Textron JACOBSEN GP400, Техническое руководство по ремонту

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HYDROSTATIC POWER TRAIN
4252490-Rev A 5-35
5
Instrument Test Procedures
Instrument Test Overview
The following tests are specifically designed to approach
hydraulic testing on a system level. Each component
within the system represents a portion of the total system
leakage. An internal leakage percentage for each
component will be calculated and recorded, enabling the
technician to view the system performance issue more
completely. The test results will help the technician to
decide which repairs will best remedy the performance
issue experienced by the operator.
The internal leakage percentage ranges are as follows:
0–10% = Good
11–20% = Marginal
21% and beyond = Bad
Example: Traction System Performance Complaint
The machine operator reports that the machine struggles
to climb hills.
The traction system is tested as outlined, and the
calculated system leakage is 31%, a result that requires
the testing of individual components. This result can also
be interpreted as system efficiency of 69%.
The components in question are as follows: traction
pump, right front wheel motor, left front wheel motor, and
rear wheel motor. Following the procedures as outlined,
test each individual component, then calculate and
record leakage percentages.
The results from this test reveal leakage of 5% in the
traction pump, 20% in the right front wheel motor, 5.3% in
the left front wheel motor, 4.1% in the rear wheel motor,
and 2.9% in the flushing valve check valve. Although all
the components lend to the overall system leakage, only
the right front wheel motor, which is at the extreme end of
the marginal range, would be considered for repair or
replacement.
Formulas:
System and Traction Pump
No Load Flow – Loaded Flow / No Load Flow x 100 =
Leak Percentage
Wheel Motors
Loaded Flow from previous component – Loaded Flow
from current component / Loaded Flow from previous
component x 100 = Leak Percentage
Calculations:
System Test
No Load Flow = 10 gpm
Loaded Flow = 6.9 gpm
10 – 6.9 / 10 x 100 = Total System Leakage 31%
Traction Pump Test
No Load Flow = 10 gpm
Loaded Flow = 9.5 gpm
10 – 9.5 / 10 x 100 = Traction Pump Leakage 5%
Right Front Wheel Motor Test
Loaded Flow from traction pump test = 9.5 gpm
Loaded Flow from right front wheel motor test = 7.6 gpm
9.5 – 7.6 / 9.5 x 100 = Right Front Wheel Motor Leakage
= 20%
Left Front Wheel Motor Test
Loaded Flow from right front wheel motor test = 7.6 gpm
Loaded Flow from left front wheel test = 7.2 gpm
7.6 – 7.2 / 7.6 x 100 = Left Front Wheel Motor Leakage =
5.3%
Rear Wheel Motor Test
Loaded Flow from left front wheel motor test = 7.2 gpm
Loaded Flow from rear wheel motor test = 6.9 gpm
7.2 – 6.9 / 7.2 x 100 = Rear Wheel Motor Leakage =
4.1%
Flushing Valve Check Valve Test
Loaded Flow from rear wheel motor test = 6.9 gpm
Loaded Flow from flushing valve check valve test = 6.7
gpm
6.9 – 6.7 / 6.9 x 100 = Rear Wheel Motor Leakage =
2.9%