Alamo MACHETE Product Service Manual page 93

MOTOR - SHUTTLE VALVE
Motor Shuttle Valve:
The Shuttle Valve is located in the Motor Housing, The purpose of the Shuttle valve is to direct
a controlled amount of Oil out of the Hydrostatic Loop and back to the Tank for Cooling
The Spool (item 3) is centered in its bore by springs on each end. While the Pump Shaft is
turning and the Camplate is in the neutral Position (Figure 44), Both ends of the Shuttle Spool are
exposed to a charge pressure. When the Camplate Angle is changed, The Pressured side if the Spool
sees an increased pressure while the opposite end is still seeing the charge pressure (return side of
circuit) (Figure 45). This causes the Spool to shift in its bore, opening a passage for Oil in the return side
of the Loop to go to the Tank through the Case Drain Line.
The Volume of Oil flowing through the Case drain Line should not exceed the Charge Pump
Volume unless excessive internal leakage exists in the Motor. The low Pressure relief is designed to
prevent the Motor seal from blowing out if excessive pressure should enter case.
The Case Drain serves to lubricate the Motor, approx. 3 GPM goes through to Lube motor. The
volume through case drain should not exceed 8 GPM, if it does check the motor for wear or a
2
1
Case Pressure
Charge Pressure
FIGURE 44
Machete (Service Manual) 04/04
© 2004 Alamo Group Inc.
(Figure 44 & 45)
malfunction.
3
1 2 3 4 5 6 7 8 9 0
1 2 3 4 5 6 7 8 9 0
1 2 3 4 5 6 7 8 9 0
1
2
System Pressure
Case Pressure
Charge Pressure
FIGURE 45
93
3
1 2 3 4 5 6 7 8 9 0
1 2 3 4 5 6 7 8 9 0
1 2 3 4 5 6 7 8 9 0
1 2 3 4 5 6 7 8 9 0 1
1 2 3 4 5 6 7 8 9 0 1
1 2 3 4 5 6 7 8 9 0 1
1 2 3 4 5 6 7 8 9 0 1