Symptoms
|
Possible causes
and remedy |
Excess median diameter
and insufficient outside diameter
|
1. Main live axle too far;
2. Hydraulic time too short;
3. Hydraulic pressure too low |
Excess median diameter
and acceptable outside diameter
|
Excess workpiece diameter
|
Acceptable median diameter
and insufficient outside diameter
|
Insufficient workpiece
diameter |
Acceptable median diameter
and excess outside diameter
|
Excess workpiece diameter
|
Insufficient median diameter
and excess outside diameter
|
1. Insufficient center
distance of main axle;
2. Excess hydraulic time;
3. Excess hydraulic pressure |
Median diameter not conical
and outside diameter conical
|
Conical workpiece |
Insufficient conical median
diameter
|
2 rolling dies not parallel
|
Particles or flakes from
hydraulic pressure
|
1. Tooth location not properly
adjusted;
2. Excess hydraulic time |
Workpiece jumps up under
hydraulic pressure
|
1. Excess height of supporting
shoe;
2. Two rolling dies with different diameters |
Workpiece screw top worn
|
1. Supporting shoe too
low;
2. Insufficient degree of supporting surface finish
|
rolling die thread face-off
damaged
|
1. rolling die face-off
excessively steep or small
2. Rolling die end surfaces not in alignment |
Workpiece radial movement
under hydraulic pressure
|
1. Excess or insufficient
workpiece diameter;
2. Excess or insufficient rolling die diameter; |
Pressure meter hand vibration
|
Oil suction blocked |
Main live axle feeding
too slow
|
1. Pipe leaks, to be repaired;
2. Oil cylinder seal damage; to be replaced |
Main live axle vibrates
while feeding and returning
|
1. Air in oil cylinder,
to be discharged;
2. Lack of lubrication oil in sliding sleeve; to be
added lubrication oil |
Oil temperature too high
|
1. Excess oil viscosity;
2. Excess time for hydraulic pressure;
3. Excess hydraulic pressure;
4. Ambient temperature too high; cooler added |
Failure to increase the
pressure
|
1. Oil pump damaged; to
be replaced
2. Insufficient oil viscosity; new oil to be used
3. Overflow relief valve failed; to be replaced |
Oil with bubbles
|
Oil level too low in the
tank or air in oil pump |
Main live axle fails feed
motion
|
Oil pump motor rotates
in wrong direction. |
Main live axle fails return
motion
|
Return spring does not
work. |
High temperature of workpiece
|
1. Main axle rotation speed
too fast;
2. Feed speed too fast;
3. Excess hydraulic pressure |
rolling die
broken or cracked
|
1. workpiece shoulder contacts
rolling die end surface;
2. workpiece shoulder contacts supporting shoe end
surface;
3.Supporting shoe not properly located and workpiece
stuck
4. Excess feed to thread length |