница 293: ...Hydraulics 9803 6410 Issue 1 34 3 34 3 Section E Section E Control Valve JS01820 Dismantling and Assembly cont d...
Страница 532: ...Contents Page No Technical Data 1 1 i Engine 9803 6410 i Issue 1 Section K Section K...