Excessive Noise Or Vibration; Motor Operates Normally In One Direction Only; Improper Output Speed - Danfoss H1B 060 Service Manual

Service Manual
H1 Bent Axis Motors, Size 060/080/110/160/210/250 cm3
Troubleshooting
Check
5. Air in system
6. Internal leakage

Excessive noise or vibration

Check
1. Oil level in reservoir
2. Air in system
3. Shaft coupling
4. Shaft alignment

Motor operates normally in one direction only

Check
1. Charge pressure
2. Pressure compensator control

Improper output speed

Check
1. Oil level in reservoir
2. Threshold setting
3. Pressure compensator setting
4. PC spool
5. Control orifices
6. Control spool
7. Control input signal
8. Internal leakage
© Danfoss | August 2018
Cause
Entrained air generates heat under pressure
Excessive internal leakage may overheat the
system.
Cause
Insufficient hydraulic fluid may cause cavitation.
Air bubbles may lead to cavitation.
Loose shaft coupling may create excess noise.
Misaligned shafts may create excessive noise and
vibration and can damage motor.
Cause
If charge pressure is low in one direction, the loop
flushing shuttle spool may be sticking to one side.
If pressure compensator operates in one direction
only, the motor may stay at minimum
displacement in the opposite direction.
Cause
Insufficient hydraulic fluid may reduce system
efficiency.
Improper threshold setting may cause motor to
have wrong displacement for given signal.
Improper pressure compensator setting may shift
motor displacement at wrong pressure.
Pressure compensator spool sticking may shift
motor to improper displacement.
Blocked or restricted orifice may cause motor to
shift improperly.
Sticky proportional control spool may cause motor
to shift improperly.
Improper input signal may cause motor to shift
improperly.
Excess internal leakage may cause lower charge
pressure and affect motor performance including
output speed.
Corrective action
Look for foam or bubbles in reservoir. Check for leaks
on inlet side of charge pump.
Install loop flushing defeat option and monitor case
flow. If case flow is excessive, motor may require major
repair. Contact your Danfoss authorized service
center.
Corrective action
Fill reservoir to proper level.
Look for foam or bubbles in reservoir. Check for leaks
on inlet side of charge pump.
Replace loose shaft coupling. Replace or repair motor
if shaft splines show excessive wear.
Correct shaft misalignment.
Corrective action
Measure charge pressure in forward and reverse. If
pressure drops significantly lower in one direction,
inspect and repair loop flushing shuttle spool.
Check brake pressure defeat spool. It may be sticking
or receiving an improper signal. Repair spool or
correct input signal.
Corrective action
Fill reservoir to proper level.
Check threshold setting. Refer to Control Service
Manual for adjustment procedure.
Check pressure compensator setting. Adjust if
necessary. Refer to Control Service Manual for
adjustment procedure.
Check pressure compensator spool. Repair or replace
if needed. Refer to Control Service Manual for
adjustment procedure.
Remove, inspect and clean all orifices.
Check control spool for proper operation. Repair if
necessary. Refer to control adjustment procedure.
Correct control input signal.
Install loop flushing defeat option and measure case
flow. If case flow is excessive, motor may require major
repair. Contact your Danfoss authorized service
center.
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