GZD15, WSM
TRANSAXLE
2-M4
(3) Check and High Pressure Relief Valve
The check and high-pressure relief valve consists of
pressure poppet (2), check valve seat (1), relief valve
spring (3), spring guide (4) and check valve spring (5).
The valve is used to prevent an overload that would
happen at a quick start, sudden stop or even during
usual running. This valve doubles as a check valve.
The check and high-pressure relief valves are laid out
facing each other as shown in the figure.
In neutral, both valves are opened and charging oil
enters into the main oil circuit through the valves. (A)
At normal operation, the check valve in the high-
pressure side is closed and it pushes and opens the
other one. An excessive charge flow goes through the
charge relief valve into HST housing. (B)
The check and high-pressure relief valve along the
high-pressure line serves as a high-pressure relief
valve. If the pressure exceeds a high-pressure limit
level, the pressure poppet opens itself against the relief
valve spring (3) force and opens the valve seat that is
located between the check valve seat (1) and the
pressure poppet (2). Now the flow goes from P3 to P1
and P2. (C)
If the P3 pressure drops, the relief valve spring forces
the valve seat closed against the pressure. The high-
pressure oil at P3 does not flow to P1 any longer.
As discussed above, the check and high-pressure
relief valve protects engines, pumps, motors, gears and
even the machine itself from overload.
Oil Temperature
Valve operation pressure
50 to 60
(122 to 140
)
18.5 to 22.5 MPa
189 to 230
2683 to 3263 psi
(1)
Check Valve Seat
(A)
In Neutral (Stop)
(2)
Pressure Poppet
(B)
When Check Valve
(3)
Relief Valve Spring
Activating (Normal
(4)
Spring Guide
Operation)
(5)
Check Valve Spring
(C)
When High Pressure
(6)
Valve Plug
Relief Valve Activating
P1:
Oil Charge Port
P2:
HST Reverse Port
P3:
HST Forward Port
0000001604E
KiSC issued 04, 2006 A
Summary of Contents for GZD15
Page 1: ...GZD15 WORKSHOP MANUAL KiSC issued 04 2006 A ...
Page 7: ...GZD15 WSM SAFETY INSTRUCTIONS 5 KiSC issued 04 2006 A ...
Page 8: ...GZD15 WSM SAFETY INSTRUCTIONS 6 KiSC issued 04 2006 A ...
Page 9: ...GZD15 WSM SAFETY INSTRUCTIONS 7 0000001495E KiSC issued 04 2006 A ...
Page 12: ...GZD15 WSM DIMENSIONS 10 DIMENSIONS KiSC issued 04 2006 A ...
Page 13: ...GZD15 WSM DIMENSIONS 11 0000001694E KiSC issued 04 2006 A ...
Page 14: ...G GENERAL KiSC issued 04 2006 A ...
Page 72: ...1 ENGINE KiSC issued 04 2006 A ...
Page 140: ...2 TRANSAXLE KiSC issued 04 2006 A ...
Page 183: ...3 FRONT AXLE KiSC issued 04 2006 A ...
Page 184: ...CONTENTS 1 STRUCTURE 3 M1 KiSC issued 04 2006 A ...
Page 194: ...4 HYDRAULIC SYSTEM KiSC issued 04 2006 A ...
Page 223: ...5 ELECTRICAL SYSTEM KiSC issued 04 2006 A ...
Page 226: ...GZD15 WSM ELECTRICAL SYSYTEM 5 M2 0000001510E KiSC issued 04 2006 A ...
Page 227: ...GZD15 WSM ELECTRICAL SYSYTEM 5 M3 0000001511E KiSC issued 04 2006 A ...
Page 255: ...6 MOWER KiSC issued 04 2006 A ...
Page 256: ...CONTENTS 1 POWER TRANSMISSION 6 M1 2 LIFTING MECHANISM 6 M2 KiSC issued 04 2006 A ...