Komatsu PC20R-8 Shop Manual page 59

3. Action of spring
3
4
LS valve
. The spring load of spring (1) in the TCC valve is
changed by the swash plate angle. In addition,
spring (1) consist of 2 types of pitch: rough and fine.
. When servo piston (4) moves, the compression of
spring (1) changes by that amount.
. If piston (4) moves to the right (
rough and fine pitch of spring (1) are compressed.
If it moves further to the right (
portion comes into close contact, so only the rough
pitch portion functions as a spring from this point.
In other words, the spring load is changed by piston
(4) extending or contracting spring (1).
. The pump absorption torque curve, which shows
the relationship between pump discharge pressure
P and discharge amount Q, is a bent curve as
P
shown in the diagram on the right because spring
(1) has different spring pitches.
PC20R-8 PC27R-8
1
), first, both the
) the fine pitch
M
Control valve
P
P
G G
H
Pump discharge pressure P
To actuator
P
LS
L
RKP01171
P
RKP01181
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