Slew Motor - jcb JS300 Service Manual

Symptom Cause
Motor does Internal damage to the
not run motor.
Internal damage to the
motor.
Relief valve in circuit not
set correctly.
Excessive Wear or damage to the
slip motor sliding surfaces or
to the high-pressure seal.
Oil hot and excessive
parts or circuit.
Abnormal Seizure of motor sliding
heating parts or circuit.
Leakage Damage or wear to oil
from oil seal lip.
seals
Damage or wear of the
shaft seal.
Abnormal pressure in the
casing.
E-240

Slew Motor

Table 5.
External Inspection
Measure the oil drain
volume.
Open the motor inlet and
outlet ports and apply 20
kgf/cm 2 (284 lbf/in 2 ) pilot
pressure to the brake
release port. Try to rotate
the shaft with a torque of
approx. 39 Nm (29 lbf ft).
Measure pressure.
Measure the oil drain
volume.
Measure the oil
temperature.
Check for any metallic
matter deposited in motor
drain oil or drain filter.
Apply a 30 kgf/cm 2 (427
lbf/in 2 ) pilot pressure to
the brake release port
and try to rotate the shaft
with a torque of
approx.39 Nm (29 lbf ft).
Check the pressure in the
casing and measure the
drain volume.
9813/5100-1
Section E - Hydraulics
Hydraulic System Fault Finding
Countermeasure
High possibility of
damage to the sliding
surfaces if the supply
volume is approximately
equal to the drain volume.
Dismantle and inspect.
High possibility of internal
damage to the motor if
the supply shaft does not
rotate smoothly when this
torque is applied.
Dismantle and inspect.
Reset to the prescribed
setting.
Leakage is too high if the
oil drain volume exceeds
5 l/min (1.1 gal/min).
Dismantle and inspect.
Reduce the oil
temperature.
If metallic matter is
discovered or the supply
shaft does not rotate
smoothly when torque is
applied, there is a high
possibility of internal
damage to the motor.
Dismantle and inspect.
Set the pressure in the
casing below 3 kg/cm 2 .
(43 lbf/in 2 ) Dismantle and
inspect if drain volume is
excessive.
Slew Motor
Repair
K Table 6. ( T
E-241).
Renew damaged parts or
renew the motor
assembly.
K Table 6. ( T
E-241).
K Table 6. ( T
E-241).
Repair or renew the
damaged parts. Renew
the motor assembly.
Renew the oil seals.
Repair the problem or
renew the motor
assembly.
Renew the oil seal.
Repair or renew the
damaged parts. Renew
the motor assembly.
E-240