A Comprehensive Method of Apportioning Reliability Goals for New Product of Hydraulic Excavator
Table 9
FEMA of the hydrocylinders.
Failure part
Potential Modes
Failure Cause
Failure Times
RPN
Improvement Measures
hydro-cylinder
creeping
extra air in the cylinder excessive internal friction unfitting assembly low machining accuracy
5
7
8
56
to strengthen quality inspection for hydro-cylinders; make sure excellent in heat radiation of the system, Adjust overflow pressure of the relief valve in hydro-cylinders adjust the back pressure of the oil return
7
4
28
Slow speed
Excessive internal leakage Larger external load higher oil temperature
10
7
9
63
7
5
35
Inadequate thrust
higher back pressure fault of the overflow valve unfitting assembly
