Travel - SANY SY195C9 Shop Manual

Structure and Function

4.5.2.2 Travel

[Pilot circuit]
● When the left or right travel spool is
switched, the side bypass circuit is closed
and pressure at port Py (travel signal port)
rises.
[Main circuit]
● When pressure at pilot port XBtL for left
travel spool (301) rises, neutral bypass (2)
at boom 1 side is closed, and working oil
supplied from the hydraulic pump (front) is
introduced into the left travel motor via port
Btl.
XAtr
4-48
SY195/205/215/225C9 Crawler Hydraulic Excavator
Atr
Travel motor
Shop Manual - June 2013
https://www.tractormanualpdf.info/
● Likewise, when pressure at port XBtr for
the right travel spool (301) rises, neutral
bypass (2) at arm 1 side is closed, and
working oil supplied from the hydraulic
pump (rear) is introduced into the right
travel motor via port Btr.
● On the other hand, return oil from the left
and right travel motor passes the left (right)
travel spool via port Atl (Atr), and returns to
working oil tank via return port (R1).
● The principle is the same when travel on
the opposite side is operated (when pres-
sure at pilot port XAtr and XAtl rises).
XBtr
ZX225-1102012